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Home My WebLink About14- Installation of Two Additional Groundwater Wells and Monitoring-PSA TASK ORDER INSTALLATION OF TWO ADDITIONAL GROUNDWATER WELLS AND MONITORING BOZEMAN LANDFILL November 14, 2014 CLIENT: CONSULTANT: The City of Bozeman Tetra Tech, Inc. P.O. Box 1230 851 Bridger Drive, Ste 6 Bozeman, Montana 59711-1230 _ Bozeman, MT 59718 Attention: Mr. Rick Hixson Attention: Mr. Mark F. Pearson INTRODUCTION This task order includes the following work activities: • Installation of two new offsite groundwater monitoring wells requested by Montana Department of Environmental Quality (DEQ) • Reporting SCOPE OF SERVICES This task order includes two tasks, which are described below. Task 1 Drilling and Installation of Two Monitoring Wells This work scope responds to the Montana DEQ's August 13, 2014 letter regarding the Draft Report of Groundwater Monitoring Well Installation and Groundwater Monitoring Activities March through May 2014, wherein DEQ requested additional monitoring wells be installed in the southern portion of the site. The DEQ approved the location of the two additional wells in a letter to City of Bozeman on October 16, 2014. The purpose of this task is to better define the extent of impacted groundwater in the southeast portion of the project area (Figure 1) and is also intended to ultimately support the implementation of a remedial alternative selected by the Corrective Measures Assessment for the subject site. The City's ability to implement this work plan is dependent upon two landowners granting access to their property. If City efforts to secure access are not successful we will request DEQ provide assistance in this regard. Past investigations identified concentrations of tetrachloroethene above Montana Groundwater Protection Standards (MGWPS1) in the southeast portion of the landfill project area, including a groundwater monitoring well, south of the landfill property, with approximately 10 micrograms per liter (MW-20). Concentrations of VOCs in surrounding wells were either below MGWPS or Non Detect. Evaluation of the data indicates that the extent of PCE in groundwater has not Task Order- Installation of Two Additional Groundwater Wells and Monitoring Bozeman Landfill, Bozeman, Montana November 14, 2014 been completely defined to the south and west of well MW-20 and the upgradient source of PCE in MW-17 is not entirely clear. This task is directed at clarifying these unknowns. This task order proposes the installation and sampling of two additional groundwater monitoring wells at locations shown on Figure t Table 1 provides information on the location, target completion depths, and purpose/justification for each well. Details of this task are described below: The two proposed wells (PMW-27 and PMW-28) will be located south and east of the landfill property on private property. PMW-27 is proposed to be located on Golf Course Partners property and PMW-28 on property owned by Churn Creek Partners LLC (Jerry Locati listed as owner). Hence, property access agreements will need to be obtained from the property owners. The proposed location of PMW-27 is targeted at being sufficiently downgradient of MW-17 and MW-20 to provide a definition of the southeastern edge of the volatile organic compounds (VOCs) plume. The location is within the golf course "rough" adjacent to the fairway and will be on Golf Course Partners property. This location was chosen as the most likely location that will be acceptable to the golf course owners, while still providing a valuable data point. The presence of VOCs in MW-17 may be the result of refuse immediately adjacent to the well or the presence of landfill gas in contact with groundwater in or near the southeast corner of the landfill. If the adjacent refuse is the source of VOCs in MW-17, then the well is a suitable representation of the extent of VOCs in groundwater in the area, however. PMW-28 is proposed to be located upgradient of MW-17 where it is anticipated that landfill gas migration may occur slightly east of the landfill boundary in this area, where it could contact groundwater and create a plume that flows back (west and southwest) underneath the landfill property. PMW-28 will also help evaluate whether there are off-site sources of VOCs east of the landfill. These locations will be staked and then the Underground Utility Notification Center will be notified to clear the locations of all underground utilities. Adjustments in these locations may be necessary to accommodate landowner preferences or to avoid underground utilities. The field investigation will consist of drilling, completion, and sampling of two groundwater monitoring wells. Details are provided below and in Table 1: • Completion depths and length of screen across the groundwater intercept have been estimated (Table 1). • Based on driller bids, site access and landowner restrictions, either air rotary or hollow stem auger drilling will be selected. The expected depth of PMW-28 (up to 95 ft.) and our past experience drilling MW-17 (hard conditions were observed that significantly slowed hollow stem auger drilling) may dictate the use of air rotary drilling. However, geologic materials are better observed with hollow stem drilling. In addition, the hollow stem auger rig is smaller and requires a smaller work area, better suited to working on the proposed properties. • Tetra Tech personnel will supervise the drilling and completion of the monitoring wells; log the soil/geologic materials during drilling; note any changes in lithology, drilling rate, water occurrence, and other conditions; confirm the intersection with groundwater and document well completion specifications. Page 2 of 4 Task Order- Installation of Two Additional Groundwater Wells and Monitoring Bozeman Landfill, Bozeman, Montana November 14, 2014 • Upon reaching the target depth, each well will be constructed of 2-inch diameter, schedule 40 PVC with 0.020-inch slots in the screened intervals. The screened interval will be placed across intersection of groundwater such that approximately one third of the screened length will be above the groundwater intercept and two thirds below the groundwater intercept. In addition to providing the PVC piping and well completion materials, the driller will install: 10-20 silica sand around the well screen to approximately one foot above top of well screen, a bentonite seal from top of sand pack to within 1.5 feet of grade, and a flush-mounted (level with ground surface) traffic-rated well protector set in concrete grout. • Drilling equipment will be decontaminated between drill holes. Decontamination activities will be conducted on the landfill property. • Upon completion, wells will be developed, with a decontaminated submersible pump and disposable tubing, to remove fine sediment and establish a hydraulic connection with the aquifer. Development water will not be containerized. • Following completion, each drilling site will be returned to conditions prior to drilling, with the exception of vegetation, which will be reestablished when conditions allow (which may not be until Spring of 2014). • Following completion of the wells, professional surveying will be conducted to establish the location and top of casing elevation above mean sea level (AMSL) for each of the new wells. • Following installation of the wells, one event of groundwater monitoring will be conducted and includes the collection of field parameter measurements (depth to groundwater, temperature, pH, specific conductivity, dissolved oxygen, and oxidation reduction potential) and collection of groundwater samples for laboratory analysis of VOCs, cations, anions, alkalinity, iron, manganese and tritium. Groundwater samples will typically be collected using a dedicated bailer. Groundwater samples will be analyzed for VOCs in accordance with either EPA Method 8260-low level. • Questions have been raised concerning a well located on the northwest corner of the landfill property at a City dog park. Well construction details for this well will be obtained from the Montana Department of Natural Resources and Conservation. Therefore, groundwater monitoring will include the collection of a water sample for laboratory analysis using the same parameter list as outlined below for the landfill monitoring wells. Task 2 Reporting Following the completion of the two well installations, described above, and receipt of the laboratory results of their initial monitoring, the Draft Report of Groundwater Monitoring Well Installation and Groundwater Monitoring Activities March through May 2014 will be finalized to include the additional data, Well monitoring data will be entered into the project database. Review of this and groundwater data collected during the December groundwater monitoring event will conducted and recommendations will be provided pertaining to a future monitoring schedule of these two additional wells. Page 3 of 4 Task Order- Installation of Two Additional Groundwater Wells and Monitoring Bozeman Landfill, Bozeman, Montana November 14, 2014 PERIOD OF PERFORMANCE Tetra Tech's anticipated schedule to complete the two groundwater well installations and sampling will be in early December 2014, assuming there is availability of a suitable driller. Reporting will be conducted following receipt of laboratory results approximately three weeks later and the Draft Report of Groundwater Monitoring Well Installation and Groundwater Monitoring Activities March through May 2014 will be finalized and submitted to the City of Bozeman. COSTS Estimated costs to complete the foregoing scope of services are summarized below: • Well Installation and Initial sampling of two wells $ 25,285 • Reporting, and Project Management $ 4,550 TOTAL $ 29,835 Attachment A de ese costs. The services will be conducted on a time and materials basis. SPECIAL CONDI : Execution of this Task Order constitutes acceptance of all terms and conditions contain Tetra Tech's Professional Services Agreement with the City of Bozeman, dated January 3, and Amendment Nos. 1, 2, 3, and 4 of the Professional Services Agreement dated 31, 1995; January 1, 1996; March 17, 1997; and December 10, 2001, respectively. CLIENT: CONSULTANT: City of Bozeman Tetra Tech _ 0 By: By: f J✓ Its: ( t't7 I� (Ctvtc1 Its: Senior Project Manager Date: l Z—�� ' ! L1 Date: November 14, 2014 Footnote: 1 The MGWPS refers to a regulatory water quality standard and has also been referred to as the maximum contaminant level and human health standard. Reference: DEQ, 2012. Circular DEQ-7 Montana Numeric Water Quality Standards. October. NOTICE OF CONFIDENTIALITY This Task Order(including attachments) contains information confidential to Tetra Tech. Inc. its subsrdianes and subcontractors It is intended only for City of Bozeman to considet Tetra Tech providing professional services at the Bozeman Landfill Any other use is prohibited without the prior written consent of Tetra Tech Page 4 of 4 I 1 MW-15 E • T) N. _ 'N9BOOMW 14 � ,. `qX ,0N 1 MW11l a ,\ m 2 \ ' . o MW 16 , MW-5 n _,,;.� MW-6 l Li ] _. :._, „, _ , % .. e MW-4 ii PMW-28 m LMW- _____,...,..„,101 \ `\, \ MW-12 l 1 . �Cj C.� v� ca .i `'oMW-18 MW-17 r? -✓ --..: MW-8A 1 �� ta 5 iM9A1'' � -c N ` E 0 °' \ MW 20l'%. ,, a [ LF2 „• coo 4 LF-3 f 4,' ! . \--1 MW 24 ✓ ✓I [�. MW 19 1 PMW 27 MW-231 MW-22 . ff`r� N .-) P� ` m 1 a - MW-25 W I N O 5 in 0 >_ 1 MW-21 I/ 51 4690 Groundwater Elevation in Feet(above mean sea level) , - ,* l U 1 ® Groundwater Monitoring Well j MW 26 I Service Layer Credits:Source:Esn,DigdaiGlobe, o , El Proposed Monitoring Well Location GeoEye.i-cubed,Earthstar Geographies, ii;m4. CNES/Airbus DS,USDA,USGS,AEX, l ' - Getmapping.Aerogrid,IGN,IGP,swisstopo,and a � � New Residential Construction '' the GIS User Community 114-710326700 N wE Proposed Groundwater Wells Minb( s NOTE: Bozeman Landfill ° 3°° 6°° All well locations are approximate. Bozeman, Montana Feel Only those wells used for preparation of groundwater contour map are shown FIGURE 1 Datum NAD83 StatePlane Montana TABLE 1 PROPOSED GROUNDWATER WELL LOCATIONS AND COMPLETION DETAILS TASK ORDER - INSTALLATION OF TWO ADDITIONAL GROUNDWATER WELLS AND MONITORING BOZEMAN LANDFILL PROPOSED PURPOSE ASSUMED ESTIMATED SCREEN SCREENE SURFACE WELL DEPTH TO TOTAL LENGTH D COMPLETION GROUNDWA DEPTH(ft) (ft) INTERVAL TER(ft) (ft) Extent of VOCs downgradient of Flush mount, PMW-27 MW 17 and MW- 35 45 15 30-45 steel well 20 protector Extent of VOCs 3-foot stickup, PMW-28 upgradient of 85 95 15 80-95 steel well MW-17 protector Tetra Tech ATTACHMENT A ESTIMATED COST INSTALLATION OF TWO ADDITIONAL GROUNDWATER WELLS AND SAMPLING BOZEMAN LANDFILL Date Submitted:November 14,2014 TASK 1 DRILLING AND INSTALLATION OF TWO MONITORING WELLS Contracting,Property Access,Underground Utilities Clearance,and Health and Safety Plan Update LABOR: RATE UNITS COST Senior Scientist,per hour $170.00 3 $510.00 Project Scientist,per hour $90.00 16 $1,440.00 Clerical,per hour $60.00 2 $120.00 DIRECT COSTS: Vehicle mileage,per mile $0.80 20 $16.00 Custom Utility Locate(if necessary),estimate $200.00 1 $200.00 Subtotal $2,286.00 Well Installation LABOR: Senior Scientist,per hour $170.00 4 $680.00 Project Scientist,per hour $90.00 60 $5,400.00 DIRECT COSTS: Vehicle mileage,per mile $0.80 50 $40.00 Miscellaneous materials,estimate $60.00 1 $60.00 Professional Surveying,estimate $2,000.00 1 $2,000.00 Subtotal $8,180.00 Subcontracted Drilling Installation of two monitoring wells for a sum of 140 feet drilling and well completion Mobilization and Per Diem Drill Rig and Support Vehicle $3.75 210 $787.50 Per Diem,per person per day $120.00 10 $1,200.00 Soil Boring,per foot $23.00 140 $3,220.00 Well Installation, per foot $26.00 140 $3,640.00 Decontamination,per hour $150.00 3 $450.00 Standby estimated,per hour $150.00 2 $300.00 Well Development,per well $250.00 2 $500.00 Drilling Contingency-15% $1,514.63 Tetra Tech subcontractor invoice processing markup(10%) $1,161.21 Subtotal $12,773.34 Tetra Tech Page 1 of 2 ATTACHMENT A ESTIMATED COST INSTALLATION OF TWO ADDITIONAL GROUNDWATER WELLS AND SAMPLING BOZEMAN LANDFILL Date Submitted:November 14,2014 Initial Groundwater Monitoring Event LABOR: RATE UNITS COST Project Scientist, per hour $90.00 7 $630.00 DIRECT COSTS: Vehicle mileage,per mile $0.80 8 $6.40 Sampling Disposables-Filter,each $19.00 3 $57.00 Sampling Disposables-Bailer,each $6.50 3 $19.50 Sampling Disposables-Low-flow tip,each $2.50 3 $7.50 Sampling Disposables-pump tubing,per foot $0.25 140 $35.00 Sampling Disposables -Miscellaneous,each $3.00 3 $9.00 Lab Sample Shipping(overnight to lab),estimate $50.00 1 $50.00 Lab Analysis(VOCs),each $95.00 3 $285.00 Lab Analysis(inorganics-Tritium),each $60.00 3 $180.00 Lab Analysis(inorganics-full list metals),each $166.50 3 $499.50 Lab Analysis(inorganics-cations,anions,TDS, Hardness) $34.00 3 $102.00 Lab Analysis(inorganics-nitrate+nitrite) $12.00 3 $36.00 Tetra Tech 10%markup on non-Tetra Tech Equipment,and Materials $128.69 Subtotal $2,045.59 TASK I DRILLING AND INSTALLATION OF TWO MONITORING WELLS TOTAL $25,284.93 TASK 2 REPORTING LABOR Senior Scientist,per hour $170.00 3 $510.00 Project Scientist,per hour $90.00 36 $3,240.00 CAD Operator,per hour $75.00 8 $600.00 Clerical,per hour $60.00 2 $120.00 DIRECT COSTS Photocopies,estimate $0.10 300 $30.00 Reprographics,estimate $50.00 1 $50.00 Subtotal $4,550.00 TASK 2 REPORTING $4,550.00 TOTAL TASK ORDER: I $29,834.93 Tetra Tech Page 2 of 2