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HomeMy WebLinkAbout2008-05-LYMAN CREEK RESERVOIR IMPROVEMENTS PROJECT LYMAN CREEK RESERVOIR IMPROVEMENTS PROJECT City of Bozeman May 2008 0 Prepared for City of Bozeman P.Q. Box 1230 Bozeman, MT 59771 Prepared by MORRISON-MAII Rill,rrrr,. 7.880 Technu logy 131vd Wca-Hoze nan,MT 597 r8 406-587.0721 F:406-922-6702 MMf #: 0417,055 LYMAN CREED RESERVOIR IMPROVEMENTS PROJECT Technical Memorandum Table of Contents Executive Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 Introduction . . . . . . . . 1 Lyman Creek Treatment Plant Improvements . . . . . . . . . . . . . . . . . . . . . . . . 1 Lyman Creek Spring Improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3 Sourdough Reservoir Improvements .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4 Construction Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 Reservoir Liner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5 Appendix A No. 1.1 Water Treatment Plant Evaluation 1.1.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1-1 1.1.2 Existing System Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1-1 1.1.2.1 Process Piping in Inlet Control Building . . . . . . . . . . . . . . . . . . . .1.1-2 1.1.2.2 Outlet Control Building . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.1-2 1.1.2.3 Disinfection System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.1-2 1.1.2A Fluoridation System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1,1 W5 1.1.2.5 System Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1-5 1.1.2.6 Safety Issues with Chemicals . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1-6 1.1.3 Design Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1-6 1.1.4 Disinfection System Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.1-7 1.1.4.1 Upgraded Bulk Hypo Disinfection System . . . . . . . . . . . . . . . . . .1.1-7 1.1.4.2 On-Site Hypochlorite Generation System . . . . . . . . . . . . . . . . . 1.1-10 1.1.4.3 Present Worth Analysis and Disinfection Alternative Evaluation 1.1-13 1.1.4.4 Recommendations for Disinfection 1.1-14 1.1.5 Fluoridation System Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . .1.1-15 1.1.6 Chemical Injection and Mixing, Residual Sampling, System Control and Safety Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1-16 1.1.6.1 Chemical Injection and Mixing Improvements . . . . . . . . . . . . . .1.1-16 1.1.6.2 Residual Sampling Location . . . . . . . . . . . . . . . . . . . . . . . . . . . 1,1-19 1.1.6.3 Outlet Control Building . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.1-21 1.1.6.4 Instrumentation and Control Improvements . . . . . . . . . . . . . . . .1.1-21 i LYMAN CREED( RESERVOIR IMPROVEMENTS PROJECT Technical Memorandum Table of Contents 1.1 .6.5 Safety Improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1.1-22 1.1.7 Summary of Recommendations . . . . . . . . . . . . . . . . . . . . . . . . . . 1.1-22 Appendix A Appendix B No. 2.1 -.. Plant Piping Modifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.1-1 2.1.1 Introduction . . . . . . . . . . . . . . .2,1-1 2.1.2 Existing System . . . . . . . . . . . . . . . . . . . I , , . . . . . . . .2.1-1 2.1.3 Recommended Improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.1-1 No. 2.2 -- Flow Control Operations Modifications . . . . . . . . . . . . . . . . . . . . . .2.2.1 2.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.2-1 2.2.2 Existing Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.2-1 2.2.3 Potential Alternatives . . . . . . . . . . . . . . . . . 2.2-2 2.2.4 Recommended Alternative . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2.2-3 No. 3.1 — Controls 3.1-1 3.1,1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.1-1 3.1.2 Existing System Description .3.1-1 3.1.2.1 Data Transfer from Lyman Creek WTP to Sourdough VVTP. . 3.1.2.2 Lyman Creek 1NTP HMI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.1-2 3.1.2.3 Monitoring/Control Equipment . . . . . . . . . . . . . . . . . . . . . . . . . . .3.1-2 3.1.3 Design Criteria . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.1-2 3.1.4 Radio Modem System Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . .3.1-3 3.1.4.1 Upgrades to the Radio Modem System . . . . . . . . . . . . . . . . . . . .3.1-3 3.1.5 HMI Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3.1-3 3.1.5.1 Upgrades to the HMIs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1-4 3.1.6 System Monitoring & Control Equipment Evaluation . . . . . . . . . . . 3.1-5 3.1.6.1 Residual Chlorine Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1.5 3.1.6.2 Reservoir Level Indication . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1-5 3.1.6.3 Outlet Control Building Equipment . . . . . . . . . . . . . . . . . . . . . . . 3,1-5 3.1.6.4 Influent Sampling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1-5 3.1.6.5 Infiltration Gallery Level Measurement . . . . . . . . . . . . . . . . . . . . 3.1-6 ii LYIVAN CREEK RESERVOIR IMPROVEMENTS PROJECT Technical Memorandum Table of Contents 3-1,7Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3.1-6 No. 4.1 — Outlet Building Entry Stoop . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.1.1 4.1.1 Introduction . . . . . . . . . . . . . . . . . . .4.1-1 4.1.2 Investigation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.1-1 4.1.3 Recommendation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.1-1 No. 4.2 —Treatment Building Entry Stoop . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.2-1 4.2.1 Introduction . . . . . . . . . . . . . . . . . . . . . , . . . . . . . . . .4.2-1 4.2.2 Investigation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.2-1 4.2.3 Recommendation . . . . . . . , . , . . . . , . . . . 4.2-2 No. 4.3 -- Heating Options for the Treatment Building . . . . . . . . . . . . . . . . . . 4.3-1 4.3-1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.3-1 4.3.2History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.3-1 4.3.3 Heating Investigation . . . . . . . . . . . . . . . . . . . . . . . .4.3-1 4.3.4 Recommended Repairs , , . . . . . . , , . , , . , . . .4.3-2 No. 4.4 —Electrical . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . 4.4-1 4.4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.4-1 4.4,2 Existing Electrical System Description . . . . . . . . . . . . . . . . . . . . . .4.4-1 4.4.3 Stand-By Generator Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . 4,4-2 4.4.3.1 Upgrades to the Stand-By Generator System . . . . . . . . . . . . . . .4.4-2 4.4.4 Control Building Electrical Panels Evaluation . . . . . . . . . . . . . . . . .4.4-3 4-4.4.1 Upgrades to the Electrical Panels . . . . . . . . . . . . . . . . . . . . . . . .4,4-3 4.4.4.2 Influent Chlorine Residual Analyzer Electrical Connection . , . , , 4-4-3 4.4.5 Heating Equipment Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . AA-3 4.4.5.1 Heating Outlet Upgrades . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . A.4-4 4.4.6 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4-4-4 No. 4.5 —Treatment Building Access . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5-1 4.5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.5-1 4.5.2 Existing Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.5-1 4.5.3 Recommended Improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5-2 No. 4.6 — Reservoir Building Vestibule and Venting . . . . . . . . . . . . . . . . . . . 4.6-1 iii LYMAN CREEK RESERVOIR IMPROVEMENTS PROJECT Technical Memorandum Table of Contents 4,6-1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.6-1 4.6.2 Investigation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.6-1 4.6.3 Recommendation 4.6-1 No. 41 — Schematic Design of Reservoir Vents . . . . . . . . . . . . . . . . . . . . . . .4.7-1 4.7.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.7-1 4.7,2 History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4,7-1 4.7.3 Louver Investigation . . . . . . . . . . . . 4.7-2 4.7.4 Recommended Repairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.7--2 No. 4.8 — Pressure Reducing Vaults . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.8-1 4.8.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.8-1 4.8.2 History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4,8-1 4.8.3 Existing Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4.8-1 4.8.4 Recommended Improvements . . . . . . . . . . . . . . . . . . . . . . . .4-8-2 No- 5-1 — Spring Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5..1.1 5.1,2 Field Investigation and Discharge Measurements . . . . . . . . . . . . . 5.1-1 5.1.3 Historical Records . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5.1-4 6.1-4 Further Investigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .5,1-7 Appendix A — Figure 1 No. 6.1 — Reservoir Liner 6-1.1 No. 7.1 — Sourdough Tank Concrete Repairs . . . . . . . . . . . . . . . . . . . . . . . .7.1-1 7.1.1 Introduction 7.1-1 7.1.2 History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.1-1 7.1.3 Rim Deterioration Investigation and Possible Cause . . . . . . . . . . . 7,11-2 7.1.4 Recommended Repairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7.1-3 No, 7.2 — Sourdough Tank Ladder Replacement . . . . . . . . . . . . . . . . . . . .7.2-1 7-2.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.2-1 7.2.2 Recommended Repairs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7,2-1 No. 7.3 — Sourdough Tank Valve Replacement . . . . . . . . . . . . . . . . . . . . . . 73-1 7.3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.3-1 7.3.2 Existing Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.3-1 iv 1LYi11 AN CREEK RESERVOIR IMPROVEMENTS PROJECT Technical Memorandum Table of Contents 7.3.:3 Recommended Repairs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.3-2 No. 7.4 — Sourdough Tank Landscaping . . . . . . . . . . . . . . . . . . . . . . . . . . . .7.4-1 7.4.1 Introduction . . . . . . . . . . . . . . 7.4.2 Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7A-1 �D" MAIER. INC. Executive Summary City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, MT PREPARED BY: James Nickelson, P.E. REVIEWED BY: Roger Somerville, P.E_ DATE: May 9, 2008 INTRODUCTION The pre-design phase of the Lyman Creek Reservoir Improvements project is intended to provide a basis for establishing solutions and budgets to improve portions of the Lyman Creek Water Supply System. A secondary task is to provide solutions and budgets for issues associated with the City's Sourdough Reservoir. It is intended that after review and discussions with City Staff, that the options will be further developed or modified, The pre-design phase only provides schematic level solutions and many details will be refined during the design phase. A copy of the pre-design scope of services is attached as Appendix A. LYMAN CREEK TREATMENT PLANT IMPROVEMENTS The following provides a general description of each of the proposed improvements_ The construction costs are provided in Table 1.1. Additional details regarding the specific issues are provided in the technical memorandums. Outlet Building Proposed improvements to the outlet building include removal of the steps, grading of the site to allow for ground level entrance to the building and the replacement of the awning over the door. Treatment Building Proposed improvements include the following items: 1 N)04171055\00=ReportslTask Memo Entro,doe May 9,2008 Lyman Creek Restoration Improyoments _�� Harrison-Maierle I��c, r Replacement of the entrance walkway in order to allow for entrance to the building without steps. Replacement of the awning over the door to limit water and ice buildup at the entrance doors. ® Remove the east portion of the fence line around the site and grade around the entrance to the building to allow for easier vehicular access. a Remove the abandoned chlorine building to allow for better access. 0 Modify chemical injection and sampling system to allow for improved operations and to expand plant capacity. Modify plant piping including the flow control and pressure reducing valves and other minor piping changes utilizing CLANAL valves. Relocate electrical and control equipment into a dry environment which includes construction of a new room within the building. Provide propane heat has the principle source of heat to the building. • Modify controls including a new radio link to the Sourdough Water Treatment Plant. Reservoir Building Proposed improvements include the reconstruction of the vestibules and the addition of roof vents. Pressure Reducing Valve Vaults Proposed improvements include improving the access with the addition of access hatches and the addition of a pressure gauge readout above ground. Table 1-1 Lyman Creek Water Treatment Plant Improvements Location Item Technical Construction Cost Memorandum Reference Outlet Building Stoop and Awn; 4.1 6,150 Treatment Building Stoop and Awning 4.2 . _---- $4,50 0 Building Access 4.5 $5,000 --- -Chlorine Building 4.5 ^---- $5 000 Removal Treatment 1 1 $50 000 Modifications Plant Piping 2.1 $75,000 Modifications _ Electrical 4.4..,.,................,.�W._ $11,000 ------...-.,.,.---- Modifications Electrical Room ..._.. 4 4...,__...---•-------- — $5 OflO�.__......._.,,........--- " Construction ...,...,...., Heating Modific°.,..,___._..,.-- ----...-----'--- ,,._�,,,_..w..'....._..,_,,,..�•--- --- ations 4,3 $12 flfl0 ---- -- I Control Modificationns.....J 3.1 _- —_ 25, _-- 2 N:\0417\055\DOGS\ReportsUask Memo IniroAoc: May 9, 2008 Lyman Creek Restoration Improvements Morrison e.�Iq, ...................................... ................. Reservoir-Building.--. Vestibules 4,6 $14,950 Vents 4.7 $17,000 Iressure , Reducing Improved Access 4,8 $10 000 Vaults Pressure gaug_e,s 4,8 $10,000*** Subtotal 250,600 Overhead/Profit 15% Contingency and 75,180 Unlisted Items (30%) ............ Subtotal 363,370 Engineerigg 127,180 Total Engineering costs to be developed after specific project components are identified. This is a placeholder value. Refined estimate forthcoming. *** We are researching much more affordable options, LYMAN CREEK SPRING IMPROVEMENTS The following provides a general description of each of the proposed improvements, The construction costs are provided in Table 1.2. Additional details regarding the specific issues are provided in the technical memorandums, The proposed improvements to increase the yield from the springs are still being developed. The following improvements are intended to reduce overflow water from the spring: Construct 12,000 gallon reservoir. • Add level sensors and radio telemetry to treatment plant. Table 1-2 Lyman Creek Spring Improvements Location Item Technical Construction Cost Memorandum Reference Flow C04�6i 2.2 '000 Modifications Associated Control 3.1 $12,000 Cost Further Spring 5,1 Not yet determined Development -—---------- NA041710551D0CS1Reports\Task Memo intro,doc May 9,2008 hKMpn_Qreek,.Restoration Improvements M o r r i S 0 n-M aie r I ej D,(L ............ Subtotal Not yet,determined Contingency and Not yet determined Unlisted Items Subtotal Not yet determined Fncineerin Not yet determined Total yet determined SOURDOUGH RESERVOIR IMPROVEMENTS The following provides a general description of each of the proposed improvements. The construction costs are provided in Table 1.3. Additional details regarding the specific issues are provided in the technical memorandums. Proposed improvements include the following: Repair concrete rim of reservoir. Replace ladder inside of the reservoir. Replace two valves in the valve vaults outside of the reservoir. Landscape improvements to the embankment on the west side of the reservoir. Table 1-3 Sourdough Reservoir Improvements Location Item Technical Construction Cost Memorandum Reference Reservoir'"'"'"'-" ''............... Concrete Repairs-, 7,11 $350,000 Ladder Replacement 7.2 $6,000 Valve Vault Valve- Replacement 7.3 $28,000 Site .............. Landsca - 7.4 JL1500 Subtotal 391,500 Overhead/Profit 15% 58,725 Contingency and 68,725 Unlisted Items (15%) ............ Subtotal 508,950 ,Engineering (15%) 76,350 Total The concrete repair options range from $150,000 to $350,000, Additional investigation work is required during the design phase to determine what option is practical. 4 NA041710551D0CS\Repor1s\Task Memo Intro.doc May 9,2008 LyiD—an Zmtk Restoration Improvements Morrison-Maierle, Inc. CONSTRUCTION RECOMMENDATIONS The scope of services identifies reviewing alternative Construction delivery methods for portions of the project_ Upon review of the recommended project components, it is recommended that consideration be given to the following three construction contract packages: N SCADA Package —This would include radio telemetry and upgrades to the HMIs. 0 Spring Area Improvements _... This would include proposed improvements to the spring that have not yet been determined. 0 Spring SCADA Package — This would include all SCADA work associated with the spring. 0 Remaining work components — This package would be the major construction package that includes all items with the exception of those noted above. It is recommended that a contract package be developed for late summer and fall construction. Once the project components are fully defined approximate time frames for shutting down the Lyman Creek water system and the Sourdough Reservoir can be determined based on water demands and other factors. RESERVOIR LINER The reservoir liner task generally included a review of available data, discussions with DEQ permitting staff and the development of a technical memorandum to summarize findings. Technical Memorandum 6.1 is included in this report. The technical memorandum includes a number of recommendations which should be reviewed. 5 N:\041714551D0C8IReports\Task Memo Intro.doc May 9,2008 APPENDIX A UNhibit C Scope of Setwices for Lyman Creek Reservoir Improvements Project December 5, 2007 Pre-Design Phase The pre-design please is intended to develop adequate information to determine the: most appropriate solution for each work item- Alternatives will be explored where appropriate. Project costs will be developed to assist in decision making and budgeting. The following sections describe the task problem, list the items to be completed for each task and identify the deliverable for the task. Additional information is provided on Exhibit A-1 and B-1 for Task 6. Task 1 Water Treatment Evaluation Problem Statement —The existing plant has a design capacity of 1,500 gpm and the desire 1S to increase capacity to 2,680 gSni, l"he existing disinfection and fluoridation systems are inadequately sued. Problems exist with the injection and sampling systems at the plant. In addition the City desires to add p1l monitoring capabilities. The City is concerned with the safety aspects of bulk liquid hypochloritc disinfection and Would like to evaluate alternative disinfection methods. Task DQscription -- This task. will evaluate alternative disinfection methods as allowed by the budget, provide recommendations regarding injection. methods and sampling points and develop budget level estimates. This task will be coordinated with the plant piping and control task, The alternative; disinfection analysis will compare line cycle costs (}f' various alternatives as well as evaluate safety issues. Task deliverable — "Fechnical memorandum with recommendations regarding water treatment issues. `1'ask 2 Plant Piping Problen-i Statement.--The existing plant has a design capacity of 1`500 gpm and the desire is to increase capacity to 2,680 gpm. Increasing the capacity will require modifications to the piping system which provides opportunities to modify the flow control valve arrangement to what the City desires. Task l.)escriptiOD — This task includes a brief hydraulic analysis of the existing, piping frorn the spring to the reservoir and recommendations for piping changes. Alternate operation methods will be examined so that all water generated by the spring is able to reach the plant. This task will be coordinated with the: control task and the water ti.eati-rent task. I Task deliverable --- Technical rnemorandurn with a recommendation regarding plant piping and alternate operation methods. Task 3 Controls Problem Statement - The existing; telemetry system is unreliable and the SCADA system is in need of improvements, Additional monitoring; is needed for the rerr'ote. spring; site. the adjacent reservoir, the adjacent outlet building; and potentially two rernote pressure reducing stations_ New glow control and metering; equipment is proposed at the treatment plant and additional sampling and monitoring; is needed. ;I�ask Description - This task includes an analysis of potential. telemetry system irnprovements and a review of the existing SCADA sy.,,iu . Options for monitoring of the remote site(s) will be evaluated. The interaction of the Br.idger Center Lift Station and the Lyman Creek facility will be reviewed and as options are reviewed this interaction Will be analyzed. Conceptual level design efforts will be undertaken 10 arrive at budgetary cost estimates for implementing the proposed improvements, Alternatives for construction delivery will be explored for the control improvements. Task deliverable - T-echnical memorandum with a recommendation regarding control issues. Task 4 Architectural, Structural, Electrical, Mechanical and Sitc Task Problem Statement - The existing plant has Borne undesirable building; features tbiat: require rehabilitation. These include poor access to the outlet building, reservoir vestibules that have: icing?, and rodent problems, inadequate reservoir venting, difficult access to the treatment building;, undersized heating System in the treatment building and an undersized emergency generator. Existing interior panels are not water proof which is a concern due to the treatment plant environment. Access to the pressure reducing vaults is also in need of modifications. Task. Descri This task includes a site survey for the modifications of the outlet building and the treatment building, evaluation of electrical needs Jbr the plant site, evaluation ot`heating, options for the treatment building, schernatic de.sigii of'the reservoir vents, description of proposed building, and access modifications and project cost estimates for the work items, This task will be coordinated with the control task and the water treatment task. Task deliverable- Technical memorandum with recommendation and cost information, 2 Task 5 Spring Investigation—Phase 1. Problem. Statement — Historically, most of the flow of Lyman Creek was diverted by the City of Bozeman at a surface water diversion located a good distance downstream from the source of water- The source of water is groundwater, discharging from the: Madison Limestone through a large spring where a fault brings metamorphic "granite" (gr_rartrofeldspathic gneiss) up against the Madison Lirnrestone to act as a clam over which water spills through the spring. The surface wager diversion, located perhaps a half mile downstream from the spring source, could divert essentially all of the surface flow provided by the spring (excluding unusually high seasonal flows or storm flows). A number of years ago, in order to avoid treatment costs stemming from new surface water rules, the City changed the point of diversion to a subsurface collector system located at the source spring approximately a half mile upstream from the original surface water diversion location. Since then, experre.nce operating the new diversion has shown that the Maximum amount of water the. subsl.vface collector will divert is much less than the surface water diversions historically enjoyed at the downstream surface diversion structure and is much less than the City's legal clairn for a diversion .from Lyman Creek. The City would like to increase the subsur ace water collection to get as much of their legal water right as possible. When the new subsurface, collection system is operating at full capacity, a substantial flow of groundwater discharges from the spring area near the subsurface collector and travels to the location of the; old surface water diversion Structure ,..is surface flow. Additional groundwater may crater the surface flow between the new subsurface collector and the old s�irface water diversion point. It appears very likely that the volume of surface flow reaching the historic point of surface diversion, while the new subsurface collector is in operation, may be equal to the difference in flow between the new subsurface collection system and the historic surface water diversions. The basic problem that must be solved is flow to capture as much additional flow from the spring source as possible, before it becoIl7es surface Water flow subject to surface water treatment rules. The conditions observed during preliminary inspection. of the site this fall suggest there are probably two components to the: surface water flow arriving at the historic surface water diversion structure. One- component of this flow is groundwater discharged to surface water flow at the spring source, right at the location of the existing subsurface collection. system. Part of this discharge is through an apparent construction drain line and part is from overflow from the existing subsurface collection systern- The other component of flow to the historic surface water diversion point, which appears to potentially be as much a.,, the .first. component or more. (at least in the fall of the year when the inspection was conducted), is discharge cif grouxidwzater into Lyman Creek at a reach of relatively steep streambed a coiisiderable distance downstream from the rnain spring. 3 This reach is .just downstream from the first pond structure downstream from the main spring. The preliminary inspection indicates the perceived gain in stream flow from groundwater discharging into the stream occurs because the gaining reach of stream is relatively steeper- than the upstrean-i reach extending back up to the source spring, The reach of steep streambed is closely associated with the location of a fault that brings soft, Tertiary- aged sediments into contact with hard, crystalline metamorphic granite (gneiss). As Lyman Creek transitions from the hard granite terrain to the downstream soft 'Tertiary sediment terrain, it drops in elevation, resulting in a short reach of relatively steep strearribed where it appears likely the stream flow increases significantly Clue to an inflow of groundwater. It is not known if the source of additional groundwater flow is from. fractures in. the: granite or if water has simply traveled through tl.1e rock rubble: in the volley floor all the way from the: source spring, to discharge from the rock rubble where the streambed gradient steepens- Accordingly, the problem that must be salved is not only how to capture more groundwater, but where. If the perceived inflow can be verified, the next question is where (lees it cone from? If its source is discharge of groundwater from local fractures in the granite, installation of additional subsurface collection capacity upstream from this Site, near the source spring, would not be particularly sucCessfuL Additional subSUrfaCC collection would instead be: required at or downstream from the source of flaw out of'tile granite instead of at the main spring. Field investigations are required to verify the foregoing initial perceptions and to develop conceptual playas about. ]low to captures additional groundwater under these circunistances, particularly if it cannot be determined ]low much of the additional inflow (if arty) Stem'$ from. the main spring at the, Madison Limestone Pauli and how much Steams [i•oa�� discharge out of the: faulted and fractured granite. A final component of the problem is how to install and operate a recording device on the existing flume near the historic paint of surface water diversion so that flow can be: measured and recorded in con unction with all. Cxisting recording flume installed at the downstream end. ofthe existing subsurface collection sy.stern, Taskmllgscri tiCail - This is the initial phase: of investigation required to determine ]low additional development of the spring might be accomplished. The initial phase will consist of'the following field investigations: 1. Flow rmeaseare:nie;nts at select locations along the stream, twice this kill, early winter an(] at least once in late .tune or early July of next year- 2. Temperature meas Lire ments of spring discharge and surface water temperatures starting at the source spring and all the way downstream to the surface diversion 4 structure, with associated air temperatures, conducted at the same tunes as the flow mcasuremcnts_ 3. Electrical conductivity (specific conductance) measurements of the spring discharge and surface water flow at selected locations, conducted at the same time,, as the flow measurements. 4. As-built elevations of critical. facilities as required for a conceptual plan for improvements to the diversion works. 5. Formulation of conceptual designs for alternatives to divert more groundwater before it becomes surface water. 6. 1'orniulation of a conceptual design to equip the downstream concrete flurne near the historic surface water diversion with a recording instrument and to improve the accuracy of the measuring device while reducing maintenance requirements. 7. Research of directional drilling capabilities in large rock rubble valley fill so that directional drilling can be considered as an alternative to wholesale excavation and hac.kfill of a new subsurface collector. 8. Formulation of a work plan to complete the additional investigations and evaluation required to support selection. of the most suitable alternative and to refine the preliminary engineering design and cost estimates. Stream Flory Measurements — It is anticipated that stream flow will be measured twice between now and the end of December 2007_ The purpose of these is.ieasureinents is twofold_ One purpose is to verily that additional groundwater is discharging into the streambed in the steep reach at the fiault between the granite and tlae Tertiary sediments as appeared to be the case during=, the initial inspections. The second purpose of the stream flow measurements 15 to quantify the amount of gi-oundwater discharging into the stream that may be captured by additional subsUrface collectors during the late fall, low-flow condition,,. The flow ineasurements will include use of the existing sharp crested rectangular weir, the existing 45" flume:, the stop log structure on the upstrearn pond as a weir, the downstream concrete flume, and miscellaneous current meter rnea sure ni crits, as necessary, particularly where existing weirs or structures are backwatered or submerged. Drain Pine FloFv Measurement — It is proposed that a nictal stock tank aasd temporary PVC pipe be Used to measure the discharge out of what appears to be a construction under-drain located between the two existing subsurface collectors. This drain pipe, combined with overflow from the existing subso face collector systeni, was the sole source of surface water flow to the existing 45" flunk during the inspection this fall. In order to measure the .I-low ftorn. the drain pipe this fall, it is proposed that a temporary PVC; pipe be slipped over the drains pipe to collect its discharge and. convey it to a 5 container of known size, i.e., a stock tank, where the rate of flow can be calculated volumetrically. If possible, the temporary stock tank will be sited downstream from the sharp crested rectangular weir installed in the: strearnbed by City staff, so any additional groundwater seepage into the stre:ambed between the drain pipe and the weir cat) be detected. The stock tank will be equipped with a drain so it can be removed after the measurements are taken. Although the proposed stream flow rneasurenients this fall will indicate how much groundwater flow is escaping capture by the existing subsurface collection system during Late fall, low-flow conditions, the measurements will not indicate how much groundwater flow remains uncaptured during su.imniert.ime high-Mow conditions. Therefore, similar mcasutements are required next summer, during the time of high flows from the spring. Mevasm nient of Spring discharge and groundwater inflow to the stream at differe eat locations next sum.nier is outside of this initial Scope of work; however, it is recognized that the work will, be required in the next phase of this effort. Overflow-Pipe_Flow. Measurement --- When the drain pipe flow is measured: similar volumetric measurements will be taken at the overflow pipe from the existing subsurface collection system, rising a 50-gallon drum or similar volumetric: conulir .er. The suns of the overflow discharge and the drain pipe discharge can their be compared to the flow through the existing 45' flume to determine if any additional uncaptured groundwater flow is entering the streani bed between the drain pipe and the flume. "Fisk deliverable •- The proposed scope of work will produce a technical memorandum with a summary report of .findings of the initial work, preliminary conceptual design alternatives, and i1 work plan for further detailed investigation that may include drilling test bores, seismic and GPR investigations of the subsufflice materials and depth to water table and bedrock, or other investigations as required. Task 6 Resei-voir Liner Problem Statement — In 2004 the City had a 45-mi.1 reinforced polypropylene, liner installed in an existing 5.0 trillion gallon concrete reservoir. After installation of the liner it leaked at rates found unacceptable by the City. 'Numerous attempts to reduce [lie leakage were made by the contractor- and eventually the liner was accepted by the City under terins developed through mediation. At the time: the City accepted the liner. it was leaking at a rate of approximately 40 to 50 gpm. The City has since had divers spend part of' a clay to find and seal some of the leaks which has reduced the; leakage to approximately 9 gpmr IIhere are two items relative to the liner that are of concern. First, the leaking water could be utilized, and second, the DEQ has indicated it will require the City to obtain a permit to continue: to discharge water from the leaking liner- 6 ;I'ask Description —']"his task includes the following items: Review of correspondence between the City and D Q regarding the need for a discharge permit. Y Discussions will be held with DEQ staff' to determine what courses of action are possible regarding the discharge. Task deliverable -- 'Fechnical memorandum addressing passible course of actions regarding the need for or requirements for a discharge permits. Application for a discharge permit is not included in this task. Task 7 Sourdough Tank and Site Repairs Problem Staternent —A number of'repair items to the Sourdough Tank and associated site were identified in the Water Facility Plan. "These include the following, 1. Repair cracking concrete around rini roof 2, Replace r'uStIng and deteriorating inside ladder 3. Abandon control valve with leaking valve stem 4. Consider adding; xeri-scape to limit vegetation around tank 5. Fix drainage issues across Sourdough road! Task Description — This task will evaluate options for each cif` the: listed items and develop budget level estimates. Task deliverable, --- "Technical memorandum with recommendations regarding Sourdough Tank repairs. Task 8 Project Coordination and Quality Assurance. Task. Description -- This task includes effiort associated with protect coordination and quality assurance review of the var•io►rs tasks, 7 U3 MORMSON ULJ"-I MAIERLE,1NC. Technical Memorandum No. 1 .1 WATER TREATMENT PLANT EVALUATION City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, MT PREPARED BY. Jeff Ashley, P.E. REVIEWED BY, James Nickelson, P.E. DATE; May 9, 2008 1.1.1 INTRODUCTION The purpose of this Technical Memorandum is to evaluate and discuss improvements to the existing Lyman Creek water treatment plant (WTP). The City of Bozeman utilizes this plant as a supplemental source to the Sourdough plant. The existing WTP has a maximum design capacity of 1,500 gpm, and the City desires to increase this capacity to 2,680 gpm. Therefore, the existing disinfection and fluoridation systems at the WTP are inadequately sized_ The WTP has also experienced problems with chemical injection and mixing, and with residual monitoring_ In addition, the City desires to add pH sampling capabilities. The City is also concerned with safety aspects of using bulk sodium hypochlorite for disinfection and wants to evaluate alternative disinfection methods. This memorandum will discuss these issues and provide recommendations and cost estimates. 1.1.2 EXISTING SYSTEM DESCRIPTION The WTP consists of the Inlet Control Building, the 5 million gallon reservoir, and the Outlet Control Building_ The Inlet Control Building consists of flow control, liquid hypochlorite injection, liquid fluoridation injection, and radon stripping. The Outlet 1.1-1 N:\04171055100C$\ReportslTech Memo-Task 1 (finai draft),ddC May 9, 2008 Lyman Creek Restoration Improy. menu v µ W _ Morrison-Maierle, Inc. Control Building consists of a supplemental disinfection point, flow and chlorine residual monitoring capabilities, and differential pressure monitoring of the reservoir. 1.1.2.1 Process Piping in Inlet Control Building The process piping and valves in the Inlet Control Building consist of 8-inch and 12-inch diameter ductile iron piping. The raw water transmission line enters the building and flow is routed through a pressure reducing valve (PRV), a flow control valve, and a magnetic flow meter. The flow meter is currently not in use. The WTP is using a transit time meter installed on the outside of the process piping. The pressure of the raw water entering the building is approximately 60 psi and is reduced to 10 to 20 psi by the PRV. The plant control system is used to operate the flow control valve to maintain a constant flow rate based on a flow set paint. From the flow meter, the pipe is routed into the radon stripping tower room. The piping configuration allows the tower to be bypassed, which is the current operation. The bypass piping and tower piping are joined in a pit where a 16-inch diameter pipe is routed underground to the reservoir. 1.1.2.2 Outlet Control Building The Outlet Control Building consists of 12-inch process piping, a supplemental disinfection point, flow and chlorine residual monitoring capabilities, and differential pressure monitoring of the reservoir. A chlorine residual sampling pump is used to route the sample line back to the Inlet Control Building. The supplemental disinfection feed line and the residual sample line share a conduit between the two buildings. 1.1.2.3 Disinfection System The WTP currently uses 12.5 percent trade strength, bulk liquid sodium hypochlorite (hypo) for disinfection_ The bulk solution is stored in a 500-gallon polyethylene tank with secondary containment in the chemical storage room, which is adjacent to the process piping room. The tank is filled by bulk deliveries of hypo approximately every two weeks. The double doors of the chemical storage room are opened and the solution is pumped into the tank. Both the hypo tank and hydrofluorsilic acid tank are clearly labeled for safety purposes. Two peristaltic type chemical feed pumps are used to feed hypo to several injection points. Per the 2004 design plans, chemical feed pump No. 1 can inject hypo into the fl- inch diameter process piping just downstream of the flow control valve, and also into the radon tower outlet piping and radon tower bypass piping. Chemical feed pump No. 2 can inject hypo into the 12-inch diameter piping in the Outlet Control Building, The primary hypo injection point is the 8-inch process piping using chemical feed pump No_ 1. This injection point can only be used when the radon tower is not in use, due to the fact that the tower may strip out some of the chlorine in the water. Since the radon 1.1-2 N 041 IIo5500CS1Reports\Tech Memo-Task 1 (finai draft).doc May 9,2008 l.Yman Creek Restoration Improvemgnts Morrison-Maierle, Inc. tower is currently bypassed, the alternate injection points downstream are not typically used. The hypochlorite feed rate (chlorine dosage) is controlled through the plant control system by pacing with the raw water flow rate. The initial chlorine dose is set at approximately 1.1 to 1.3 mg/L. A chlorine residual sampling location is provided in the process piping room immediately downstream of the flow meter. However, WTP staff feels that adequate mixing is not provided this close to the chlorine injection point in order to provide reliable chlorine residual measurement. According to the WTP superintendent, the desired chlorine residual leaving the reservoir is approximately 1.1 mg/L. As discussed, another residual sampling location is taken from the Outlet Control Building, which is downstream of the storage reservoir. Due to the long detention time (as long as one week) between the time chlorine is injected into the raw water, and the time chlorine residual is measured, chlorine residual pacing is impossible. Furthermore, there is no residual sampling location downstream of the hypo injection point in the Outlet Control Building. Therefore, an adjusted chlorine dosage using the supplemental chlorine injection point cannot be verified. Currently, the WTP obtains bulk hypo deliveries once approximately every two weeks to top off the storage tank, The City provided delivery data from April to December 2007 that indicates bulk hypo deliveries totaled 3,757 gallons. Over this time span, the hypo delivered was consumed for disinfection. The WTP control system also calculates hypo consumption and chlorine dose using the hypo tank level measurements, the diameter of the 500-gallon tank, and the chemical characteristics of bulk hypo, This is reported in the system data as pounds per day of chlorine added and also as the chlorine concentration dose. As another check of hypo consumption and chlorine dose, the City's data were compared to values calculated by Morrison-Maierle, Inc_ using a similar method as compared to the WTP control system. This approach was utilized as a triple check on the actual hypo volume consumed and the actual chlorine dose delivered to the raw water. This analysis is summarized in Table 1-1 for average daily conditions and Table 1-2 for maximum day conditions. From Table 1-1, the calculations from the bulk hypo delivered to the WTP match very closely with the values calculated from the control system data. The hypo usage from all of 2007 is slightly lower than that from April to December 2007 due to lower flows in February and March. Overall, the data suggest that the average daily hypo consumption in 2007 was between 14 and 15 gallons per day resulting in a calculated chlorine dose of approximately 1.2 mg/L. For 2007, the average chlorine residual measured at the Outlet Control Building was 1.13 mg/L suggesting that there is very little chlorine demand in the raw water. Annual hypo consumption was estimated to be 4,442 gallons from February through December 2007 costing the City nearly $25,000 at the current unit cost of $5.51 per gallon. The average daily flow of 1,642,000 gpd results in a continuous flowrate of 1,140 gpm over 24-hours. 1.1-3 N:W4171055T0CSIReports\Tech Memo-Task i (final draft).doc May 9, 2008 Liman Creek Restoration IMP rvemertts T Morrison-Maierle Inc. .n le l. , Table 1-1 Lyman Creek WTP 2007 Averaoyxpo Consum Lion and Chlorine Dose Average Flaw Average Hypo Average Cl� Used Average C 1 2 nose Data source (gpd)' Used (gpd) (PI}d) (mg/L) April 10, 2007 to December 14, 2007 _ ,,.,.,..,..,..,.._..,..,,.,.., Bulk Hypa f7elivery 15,1 15,8 1.15 Records .•1_. -- WTP Central SystemCalcuEat ions 1,642,000 15.8 1.15 Morrison-Maierle, Inc. g 1.17 Calculation s All of 2007' WTP Control System u 14.2 1.16 Calculations 1,464,000 14.5 4 1 18 Morrison-Maierle, Inc, 5 Calculations? 13.9 1. Average flow calculated from daily control system monitoring 2. Uses hypo level in tank from control system,diameter of tank,and hypo characteristics 3. Assumes 12.5%hypo trade strength and approximately 1 pound of active chlorine per gallon of hypo. -_4. �.. .,..uary-_200 -----g- December 19, (.J .:......,_.20 ex limited plant op4rr�lior3j �, Data from February 1,2007 throw h Qecember 19,2007 January 200.7 data excluded due to „. _ Table 1-2 Lyman Creek WTP 2007 Maximum Day H o ConsumytiJon and Chlorine pose Max Day Flow Max Day Hypo Max Day CI Max Day C12 Dose Data Source (gpd)' Used (gpd) Used (ppd) (mg1L) April 10, 2007 to December 14, 2007 --- Bulk Hypo Delivery 22.1 23.0 Records WTP Control System 2,530,560 - 27.3 2.03 Calculations Morrison-Maierle, Inc. Calculations 26.5 --'- 27,6 2.10--- All of 2007' WTP Control System - Calcuiations 7,3 2.03 2,530,560 _,,,..,.,...— Morr—is on-Maierle, Inc, 26,5 27.6 2,10 Calculations 9... nontrot System monitoring Flow calculated from dail n y 2. Uses hypo level in tank from control system,diameter of tank, and hypo chafacteristics 3. Assumes 12.5%hypo trade strength and approximately 1 pound of active chlorine per gallon of hypo, 4. Data from Fabruary 1, 2007 through December 19, 2007(January 2007 data excluded due to limited plant oppratlon), 5. 287 gallons used between 811107 and 8/14/07 1.1-4 W04171055100CSIReportslTech Memo-Task 1 (final draft).doc May 9,2008 Lyman Creek Restoration Improvemgnts Morrispll-Maierle, Inc. The data in Table 1-2 provide an estimate of maximum day hypo consumption during 2007. The maximum day hypo consumed based on the bulk delivery records is slightly less than that calculated through the control system data. This is due to the bulk delivery maximum day value be an average takers over approximately two weeks. Therefore, this better represents a maximum week value. A more accurate maximum day consumption is based on the system data. For 2007, the maximum day hypo consumption was approximately 26 gallons per day and the calculated maximum chlorine dose was 2.1 mg/L. The maximum chlorine residual at the Outlet Control Building was 1.76 mg/L. The maximum daily flow of 2,530,560 gpd results in a continuous flowrate of 1,757 gpm over 24-hours (June 29-30, 2007). This is more than the maximum design capacity of 1,500 gpm. The flow set point for this 24Thour period was 1,500 gpm according to the WTP control system data. On a trial basis in 2007, the system was manually run as high as 1,900 gpm, 1.1.2.4 Fluoridation System The fluoridation system is very similar to the bulk hypo system at the WTI . Supplemental fluoride is added to the raw water in the form of hydrofluorsilic acid to obtain a total fluoride concentration of approximately 1 mg/L. The bulk solution is stored in an approximate 300-gallon polyethylene tank with secondary containment in the chemical storage room. The tank is filled by bulk deliveries approximately every two weeks along with the hypo delivery. One peristaltic type chemical feed pump is plumbed to an injection point located just after the flow control valve in the process piping. The fluoride feed rate is controlled through the control system by pacing with the raw water flow rate. Fluoride residual pacing is not provided in the existing system. Plant data from April to December 2007 indicates that bulk hydrofluorsilic acid deliveries totaled 2,033 gallons. This total represents an average of 8.2 gallons per day. Daily data obtained from the control system was also used to determine the hydrofluorsilic acid consumption for February through December 2007, This data indicate that the average fluoride added to the system was 11.3 pounds per day for an average dose of 1.14 mg/L. The total consumed hydrofluorsilic acid for 2007 was estimated to be approximately 2,500 gallons costing the City $17,000 based on the current unit cost of $0,68 per pound ($6.93 per gallon). 1.1.2.5 System Control The WTP utilizes a local control system connected to the City's SCADA system, Primary system control functions include flow rate control, raw water and outlet flow monitoring, hypochlorite and fluoride flow pacing, raw water turbidity monitoring, reservoir level monitoring, chlorine residual monitoring, and bulk chemical storage tank levels, which are read manually each day and logged into the system_ WTP staff operate the plant by inputting the desired flowrate into the control system. The flow control valve is then actuated to maintain this flow. Based on data from the City from 2005 to 2007, the flow set points generally range from 500 to 800 gpm in the winter, 800 to 1,400 gpm in the spring, 1,500 gpm during the peak summer months and back down 1,1-5 NA0417105500C51Reports\Tech Memo-Task 1 (final draft),doc May 9, 2008 Lyman Creek Restoration Improvements _ _ _ Morrison-Maierle, Inc, to 800 to 1,300 gpm in the fall. The flow set points are subject to how much raw water can be collected in the spring boxes. In general, the winter flow from the spring is about half of the summer flow. The WTP is typically operated 24-hours per day, year round except for temporary shutdowns in December or January. The primary control issue for plant personnel is the lack of effective chlorine residual monitoring upstream of the reservoir, which results in the inability to pace disinfection based on chlorine residual. These issues will be further discussed later in this memorandum. 1.1.2.6 Safety Issues with Chemicals Bulk hypo at 12.5 percent trade strength is classified as a strong oxidizer. A typical Material Safety Data Sheet states that hypo is harmful if inhaled and will cause skin and eye irritation. Hypo solution itself and off gassing of hypo can be corrosive in interior environments, especially to metal items such as electrical and control panels. Therefore, great care must be taken in delivery, storage and use of bulk hypo solutions. The City is rightly concerned about safety in regards to delivery, storage and use of both hypo and hydrofluorsilic acid at the WTP. A WTP operator was sent to the emergency room in 2006 due to an accident while filling the chemical storage tanks. The City has implemented a double check safety system since this time to avoid future accidents. Safety issues with an upgraded system to meet the higher capacity needs of the WTP will be discussed later in this memorandum. 1.1.3 DESIGN CRITERIA As previously mentioned, the City desires to increase the capacity of the WTP from 1,500 gpm maximum flow to 2,680 gpm. This is an increase of nearly 80 percent. The evaluation of increasing the available flow from the spring is included in another Technical Memorandum. Based on discussions with the WTP superintendent, the upgraded WTI' will be operated in a similar fashion as the current operation. Plow from the spring is limited in the winter, but an overall increase in spring flow is anticipated with spring box improvements. Therefore, the design criteria will be based on the following: • 24/7 operation, year round • Maximum flow capacity set point of 2,680 gpm or 3.86 mgd (summer) Seasonal flow set points proportioned from maximum flow set point (limited to captured flow from the spring box) Average chlorine dose of 1.2 mg/L p Maximum chlorine dose of 2.0 mg/L The ultimate design capacity will be based on the maximum flow of 2,680 gpm over a 24-hour period of plant operation. However, annual operation and maintenance costs used in comparing disinfection alternatives will use the proportioned seasonal flow set 1,1_6 NA0417105500MReportsJech Memo-Task 1 (final draft).doc May 9,2008 t man Creek Restaati � �emnts _ n � mw�w Morrison-Maierie, Inc. points. Using the daily flow set points provided from the control system from 2005 to 2007, an annual average and maximum day flow through the plant were calculated. Table 1-3 presents this design criteria. Note that the actual 2007 maximum daily flow from the WTP was 2.53 mgd from Table 1-2, This value is greater than the current design capacity of 2,16 mgd (1,500 gpm), For the WTP improvements, it is assumed that the City's maximum water right flow of 2,680 gpm, and thus 3.86 mgd from Table 1-3, will be used for design purposes. Table 1-3 Lyman Creek WTP ImRrovements — Design Criteria Existing WTP Increased WTP Parameter Capacity (mgd)' Capacity (mgd) Annual Average 1.51 2.69 ow Maximum Day Flow 2.16 3,96 1, Based on typical daily flow set points from 2005 to 2007 City data 2. Proportioned flow based on increase in maximum flow capacity(2,680 cOpm/1,500 gpm), 1.1.4 DISINFECTION SYSTEM EVALUATION Due to the safety concerns that the City has with the existing bulk hypo disinfection system, this memorandum will investigate an alternative disinfection method, The alternative method will be evaluated against an upgraded bulk hypo system to meet the new design criteria. This section discusses the details of both systems. Improved chemical injection, mixing, chlorine residual monitoring and pacing are common components to both systems and will be discussed later in this memorandum, 1.1.4.1 Upgraded Bulk Hypo Disinfection System An upgraded bulk hypo disinfection system would consist of the same primary components as the existing system. This includes scheduled delivery of bulk hypo, chemical storage and containment, chemical metering pumps and chemical injection, Due to the increased capacity of the WTP, larger chemical storage tanks and potentially larger chemical metering pumps are needed. Table 1-4 provides details of bulk hypo storage and metering criteria. 1.1-7 N:104171055100=ReportslTech Memo-Task 1 (final dfafi),doc May 9,2008 Lyman Creek Reston tion improvements Morrison-ly aierle, InG Table 1-4 Lyman Creek WTP Improvements t1 graded Bulk My o []isinfection System Desin Criteria l Increased Active Metering WTP Chlorine Hypo Hypo Storage Dump Capacity Required Required for 2 Weeks Capacity Parameter (mgd) (ppd) (gpd) (gallons) (gallhr) Chlorine [lose 1.2 mg11-2 Annual -- Average Flow 362 1 1 Maximum Day 3.86 39 37 519 1.5 Flow Chlorine Dose= 2.0 mg/C Annual 2,69 - - ....... 45 43 803.w�_,. Average Flow 1.$ Maximum Day 3,86 64 62 864 2.6 Flow ..,,,.�...._.,_.._, Chlorine D08e,M...,,..2,._..,0 m 91L (degraded hypo s--t r,..e- ..n.,g..th)-3 ., Annual 2.69 45 54 A—-- - - 4 2,2 Average Flow Maximum Day 64 77--- 1 Flaw 081 3'2 I. 24-hour WTP operation. p 2, Assumes 12.5%hypo trade strength and approximately 1 pound of active chlorine per gallon of hypo. Assumes 10%hypo trade strength and approximately 0.8 pounds of active chlorine per gallon of hypo. The data in Table 1-4 indicate that the a 1.2 mg/L chlorine dose will increase the hypo consumption to 26 gpd on an annual average basis compared to the existing 14 to 15 gpd, For the maximum day flow of 3.86 mgd, 37 gpd of hypo is needed. A working storage volume of 500 gallons would be sufficient for approximately two weeks of hypo at the maximum flow at a 1.2 mg/L chlorine dose. Therefore, bulk chemical deliveries would occur once every two weeks during the summer at this dose, and could be less frequent during other times of the year. A 2.0 mg/L chlorine dose would only be used occasionally according to the WTP superintendent. For maximum design capacity, this dose can be applied to the summer months. According to Table 1-4, a 2.0 mg/1 chlorine dose would result in 52 gpd of hypo consumed and a two week storage requirement of 864 gallons at maximum day flow. Bulk hypo solution is known to degrade over time even in as little as 30 or 45 days. Therefore, the hypo being injected into the system near the end of a 30 or 45 day period may not be at the full 12.5 percent trade strength. Hypo can be dose paced with improved chlorine residual monitoring to account for this degradation_ However, a weaker hypo solution will result in more volume required for the same chlorine dose. Therefore, the storage requirements stated for a full strength hypo solution would be inadequate for a weaker hypo solution. A conservative method to calculate bulk hypo 1.1-8 N:10417T551DOC8\ReportMT®ch Memo•Task 1 (final draft).doc May 0,2008 Lumgn Creek Restoration Improvements T � Morrison-Maierle Inc_ storage requirements is to assume the hypo has degraded to 10 percent trade strength. This results in a two week storage volume of 1,081 gallons to accommodate maximum day flow at 2.0 mg/L chlorine dose. Therefore, a conservative hypo storage volume assuming deliveries every two weeks is approximately 1,100 gallons, or about double the existing storage volume. For this memorandum, it is assumed that the radon tower room is unavailable for chemical storage. Therefore, all storage of hypo and hydrofluorsilic acid for this alternative must be located in the chemical storage room. The chemical storage room is relatively small in size and the double doors leading into the room are a standard 72W inches wide x 84Tinches high. Therefore, the storage volume for the upgraded WTP is limited based on fitting tanks through the doors.. In order to maximize hypo storage, while also leaving space for an increased hydrofluorsilic acid tank, various tanks from two manufacturers were evaluated. A flat bottom/open top 1,000 gallon cylindrical tank from Chem-Tainer is 70,5-inches in diameter and 72.5-inches in height. With 12-inches of freeboard, a working volume of approximately 900 gallons is provided. The largest hypo storage tank that can fit inside the double doors and still provide room for a hydrofluorsilic acid tank is approximately 1,200 gallons. A flat bottom/open top 1,200 gallon cylindrical hypo tank from Poly Processing is 73-inches in diameter and 67-inches in height. This tank tilted sideways would fit through the double doers. With 12-inches of freeboard, a working volume of approximately 1,000 gallons is provided, or approximately double the existing bulk hypo storage. This volume provides nearly 30-days of hypo storage at the maximum day flow, assuming a full 12,5 percent trade strength hypo solution and a chlorine dose of 1.2 mg/L. At the maximum day flow, a full 12,5 percent trade strength hypo solution and a chlorine dose of 2.0 mg/L, approximately 16 days of hypo storage is provided. Therefore, during the summer, hypo deliveries could continue to be every two weeks, In the winter, hypo delivery intervals could be extended to one month if desired. Frequent hypo deliveries in the summer should result in a nearly full strength hypo solution. In the winter, long periods between hypo deliveries may result in a degradation of hypo strength. The City may choose to use only 500 gallons of working storage in the winter to limit hypo degradation. The Poly Processing 1,200-gallon tank including the hinged cover costs approximately $6,000, The Chem-Wainer 1,000-gallon tank costs approximately $5,000 with the hinged cover. In place of the hinged cover, a dust cover and bulk head fitting for tank filling cost approximately $500. The Chem-Tainer tank alone would be $3000, Maintaining the existing 500-gallon hypo storage tank and adding another 500-gallon hypo storage tank would also give the WTP approximately 1,000 gallons of working storage. However, the two smaller tanks would take up more floor space than one larger tank, and may not leave room for a larger hydrofluorsilic acid tank. For secondary containment, Chem-Tainer provides a 1,350 gallon flat bottom/open top cylindrical tank measuring 82.5-inches in diameter at the bottom and 60-inches in height_ As long as 12-inches of freeboard is maintained in either the 1,000 gallon or 1.1-9 NA04171055000S1Reports\Tech Memo-Task 1 (final draft).doc May 9,2008 Lyman Creek Restoration f,mproye,ments _„ _wMM rrQ son-M terle Inc. 1,200 gallon hypo storage tank options discussed above, the 1,350 gallon tank will work for secondary containment. The diameter of this tank at the top is 86-inches due to the lip that supports the cover. Therefore, this tank may not fit through the double doors. However, the cover is not needed for use as secondary containment and the lip can simply be cut off of the tank, which should allow the tank to be turned sideways and fit through the double doors. This tank' is approximately $4,000. Chem-Tainer also provides a 78,5-inch x 78.5-inch x 69.25-inch high square containment tank_ This tank should fit through the double doors as is but the inside tank dimensions would only allow the 1,000 gallon Chem-Tainer storage tank to fit inside. This containment tank costs approximately $4,600, The WTP staff should measure the exact opening of the double doors including the outside canopy to confirm the dimensions. Another option for the WTP is to expand the chemical storage room by moving part of the interior wall to the west. This may allow room for two 1,000 gallon hypo storage tanks to provide a total of 2,000 gallons of storage if desired. An upsized hydrofluorsilic acid tank would also fit inside the expanded chemical storage room. For the injection of hypo solution, the existing chemical metering pumps should have capacity for the increased demand. The pump heads can be replaced with higher capacity heads if needed. However, another metering pump would provide redundancy for the system. This standby pump could be plumbed to both the primary and secondary injection points. 1.1.4.2 On-Site Hypochlorite Generation System On-site hypochlorite generation systems have become an attractive option for some water treatment plants within the last few years. These systems generally have higher capital costs when compared to gaseous chlorine or bulk hypo, but are relatively inexpensive to operate. On-site hypo generation uses three common consumables; salt, water and electricity. A typical mass balance is the following: 3 pounds of salt + 15 gallons of water + 2 kWlhrs of electricity = 1 pound of C12 On-site generation systems operate by feeding a softened water stream into a brine tank. The salt dissolves to form a brine solution, which is further diluted to the desired salt solution. The salt solution is then pumped through the electrolytic cells, which apply a low voltage DC current to the brine to produce sodium hypochlorite. The generated hypo is then stored in a tank and then metered into the water system as needed. These systems operate in a batch mode to supply hypo for a one or two day period. When the tank reaches a low-level set point, the system automatically restarts to replenish the hypo supply. An important factor to consider with on-site hypo generation is that the electrolytic cells convert salt and electricity into a 0.8 percent strength hypo solution. Due to the lower concentration as compared to 12.5 percent bulk hypo, more of the generated solution is 1,1-10 N:\0417\05500CS\ReporWTech Memo-Task 1 (final draft),doo May 9,2008 Lyman Creek Restoration Improvements _ Morrison-Maierle. Inc. needed on a volume basis for the same amount of chlorine. Table 1-5 provides details of the generated hypo storage and metering criteria and can be compared to Table 1-4. Table 1-5 Lyman Creek WTP Improvements On-Site Hypo Generation System Design Criteria' Increased Active Generated Metering WTP Chlorine Hypo Hypo Storage Pump Capacity Required Required for 2 days Capacity Parameter (mgd) (ppd)2 (gpd)' (gallons) (gal/hr) Chlorine Dose = 1.2 mg/L2 Annual 2.69 27 404 808 16.8 Average Flow Maximum Day 3.86 39 579 1,158 24.1 Flow Chlorine Dose = 2.0 mg/L2 Annual 2.69 45 673 1,347 28.1 Average Flow Maximum Day 3.86 64 965 1,930 40.2 Flow 1. 24-hour WTP operation. 2 Assumes 0.8%hypo strength and approximately 0,07 pounds of active chlorine per gallon of hypo. The data in Table 1-5 indicate that the generated volume hypo required per day is consistent with the difference in hypo strength compared to the bulk 12.5 percent trade strength solution. At a 2.0 mg/L chlorine dose, at least 2,000 gallons of total storage would be needed for a 2-day storage volume. Similar to the upgraded bulk hypo system discussion, this size tank would not fit inside the existing chemical storage room. In order to fit the on-site generation equipment and storage tanks in the existing WTP, an on-site generation system option would require use of the radon tower room. Therefore, the tower would have to be removed. The on-site generation system skid could be located in the chemical storage room. The dimensions of the skid are approximately 12 feet x 4 feet. The brine tank, hypo storage tanks and the hydrofluorsilic acid tank could be located in the radon tower room. This room provides enough floor space to accommodate the full hypo storage requirement of at least 2,000 gallons. Due to the diluted hypo generated, the metering pumps would be required to pump more volume. The capacity of the existing metering pumps should be evaluated for this increased flow. However, new metering pumps would not be a significant cost compared to the on-site generation system overall cost and typically can be included in the on-site generation equipment package. 1.1-11 N\0417\055\DOCS\Reports\Tech Memo-Task 1 (final draft).doc May 9, 2008 Lyman Creek €gaWration Improvements ry „Mw mTMorrison-Maierle, Inc. There are several benefits of on-site generation systems compared to bulk hypo systems. The first benefit is that WTP staff would be working with a less hazardous substance due to the 0.8 percent hypo strength of the generated solution. The diluted hypo is less corrosive than a 12.5 percent trade strength solution, and usually doesn't require secondary containment. Furthermore, 0.8 percent hypo is much more stable than the more concentrated bulk solution and will not degrade as rapidly over time. On- site generation systems also eliminate bulk hypo deliveries to the plant site. This may be a significant advantage for the Lyman Creek WTP given the remote location and the cost of chemicals. A brine tank is included with the on-site generation equipment package, and typically contains a week's supply of salt at the maximum day demand, For the WTP, a 200- gallon tank would be required. The salt requirement for a week of maximum day flow at a 2.0 mg/L chlorine dose is equivalent to approximately 1,344 pounds. The City would probably be required to replace salt on a weekly basis during the summer months. Salt can be purchased in typical 40-pound or 80-pound sacks or in super sacks that weigh 2,000 pounds. Forty-pound sacks would require the operators to manually lift and pour salt into the brine tank. Super sacks would require mechanical assistance to bring the sacks into a storage area and to transfer salt into the brine tank. Assuming the radon tower is removed as part of the improvements project, this room could be used for the delivery and loading of salt into the brine tank with super sacks with the installation of a monorail, Storage of salt must also be considered in order to minimize deliveries to the WTP. At the daily average chlorine demand of 27 pounds per day, 2,400 pounds of salt is required over a month's time. This is equivalent to a little more than one 2,000-pound super sack or 60, 40-pound sacks of salt. A larger brine tank could be utilized to minimize the handling of salt. For an additional capital expense, a salt hopper could be installed that would reduce the labor and storage requirements, Some facilities that have on-site generation systems receive bulk shipments of salt that is blown into a hopper. The salt is then mechanically transferred from the hopper into the brine tank. Morrison-Maierle, Inc. recently had a discussion with Brian Swan, the WTP operator for the City of Colstrip. Colstrip installed an on-site hypo generation system in 2007. The equipment procurement package was prepared by Morrison-Maierle, Inc. The staff at the WTP manually adds salt to the brine tank of their system. Current salt demand is approximately 400 to 500 pounds per day in the summer, requiring daily salt handling. In the winter, only weekly salt handling is required. The Colstrip WTP treats approximately the same volume of water as the current Lyman Creek WTP, However, the Colstrip WTP utilizes a surface water source that requires a higher chlorine dose for disinfection. Mr. Swan indicated that routine maintenance is limited to salt handling. The system has been installed for over one year and the electrodes have been cleaned once. This involves a clean-in-place procedure where acid is pumped into the electrodes and then flushed with water. The cleaning procedure takes about an hour. Mr. Swan indicated that the electrodes will require cleaning twice per year. Overall, the 1,1-12 iV:10417\06500MReportsvrech Memo-Task 1 (final draft).doc May 9. 2008 LY_man Cree Rgstara#ion Improvements �-� Morrison-Maierle Inc. City is satisfied with their decision to switch from gas chlorine to on-site hypo generation. One other factor that is common to on-site generation systems is the production of a small amount of hydrogen gas as a by-product of the electrolytic reaction. The amount of hydrogen gas produced is well below the lower explosive limit for hydrogen. However, this gas could build up in the hypo storage tank. To prevent gas buildup in the system, manufacturers supply a blower that continuously vents the headspace in the storage tank to the atmosphere. Literature from an on-site generation manufacturer is included in Appendix A, 1.1.4.3 Present Werth Analysis and Disinfection Alternative Evaluation In order to compare the two disinfection alternatives, this memorandum will look at the capital and O&M costs. The capital and O&M costs for both disinfection alternatives is included in Appendix S. Also included is a present worth analysis taken over 20 years at an interest rate of 6 percent. Table 1-6 presents this information. A 20-year period is common for many utilities when evaluating costs. However, the City should consider whether a shorter time frame would be more applicable for the WTP. Table 1-6 Lyman Creek WTP Improvements Disinfection System Alternative Present Worth Analsis'p: AyxN � On-Site Hypo Parameter Bulk Hypo System Generation System TmnN.�Trt.M1�.X�pGIX::_'SI!"Ifn'.YJ,..4.u'wtu':..'.h:aLwi-..•......•._.....-. .._ . Capital Cost $18,000---- — -- -$276,600�, - . Annual O&M Cast $37,750 - $5,900 Tota3Present Worth $451,000 $344,500 Cost 1. See Appendix 8 for details. 2. Chlorine dose of 1.2 mg/L year round, 24-honer operation. 3. 20-year present worth at 6%, The data from Table 1-6 indicates that the upgraded bulk hypo system requires a relatively small upfront capital cost, but a large annual expense. The annual cost consists of purchasing bulk hypo, which was estimated to be $4.00 per gallon. The City currently pays $5.51 per gallon, but the WTP superintendant stated that the future cost may be lower due to increased bulk shipments to the Sourdough WTP. The on-site hypo generation system has a large upfront capital cost but a significantly lower annual cost consisting of salt, electricity and an equipment replacement fund to replace the electrolytic cells. The electrolytic cells typically have a life of seven to ten years and the replacement cost is estimated to be $8,000. 1.1-13 NA0417\0WD0C;81Reports\Tech Memo.Task 1 (final draft).doo May 9, 2008 LYrnan Creek Restoration imprQvgr ell�,s Morrison-Maierle, Inc, Note that labor costs were not included in this analysis. Although there will be labor costs for salt replacement and cleaning of the electrolytic cells for the on-site generation system, these costs are not expected to be significant. The feed water into the system is run through a dual tank water softener. Therefore, significant hardness deposits on the electrolytic cells are not typical and should only require cleaning approximately once or twice per year. The electrodes are visible in the housings and the operators can see when a thin layer of deposits begins to form. The total present worth costs indicate that the on-site alternative is nearly 25 percent less expensive than the bulk hypo system over a 20-year planning period, Another way to look at the cost difference is the on-site system will save approximately $32,000 in annual O&M costs and has a payback period of just under nine years. These estimates assume that the average chlorine dose is 1,2 mg/L. If the average dose is 2.0 mg/L, the on-site alternative is nearly 50 percent less expensive on a present worth basis. Annual O&M savings total approximately $54,000 with a payback period of just over five years, If a 10-year planning horizon was used in the evaluation, the economics would change significantly. For an average chlorine dose of 1.2 mg/L, the upgraded hypo system would be approximately 10 percent more cost effective than the on-site alternative. For an average chlorine dose of 2.0 mg/L, the on-site system is more cost effective by nearly 30 percent. 1. 1.4.4 Recommendations for Disinfection From the discussion in the previous section, an on-site generation system may have economic benefits for the City given the assumptions stated above for removal of the radon tower and a 20-year planning period. These systems also provide non-economic benefits including the elimination of safety issues associated with bulk hypo delivery, storage and operation, plus the fact that the generated hypo solution is much more stable than bulk hypo. Safety is obviously a concern for the City, and an on-site generation system can alleviate many of the issues with bulk hypo. The more stable generated hypo solution also provides for easier dosing control, The City has indicated that the radon tower will remain in the WTP pending further evaluation of the Radon Rule. Therefore, an on-site generation system installed in the upcoming improvements project would require construction of a new building with equipment for salt handling. Not only would a new building be a considerable increase in capital cost for the City, WTP operators would be required to maintain the building and equipment in addition to their duties with the existing building, A new building would cost approximately $100,000, increasing the capital cost for the on-site alternative listed in Table 1-0 to approximately $400,000, This results in the on-site alternative being a cost effective option (by about 30 percent) only at an average chlorine dose of 2.0 mg/L. over a 20-year planning period. This cost does not include additional maintenance of a new building. There would also be heating and cooling costs year round for the new building. Another cost factor to consider would be hydrofluorsilic acid delivery. With 1.1-14 W0 4 1 710 5 51DOCS1Reports\Tech Kam-Task 1 (final draft).doc May 9,2008 Lyman Creek Restoration Improvements Morrison-Maierle. Inc. delivery of only hydrofluorsilic acid to the WTP site and not hypo, the unit cost per gallon of hydrofluorsilic acid may increase. Implementation of the on-site alternative at the WTP would include many uncertainties that may affect the economic assumptions discussed in Section 1.4.3. In addition, the relatively large capital expense for the new building and equipment is currently not in the budget for the improvements project. Therefore, it is recommended that the WTP upgrade the existing hypo system as described in Section 1.4.1 and summarized below; • Install a new hypo storage tank in the chemical storage room (along with secondary containment) to provide 900 to 1,000 gallons of working hypo storage Purchase a standby hypo metering pump to be plumbed to both the primary and secondary disinfection locations Replace the pump heads on existing chlorine metering pumps if necessary As discussed, additional hypo storage could be installed with expansion of the chemical storage room. The total hypo storage could potentially be 2,000 gallons with these modifications. 1.1.5 FLUORIDATION SYSTEM EVALUATION If the City wishes to continue to add fluoride to the raw water from the Lyman Creek source, an upgraded system will be required based on the design criteria presented in Section 1.3. For the increased volume of hydrofluorsilic acid required, the 2007 consumed volume can simply be increased by 78 percent, the ratio of the new annual average flow of 2.69 mgd compared to the existing annual average flow of 1.51 mgd. This results in an annual consumption of approximately 4,450 gallons or 12.2 gallons per day of hydrofluorsilic acid. Table 1-7 provides details of the upgraded hydrofluorsilic acid storage and metering criteria. Table 1-7" Lyman Creek WTI' Improvements Upgraded Fluoridation System Desi n Criteria' Wydrofluorsilic Metering bump Increased WTP Acid Required Storage for 2 Capacity Parameter Capacity (mgd) (gpd)2 Weeks (gallons) (gallhr) Annual Average ---Flow 2 fi9 12,2 170 0,5 _ _ Maximum Qay -- 3.86 .----- 17.6 ----- ----- .245 0.7 Flow 1. 24-haur WTP operation. 2, Proportioned volume increase from existing conditions, 1 mg/L,dose, 1.1-15 NA04 1 710 5 51DOCS1Reports\Tech Memo-Task 1 (final draft).doc May 9,2008 Lyman Creek restoration Irrtprovements _Mrri.son-Maierle jnc, The data in Fable 1-7 indicate that for the maximum day flow of 3,86 mgd, 17.5 gpd of hydrofluorsilic acid is needed. The existing 300-gallon tank would be sufficient for the upgraded VVTP. However, a 500-gallon tank would provide more flexibility for the VVTP and provide nearly a month of storage. . The recommendation of this memorandum is to upgrade the fluoridation system storage capacity using the existing 500-gallon hypo storage and containment tanks, These tanks will fit inside the chemical storage room along with the upgraded hypo storage and containment tanks described previously. For the injection of hydrofluorsilic acid, the existing chemical metering pumps should have capacity for the increased demand. Improvements to chemical injection are discussed in the next section. The City may need to relocate the fluoride injection location to the Outlet Control Building based on potential groundwater discharge permitting concerns. 1.1.6 CHEMICAL INJECTION AND MIXING, RESIDUAL SAMPLING, SYSTEM CONTROL, AND SAFETY ISSUES This section discusses recommended improvements to chemical injection and mixing, residual sampling, system control, and addresses safety issues associated with the upgraded WTP. 1.1.6.1 Chemical Injection and Mixing improvements The chemical injection systems at the WTP use standard corporation stop injection diffusers installed into the process piping_ Typically, these provide the proper injection and chemical mixing when injected into the center of the process pipe to maximize dispersion of the chemical with the raw water, and at higher velocities to ensure turbulent flow. Adequate pipe distance must also be provided between injection and residual sampling. The City feels that the current configuration of the process piping in the Inlet Control Building does not provide a good sampling point for chlorine residual monitoring before proper mixing is attained, The sample tap and chlorine residual analyzer are located approximately eight feet downstream of chemical injection in the process piping room on the downstream side of a 90-degree bend. The City believes that this location does not allow for adequate mixing after injection. Furthermore, the hardness in the raw water (approximately 166 mg/L total hardness as calcium carbonate) causes the injectors to become plugged with calcium and magnesium deposits. The WTP staff removes and cleans the injectors every week. For this evaluation, it is assumed that the radon tower will remain at the WTP and there is the potential to use the tower. Some chlorine may be stripped out of the water if chlorine is injected before the tower when it is in use. This would be a very difficult process to control to maintain a certain chlorine residual. To some degree, fluoride may also be stripped from the water. Therefore, it is recommended to have a chemical injection point downstream of the radon tower. Another chemical injection point may be utilized upstream of the tower to use during bypass of the tower. Five options for chemical injection and mixing will be discussed in the Section. These include the following: 1 1-116 NA04 M05500CS%RepoftslTech Memo-Task 1 (final draft).doc May 9,2008 Lymarr Creek Restoration Im rovements Morrispn-Maierle, If1C, Existing injection/diffuser assembly • Static mixer 0 Softened water carrier stream In-line rapid mixer • Rapid mix tank Existing Injection/Diffuser Assg_Mbly. The first option is to simply continue to use corporation stop injectors/diffusers. In general, these provide adequate injection and mixing of chemicals for full pipe flow assuming a high enough velocity to produce turbulent flow and enough pipe length between injection and sampling. This option also allows for a "hot tap", where the injector/diffuser can be removed from the process piping without depressurizing the system, The current piping configuration results in approximately 9 feet per second velocity and turbulent flow in the pipe. For the upgraded WTP, a 12-inch diameter pipe would result in approximately 7 feet per second velocity and would still maintain a turbulent flow condition. For a residual sampling location, there is no common engineering standard for the required distance downstream of chemical injection to ensure proper mixing. Adequate velocity producing turbulent flow and the presence of piping bends help to provide mixing. Therefore, the sampling location should be located as far downstream from chemical injection as reasonable. Relocating the existing chlorine residual sampling location further downstream in the Inlet Control Building would most likely improve performance. Static Mixer: An improvement to the use of a corporation stop injector/diffuser is the use of a static mixer installed just downstream of chemical injection. This would provide rapid mixing in close proximity to the injection point_ Typically, corporation stop injector/diffusers are still utilized with static mixers for injection. There are generally two types of static mixers„ a helical vane type and a wafer type. The helical vane type static mixers can be very long, especially with larger pipe sizes. The advantage of the wafer type static mixer is that it only requires a short pipe length to install between two flanges. Some manufacturers offer chemical injectors built into a static mixer. A static mixer would still be subject to the potential deposition of calcium and magnesium from the hardness in the raw water onto the mixer vanes, The WTP superintendent has stated that he has had personal experience with static mixers becoming plugged with deposits. However, these mixers do provide for near instantaneous mixing of chemicals and may offer a real advantage for the WTP. Cleaning and maintaining a static mixer would require plant shutdown_ The cost for a static mixer would be approximately $8,000 to $10,000 depending on pipe size. Further evaluation is needed to determine the diameter required for a flow rate 2,680 gpm. It is estimated to be between 8 and 12- inches. Softened Water Carrier Stream. Another approach would be to use a softened water carrier stream. A small amount of raw water would be run through a dual tank water softener. Hypo could be injected into the softened water stream and the combined stream could then be injected into the process piping using a corporation stop injector/diffuser. The softened water stream may act to flush the diffuser in the process piping and reduce the accumulation of deposits. WTP staff would still need to observe 1,1-17 N:1041710551DOCS\Reparts\Tech Memo-Task 1 (final draft),doc May 9,2008 Lyman Creek Restoration Improvements, _ µ, , Morrison-Maierle inc. the diffusers and develop a maintenance routine for cleaning. Maintaining the water softener would also be required with this option. The raw water stream could be taken from the raw water piping upstream of the PRV in the Inlet Control Building at a pressure of approximately 60 psi. The water softener is not expected to have a large pressure drop. Therefore, the softened water stream may have a high enough pressure to be injected straight into the raw water piping downstream of the PRV (10 to 20 psi) without the aid of a booster pump. The pressure drop in the softener and the appropriate softened water flow rate should be evaluated further if this option is determined to be viable. As an example, for an annual average flow of 2.69 mgd and a 1.2 mg/L chlorine dose, 1.1 gph (0.02 gpm) of hypo (from Table 1-4) could be injected into a 10 gpm softened water stream. Commercial water softeners can generally produce 10 to 40 gpm of softened water on a continuous basis. With a higher flowrate, the velocity of the combined softened water and hypo would increase. A higher velocity may provide better flushing of the injector/diffuser in the process piping. However, more salt would be required for a higher softened water flowrate. In-loin. _e._Rap_id..Mixer: In-line rapid mixers are also used in water treatment facilities for mixing of chemicals. These consist of a motor and shaft mounted on a vertical flange of the process piping, such as a tee fitting. Blades are attached to the shaft, which is extended into the process pipe. Chemicals are injected just upstream of the in-line mixer using a corporation stop injector/diffuser. The motor turns the shaft to provide mixing in the pipe. Similar to a static mixer, this equipment would be susceptible to hardness deposits and would require routine maintenance. Maintenance of these mixers would require some plant downtime to access the blades for cleaning. The cost for an in-line mixer would be approximately $17,000 from a budgetary quote from Walker Process. An 8-inch diameter in-line rapid mixer would be required for 2,680 gpm. Ra ip_d Mix Tank: Another mixing technique used in water treatment is a rapid mix tank. This is an open tank system, as opposed to a pressure pipe system, utilizing a high speed mixer. Chemicals can be dripped into the open tank to provide an air gap between the chemical feed piping and the raw water. This would eliminate plugging of the chemical injectors with hardness deposits. However, maintenance of the mixer would be required including potentially having to remove deposits from the mixer blades. Since this is an open system, the tank would have to be located in the proper location. Downstream of the Inlet Control Building in the 16-inch piping to the reservoir may be an ideal location. The 16-inch piping has an invert leaving the building of 5017.9. The pipe is routed to the north and has a fall of approximately 0.7 feet for an invert of 5017,2, The reservoir bottom is at 4989.25 near the 16-inch pipe discharge into the reservoir. The water depth in the reservoir ranges from 20 to 30 feet deep. This results in a water elevation between 5010.0 and 5020.0. Therefore, at times a free discharge condition exists in the 16-inch piping from the Inlet Control Building. The benefit of a rapid mix tank would be that one chemical injection point could be used, which is not dependent on the use or bypassing of the radon tower. A residual 1,1-18 W04 1 7105 51DOCS\Reports\Tech Memo-Task 1 (final drcift).doc May 9, 2008 Lymar7 Creek Restoration Improvements m Morrison-Maierlejnc, pump vault may be required downstream of the rapid mix tank for residual monitoring. This pump may be able to be located in the mix tank structure or potentially inside the Inlet Control Building depending on the suction sample line length. The chemical injection line could be routed underground below frost depth, and then up the outside wall of the structure and through the wall. The injection line could then be mounted to the top slap and the chemical can be dripped into the raw water. Heat tape would be used to prevent freezing of the chemical lines_ The mix tank would be a relatively large sub-surface structure in order to provide vertical baffling to ensure proper mixing, and to provide water level control. Access hatches could be provided on the top of the structure for access. However, the plant may have to be shut down to maintain the equipment. This structure would have to be insulated near the ground surface and potentially heated to prevent freezing for the chemical injection nozzles. Overall, this option would likely be the most expensive of those discussed in this section and may prove to create more maintenance issues then the VVTP currently faces. Maintaining the equipment in the winter months would be difficult with low temperatures and snow. For an added expense, a small heated building could be constructed over a portion of the mix tank. The overall conclusion of this evaluation is that there are several options for chemical injection and proper mixing that would provide benefits over the existing system. The primary issue with the existing setup is the lack of residual monitoring and the lack of an adequate residual monitoring location. A secondary issue is the weekly maintenance associated with cleaning diffusers_ Each of the in-pipe options discussed above may still result in hardness deposits on equipment. The raw water is considered a hard water, but is well within the typical range seen in Montana groundwater and spring water. The only option that would eliminate hardness deposits on the chemical injectors is the use of a rapid mix tank providing an air gap between the injectors and the raw water. As discussed above, this option would be the most expensive and would have other maintenance issues to consider. 1.1.6.2 Residual Sampling Location The location selected for chlorine residual sampling before the reservoir should be downstream of the radon tower (assuming the radon tower may be used in the future), and must be preceded by proper chemical injection and mixing. As mentioned above, the 16-inch pipe from the Inlet Control Building to the reservoir has a free discharge flow condition at times. This may result in partially full pipe flow. Furthermore, the radon tower bypass piping and the radon tower itself produce a cascading water effect as the piping is routed up 10 to 12 feet above the floor (floor elevation = 5025.00) and then down into the pit where the bypass piping and radon tower discharge piping connect_ Since the high water level in the reservoir is a maximum of 5020.00, the radon tower discharge and bypass piping do not have full pipe flow. This makes it very difficult to ensure proper chemical injection and mixing in short sections of pipe in the room, and doesn't provide a good sampling location. Therefore, with potential future use of the 1,1-19 N:104 1 710 5500CSIReportslTech Memo•Task 1 (final draft).dpc May 9, 2008 Oman Creek Re,storation Improvements Morrison-Maierle, Inc. radon tower, residual sampling cannot be located in the Inlet Control Building without a major redesign of the radon tower and piping. Three options are presented in this section to address the issues of chemical injection, mixing and residual sampling for the WTP: m Option 1 — Chemical injection in Inlet Control Building, residual sampling vault near reservoir 0 Option 2 — Chemical injection and residual sampling in rapid mix tank structure Option 3 — Continued radon tower bypass, chemical injection and residual sampling in Inlet Control Building Option 1. This option uses standard corporation stop injectors/diffusers to inject chlorine inside the Inlet Control Building downstream of the radon tower. A residual sampling location would have to be located far enough downstream from the Inlet Control Building to ensure proper mixing and full pipe flow. According to the 2004 design plans, the 16-inch pipe penetration through the north reservoir wall has an invert of approximately 5017, which is above the minimum water level of 5010.00 in the reservoir. Therefore„ the sample suction line would have to extend down into the reservoir and into the 16-inch pipe to ensure full pipe flow. The sampling pump would have to be self-priming and located in a vault just to the east of the reservoir. The discharge line could then be routed back to the Inlet Control Building. WTP staff will be required to remove and clean the diffusers every week or as required for proper operation and minimize deposition of hardness deposits, and provide maintenance to the sample pump, Op ion 2. This option utilizes the rapid mix tank as discussed in the previous section. The rapid mix tank is not affected by partially full pipe flow in the Inlet Control Building. Water level would be controlled in the tank to create the necessary depth for the mixing chamber. This depth would be approximately 5022.00, which allows 2 feet of fall into the reservoir at the maximum water depth of 5020,00. The residual sample could be taken from the downstream side of the mix tank, As discussed, this option would likely be the most expensive and would require year-round maintenance of an outdoor structure, Option 3: Another option to consider involves either the removal or continued bypass of the radon tower. If it is determined that the City is in compliance with the Radon Rule, this option would be viable. The bypass piping could be reconfigured from the process piping room. A new bypass pipe could be routed two to four feet above the floor along the west wall of the radon tower room. Near the northwest corner of the room, the pipe could be routed up and connect with the existing bypass piping located approximately 10 feet above the floor, Flow would then follow the existing bypass pipe down into the pit and underground to the reservoir. Keeping the bypass pipe low and then routing it higher will create a full pipe flow condition. Therefore, a residual sample can be taken from the low section of this pipe. Chemicals can be injected into the pipe in the process piping room or in the radon tower room allowing as much pipe length and piping bends between chemical injection and sampling as possible for better mixing. A static mixer or in-line rapid mixer could be used to shorten this distance if desired. 1,1-2o NA041710551DOCSIRepori:5'Tech Memo-Task 1 (final draft).doc May 9,2008 Lyman Creek Restoration Irrrpro�eme,nts_w Morrison-Main erle,Enc, Option 3 would provide several benefits for the City. All chemical injection and residual sampling would occur inside the existing Inlet Control Building_ Also, only one chemical injection paint is required. This option would also be the most cost effective solution to alleviate the existing issues with chemical injection, mixing and residual sampling. Therefore, it is recommended that the City review their compliance with the Radon Rule. If the radon tower must be kept on-line, Option 1 and 2 discussed above should be evaluated further. 1.1.6.3 Outlet Control Building The Outlet Control Building currently consists of a supplemental disinfection point, flow and chlorine residual monitoring capabilities, and differential pressure monitoring of the reservoir. The City wishes to continue to utilize these functions, however, several improvements are required. Technical Memorandum No. 3 discusses details of level monitoring inside the reservoir structure, thus eliminating the differential pressure system. As previously discussed, the City may need to relocate the fluoride injection point from the Inlet Control Building to the Outlet Control Building. Chlorine can continue to be monitored for a post-reservoir residual and the supplemental chlorine injection point can be used to boost the residual if needed, However, to ensure an adequate chlorine concentration in the discharge from the Outlet Control Building, another monitoring location is needed. With the addition of a static or rapid in-line mixer just downstream of chemical injection, the monitoring location can be located inside the building and would provide accurate results. However, if only corporation stop injectors/diffusers are used for chlorine injection with no supplemental mixing, a sampling pump vault would be required downstream of the building to ensure proper mixing. As discussed, an external structure would need to be maintained year-round and may be difficult during winter months. Injection and monitoring could both be placed inside the Outlet Control Building and set as far apart as possible. However, proper mixing of the chlorine before monitoring may not be attained. This would be similar to the existing injection/monitoring setup in the process piping room at the Inlet Control Building, If this option was implemented, the City could take manual samples downstream in the distribution system as needed to check chlorine residual. 1.1.6.4 Instrumentation and Control Improvements With the addition of residual sampling upstream of the reservoir, chlorine and phi can be monitored in the Inlet Control Building. The chlorine residual can be used to pace the control system and increase or decrease the feed rate. The upgraded control system will also include flow pacing of chlorine as well as manual application. Details of the instrumentation and controls are discussed in Technical Memorandum No, 3. 1,1W21 W041710551L]0CSIRepor1:s\Tech Memo-Task 1 (final draft).doo May 9,2008 L man reek Restoration Err►provements M - MbrrisQn-Maierle, Inc. 1.1.6.5 Safety Improvements As discussed in Section 1 AA, it is recommended to upgrade the existing hypo disinfection system at the 1NTP, The City should continue to utilize the double check safety procedure with all deliveries to the site. This is especially important with bulk hypo and hydrofluorsilic acid, The City could consider moving the chlorine injection location to the radon tower room or to a chemical injection vault in the raw water pipe upstream of the process piping room. Injection in the radon tower room would isolate the mechanical equipment, control panels, the SCADA computer and analytical instruments in the process piping room from potential damage due to a hypo leek. However, it would also shorten the distance between injection and monitoring, which may not provide adequate chlorine mixing. An external chemical injection vault would involve maintenance of an external structure as discussed previously. It is recommended to maintain the primary chlorine injection point in the process piping room to provide the maximum distance between injection and monitoring as discussed in. Option 3 in Section 1.6.2. Continued routine cleaning of the injectors should help maintain proper operation.. To improve safety and protect equipment in the process piping room, it is recommended to utilize an instrument cabinet and waterproof electrical panel enclosures. 1.13 SUMMARY OF RECOMMENDATIONS A summary of the recommendations of this memorandum are as follows: Evaluate compliance with Radon Rule Confirm dimensions of double doors into chemical storage room • Upgrade the existing hypo disinfection system with 900 to 1,000 gallons of working hypo storage along with secondary containment Purchase standby hypo metering pump to be plumbed to both primary and secondary disinfection locations • Upsize hydrofluorsilic acid storage tank by using the existing 500-gallon hypo storage tank and containment tank • Consider in-pipe chemical mixing improvements in Inlet and Outlet Control Building (static or rapid in-line mixers) • Chlorine injection to remain in process piping room with improvements to protect instruments and electrical panels • Reconfigure radon tower bypass piping to provide full pipe flow for residual sampling • Chlorine residual and pH monitoring in new radon tower bypass piping in Inlet Control Building • Outlet Control Building improvements including new residual monitoring • Separate supplemental chlorine injection and chlorine residual monitoring as far as possible in Outlet Control Building piping The estimated construction cost for the recommended improvements is $60,000, 1,1-22 NV417\05500=Reports\Tech Memo-Task 1 (final draft),doc May 9,2006 Lyman-Creek Restara i.¢n Improvements T_ Morrison,Maierlg, Inc, Appendix A — On-site Hypo Generation System Literature Appendix B — Disinfection System Cost Evaluation 1,1-23 NA041710550QCS\Reports\Tech Memo-Task 1 (final draft).doc May 9, 2008 APPENDIX A blafnfaaNun r'ra=Yuale I TM I V!, .,1.t.l''•t .. 1!t C!' ,. .. - . , .. , ». . q,,.t j f n 5,: j Severn Trent Services offers the ClorTecTM On-site Hypochlorite Generating Systems, that easily produce 0.8% sodium hypochlorite by combining three common ' consurnables., salt, water and electricity, to provide a Y powerful disinfection method for any application; food and beverage, potable water, wastewater, odor and corrosion , control, cooling towers, oxidation and swimming pool 1 �} disinfection. cfa r' all The ClorTec systems are skid mounted and consist of electrolytic cells), Power supply/rectifier, control Panel/ " :Av PLC, water softener, brine proportioning pump, hydrogen X dilution blower and an optional water chiller/heater, all in ° one compact unit design conducive to easy installation and ..; P g Y "_,,, start-up, The sirriple-to-install skid-mounted systems can be fully operational and generating hypochlorite in less than 24 hours. Features; Benefits: Compact, skid-mounted system Eliminates dependence on chemical Hypochlorite produced on-site, on demand suppliers Superior Warranty Easy to install and operate NSF 61, ETV certification Reduced disinfection by-product Eliminates need to store hazardous chemicals formation onsite Improved water quality Eliminates handling and transportation of On-demand sodium hypochlorite hazardous materials production t Reduced maintenance V 4. Exempt from process Safety Management " E-4 k. Exempt from Risk Management planning SFsi r< 1 Is T s.N r. r ' " •;;e'y� Fa w - . Severn Trent Services M rr`7i t� NA 2660 ro(unibia Street Torrance,CA 9.0503 Te[ '310 618 9700 ���x�: ;-� �.' , • Tal►�re�� 800 52�t 554? f"pax 31O 6184384 r ira�b�severntrerliSdrviCeS;cdrn ' e t entsruics,corr� IuvVVP.S Verr1 r ., CLOR'ITEC ON SITE, SOl)It1.lVl H"YPOCHLORITE REFE11FNCE LIST • City of Daytona Beach Marvin Owens—Plant Superintendent, Ralph Brennan Water Trcatment Facility 3651 LPGA Blvd. Daytona, FL Tel -386 671-8831 Cell—386 547-2322 (2) 2,000 lb/day systems • City of. Tempe Brad Fuller—Plant Superintendent 6600 South Price Ruud Temp,AZ 65280 Tel—480 350-2853 (2) CT-2250 & (2) CT-3000 • Yorba Unda WD Lcon do los.Reyes-- Water Quality Engineer 913 South Richfield Road Placentia, CA 92870 Tel—714 701-2020 Cell—71.4 448-0158 (3) CT-300 Systems • Eastern Municipal Water District Contact—John Dotinga Operations Supervisor Tel 951 672-7699 Type of Systems—Over 20 systems in the field ranging from 12 lbs/day to 450 lhs/day Application—Providing disinfection at Rooster Pump Stations and at several Water Treatment Plants • Olivenhain WTI' Dave Smith—Plant Superintendent 1966 Olivenhain Road Encinitas, CA 92024 1'el--760 740-1385 x 182 (1) CT-2250 • Palmdale WD Kelly Jeters—Operations Supervisor 2029 East Avenue Q References in Montana for Severn Trent's ClorTee On-Site Disinfection System City of Billings Staples Water Booster Station Toin. Ross— Operations Super Phone: 406-247-8683 City of Havre Water l~iltratioii Treatment Plant Bob Presnell — Water Sniper Phone: 406-265-52I 5 City of Colstrip Water [11tration 'I'reatnycnt Plant John Bleth--- D1reCtOT of'Public Works Phone: 406-748-2 300 Spanish Peaks Welter Booster Station Jon O sen - Engineer 11bone: 406-579-8154 APPENDIX B 1 k � Ry Y O w u, 7 N N V) n (7 N Q� Q, 41 N O O b p U z c � a � c � o .0 � � U m O 6 a al �tl 4' v r9 ry is is � c � N cd ,�1m Egg Cw U3 V 0- CJ I.I.! l!J "�t 11-i vim-• o ul w w E g b P C) q $ C+ o � l j s o � C�a � CO.J Q g 0 N m 0 d� r o O O © C] q N Q C7 C �p U7 to O r e y� L OLo Ca O i7 C rti : ro b p'1 Q1 ? Of q3 F? N V- " Lnb ow44 v► kR to t4 is eg as W 44 m� w p 0 « 00 0 0 Q Q C o e a, pt700 0 wO04-) � ottr on 0 ova C] 59 ! t,�y tr, I�f7 c 64 69 a, C � tn � www JICJCJ U C��7 w .�J �� , � a � �7 C) � 00 ro m a ro ter" "- � r tncnr D as m m z o H m N J ? _ q m ." EA 2 e v ilf G. r N. O p � 2 ,.�.. 0) N O o En V)y q b vi m ° O m C7 } ro E o N m z M ! n 2 a � C? ac c S O O m E as iv 0 l U. R m cQ O c cf O .N u M c cr1 N U f11 CJ - ui W. LM 0 n 2 Lu Cc w Q tl) i1J CK 0) n DISINFECTION COST EVALUATION Interest Rate % = B'/; Option Capital$ Annual $ Bulk Hypo $18,000 $37,751 On-Site System $276,600 $5,919 Present Worth Values Year Bulk H po On-site 20 $451,001 $344,495 ° MORRISON DO MERLE,INC, ,m Ampin.v rAn.d I>,npunr Technical Memorandum No. 2.1 PLAN" PIPING MODIFICATIONS City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, MT PREPARED BY: James Nickelson, P,E, REVIEWED BY: Jim Ullman, P.E_ DATE: May 9, 2008 2.1.1 INTRODUCTION The existing Lyman Creek Water Treatment Plant is equipped with undersized piping to accommodate the full water right available_ In addition the flow control valve and flow meter system is in need of modifications. This memorandum addresses these problems and the recommended corrections. 2.1.2 EXISTING SYSTEM The existing piping within the building is 8" and was designed for a flow rate of 1,500 gallons per minute. The available water right is 2,680 gallons per minute which is the desired design flow rate. The existing flow control valve does not function as desired and the flow meter that was provided with the original project does not function. In addition to these two major issues there are number of other minor items that need to be addressed. 2.1,3 RECOMMENDED IMPROVEMENTS The recommended improvements include the following: Upsizing the flow control and treatment pipe train from 8" to 12" • Adding a new CLAVAL pressuring reducing valve • Adding a new CLAVAL flow control — metering valve • Lowering the treatment plant pipe train for easier maintenance 2,1-1 NA041710551D0CS1Reparts\Task Menio 2,1,dac May 9.2008 Lyman Creek Restoration Improvements Morrison-Maierle,_Enc. s Relocating the tumidity meter closer to near the sample location Reconfigure chemical injection points and sampling points as discussed in Technical Memorandum No_ 1 The construction cost for these improvements is estimated to be $75,000. 2.1-2 W041710551DOC:SIReports\Task Memo 2.1,doc May 9. 2008 ua MOTHSON f-0- MAIERLE,w. Technical Memorandum No. 2.2 FLOW CONTROL OPERATIONS MODIFICATIONS City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, MT PREPARED BY: James Nickelson, RE. REVIEWED BY: ,Jim Ullman, P.E. DATE: May 9, 2008 2.2.1 INTRODUCTION The flow control for the Lyman Creek Water Treatment Plant supply is located at the treatment plant. The flow rate is periodically modified by changing the setting of the flow control valve. Due to the need to maintain a pressurized pipe line from the spring to the plant the current method of operation does not capture all of the available flow from the spring. This memorandum will be updated when additional information is available from the spring investigation phase. 2.2.2 EXISTING CONDITIONS The existing pipe line flow is controlled by a flow control valve at the treatment plant. The flow rate is manually set based on the water demand of the distribution system and the need to maintain a pressurized pipe line. Water enters the pipe line at a manhole diversion structure which is fed by the spring lines. The water level in the manhole is maintained at a level that allows for water to be wasted into Lyman Creek. Maintaining water at this high of level in the manhole is required to maintain full flow in the pipe line which is needed in order for the pressure reducing valves to function properly. The amount of water that is wasted into Lyman Creek at the diversion manhole varies based on the time of year and the fluctuation of the flow from the spring. The only method that the operators have to assure a pressurized pipe line is to physically go to 2,2W1 NA0417%OWDOMReportslTask Memo 2.2.doc May 9,2008 4yman Creek Restoration Im royements „rv�Qrri son-Maierle, Inc. the spring and visually evaluate the amount of water being wasted. Since allowing the pipe line to flow at less than full flow presents the risk of shutting the supply line down, the operators need to be conservative in setting the flow control valve at the treatment plant. Thus water is wasted at the spring that could otherwise be utilized. In addition to the direct discharge of spring water into Lyman Creek under current operations, there is a high possibility that maintaining this high water level in the diversion manhole prevents fully capturing water from the lower spring gallery. While the magnitude of this loss in spring production cannot be directly determined, there is certainly evidence of water surfacing at the spring which indicates that not all of the available water from the spring is being discharged into the diversion manhole. 2.2.3 Potential Alternatives There are a number of possible flow control operation strategies that could be utilized to increase the amount of water available to the treatment plant. The following discusses a number of scenarios that could be utilized to more fully utilize this water source. Option 1 — Operate pipe line with upstream control This option would convert the current pressurized pipe line into a gravity pipe line. This would allow all of the water generated at the spring to discharge into the pipe line. Excess water delivered to the treatment plant would need to be routed around the plant or discharged into Lyman Creek at the lower diversion pond. Since discharging excess water down the gully below the treatment plant would cause a host of problems with the neighbors, diverting the excess water at the lower diversion pond appears to be a more acceptable alternative. While this option would allow for the capture of additional water it has a number of problems. While there are a number of apparent problems with this option the most significant would be the entrainment of air into the water which would cause havoc with the control and treatment process at the treatment plant. The following identifies a number of items needed to implement this option: - Remove pressure reducing valves in upper portion of system Add reservoir at lower diversion pond to allow pipe to depressurize and reduce entrained air W Modify flow control system at plant Option 2 —Add level sensors with telemetry to current diversion manhole This option would simply add a means to monitor the water level in the diversion manhole and report it back to the SCAQA system. An alarm could be triggered if the water level dropped below a predetermined level and the operator would then have the ability to adjust the flow to maintain full pipe flow from the spring to the plant. It would also be possible to automate the flow control based on the water level in the diversion manhole. This is a relatively low cost solution to reducing some of the risk associated with allowing the pipe to go from pressure flow to gravity flow and would provide operators with real time data from the spring_ 2.2-2 N:104 1 710 5 51DdCSIReports\Task Mema 2.2.dor. May 9,NO Lyman Creek Restoration lmnrayemen � Morripn-Maierle, lnc, There are two drawbacks to this option. The first is that the diversion manhole does not provide very much storage which will require the operators to continue operating the water line in a conservative manor and continue wasting water. The second is that the water level in the manhole would need to be maintained close to the elevation of the overflow pipe which would limit the ability to pull additional water from the lower spring. The manhole is only four feet in diameter. Therefore the manhole stores 94 gallons of water per vertical foot. If the flow rate from the spring decreases by 10 gpm and if the water demand at the plant is constant, the water level in the manhole will drop one foot every ten minutes which does not allow adequate time to adjust the water demand at the plant before the pipe line will begin to take in air. Option 3 — Add a small reservoir below the diversion manhole with telemetry This option would consist of adding a new tank downstream of the current diversion manhole along with telemetry to provide data back to the treatment plant. The reservoir would add some storage to the system to accommodate flow variations to some degree. The level in the reservoir could be monitored and overflow discharge could be measured to determine the flow rate of the spring. This data would provide the information needed to maximise the amount of water available to the treatment plant. 2.2.4 Recommended Alternative The recommended alternative is to implement Option 3. The details regarding this option are dependent on the further investigation of the spring and the location of potential additional infiltration galleries. However, in order to provide a starting point for exploring this option and budgeting for the project the following scenario has been developed. Add a small reservoir approximately 200 feet downstream of the diversion manhole_ This reservoir would receive all of the water generated from the spring. The reservoir would have an overflow pipe discharging to the creek equipped with a weir to monitor flow. The reservoir would need to be large enough to accommodate minor changes in flow from the spring to prevent the reservoir from emptying before an operator car) reduce the flow going to the treatment plant. A reservoir that is 10 feet wide, 20 feet long and 8 feet high would provide for approximately 12,000 gallons of storage. if the flow from the spring decreased by 10 gallons per minute the storage would provide supplemental flow for a 20 hour period_ This would allow the flow control valve at the treatment plant to be adjusted during a normal work shift_ The flow control valve at the plant could be automatically controlled based on the water level in the reservoir which would allow for capturing all of the flow from the spring. However, automatically and continuously changing the flow into the treatment plant could cause problems with the treatment process. It is recommended that the flow control valve continue to be set by the operators. The valve should be set to allow for a small amount of water to be discharge back into the creek at the new reservoir site. Once the system is in operation and adequate data is collected to determine the rate of change of flow from the spring, the amount of overflow water can be adjusted 2.2-3 NAD41710551D0CS\ReportslTask Memo 2.2,doo May 9,2008 Lyman Creek Restoration Improvements Morrison-Maierle, Inc. accordingly. It is anticipated that the amount of water being wasted into the creek can be reduced from the current flow of 60 to 100 gallons per minute to something in the range of 10 to 20 gallons per minute or less if the spring flow is found to be very consistent. The overflow water from the reservoir can be measured with a level sensor and a weir. The level in the reservoir can be measured with a level sensor. It is anticipated the flow data from the weir would be utilized by the operators to set the flow control valve at the plant and that the level sensor in the reservoir would trigger an alarm based on either a low water level threshold or a rate of change threshold if the reservoir is being operated with no overflow. Reservoir Construction Cost - $35,000 The telemetry associated with this item and associated cost is included in the Control Technical Memorandum, 2.2-4 NV49710WOOMReportslTask Memo 2.2.doc May 9,2008 MORRISON L1 J 1 MA�rNc, Technical Memorandum No. 3.1 CONTROLS City of Bozeman Lyman Creek Reservoir Improvements Project PREPARED BY; Michael W. Brandt, P.E. REVIEWED BY; James Nickelson, P.E. DATE; May 9, 2008 3.1.1 INTRODUCTION The purpose of this Technical Memorandum is to evaluate and discuss improvements to the existing Lyman Creek wafter treatment plant (WTP) SCADA system. Several problems with the existing SCADA system have been identified that deal with reliability of information at the Lyman Creek site being shared with the Sourdough Water Treatment plant, changes in the local HMI at Lyman Creek that would allow easier control of the system and changes to some i-nonitoring/control equipment to provide more process information and elimination of control anomalies. This memorandum will discuss these issues and provide recommendations and cost estimates. 3.1.2 EXISTING SYSTEM DESCRIPTION The SCADA system at Lyman Creek WTP consists of a local programmable logic controller (PLC), a local Human Machine Interface (HMI), a radio modem and the associated monitoring/control equipment on the site. All information on the local HMI is sent via radio to the City shop and then retransmitted through a T1 line to a HMI at the Sourdough Water Treatment plant. In addition to this system, the Lyman Creek SCADA also communicates through another radio modern to the Bridger Center Lift Station to collect its information. This information is then transferred through the first radio modem to the City shop for use by the Water Distribution staff. The Water Distribution staff also monitors the level of the Lyman Creek reservoir and the flow rate of the reservoir output. 3.1-1 NA0447105500CS\ReportslTach Manic)-Task 3 Controls Final,doc May 9,2008 Lyman Creek Restoration Improvements Morrison-Maierle, Inc. 3.1.2.1 Data Transfer from Lyman Creek WTP to Sourdough WTP. The main concern by the Water Treatment personnel is the reliability of data transfer between Lyman Creek WTP and Sourdough WTP, Data from Lyman Creek is sent via radio modem to the City Shop, through the City server and then is sent via a T1 connection to the Sourdough WTP. This T1 link has experienced many reliability issues due to its age and damage from development between the two locations, mostly from being cut by excavation and Computer server problems. During these interruptions, all data transfer from Lyman Creek to Sourdough is lost. This results in Water Treatment personnel having to travel to the Lyman Creek site to determine if the plant is operating correctly and no problems or alarms have occurred. 3.1.2.2 Lyman Creek WTP HMI Water Treatment personnel have expressed frustration with the existing Wonderware based HMI for ease of use. This relates to not having the ability to easily adjust system setpoints with some setpoints that cannot be adjusted, having manual overrides for control, being able to shut down the Lyman Creek facility from the Sourdough facility, trending and reporting data, and having an intrusion alarm shut down the plant operation. The HMI located at the Sourdough WTP is also a Wonderware system and would require the same modifications as the Lyman Creek WTP. The Sourdough Wonderware based HMI is separate from the Sourdough WTP system that controls the operation of the plant. 3.1.2.3 Monitoring/Control Equipment The existing system utilizes a PLC and HMI display at the Lyman Creek WTP building. The local monitoring/control equipment is connected to the PLC inputs and processed by the PLC. The HMI displays the information. Outputs from the PLC are used to control valves and pumps at the Lyman Creek site. One concern with the existing equipment is the measurement of the reservoir level. Currently the reservoir level is measured at the outflow building via pressure gage. During certain conditions, Water Treatment personnel have seen instantaneous level drops in the reservoir level of up to 5 feet. Additional existing control issues are also discussed in Technical Memorandum #1 and below in the HMI evaluation. 3.1.3 DESIGN CRITERIA As previously mentioned, the City desires to increase the reliability of the data connection between the Lyman Creek WTP and the Sourdough WTP. Any upgrades or changes to the system will need to account for the information required by the Water Distribution personnel. Modifications to the radio modem system would require assuring all the information required by the Water Distribution personnel is left in tack. 3.1-2 N;\0417\055\DOCS\Reports\Tech Memo-Task 3 Controls Final.doc May 9, 2008 Hyman Creek Restoretloft Improvement MgrriSonTMaisrle, Inc, The City also requires a user friendly HMI at the Lyman Creek facility. The HMI located at the Sourdough WTP is also a Wonderware system and would require the same modifications as the Lyman Creek WTP, 3.1.4 RADIO MODEM SYSTEM EVALUATION The existing radio modem system operates on licensed frequency radios with transmit and receive frequencies of 458.55 MHz and 453,55 MHz. All locations transmit to the City Shop with the exception of the previously mentioned Bridger Center lift station that transmits to the Lyman Creek site and then is repeated to the City Shop and the Sourdough Bypass location that transmits and receives directly to the Sourdough WTP. The T1 data link from the City Shop to the Sourdough WTP was used because of poor radio signal quality between the two locations. A recent addition to this system was the installation of an ELPRO 905U-L unlicensed 900 MHz Spread Spectrum, UO radio modem link between the Hilltop Tank and the Sourdough WTP to transfer tank level data. 3.1.4.1 Upgrades to the Radio Modem System Upgrades to the radio modem would consist of an ELPRO 905U-E Ethernet radio installed at the Sourdough WTP, An identical radio modem would be installed at the Lyman Creek WTP and transmit data from Lyman Creek to Sourdough WTP either directly or use the Hilltop tank site as a repeater. A formal radio path survey would be required to determine if the signal strength is sufficient to go directly from Lyman Creek WTP to Sourdough WTP_ If the signal is not sufficient between the two sites, then the signal could be repeated at the Hilltop tank location with a third radio identical to the other two. The data at the Lyman Creek site would be sent to the City Shop for the signals needed by the Water Distribution personnel, but it would not need to be sent out over the T1 line to the Sourdough WTP. The new radio modem would send the identical data directly or through the Hilltop tank radio modem from the Lyman Creek site to the Sourdough site. Modifications to the HMIs at each location would need modifications to accommodate the additional radio and data being sent between them. These modifications will be discussed in the next section. Estimated cost for this upgrade is $5000,00, 3.1.5 HMI EVALUATION As previously mentioned, the existing HMI at both locations uses Wonderware software for the HMI. A list of Operator comments were gathered on items that they would like to see added or eliminated from the HMI at the Lyman Creek WTP, but these would also be applicable in the Sourdough WTP HMI. Below is the list of items; 3.1-3 W0417105500CS1ReportslTech Memo-Task 3 Contfols Finatdoc May 9,2008 Lyman Creek Restoration Improvements Morrison-Maierlc, Inc. a Ability to change alarm setpoints * Manual override for control, from Auto mode to Manual mode 0 Capability of shutting down the Lyman Creek WTP from the Sourdough WTP Y User friendly operator setpoint adjustments * Influent Chlorine analyzer readout on HMI * No plant shutdown on an intrusion alarm * Better trending & reporting of data at Lyman Creek 3.1.5.1 Upgrades to the HIVIls The Wonderware software at both locations can be reused, upgraded or changed to an entirely new platform such as RSView. The reuse or upgrade of Wonderware would be the cheapest option because upgrade cost are usually cheaper than purchase cost of the software. For making the changes/additions of the items mentioned above there are a couple of options available. The first and possibly the lowest cost approach would be for the original integrator, Industrial Automation Consulting, Inc., to incorporate the changes to the HMIs at both locations_ Since they wrote the code for the HMIs and the PLCs for the City system, they have the code that has been downloaded into the PLCs and HMIs. The downside is that they do not represent or sell the unlicensed radios mentioned previously and would need to purchase or subcontract the radio installation and set-up to a competing integrator. The second option would be to have the integrator who represents and installs the radios to redesign the HMIs and PLC at Lyman Creek_ The redesign of the HMIs would entail the rewriting of the HMI code. It is more cost effective to start from scratch on the code in lieu of attempting to decipher the original code to determine how to make it operate with the new additions. One part of the old code that would need to be reused is the addressing used for the existing radios at their respective locations. These are needed to keep the existing information that the Water Distribution personnel use in their system, i.e., the Bridger Center lift station information and the Lyman Creek reservoir and outflow rate. The recommendation would be to have the integrator who represents and installs the radios currently being used to transmit the Hilltop tank level directly to the Sourdough WTP to perform the HMI upgrades and new radio installation at Lyman Creek, WTP. Using one integrator eliminates any friction between two competing entities. Further consideration should be given to the City's satisfaction with past performance. Given the importance of system reliability and desired ease of use, the City should put integrator performance ahead of system cost. Estimated cost for this upgrade is by the current integrator is $15,000 and using a new integrator is $20,000,00, 3,14 N,1041710551D0CS\Reports\Tech Memo-Task 3 Controls rinal.doc May 912008 Lyman,,CT LeK R�est0ration Ir prp „ -Maierle, Inc.r µ _ ison 3.1.6 SYSTEM MONITORING & CONTROL EQUIPMENT EVALUATION Technical Memorandums 1 & 2 discusses the evaluation and recommended changes to the system monitoring and control equipment_ This section will deal with incorporating any new equipment or unused features of existing equipment into the HMI_ The exact additions depend on the changes selected by the City in Technical Memorandums 1 & 2. An additional analog input module will be needed for the additional monitoring/control equipment that have 4-20 mA outputs since the PLC panel drawings show all of the analog inputs currently populated. An ultrasonic flowmeter was added inside the Control Building that needs to be permanently mounted on a wall and its electrical & control connections installed in conduit. 3.1.6.1 Residual Chlorine Sampling The output of the residual chlorine monitor will be connected to the PLC at Lyman Creek WTP and the level displayed an the HMI 3.1.6.2 Reservoir Level Indication To eliminate the anomaly seen by the Water Treatment personnel where the level of the reservoir drops around 5 feet instantaneously it is proposed that an ultrasonic level indicator be mounted in the reservoir. The transmitter for this unit could be mounted inside the reservoir entryway or inside the control building. The output of the level transmitter would be connected to an analog input on the PLC and be displayed on the HMI_ 3.1.6.3 Outlet Control Building Equipment The Outlet Control Building currently consists of a supplemental disinfection point, flow and chlorine residual monitoring capabilities, and differential pressure monitoring of the reservoir. As discussed in 1.6.2, the differential pressure monitoring for the reservoir would be eliminated. This would allow the reuse of the control conductors back to the Control Building by another sampling device. Existing control signal conduits also allow ample space for additional control conductors. 3.1.6.4 Influent Sampling The chlorine residual and pH will continue to be monitored in the Inlet Control Building, but the sample points will be moved to the piping in the radon stripping room. The chlorine residual can be used to pace the control system and increase or decrease the feed rate. Sampling outputs would be connected to the PLC and displayed on the HMI. The cost to install the equipment is included in Technical Memorandum 1. The cost to add these new items to the control system and HMI are included in the previous section. 3,145 N:1D41710a500C$%Reports\Tech Merno-Task 3 ContrO15 Final.doc May 9.2008 Lyrnan Creek Restoration-I, oviprments Morrison-Maierle, Inc, 3.1.6.5 Infiltration Gallery Level Measurement It is desired to measure infiltration gallery tank level and weir level for flow rate and radio this information down to the Lyman Creek site for use by the SCADA system. The addition of level and flow indication at the infiltration gallery presents two approaches for powering the equipment. Currently there is no AC power at the site with the closest power source approximately two miles away. The first approach for power would be to run a service from the Lyman Creek site up the pipeline easement to the infiltration gallery location. The estimated cost of this approach from Northwestern Energy would be $100,000,00. The second method would be to install a solar panel & battery storage package for the power required by the equipment. This system would be sized to continuously power the radio and measurement. The estimated cost of this approach would be $8000.00 It is proposed to install the same radio at this location that was described in Section 3.4.1. The level sensing and flow rate equipment would be Pulsar Ultra Twin series controller with two non-contacting ultrasonic elements. The 4-2OmA outputs of the controller would be transmitted to the Lyman Creek site_ This information would be processed and made available to the SCADA system at Lyman Creek and Sourdough V TP. The estimated cost of this equipment would be $4000,00 The estimated cost of the power system and control equipment would be $12,000,00, 3.1.7 SUMMARY A summary of the recommendations of this memorandum are as follows: • Install new radio link from Lyman Creek WTP to Sourdough WTP, while leaving the existing system intact. • Redesign of the HMI by integrator who represents and installs the new radio link, with additions requested by the City. • Installation of new monitoring/control equipment at the Lyman Creek site. • Outlet Control Building improvements including new residual monitoring. « Installation of level & flow monitoring equipment at the infiltration gallery, powered by a solar/battery system, with a radio modem to Lyman Creek site. 3.1-6 N:T41710551D0CSIR©portslTech MOM-'rask 3 Controls Final,doc May 9,2008 MIERLE,INC. RSON LE. dn.EhrFarob"d 0 1m J� Technical Memorandum No. 4.1 OUTLET BUILDING ENTRY STOOP CONCEPTUAL ARCHITECTURAL DESIGN City of Bozeman Nyman Creek Reservoir Improvements Project Bozeman, MT PREPARED BY: Scott Hedglin, AIA Dowling Sandholm Architects REVIEWED BY: Jeff Sandholm, AIA DATE: May 9, 2008 4.1.1 INTRODUCTION As part of the Lyman Creek Reservoir Improvements Pre-Design Phase, the entry steps and stoop at the Outlet Building were reviewed. The investigation included a site visit and review of the existing drawings. 4.1.2 INVESTIGATION The existing configuration of the access steps and stoop at the Outlet Building encourages the accumulation of snow and creates an unsafe condition which also impedes the proper operation of the door. The steps and the retaining wall form a "sunken," shaded stoop which also slows the melting of the snow and ice. 4.1.3 RECOMMENDATION It is recommended that the steps and the associated retaining wall be removed and the site be graded to allow access to be perpendicular to the existing condition. A small retaining wall immediately north of the door and perpendicular to the building would allow the created void to be filled and graded to cover the newly exposed foundation. The grading should be designed to minimize the length of the new retaining wall. The 4.1-1 N;104 1 7105 5\D0CSIRep0FW"Fask 4„Architectural,Structural,Mecf)anical,SiWOutlet Bldg Architectural doc May 9,2008 jiman Cr�gk Restoration Improvements �w Morrison-Maierle Inc. orientation and direct solar exposure of the new stoop will aid in the melting of the snow and ice. As requested by the City, replacement of the awning will also provide better protection from the weather. Estimated Construction Cost: Den7olition/Removal of existing Steps; $750 Removal of existing Awning: $300 New Concrete Landing (4'x8'): $500 New Retaining Wall (Concrete or CMU): $600 New Awning: allow $1500 Re-Grading of affected area: allow $2000 Additional Fill: allow $500 Construction Cos ..............$ t Total: 6950 • -,—... ...�' `.r..y. .. '. ...' F""^'"+` k"•'",.'Fad" IR�n"R� �.m„ ,:..y:'d"4u1P6• ^' P •G'nyt,.,( 4• _, n%HI f� r�{Sy Y ^"� �'9y��,�yf 41 P r��'yr�"�'�ty�a'S^A r�i�' xl i' w r..a � A. •�y A S ° RE Px �, �Pr�✓P 7�,h"1� a' �tl*" r tY a� � a�`II �, �,m;;•, , �, ;emu; ,�,�. , ,y r,�•� •, "� 1" ,�%7 a � �, t `� .�P�mar�Y�#�? "'�"S w,^ E'� �d.�i.N'.°Mt'". x'!. �P., w^jdQQ����;k�P�c'�J^ �y •, ,iri r �', .,a5.ri�L_.?:is s,� •�Fror: .. _ _ 'Cr X1, ry 1 �^ �..,.�� �I� ....?d., 4.1-2 W04 1 710 551DOMNeport5lTask 4 Architeetural,5truetUral,McChanical, Site\Outlet Bldg Architectumwoc May 9, 2008 I M010SON LJ MERLE,INC. Technical Memorandum No. 4.2 TREATMENT BUILDING ENTRY STOOP CONCEPTUAL ARCHITECTURAL DESIGN City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, MT PREPARED BY; Scott Hedglin, AIA Dowling Sandholm Architects REVIEWED BY: Jeff Sandholm, AIA DATE: May 9, 2008 4.2.1 INTRODUCTION As part of the Lyman Creek Reservoir Improvements Pre-Design Phase, the entry steps and stoop at the Treatment Building were reviewed. The investigation included a site visit and review of the existing drawings. 4.2.2 INVESTIGATION Delivery of chemicals and supplies is being hindered by the approximate 1" settlement of the concrete stoop at the entry door thresholds, the steps and height difference between stoop and surrounding grade, and the inadequate size of the stoop in maneuvering a hand dolly around the out-swinging door. An underground concrete tank is located approximately 10-12 feet away from the south wall of the treatment building. No problems with snow and ice buildup were reported at this south facing stoop. 4.2-1 NA04171 WD00S1Repoi1s\Task Q-Architectural, Structural,Mechanical,SiteMeatment Bldg Architectural.doc May 9,2008 LLman..,Croek ZWQration Improvements Morrison-Kv ierle, Inc, 4.2.3 RECOMMENDATION It is recommended that the stoop be replace with a new concrete landing at the south entry of the Treatment Building. The new landing should be at or near the same floor elevation as the building and should be of an adequate width to maneuver supplies around the approximate 3 foot swing of the doors_ Additional gravel fill can be used to bring the surrounding grade up to the height of landing to ease the movement of wheeled carts/dolly from the parking area into the building. As requested by the City, replacement of the awnings will also provide better protection from the weather, Estimated Construction Cost: Demolition/Removal of existing Stoop: $500 Removal of existing Awnings: $600 New Concrete Landing (12'x6'): $750 New Awning: allow $2500 Additional Fill: allow �250 Construction Cost Total: $4500 a ,..;:.;,.Y• "mow `,. y ,', •Y ,e n !�u� r k4 ,u1 �,� +. / Tjl C b 1 y 7 p IC�}`r .9w 9p S ��l.pJxrt}"�E��y�h>1T7'1wvM f k' W." fwas"14 m} 1., 4,2-2 NA041710551DQCS\Rep0rts\Task 4-Architectural.Structural, Mechanical,SitevTreatment Bldg Arch itectu ral.doc May 9, 2008 LJUf �rrERLfEn INC, Technical Memorandum No. 4.3 Heating Options for the Treatment wilding City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, NIT PREPARED BY: Jennifer A. Burgett, P.E. REVIEWED BY: Tom Heinecke, P.E. DATE: May 9, 2008 4.3.1 INTRODUCTION Exploring the heating options for the Lyman Creek Treatment Building is park of the scope of services included in the Lyman Creek Reservoir Improvements Pre-Design Phase Project for the City of Bozeman. An investigation of the existing heating system was provided to identify current problems. This investigation included a review of the existing as-built drawings as well as a site visit. 4.3.2 HISTORY The Lyman Creek Treatment Building was upgraded in 2004. During the 2004 upgrade and improvement process hard-wired electric unit heaters were installed as the primary source of heat for the building. Because of its location, the Lyman Creek facility is subject to more extreme weather conditions than Bozeman is. The heating system as it was designed and installed was found to be inadequate. Subsequently, small, portable, 240-volt unit heaters were added to the building. These heaters draw 20 amps and have receptacle-type electrical connections that have been burning out at the receptacle. 4.3.3 HEATING INVESTIGATION Morrison-Maierle, Inc. conducted an on site visual inspection of the existing heating system in the treatment building. There are currently three of the unit heaters from the 4.3-1 W04 1 710 5 51C)0051Reports\Task 4-Architectural, Structural,Mechanical,SiteWechanical Task 402b.doc May 9,2008 y_r_n n Creek Restoration Improvements T _ Morrison-Maierle, Inc. 2004 improvement design still in operation: One in the radon stripping room; one in the equipment room; and an electric wall heater in the bathroom. The unit heaters were not able to provide a comfortable temperature to the occupants of the treatment building; therefore, additional portable unit heaters have been added to the originally designed heating system. The unit heater located in the main control room has been replaced with two portable, 20 amp "The Hot One" units. A supplemental "The Hot One" unit was also located in the radon stripping room. The small portable units have occasionally been burning out at the receptacle indicating that either they occasionally draw more current than their specifications indicate or their circuits are undersized for the amount of current they are drawing. 4.3.4 RECOMMENDED REPAIRS It is our opinion and recommendation that the heating system be redesigned and upgraded immediately. The existing heating system, while providing heat, appears to be putting the facility in danger of a fire. It is our opinion that the portable unit heaters be removed from the system. It is also recommended that a programmable thermostat be included in all heating options listed below. This feature would save energy as well as provide a comfortable space during known occupied times. In each option below, the heating system will be conservatively recalculated to accommodate the extreme weather conditions at Lyman Creek. Possible options to improve the heating system are listed below: 1. Upgrading the existing electrical heating system 2. Replacing the heating system with a propane heating system 3. Supplementing the existing heating system with a propane heating system Option 1 — Upgrading the Existing Electrical Heating System Option 1 would consist of the addition of new hardwired electrical unit heaters to the main control room and the radon stripping room. The heating loads for the building would be recalculated and it would be determined how many additional BTU's are required for comfort in the building during extreme winter temperatures. New electrical unit heaters placed in the corners of the effected rooms would provide the additional heating necessary. The conduit and boxes that the receptacles for the portable unit heaters occupy could be reused for the wiring to the new unit heaters. The circuiting to the existing unit heaters would have to be recalculated and field inspected to ensure they are not overloaded. Also, in order for the building to heat during a power outage the new unit heaters must be connected to the generator. There is not currently space available on the existing electrical Panel A for an emergency power circuit to the new unit heaters, thus Option 1 is not recommended as power outages occur frequently. Total Construction Cost = $10,000 4.3-2 W04171055\00CSIReportslTask 4-Architectural, Structural,Mechanical,SitelMechanical Task 402b.doc May 0, 2008 Lyman Creek Restoration ImproementsW. Morrison-MaierleInc. Option 2 — Replacing the Heating System with a Propane Heating System Option 2 would consist of replacing the entire heating system with propane unit heaters mounted in the corners of the interior rooms. In order to execute this option, a propane tank must be located on the site. The tank could be buried or slab mounted. This option would not rely on the generator for operation during a power outage. As long as the tank has propane, the heating system will be operational. Discussions with the owner must take place for this option to determine how often the propane tank could be filled in. order to determine its size. Likely, a 300 gallon tank with monthly deliveries would be adequate. This option would also decrease the load on the electrical generator. Total Construction Cost T $12,000 Option 3 — Supplementing the Existing Heating System with a Propane Heating System Option 3 would consist of the addition of a propane heating system to supplement the existing hard-wired electrical heaters. The heating loads for the building would be recalculated and it would be determined how many additional BTU's are required for comfort in the building during extreme winter temperatures. Additional propane-fired unit heaters would be added to the areas that require additional BTU's. In order to execute this option, a propane flank must be located on the site. The tank could be buried or slab mounted. This option would not necessarily rely on the generator for operation during a power outage. As long as the tank has propane, part of the heating system would be operational_ Discussions with the owner must take place for this option to determine how often the propane tank could be filled in order to determine its size. Likely, a 300 gallon tank with monthly deliveries would be adequate. Total Construction Cost = $10,000 4,3-3 N:10417105510oC51Reports%Task 4-Architectural,Structural,Mechanical,S'iteNechanical Task 402b,doc May 9,2008 U J�M0RRISON MAIERLE,INC, dnf,yAuve(narnR lanj,,.ny Technical Memorandum No. 4.4 ELECTRICAL City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, MT PREPARED BY: Michael W. Brandt, P.E. REVIEWED BY: James Nickelson, P.E. DATE: May 9, 2008 4.4.1 INTRODUCTION The purpose of this Technical Memorandum is to evaluate and discuss improvements to the existing Lyman Creek WTP electrical system. The City Water Treatment personnel have presented several concerns with the existing electrical system. These include the size of the existing generator, interior electrical panels that are not waterproof rated and the problems associated with heater outlets that have melted while in use. This memorandum will discuss these issues and provide recommendations and cost estimates. 4.4.2 EXISTING ELECTRICAL SYSTEM DESCRIPTION The electrical system at the Lyman Creek WTP consists of a 200 A, 120/240 VAC, 1- phase, 3 wire, 60 Hz service. The service point is a 200 A fused disconnect switch that feeds a 225 A rated Main 'Distribution Panel (MDP), Loads on MDP include some lighting and outlets, generator battery charger & block heater, water heater, reservoir vestibules power and radon fan_ The MDP also contains a 125 A feed to the Automatic Transfer Switch (ATS). The ATS is rated at 200 A. The common of the ATS feeds Panel A. Panel A loads include a feed to Panel B in the Outfall Building and all the remaining Control Building lighting, receptacles, electric heating and controls. During a 4.4-1 NAG417105510 =Reports\Tasit4-Architectural, Structural, Mechanical,SitelTach Memo-TasR 4 Electrical Finai.doc May 9,2008 Ympn,MCreek Rpspration Improvements _ w Morrison,-M,aierl%.lnc, power outage both Panels A & B will be connected to the generator. The generator is a diesel fired 30 kW, 120/240 VAC, 1-phase, 3 wire, 60 Hz unit. 4.4.3 STAND-BY GENERATOR EVALUATION The existing stand-by generator is a Generac, model number 2798750100, diesel fired 30 kW, 1201240 VAC, 1-phase, 3 wire, 60 Hz unit. The rated output of the generator is 125 A. The Connected load according to the As-Built drawings is 23.6 KVA or 98,3 Amps @ 240 VAC, Panel A = 19.9 KVA and Panel B = 3.7 KVA. Under normal conditions at the site, the plant operates unattended, so there are not large lighting or receptacle loads present. During the warmer months, there is also a low demand for heat. Therefore, during a stand-by power condition, the demand on the generator is not great. The condition that would cause the worst case demand on the generator would be during an extremely cold day when all of the unit heaters were on. If the utility power was lost and the generator was called, this load would be transferred to the generator. A test was performed on the generator on April 30, 2008 at the Lyman Creek site. The current was measured on the two phases in the ATS that feed Panel A. With utility power supplying the building, a measurement was made with the lighting and control loads as well as all of the heaters on. A second measurement was made with the lighting and control loads on and the heaters off- The current was then measured in the same manner with the building on generator power. The measurements are shown in Table 4.1. Table 4.1 Lyman Creek WTP Panel A Current Measurements ,..._. ,,.�,�..r��:,...._..:...........:.._.._...._ Power source Phase A Current wl Phase B Current wl Phase A Current Phase 8 Currant Heat(Amps) Heat Arnpl w wln Heat Am s wto Heat(Amps)M __..,,...,....,,,.....,.,,. ..,,'. ,, .__..------- ---- -- t 79,4 77.4 15,4 14.1 Generator ------- -------.._.._-,'79.4. ,....,,,,.,._.--•- ------- 77A 15.3 14.1 There was no abnormalities noted when the entire load was transferred to the generator. 4.4.3.1 Upgrades to the Stand-By Generator System Since the existing generator appears to be of a sufficient size to handle the total demand load connected to it, replacement of the existing unit with a larger rated model is not recommended at this time- The only recommended change to the stand-by system would be to remove the electric heating in the Control Building. The discussion of propane fired heaters is discussed in Technical Memorandum 4.3. The removal of the heating loads of the Control Building from the generator would allow future loads to be added to either Panel A or Panel B- 4.4-2 W041710WDOCSIReports4"rask 4-Architectural,Structural,Mechanical,SiteVTech Memo.'task 4 Electrical f=inal.doc May 9,2008 Lyman Creek Restar Lion Erxiprov�m�nts m _Morrison-Maierle, Inc. With propane available on-site, propane fired generators could be evaluated for any future upgrade. 4.4.4 CONTROL BUILDING ELECTRICAL PANELS EVALUATION As previously mentioned, Water Treatment personnel have expressed concern that the interior electrical panels are not water-proof, In the existing building the water piping and the electrical and control equipment are in the same room. The Water Treatment personnel have experienced a catastrophic leak in the water piping in the past that resulted in a condition similar to hose directed water at the panels and computer equipment. The existing electrical panels are a Type NEMA 1 enclosure type which do not protect against water infiltration. 4,4.4.1 Upgrades to the Electrical Panels Circuit breaker panels are available in indoor and outdoor rated enclosures. They are also available in enclosures rated for hazardous environments. Given the cost of hazardous location rated panels, the discussion will focus on indoor and outdoor panels. Outdoor rated panels, NEMA Type 3R, are designed to offer a degree of protection against the ingress of water (rain, sleet, snow) but not for splashing water or hose directed water. The cost of replacing the electrical panels with a NEMA 3R panels would not be cost effective for the benefit gained and the panels would still not provide protection against hose directed water. The recommendation is to construct a walled roam inside the control room and relocate or install new electrical panels inside the room. The room would enclose the existing HMI computer, PLC cabinet and bathroom. The room would require walls extending to ceiling based on an architect's recommendation. This approach would also have the additional benefit of protecting the HMI computer and the PLC cabinet in the event of a water leak. 4.4,4.2 Influent Chlorine Residual Analyzer Electrical Connection The influent chlorine residual analyzer is not connected to the existing Uninterruptible Dower Supply (UPS) and loses power during a utility power loss. its power is restored when the generator comes on-line, but in that time period, the HMI reports a residual chlorine low level alarm. The Water Treatment personnel would like the power connection to the residual analyzer be changed to connect it to the UPS, This would eliminate the false alarms in the transition time from utility to generator power, 4.4.6 HEATING EQUIPMENT EVALUATION Technical Memorandum 4.3 describes the existing heating system in the Control Building. The electrical power supply to the heating system was evaluated in an 4.4-3 W04171QWDOCSlReport5lTask 4-ArcNtectural,Structural,Mechanical,5ite\Torh Memo-Task 4 Electrical Final.doc May 9,2008 Lyman,Cree.K Restoration Irn�rbvemen,ts �N w Morrison-Maierle, lnc, attempt to determine the cause of the melted/burned outlets connected to the unit heaters, On the April 30, 2008 site visit, the current draw of the two unit heaters in the control room was measured, Unit heater #2 (UH42) located above the water heater is fed from 25 A, 2-pole breaker in Panel A-9,11. Unit heater #3 (UH-3) located in the NE corner of the control room is fed from 15 A, 2-pole breaker in Panel A-2,4. Each circuit uses #10 AWG conductors rated at 30 A. Both heaters are identical, The Hot One, model #RCP402S, 240 VAC, 4kW, 16.7 A maximum current draw with a 20 A plug, The measured current draw on UH-2 was 15.0 A on one phase and 15.1 A on the other. The measured current draw on UH-3 was 16.5 A on one phase and 16.5 A on the other. Roth units were set to maximum heat output. The difference between the two units cannot be explained, except the Water Treatment personnel indicated that UHT2 was a newer unit. 4.4.6.1 Heating outlet Upgrades An immediate recommendation is replacing the 25 A, 2-pole circuit breaker connected to UH-2 with a 20 A, 2-pole breaker, The receptacles that the heaters are connected to are only rated for 20 A, and should not be connected to a 25 A breaker_ The long term solution is the replacement of the electric unit heaters with propane fired units. Replacement of the electric unit heaters with propane units would also have the additional benefit of removing load from the generator, allowing other loads to be added in the future. 4.4.6 SUMMARY A summary of the recommendations of this memorandum are as follows: Existing generator size is adequate for current loads- * Relocation of the electrical panels in a walled room within the control room. Estimated electrical cost is $10,000.00_ Estimated wall construction cost is 6 Connect residual chlorine analyzer to the UPS. Estimated cost $250.00. * Immediate replacement of UH-2's breaker with a 20A rated breaker, and replacement of the electric unit heaters with propane fired models. Estimated cost for breaker replacement is $75.00. Estimated cost for wiring to propane heaters for the fan motors is $500.00. 4,4-4 N'10417\05500C:81RepartslTask 4-Architectural,Structural,Mechanical,Site7ech Memo-`task 4 Electrical Final.doo May 9,2008 ............................................................. .......... ........... ............................ ...... ........... ....................... ....... ...............— .............. . ......... 10 ..1 I IF Y, x L 2, ............ ........ t 3 ........................ <-.4444-ig-, ;73 ! \..r I r =: "J 5,.,/ 1 IK . ..........71 ........... J,:-�:777T ................ 4. 411- /•1�y '; ............. T L IN E—HEMI,7" ............... 0 kx ('e 1 10 w I I - 10= .............. �Q ....................... I ............... ....... .................. .......... ........ ...... ------- GO) C.) .................. 5 .......... T 4;, I l i rJ 1 � I»,� I .................................. ........... u;.., MORRISON 111 MAIRRLE,INc, Technical Memorandum No. 4.5 TREATMENT BUILDING ACCESS City of Bozeman Lyman Creek Reservoir improvements Project Bozeman, IVI7 PREPARED BY: James Nickelson, P.E. REVIEWED BY: Jim Ullman, P.E. DATE: May 9, 2008 4.5.1 INTRODUCTION The treatment building at the Lyman Creek Facility is accessed through two man doors on the south side of the building and a large garage door on the east side of the building. Due to safety concerns, actress improvements are needed. This memo further describes the site conditions and explores some options for improving access to the structure. 4.5.2 EXISTING CONDITIONS The two man doors on the south side of the building provide the main access to the building, The door on the right is a double door to provide access for chemical deliveries and for replacement of the chemical storage vessels. The door on the left is the main entrance to the plant. Both doors are accessed via a stepped slab that has subsided some since the initial construction. The steps prohibit easy access to the doors and the relatively narrow landing makes deliveries difficult. Vehicular access to these doors is complicated by the grade variation between the building and the ground and the slope of the access drive. The garage door located on the east side of the building is intended for maintenance activities associated with the radon stripping tower. As the tower is not in use, the door 4.5-1 N:1041'A0551D0CS\ReportslTask 4.Architectural,Structural,Meoharkal,&telTreatment Building Access.doc May 9,2008 Lyman Creek Res1kar t� ign Improvements �W. . Marrison-Maierlta Inc, sees minimal use, however, the door appears to provide adequate access for periodic maintenance activities. 4,5.3 RECOMMENDED IMPROVEMENTS There are a range of options available to improve the access situation to the building. In order to provide adequate entry into the building by personnel, a new concrete landing is needed_ This item is addressed in Technical Memorandum No. 4.2. In addition to this improvement, there are a number of other required or desirable improvements. Provide Improved Vehicular Access There are two improvements that will provide improved vehicular access_ Removing the fence on the east side of the site will allow for ease of vehicular access to the building. The total length of fence is approximately 75 feet. The second item to improve access to the building is to fill the pad on the south side of the structure. This will require providing new rings and covers to access the septic tank and gravel fill material. A drawback of providing fill for the pad is that the access drive to the outlet building will need to be steepened slightly near the top of it; however, the majority of this drive is at a 20% grade and the gravel fill work can be completed without exceeding this grade, Construction cost for completing these items is estimated to be $5,000. Remove Old Chlorine Building The existing gas chlorine building is no longer needed. It presents an obstacle to enter the site and has no proposed use. Removing the building and adjacent slab, including the crane anchor pad, is estimated to cost $5,000. 4.5-2 N:104i710WDOCS\ReportslTask 4-Architectural,Structural,Mechanical,SiteMeatmEent Building kxess,doc May 9,2008 E MOR MSON M, MAMEPJ E,1NC, .rn Empl„c.r.rMnrA,unw,m Technical Memorandum No. 4.6 RESERVOIR BUILDING VESTIBULE AND VENTING CONCEPTUAL ARCHITECTURAL DESIGN City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, MT PREPARED BY: Scott Wedglin, AIA Dowling Sandholm Architects REVIEWED BY. Jeff Sandholm, AIA DATE: May 9, 2008 4.6.1 INTRODUCTION As park of the Lyman Creek Reservoir Improvements Pre-Design Phase, the entry vestibules and venting of the Reservoir Building were reviewed. The investigation included a site visit and review of the existing drawings. 4.6.2 INVESTIGATION The inappropriate ventilation and routing of humid air through the unconditioned, steel- framed vestibule via the louvered doors results in condensation, excessive rust, and eventual ice build up during cold weather. It is reasonable to believe that the ice-melt chemicals compound the excessive rust problem. The wall assembly and supplemental spray-in insulation is also inadequate in deterring rodents from burrowing through it. 4.6.3 RECOMMENDATION It is recommended that the vent locations be changed (please see Technical Memo # 4,2) and the entry vestibule steel framed wall and roof structures be replaced. New non-louvered, sealed, insulated, flush panel doors will mitigate the penetration of humid air into the vestibules and reduce the amount of condensation and ice build-up, As a 4.6-1 N:\0417\055\D0C8Reports\Task 4-Architectural,Structural,Mechanical,Site\Reservoir Bldg Architectural.doc May 54,2008 Lyman Creek Restoration Improvements^ _ „ w Morrison-Maierie. Inc. design option (included in pricing below) it is recommended to include glazing of approximately 20% of the wail area to create a natural convective current to aid in reduction of condensation and to allow natural daylighting of the vestibule. A projecting precast concrete roof panel with adhered membrane and fleshings will add to the moisture and rust resistant shell while providing some weather protection of the entry and shading of the windows during summer months. It is assumed that the existing concrete slab and retaining walls are structurally adequate and can remain. Estimated Construction Cost (2 vestibules): Demolition/Removal of existing Vestibules: $1500 CMU Block walls: $2000 Steel Insulated Doors (w/ seals): $3700 Tempered Glass Windows: $2000 Window Security Grilles: allow $500 Roof Structure: $4000 Roof Membrane and Flashings: $750 Flashin s for Relocated Vents: allow 500 Construction Cost Total. $14,950 r�..y,- ,A. ::7r�r F.A''vh'iri+•+. ., 4 �T I Y it r I V�J V�fila \•',' �y '��C"lIY WCC T'r h`�ayrKDb t \ �°•'\!� 1 e � , t�I x v ki�. � 5vr1A .',�•f � R.n yu 1 1� d I ` 5,1 V�,ti r�:�' ,: ''rM'r.��4lf .^,,,V,':'�l(,. ,.r 7yK•::I i....,V� r W pMtn i�•.'.,J,�n Y^r 6�""If;H i.. Sa1r"^'1ti�raxa/',� ";a• �'w�.��eY�.arr'Ir�v'L*'". ,�.r;. \ '�'"'"rV'' �t•rya NNW 1� 4.6-2 N:10417105500C51ReportslTask 4-Arobitecturaf,Structural,Mechanical,SitelReservoir Bldg Architectural.doc May 9,2008 dilMORRISON MIERLE,INC, ,r Technical Memorandum; No. 4.7 Schematic Design of Reservoir Vents City of Bozeman Lyman Creek Restoration Improvements Bozeman, MT PREPARED BY: Jennifer A. Burgett, P.E. REVIEWED BY: Tom Heinecke, P.E. DATE. May 9, 2008 4.7.1 INTRODUCTION The schematic redesign of venting system for the Lyman Creek reservoir tank is part of the scope of services included in the Lyman Creek Reservoir Improvements Pre-Design Phase Project for the City of Bozeman. An investigation of the existing reservoir venting was provided to identify current problems. This investigation included a review of the existing as-built drawings and a site visit. 4.7.2 HISTORY The Lyman Creek reservoir tank was upgraded in 2004, During the 2004 upgrade and improvement process vestibules were added with louvered doors to provide ventilation to the tank. Over the last few years these louvers have presented problems with freezing and ice build up in the vestibules. At times the doors cannot be opened due to ice build up. The Lyman Creek reservoir tank has a 5 million gallon capacity and a possible flow rate of 2,680 gallons per minute. The existing outlet pipe is 18" in diameter. Vents must be placed based on these criteria to ensure the tank does not pressurize and effect flow through the reservoir. 4.7-1 K\041 DO5500=ReportslTask 4-Architectural,StructUrat,Mechanical,SiteWechanlcal'rask 402,doc May 9,2008 Lyman Creek Restoration Improvements�- w Morrison-Maierle, Inc. 4.7.3 LOUVER INVESTIGATION Morrison-Maierle, Inc. conducted an on site visual inspection of the louvered vestibule doors at the tank entrances, Each set of double doors has screened louvers. The air is very humid 'inside the tank. When the outside temperature falls below 32 degrees there is a possibility of ice forming on cold surfaces where the humid air has condensed. 4.7.4 RECOMMENDED REPAIRS It is our opinion and recommendation that the louvers be removed from the doors or the doors be replaced with solid doors. Venting will still be necessary in the reservoir tank and could happen through two different options listed below: 1. Vents through the roof with a vent security shroud, 2. Louvers through the east and west walls. Option 1 —Vents Through the Existing Roof with a Vent Security Shroud Option 1 would consist of drilling holes, approximately 16" in diameter, through the existing pre-cast roof deck between the stems of the double tee beams and installing four steel pipe vents extending 8" above reservoir roof surface. A vent security shroud would then be attached to the top of each vent to prevent incursion or introduction of contaminants into the water supply. Multiple vents will be necessary in order to reduce pressure fluctuation on the roof's structure, as it was not designed for suction loads. The vent shrouds can be specified as "clog resistant from frost or debris" according to the manufacturer's data sheets. This type of vent shroud is currently installed on the top of the Sourdough Tank Dome. Total Construction Cost = $17,000 Option 2 -- Louvers Through the East and West Walls Option 2 would consist of adding louvers through the east and west walls of the existing building. Preliminary calculations indicate that 1.8 square feet of free area is the necessary total venting size. This will result in at least one 24" x 24" louver in both the east and west existing wails. These louvers will have the same problems with freezing up and icing over, however, the ice will not be occluding the entrances to the tank. Because of the likelihood of freezing it is recommended that the louvers be oversized. Possibly 36" x 24" louvers on the east wall and west wall. While this option would be considerably less expensive then Option 1, it is not recommended as the likelihood of icing issues would make the venting ineffective during cold weather. 4.7-2 N:\041'/\0$6 0CS\Reports\Task 4-Architectural, Structural,Mechanical,SitoNechanical Task 402.doc May 9,2008 - MOWS ISON LIJ' MAIERLE,INC. b.Fmr�nrelAmd1;.,wn Technical Memorandum No. 4.8 Pressure Reducing Vaults - Modifications City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, MT PREPARED BY, James Nickelson, P.E- REVIEWED BY: Roger Somerville, P.E. DATE: May 9, 2008 4.8.1 INTRODUCTION The water supply main between the Lyman Creek Spring and the water treatment plant is provided with a series of pressure reducing valves to reduce pressure in the pipeline. These valves are installed in concrete vaults with difficult access. This memo provides one possible solution to improving access to the vaults. 4.8.2 HISTORY The Lyman Creek supply line was constructed in a number of projects over the years. In 1989 the middle section of the pipeline was installed between the lower diversion pond and the upper diversion pond. This stretch of the pipe line contains four pressure reducing valves installed in two concrete vaults. The original construction of the vaults consisted of an open bottom structure with concrete sidewalls and an insulated plywood roof. The plywood roof deteriorated over title and the City installed concrete lids on the vaults. 4.8.3 EXISTING CONDITIONS The pressure reducing vaults present an operation and maintenance challenge in that they are difficult to access. Accessing the vaults in the winter time is difficult due to snow cover which precludes vehicular access to the vaults and also covers the access lids. Access to the vaults is through a standard sized manhole cover. A ladder is 4,8-1 W0 4 1 710 5 51D0CSIReports\Task 4•Architectural,Structural,Mechanical,SitelPressure Reducing Vaults doc May 9,2008 Lyman Creek Restoration Improvements w„ Morrison-Maier€e Inc installed on the wall of the vault to allow access; however, the access cover is located off center to the ladder making access dangerous. A secondary concern is that the vaults present a confined space environment which requires specific steps be taken prior to and during entry. The operators need to access the vaults to monitor pressures and to complete short term and long term maintenance activities on the vaults. 4.8.4 RECOMMENDED IMPROVEMENTS There are a range of options available to improve the access situation with the vaults, A two prong approach to the problem is suggestion. The first item is to improve access and the second item is to provide for monitoring of the upstream and downstream pressure above ground. In order to improve access to the vaults it is suggested that a standard access hatch be installed in the concrete roof. A 36" x 36" hatch would provide for more reasonable access than the current off center manhole. A new ladder with standard steps is suggested as a means of providing safer access to the vault. A safety post is a suggested addition to a new ladder, this allows for easier access to the ladder. One such option is a product called LadderUp which is manufactured by BILCO. Construction Cost - $10,000 (2 vaults) One alternate that was considered was to install a double door hatch with steps to provide for easier access to the vaults. This option would approximately double the cost of the improvements. While this would allow for easier access during most times of the year, it would require much more shoveling for winter time access, City staff has indicated that the most frequent operation activity at the vault is to read the pressure gauges installed upstream and downstream of the pressure reducing valves. Allowing for the pressure to be monitored without entering the vaults would limit the number of entries into the vaults. It is suggested that consideration be given to installing pressure transducers in the pipeline wired to remote sensors mounted on a post outside of the vaults_ While this type of installation would be subject to vandalism in most locations, it appears that the limited public use of the area would limit vandalism. One option is to install a solar panel to power the pressure transducer and meter readout, We are still exploring simpler less expensive alternatives that would be powered by low voltage disposable batteries. The cost noted below is based on the solar panel option, Construction Cost - $10,000 (2 vaults) 4.8-2 NA04 1 7105 500=keportslTask 4 W Architectural,Structural,Mechanical, 5ite\Pr©ssure Reducing Vaults.doc May g,2008 010SON MERLE,INC. d+Rwrd„rerrhwee c,,,.�,,,. Technical Memorandum No. 5.1 SPRING INVESTIGATION City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, MT PREPARED BY: Brian Wainright REVIEWED BY: James Nickelson, P.F. DATE: May 9, 2008 5.1.1 INTRODUCTION The objective of the pre-design phase of the spring investigation portion of the project is to compile and analyze available data; conduct a series of flow and specific conductance measurements; formulate conceptual level designs to collect additional groundwater from the spring source; and develop a plan to complete additional investigations for the most feasible options. The intent of this memorandum is to provide a summary of the field work completed to date and provide an analysis of the historical data. The memorandum looks at the following tasks: (1) Preliminary field investigations and measurements aimed at identifying the sources of groundwater discharge to be captured and the most appropriate method for collecting the discharge. (2) Analysis of historical data measured by city personnel and identification of improvements to existing measurement devices and procedures to improve accuracy and reliability of measurements in order to accurately quantify potential recoverable flow. (3) Summarizes remaining pre-design phase work. 5.1.2 FIELD INVESTIGATION AND DISCHARGE MEASUREMENTS Methods Field investigations and measurements were performed on September 28 and again on November 9, 2007. Measurements consisted of in-stream flow measurements at three 5.1-1 N:1041710551D0C8\Reportslta9k memo 5.1.doc May 5, 2008 Lyman Creek Restoration Imprqy en _ Mw...... Morrison-Maierfe, Inc, locations, measurements at 4 existing devices and a volumetric calculation at the existing overflow pipe. Additionally temperature and conductivity measurements were recorded at a number of locations throughout the project area on September 28, 2007_ All measurements were taken below the existing groundwater diversion structure. The Upper (Section 1) and Lower (Section 3) Canyon sites were situated near existing measuring devices in order to compare results and determine relative measurement accuracies of the existing devices. Section 1 is located just downstream of an existing weir which was determined to be unusable do to excessive leakage around the device. This site is also just upstream of the trapezoidal flume and overflow discharge pipe. The in-stream measurement was added to the overflow discharge pipe and the total was used in the comparison between the existing measurement point (trapezoidal flume) and measured discharge at Section 1. Section 3 is just upstream from the Parshall Flume, which is the sites analog, and approximately 200 feet upstream of the historical surface water diversion structure. The Middle Canyon} Site (Section 2) is downstream of the historical upper surface water diversion structure and the associated weir (Upper Weir)_ Section 2 and the Upper Weir are separated by a significant distance and evidence exists in the area between the two measuring points of spring discharge to Wyman Creek, so the two sites were not directly compared, Temperature and conductivity measurements were performed on Lyman creek itself and at several locations where springs and seeps were collecting on the surface along the margins of Lyman Creek. These measurements were designed to examine the provenance of spring waters discharged to the surface. A profile was developed to identify differences in conductivity and temperature that would indicated varying sources of spring water. Results September 28 2007 Measurements In-stream flow measurements indicate that Lyman Creek below the spring collection box is flowing at 0.69 cfs and the overflow pipe was discharging 0.22 cfs; totaling 0.91 cfs. The trapezoidal flume measured 0.93 cfs showing a 2.2% difference between the measurements. In-stream measurements at Section 3 total 1.67 cfs while the flow through the Parshall Flume totals 1,71 cfs (2.3% difference). The measurements at each site correlate well with one another and produce reasonable results. Comparing the overall accuracy between the two types of flow measurements shows a reasonable correlation between the in-stream measurements and the measurements taken from existing devices. Section 2 and the Upper Weir were then used to identify areas of possible inflow to the stream. The Upper Weir indicates 0.94 cfs; little change from the trapezoidal flume and therefore likely a stable reach (Reach A) and is neither gaining or losing significantly (please refer to Appendix A, Figure 1 for graphical representations of each site and a map delineating each reach), The Section 2 in-stream measurement site shows 1.51 cfs; an increase of 0.57 cfs from the Upper Weir (Reach B). This large increase (38%) indicates that Leach B is a gaining reach. Between Section 2 and Section 3 (Reach C) there is a gain of 0.2 cfs, also indicating that at least portions of that reach are gaining, 5.1-2 NA04171055\DOGS\Repc ts\taSk memo 5,1,doc May 9, 2008 Oman Creek Restoratiarn.Improvements w Morrison-Maier€e nr, .,.� Temperature and conductivity measurements were recorded and subsequently examined to identify possible variations in source water characteristics. Water temperatures within Lyman creek decrease slightly just below the lower fault (the contact between Tertiary Sedimentary strata to the south and the crystalline gneiss to the north) while conductivity increases slightly. Measurements performed at groundwater seeps along the banks of the stream show a similar increase in conductivity and decrease in temperature. The increased conductivity and decreased temperature suggests that the water being discharged below the fault could have a different provenance than the water being discharged upstream of the fault. November 9. 2007 .Measurements Comparisons of the November measurements indicate a similar trend as noted during the September 2007 measurements but exhibit more variation between in-stream measurements and measurements taken from the existing devices. The difference noted at Section 1 was similar to the September measurements but Section 3 varied greatly and is likely attributable to a flume measurement error. In addition the November measurements indicate that the stream is gaining in Reach A as well as Leach B. The overall increase is similar to that noted in September but apparently distributed between the two reaches instead of confined to Reach B, Temperature and conductivity measurements were not recorded. Table 1 and 2 summarizes flow measurement data from the September 28 and November 0, 2007- measurement events_ Table 3 summarizes temperature and specific conductance measurements taken on September 28, 2007, Table 1. Frow Measurements Type of_ 9/28/2007 Location 1 ime N Measurement Reading Units Flow in Flow in CFS GPM U or Canyon Site SeGtlor: 1 15:00 Current Meter 0.69 _ $09,,,. S rin overflow 15,45 Volumetric(5 gal) 100 m 0,22 100 _,..,..,,._,.,,.... ., _w. -- _ . .,......,., Ape__ - 45 degree flume µ16:00 Direct Read 0.58 feet 0�3 418 U et lsond St4 Log 3'Beard ----------� 10,...... .......... Up@_— P g ( ) :30 Tape Measureµ 2.5 inches _ - 0.94 421 Middle Canyon Site(Section 2) __—_ Oust below fault 13:30 Current Meter 1,61 677 Lower Canyon Site(Section 3) above Parshall Flume 11:30 Current Meter _1.67 748 Flume Measurement 11:11V15 Tape Measure 0.375 feet ..,...., to Log 11;30 Tape Measure w ` 1.75 inches 0.93 _ 415 Lower Pond$,..,._.- ... Flow to Treatment Plant n!a Plant Meter 1,002 gprn F 2,23 1,002 5.1-3 N;104171d551DOCSIReportsltask memo 5.1.doo May 9, 2008 Lyman Creek Restoration Improvements w- . M - Morrison-Maierle, Inc, Table 2. Flow Measurements 1119/2007 Location Time - Type of Reeding Units Flow in ---Flow in Measurement CFS GPM leer Canon Site�sction l� w - y„� Cutront Meter 0.6& 305 Spring overflow _ Volumetric 511M.. GU+3 7" .._.9Cn__ 0,14 64 45 degree flume 10:30 Direct Read 0.54 feet 0,79 354 Upper Fond Staff L4 (3'gpard� �- 10:25 'ra a Measure 0.23 feet- �� 1.09 *486 Middle Canyon Site(,Section 2) Oust below fault) 13:33 Current Meter 1,32 592 Lower Canyon Site(Section 3) above Parshall Flume 14:39 Current Meter 1,42 636 Flume Measurement 10:15 Tape Measure 0.23 feet 0,83 372 -Lower Pond...._.,.Stop,.�n.`�- - -__._....._. --- --- - bid not measure Flow to Treatment Plant nla Plant Meter 907 gpm T 2.02 907MI 'over flow was leaking above outlet,measured both direct dischar a and leakin2 discharge then added rates together, Table 3.Temperature and ECC 9128120D7 Time toc T®m Air.•.•,•.. Tom Water ater Location de rees C� (do roes C W� Black ripe _ _ _ _ 12:00 308.7 19 13 11;55 308,5 --- -•- - ,... '" - - .......,,,.�.., . 13M u er Rectan ular Weir at spring boxes_ _ Spring Overflow ----- - -• 11:521 308.7 21 13 45 degree flume 11;45 ----------.-307.5,,, _.•,,,,..,,.....w.,_.,..,w�u.._.,..2.�--- - 13- tJ -11:39 - 309.5 —_- _29, .._„ 13,,., Lyman Creek next to seep _ 16:18 _ 306,0 21 13 Seep at fault location_ _ 16:141 w A 333.1 -- 21 ___---- 12 Middle Canyon Site(St;ctior,2) -- ust below fault 11;32 316.5 18 12 Lower Canyon Site(Section 3) (above Parshall Flume _ - - - 11;0b 317.5 23 12 ECC Balance 316.99862 5.1.3 HISTORICAL RECORDS Discharge .Analysis The City of Bozeman has monitored the flow of Lyman Creek for many years and an analysis of those records was performed. The data was received in a variety of forms and covering varying points of measurement. The Trapezoidal Flume just downstream from the spring collection box showed the most continuous record over the past few years but was only available in graph format which rendered the data less useful than desired. Data from the Trapezoidal Fiume was not used as it was not possible to combine the flume data with plant influent volumes to characterize overall stream discharge- A significant amount of data was presented for the two-foot Parshall Flume located just above the lower surface wafter diversion point- The period of record for the Parshall Flume was from 1970 through 1988 and from 2001 through 2007. Upon arrival on site it was discovered that the flume was silted in, the stilling well filled with debris and that water was not flowing uniformly through the flume. This rendered recent measurements 5.144 N:10417105600CS%Reportsltask memo 5.1.doc May 9,2008 y an Creek.F��storation improvements Morrison-Maig a Inc. (2001 to 2007) usable only as general indicators depicting timing of base-flow and peak- flow events. The record of data gathered from 1970 to 1988 was plotted on a graph in order to identify general trends and determine the timing and magnitude of spring run off and identify base-flow for Lyman Creek at the lower flume. Figure 1 is a plot of the 19 years of data for the two-foot Parshall Flume presented in cubic feet per second (cfs). This plot identifies base-flow occurring primarily between January and March annually and ranging generally between 2.5 and 3.5 cfs. Peak annual flow occurs around the end of June with widely ranging peak discharge rates. Figures 1. Lyman Creek Discharge at the Two-Foot Parshall Fiume. Period of Record: 1970 to 1988 2D .. ....... ............. ..... , 1 _ Estimated Hydro ra fi • Reported Discharge at Flume ; I ; I i E � I ! 12 i, ., ... I,., i,,, „• I I i p ..ir I r..1.r...1„J rI,T' L.I''7.rrr-i—,r,r1,.T.L�..t�..r.�.,r.t.,�,.�.�„L..�.,t.,3�,�,,,,t.,r,,,F�.r„r-r-f°rr,•r•�.r°r'1.�_r1.,.1.�.,,t..t_L,.�„r,,,rt-i 'N N., roR ba, fib. *. R R iy A R R r Also presented was a seven year record of hand measurements at a variety of points along Lyman Creek including data for the sharp crested weir at the upper surface water diversion point. The weir records appear to be the most reliable as weirs are less likely to foul and dictate a consistent measuring point. Data from the weir measurements was plotted on a graph in order to identify, potential base flow, timing of peak flows and the: amplitude of changes in flow throughout the period of record_ The data serves to illustrate a rudimentary picture of historical flow for the past 7 years. Figure 2 displays the sum of measured discharge at the Upper Weir and Influent to the Treatment facility. This sum represents the total discharge of Lyman Creek at the upper surface water diversion point. 5.1-5 N:10417NOWOOMReportsltask memo 5.1.ddc May 9, 2008 Lyman Creek Restoration ImprOVe Morrison-Ma ierlLb, Inc. Figure 2. Lyman Creek Combined Discharge Based on Measured Flow at the Upper Weir and Treatment Plant Influent. 12 ........... ............ 2001 through 2007 — Discharge at Upper Weir 6 Measured QiFcharge �h ............... ........... 4 I r"7' T'T'T­�'T FF'J'T-17-1-7-1-1. V., I 0 -�-'Irr I T'T F!--177 T7 T"'L71 It should be noted that the average base-flow at the Upper Weir is approximately 1,5 and 2 cfs lower than base-flow noted in Figure 1 representing the lower flume, As noted earlier it is apparent that groundwater discharges to Lyman Creek downstream of the upper diversion point resulting in greater overall flow through the Marshall Flume than through the Upper Weir, In addition it is possible that base-flows have declined over the years. A comparison of historical flows through each of these measuring devices was intended to identify possible base-flow trends but as the accuracy of recent data for the Marshall Flume is in question and earlier data is limited to the lower diversion site it was not possible to formulate a reliable comparison. A cursory review of the data does indicate greater historical flow through the lower diversion point than through the upper indicating that Lyman Creek has been gaining between the two sites but the potential inconsistency within the data precludes confidently forming such a conclusion. Existing Devices Historically discharge measurements have been performed by city staff at half-a-dozen locations with in the project area. The most continuous record, on a daily basis, is the trapezoidal flume located just downstream of the current groundwater diversion works. This record shows nearly continuous data over a period of record of a few years and would be more valuable if it were available in tabular format. Currently only a graphical output is available which gives a basic picture of flow through the flume but prohibits in- depth analysis of the record. Specifically it would be valuable to combine flow through the flume with records of plant influent to examine total discharge of the upper spring, 5,1-6 N:\0417\055\DOGS\ReportsNtasR memo 5,1,doc May 9,2008 Lyman Creek Restoration Improvements µ„ Morrison-Maier[p Inc. The possibility of exporting data in tabular format as well as graphical should be explored to maximize the usefulness of the data recorder in the Trapezoidal Flume, The longest period of record exists for the Parshall Flume, located just upstream of the original (lower) surface water diversion structure. A period of record from 1970 through 1988 exists as well as a shorter record from 2001 to 2007. Limitations within this data record revolve primarily around cleaning and maintenance of the flume. Initial field work at the flume site showed the flume silted in and diminished confidence in the accuracy of measurements taken at the flume, specifically in the latter period of record. Measurements taken at the upper weir offer a moderately continuous record over the last eight years and the design of the weir dictates a consistent point of measurement. Data from this site should provide a reliable record of stream discharge variations, however, the overall accuracy of measurements at this site are in question as readings have been taken too close to the crest of the weir and may vary slightly from actual flows. Identification of a measuring site situated the proper distance from the weir's crest and installation of a staff gage is recommended to increase overall accuracy. Specific improvements to each current measuring device include; regular cleaning and maintenance procedure of the device and staff gage, a simple, written measurement procedure, identification of recommended measuring locations associated with each device and the installation of a staff gage at the recommended location to assist in recording consistent readings. Records should include associated cleaning and maintenance, personnel performing the measurement as well as the requisite readings and calculations. Additional detail in regards to long term data collection will be provided in a later memorandum. 5.1.4 FURTHER INVESTIGATION Additional flow measurements and field investigations are ongoing at the writing of this memorandum. This further investigative work will lead to completion of the tasks outlined in the scope of work including conceptual designs to divert additional groundwater and formulation of a work plan to further investigate the most promising alternative. 5,1-7 NA041710551010CS1Reportsltask memo 5.1.doc May 9,2008 APPENDIX A r.rfi .ti 1 Hr 1. I .. - M1OIt71E7111 la. As "�'r. �t " a• n ol If ' ,r . • r fir. � � Lr.;,r., r r w a IY 2 - - - - r w D Ln a W I � J W m � , 1 5 � W 1 � n ca U MOMSON .D. Aa"�MNEIZLE,iw Technical Memorandum No. 6.1 Reservoir Liner City of Bozeman Lyman Creek Reservoir Improvements Bozeman, MT PREPARED BY: Richard T, Sprague REVIEWED BY: James Nickelson MATE: February 25, 2008 Meeting Summary 4n Thursday, February 14, 2008, representatives of Bozeman, Morrison Maierle and HDR Engineering met with MDEQ personnel to discuss the Lyman Creek Reservoir discharge pernnit, The following paragraphs summarize our discussions: • For the meeting, the City of Bozeman was represented by Rick Moroney (Bozeman), James Nickelson (Morrison Maierle) and Dick Sprague (HDR), MDEQ was represented by Kari Smith, Rachel Clark and John Wadhams. Tom Reid was not able to make the meeting. • Dick Sprague passed around an agenda, and began the discussions. He stated that all lining systems leak, and that 10 States Standards anticipate this leakage for wastewater treatment ponds. The only question is the magnitude of the leakage. MDEQ did not really challenge these statements, and acknowledged that Montana uses standards derived from 10 States Standards. • Kari Smith summarized MDEQ's issuance of a General Permit for Disinfected Drinking Water for a temporary discharge of water, as well as the State's rescinding of that permit. o This Permit was issued in response to an application by the City of Bozeman for a temporary discharge to drain the reservoir. The application 6.1-1 NV4171055000SIReportsl jner Memo Fabruray 25.2008,doo May 9, 2008 Lyman Creek Restoration Im r� ovemenEs� Morrison-Maierle, Erkc. stated that a pond downstream in an ephemeral stream would be the first water of the state potentially affected. MDEQ stated that this permit was probably issued in error; the construction of Lyman Creek Reservoir directly in the ephemeral stream bed placed it directly in waters of the state. A General Permit would not be applicable for this situation, and an individual permit should have been written. ca Subsequent to the 2003 discharge, MDEQ received two citizen complaints regarding discharge of water from Lyman Creek Reservoir. In response, MDEQ investigated the situation and found water discharging from the underdrain into the ephemeral stream. MDEQ took samples and detected free chlorine in the discharge, the ephemeral stream downstream, the pond downstream, and beyond the pond. While the concentrations of chlorine were decreasing with distance, the water quality standard for chlorine is 0,011 mg/l; since this concentration is not detectable using current analytical tests, the discharge standard is `none detectable' using a detection limit of 0.1 mg/l. o After MDEQ issued Violation Letters and rescinded the General Permit, Bozeman sent a letter to the Water Quality Division requesting that the Board of Environmental Review hear the City's appeal of the determination that the discharge into the ephemeral stream constituted discharge into waters of the state. MDEQ stated that the appeal letter should have been sent to the Board of Environmental Review, not to the Water Quality Division; the Division has not forwarded it to the Board, and does not believe that it has an obligation to do so. If Bozeman wants an appeal, the City should resubmit the request directly to the Board, According to Ms. Smith, this appeal can proceed concurrently with working toward resolution of the discharge. • The MDEQ has requested an application from Bozeman for discharge of chlorinated and fluorinated water into the waters of the state. This permit is required because Lyman Creek Reservoir has pipes (both overflow and underflow) that could discharge treated water into the ephemeral stream. MDEQ was quite clear that actual discharge was not the only cause for requiring a permit; potential for discharge is sufficient to require a permit, and either a valved discharge pipe or a gravity overflow pipe constitutes potential for discharge. The permit application may need to address both surface water and groundwater discharges from Lyman Creek Reservoir. MDEQ pointed out that there is a discharge limit for chlorine to surface water, but not to groundwater. There are discharge limits for fluorine to both surface water and groundwater. w MDEQ stated that they would work actively with Bozeman to rapidly develop a draft permit for public notification. This process will be expedited by filing of a complete discharge permit application. They cannot control the public notification /public hearing part of the process because this process depends on the number of comments and requests for a hearing from the public. John Wadhams will be the permit writer. 6.1-2 N:1041 D05%C)OC$\Reports\Liner Merno Februray 25,2008.doc May J,2008 Lyman Creek Restoration Improvements MarrisonµM ierle nC, Other Observations F The geomembrane liner in Lyman Creek Reservoir is leaking at a rate of approximately 8 to 15 gpm based on measurements taken by City of Bozeman staff in November 2007. This is less than leakage rate following repairs to the geomembrane liner, and much less than the historic leakage reported by City staff for the period prior to installation of the geomembrane liner. ® 10 States Standards (referred to above) sets a leakage of 500 gallons per acre per day as the upper limit for acceptability of leakage from a clay-lined wastewater pond with a water depth of six feet. While the Lyman Creek Reservoir is lined with a geomembrane instead of clay, it provides a benchmark for us to use in assessing the condition of the lined reservoir. For the reservoir, this is equal to approximately 1,4 gpm assuming an average depth of 24 feet and a surface area of one acre. We can conclude that the geomembrane liner is leaking at five to ten times the rate expected for a clay-lined facility; geomembrane liners generally leak less than clay liners, • The City settled with the designer, general contractor and geomembrane installer in 2006, The settlement appears to release all parties from future liability, with an exception of manufacturers' material and equipment warranties (Section 5.13 on page 3). Ceomembrane manufacturers generally limit warrantee liability to the prorated remaining life based upon an expected life of 20 years, It is not clear that the geomembrane material is failing to meet specifications, and it is likely that the City would receive less in warrantee payments than it would cost to prove that the material is failing (if it is, in fact, failing) and to file and prosecute a lawsuit. Y Replacement of the geomembrane is likely to cost $200,000 to $300,000, perhaps more if the existing geomembrane must be removed. It is not clear that the value of the lost water will allow recovery of this capital expenditure in a reasonable amount of time. These simple calculations should be performed early in the permitting process. i The columns that support the reservoir roof were constructed during the rehabilitation of the Lyman Creek Reservoir. It is likely that the design engineer assumed that the geomembrane lining would control most seepage, and designed the column footings with this in mind. Morrison Maierle and HDR have not verified that the column footings were designed and constructed to support the columns in relatively wet soils. This verification should occur as part of the discharge permitting process. Conclusions 4 The Lyman Creek Reservoir is leaking more than expected for a geomembrane- lined reservoir, but this leakage is less than prior to rehabilitation. • MIDEQ will require the City of Bozeman to submit a water discharge permit application. They will likely require that this permit application consider both surface water and groundwater discharges. Either or both discharges may 6.1-3 N;N0417\065\DOCS\Report5\Liner Memo Februray 25,2008.doc May 9,2008 Lyipan Creek-Restoration Improvements �Marris ierle, Inc. require treatment prior to discharge, or changes in operation to remove water treatment chemicals from the discharge(s). o The City may appeal the classification of the discharge as a surface water discharge to the Board of Environmental Review. This appeal is not likely to obtain a reclassification. However, MDEQ will process the discharge permit application regardless of an appeal. • The rehabilitation of the reservoir included construction of a roof supported by columns. It is not clear that the design considered construction of column foundations in wet soils, Recommendations • Verify that column foundation calculations considered wet soil conditions. Determine the preferred methodology for removing water treatment chemicals from the discharge(s) and submit a permit application to MDEQ. • Determine whether pursuit of an appeal of discharge classification makes sense. Use the value of lost water to determine whether replacement of the geomembrane makes financial sense_ Investigate relocating the injection point for fluoride to downstream of the reservoir to remove this element from the reservoir. Reference Materials • Settlement Agreement and Release of Claims, October 2006, • Great Lakes-Upper Mississippi River Board of State Sanitary Engineers ("10 States Standards"), 2004 edition, available at http://www.hes.org . • Richardson, Gregory N. and Richard T. Sprague, "Coordinating Regulations in Design and Construction of Modern Landfill Liners and Closure Caps", in MSW Management, pp. 92 — 98, May/June 2000, • Sprague, Richard T., "Design and Construction Quality Assurance for Geomembrane Systems in Waste Containment", in Geotechnical News, pp_ 22 — 24, September 1989. • Sprague, Richard T. and Ronald K. Frobel, "Performance Test Methods for Geomembranes and Geocomposites Used in the Design of Waste Containment Facilities", G_eosynthetic Testing for Waste Containment Applications ASTM STP 1081 , Robert M. Koerner, editor, ASTM, Philadelphia, 1990. 6.1-4 N;104171055100C51ReportslLiner Memo Februray 26,2008,doe May 9,2008 MORRISON LID MA,IEM,I ,INC. Technical Memorandum No. 7.1 SOURDOUGH TANK CONCRETE REPAIRS City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, IVIT PREPARED BY: Jay B. Fischer, P.E, REVIEWED BY: Kurt W. Keith, P.E. DATE: May 9, 2008 7.1.1 INTRODUCTION The investigation of deteriorating concrete on the rim of the Sourdough Tank is park of the scope of services included in the Lyman Creek Reservoir Improvements Pre-Design Phase Project for the City of Bozeman. Before; a restoration solution was selected, an investigation of the deteriorating structure was provided to identify the extent of the damage and probable causes of deterioration. The investigation also included a review of the existing as-built drawings to determine if the deterioration is affecting the structural stability of the structure. 7.1.2 HISTORY The Sourdough Reservoir was built in 1957 with a maximum capacity of 4_0 MG. The reservoir was constructed out of cast-in-place concrete with conventional steel reinforcing in the cylindrical tank and the domed roof. The tank has an inside diameter of 147 feet with a max liquid elevation of 31 feet 6 inches. The exterior of the tank walls are wrapped with circumferential pre-stressed wire wrapping, with a high number of wires per vertical foot at the bottom of the wall tapering to a minimum number per vertical foot at the top of wall. The cylindrical tank is 7,1-1 NA041710551DQ=ReporWTask 7-Sourdough Tank and Site Repairs\Tank Rim Craeking\Structuraf TM-1 1—Cracking Concrete at Rirn.doc May 9, 2008 Liman ,reek Restoration Improvements N�„w_MN Morrison-Maierlfl, Inc, separated from the domed roof and foundation system by an expansion joint with no steel extending into the foundation system or roof. Water stops are provided at the top of tank and the bottom. The tank wall has a thickness of 10 inches with a 1 114 inch thick pneumatic mortar exterior to cover the wrapped wire pre-stressing tendons. The rim of the dome roof has 10 inch wide by 22 inch deep circumferentially pre- stressed dome ring at the base of the roof to resist typical dome thrust. The pre- stressing on the dome ring is similar to the tank prestressing, but independent from the tank wall wrapped wire. The dome ring has pre-stressed wrapped wire on the exterior of the ring with 2 % inch thick pneumatic mortar exterior. The thickness of the domed roof tapers from 8 inches thick at the dome ring to 4 inches at the center of the roof. 7.1.3 RIM DETERIORATION INVESTIGATION AND POSSIBLE CAUSE Morrison-Maierle, Inc. conducted an on site visual inspection of the tank roof and found the existing pneumatic mortar covering the pre-stressed wrapped wire on the dome ring to be cracked and spalled, Specifically the mortar covering the circumference of the dome ring was cracking longitudinally and delaminating from the wrapped wire exposing the wrapped wire to moisture. This was typical around the entire circumference of the tank. However, the southern side seemed to have the most severe deterioration. On the southern side the mortar had broken off, fully exposing the wrapped wire. In these areas, a few wraps of the wire have separated and lost their prestressing. There are several factors which may have contributed to the corrosion of the wrapped wire. In this case the exposure to moisture has caused the severe corrosion of the wrapped wire. Typically reinforcement in concrete structures is protected from corrosion by encasement in alkaline concrete materials that react with the steel to form a protective oxide coating. However, if moisture is able to penetrate the concrete corrosion can occur. There are several processes which can introduce moisture. Listed below are some of the more common processes. 1. Plastic shrinkage cracking. 2. Dry shrinkage. 3. Cracking from freeze-thaw processes. 4. Permeability of concrete. 5_ Age of concrete. 5, Improper detailing and construction 7. Combination of any of the above. The Sourdough Reservoir was constructed in 1957, With this age of concrete structure, it is frequently determined that freeze/thaw protection (air entrainment) was not taken into account, affecting the durability of the concrete and/or mortar. With no protection from freeze/thaw cycles, the concrete and/or mortar will gradually open passageways allowing moisture to penetrate leading to corrosion of the reinforcing, Improper detailing 7.1-2 NV417\055%DQMReports\Task 7-Sourdough Tank 811d Site RepairslTank Rim Crack ing%Structurat TM-1.1,Cracking Concrete at Rim.doc May 9, 2008 Lirrtpn Creek ReStoratlon Improvements Morrison-Maierle Inc. �. .. �., and construction is another possible way moisture can penetrate into concrete structures. A moisture passageway can be created by not sealing concrete joints, During our site visit we observed there was an unsealed joint at the top surface of the dome ring/roof interface between the concrete and the mortar covering the wrapped wires, This joint could have allowed the initial moisture to penetrate into the concrete section causing the reinforcing to corrode. With moisture penetrating the concrete the corrosion on the reinforcement intensifies, and the concrete becomes stressed by the expansive nature of the corrosion, Also, without proper freeze/thaw protection the moisture does not have room to expand as it freezes and additional tensile stresses are applied to the concrete. When the stress in concrete increases beyond its tension capacity the concrete will crack and delaminate, Evidence of this was seen on the south side of the tank which will go through several freeze/thaw cycles, 7,1.4 RECOMMENDED REPAIRS It is our opinion and recommendation to repair the concrete dome ring immediately, Depending on the number of wrapped wires that have lost their pre-stressing and the severity of the corrosion, the dome ring and roof are in jeopardy of becoming structurally unstable. We recommend removing the existing loose mortar cover and corroded wires that have lost their pre-stressing and apply new pre-stressing strands to reinforce the dome ring. This repair would consist of placing a 1/2" layer of shotcrete over the existing wires once the defective wires have been removed. For added protection from future corrosion a layer of galvanic protection can be placed prior to the '/2" shotcrete. After the shotcrete is placed new pre-stressing stand anchor systems would be applied to recompress the existing dome ring. After the strands are in place and the required force is applied to the strands, a new 4° mortar/concrete cover would be applied with sufficient detailing, freeze/thaw protection and clear cover to prevent future corrosion problems. This repair assumes there are existing wrapped wires in good structural condition providing adequate strength to safely accomplish the removal of the loose mortar and corroded wires without shoring the existing roof and taking the tank off line for the duration of the repair. Total Construction Cost = $150,000 If the existing prestressed wrapped wires are more severely corroded or other unknown conditions exist the cost of the repair will increase. Possible cost increases could consist of additional wire removal leading to shoring of the existing dome roof. Total Construction Cost w/ Shoring = $350,000 7.1-3 N:\041'710551DoC:SlReportslTask 7-Sourdough Tank and Site RepairslTank Rim CrackinmStructural TM-1.1_Cracking Concrete at Rim.doc May 9, 2008 D.-I MORRISON �:D MAIERLE,INC Technical Memorandum No. 7.2 SOURDOUGH TANK LACQUER REPLACEMENT City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, MT PREPARED BY. James Nickelson, P.E. REVIEWED BY: Jim Ullman, RE. DATE; May 9, 2008 7.2.1 INTRODUCTION The interior access ladder to the reservoir is deteriorating due to age and is in need of replacement_ This is the original ladder that was installed in 1957 and while functional when installed, its useful life has past. The ladder is of steel construction and is approximately 35 feet high. 7.2.2 RECOMMENDED REPAIRS It is recommended that the ladder be replaced with a stainless steel or aluminum ladder. The reservoir would need to be removed from service and drained in order to remove the old ladder and install a new ladder. The construction cost is estimated as follows.- Construction Cost - $6,000 7.2-1 N:\041710551D0C91RaportslTask 7-Sourdough Tank and Site Repairsll'ank ladder.doc May 9. 2008 -II Mffl�RCSON LILT MMERLE,INC. Technical Memorandum No. 7.3 SOURDOUGH TANK VALVE REPLACEMENT City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, MT PREPARED BY: James Nickelson, P.E. REVIEWED BY: Jim Ullman, P.E. DATE: May 9, 2008 7.3.1 INTRODUCTION The valves associated with the piping entering and exiting the reservoir date back to as far as the original construction of the reservoir. While many of the valves still function, there are two valves that are in need of replacement. The purpose of this memorandum is to develop a general plan and costs to replace the valves. 7.3.2 EXISTING CONDITIONS There are two valve vaults located at the reservoir site, each which contains a valve that needs replacement, The locations of the two valves are shown on Figure No. 1. The north valve vault was installed with the original reservoir construction in the 1950's. The south vault was installed in the early 1980's. The north vault contains isolation valves for the 18" and 24" supplies to town. The 18" gate valve does not seal and needs to be replaced. The replacement of this valve is complicated by the fact that under present conditions there is no means to isolate the valve from the water distribution system so it would need replacement under live conditions. However, the Water Department is currently scheduled to install a new isolation valve downstream of the reservoir so the 18" valve can be isolated from the 7.3-1 NA0 4 1 710 5 51DOCSIReports\Task 7-Sourdough Tank and Site RepairsWalve Replacement.doG May 9.2008 Lyman Creek restoration Improvements_ � r.. 4_ � Morrison-Maierle, Inc. system. For the purposes of this project it is assumed that this new isolation valve has been installed. The north vault also contains a 24" line that enters the valve vault from the east This line was the original feed from the water treatment plant to the reservoir. due the potential of contamination of the water supply this feed has been generally isolated from the reservoir and distribution system. To complete the isolation this 24" line should be disconnected in this valve vault. The south valve vault contains a 24" butterfly valve that leaks and does not seal. This valve was the primary feed to the reservoir from the early 1980's to the recent construction of the bypass building. This valve can be isolated from the reservoir, the supply line to the plant and distribution system by a series of valves. This valve also leaks water into the vault which drains onto the site and causes drainage and icing problems on Sourdough Road. 7.3.3 RECOMMENDED REPAIRS The recommended repairs include the replacement of the two leaking valves and elimination of the abandoned line. Potential alternatives exist, such as attempting to repair valves in place or replacing the 24" valve with a solid sleeve; however, the possibility of failure and the loss of isolation capabilities does not appear to make the alternatives desirable, Construction cost estimates have been developed and are summarized below: 18" Gate Valve Replacement and 24" x 18" Tee Removal ( 24" x 18" Tee replaced with 24" x 18" 901 bend) — Construction Cost $18,000 24" Butterfly Replacement — Construction Cost $10,000 7.3-2 NA04171055\D0CSIRepcAs\Task 7-Sourdough'Tank and Site RepairsWalve Replaeement.doc May 9,2008 r `1 •+5 \ r i I VALVE SO ip 1 Ow 4 1 8A�CiATE VALVE i TO BE REPLACED j \ '24" OUTTERF'CY VALVE YE �EPLACED CH11 ! lj i y r-•'' r + _ IN� W /24" NOT USED 24" NORMALLY WLf�SED >E....I � �� 4,Y f f SUPPLY LINE ;. :Q irY i fff 130URDOUCH In RESERVOIR f `, i W rL EL w +5 A I �..� 18" NOT USED M :M.. ��M. , .. _.�. i I .,,,,.,,.._.. r,.....�......,__._... SCALE: NONIF Sul Tacnology alvd. VRAWN HY,�� SOURDOUGH RESERVOIR NRCSJECI'MORRISONR I H0.9woo MT 59718 cEIK•u HY..A),RCl.........• 0117055 ` BOZEMAN MONTANA Phone,(40(i)Sy7-cYx, APPR,3Y JRNPlolnoes QiERLE, INC. Sr Far!(406)567-1176 FIGURE NUMBER PATE:_Q;UQq�,_ 1n F+Aip4p•u-bA�nrdG'arnprnv VALVE REPLACEMENT FIG. 1 4ry(AVRIyAir unwu�x(Iu,Mn�rwAl:.inl.'.Yb)rl N:\06171or!,%ACAD1CancuuASouADough-Exhihi6dwg F'Initgd by.Jullman MNy/0712006•i 1.26A4 mn MORMSON Lill, IYll IERLE INC, Technical Memorandum No. 7.4 SOURDOUGH TANK LANDSCAPING City of Bozeman Lyman Creek Reservoir Improvements Project Bozeman, IVIT PREPARED BY: James Nickelson, P.E. REVIEWED BY: Jim Ullman, P.E, DATE: May 9, 2008 7.4.1 INTRODUCTION The Sourdough tank was constructed in 1957 and landscaping was limited to grading and reseeding the bare ground. Since that time a number of volunteer shrubs and trees have grown on the westerly embankment of the reservoir site. The shrubs and trees have become a maintenance concern. 7.4.2 OPTIONS A number of options are available for landscaping the west embankment below the reservoir. The following options provide various levels of beautification, maintenance requirements and irrigation needs. Option 1 T River Rock Xeriscape This option would include the removal of vegetation from the embankment and the installation of a landscape mat with a river rock cover. The advantage of this option is that it would require little routine maintenance_ Construction Cost - $7,500 7.4-1 NA049710551D0CSIReporWTask 7-Sourdough)Tank and Site RepFairelLandscaping.doc May 9,2008 , Ym. n Creek RQ�. wration Improvements ^_ _ Morrison-Maierip lnc,, Option 2 --- Low Water Use Shrubs This option includes removal of the vegetation from the embankment and the installation of a number of low water use shrubs in a river rock bed. The shrubs would require a drip irrigation system in order to be sustainable. This option will require periodic maintenance including operation of the irrigation system and upkeep on the plantings, The option maybe desirable if the city desires a more decorative facility. Construction Cost - $12,000 Option 3 — Maintain Current Maintenance Activities This option would continue the periodic cutting of the aspen trees and other shrubs on the embankment. Construction Cost - $0 7.4-2 N 10417�0551DQCSIRopottskTaSk 7-Sourdough Tank and Site Repairs\Landscaping.doc May 9,2008