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HomeMy WebLinkAbout007 Response to ENG Comments May 25, 2022 Alicia Paz-Solis City of Bozeman – Engineering Department 20 East Olive Street Bozeman, MT 59715 Re: Engineering Comments on Concept Application #21230 For the 1608 W. Beall St Townhomes (The Lofts on Beall) Dear Alicia: This letter is intended to provide a narrative response to Engineering comments dated July 14, 2021 on the Concept application (#21230) for the 1608 W. Beall St. townhome project. Please note that the site layout was updated after the comments were received. Therefore, these comments and responses may not be entirely applicable, so are noted as such. The site layout update was made such that a Conditional Use Permit could be obtained for the development, as described in the Conditional Use Permit application document. Provided below are the City comments (on the previous site plan layout) and the current responses (with respect to the new, updated site plan layout). Comments have been individually addressed with responses in bold. Easements 1. BMC 38.410.060.B.2 - The applicant must provide a ten (10) foot utility easement (power, gas, communication, etc.) along the development’s property frontage. A draft easement document and exhibit has been provided showing the 10-foot utility easement along the back (south) line of the property. No utilities currently exist or are proposed within the front 10 feet of the property. No 10-foot-wide utility easement is currently proposed along the property frontage (W. Beall St.). It is our understanding that no utilities currently exist within the front (north) 10 feet of the property. Existing power comes from the south side of the site (existing transformer) and is extended north into the site as shown on the attached drawings and on the attached preliminary layout provided by Northwestern Energy. Gas exists on the south side of the site as well. Gas is not proposed for the project (all electric). Gas also exists within W. Beall St. north of the site as shown on the property survey. We understand Northwestern Energy would need to approve a 10-foot-wide utility easement on the south side only (not on the north side of the site). Since no utilities exist Alicia Paz-Solis May 25, 2022 Page 2 of 10 there currently, none are proposed, and adjacent sites are built out and/or can get service from the south, there is no need for a 10-foot-wide utility easement along W. Beall. St. 2. BMC 38.410.060.C.1 - The applicant must provide a thirty (30) foot public utility easement to accommodate both water and sewer. An additional ten feet of width is required for each additional main that occupies the easement. A draft of the 30-foot-wide public utility easement for water and sewer mains has been provided with the Site plan submittal. We have had discussions with the City regarding the layout/alignment of the water and sewer main extensions, resulting in the current configuration. The proposed easement fully encompasses the water and sewer lines, beginning at the north entrance of the property from W. Beall Street and extending south roughly 100-feet. 3. BMC 38.410.060.C - The applicant must provide a drainage easement for drainage crossing lot boundaries prior to master site plan approval. The site layout does not include any drainage crossing lot boundaries. Therefore, no drainage easement has been provided. a. It appears that a small drainage ditch is located on the south side of the subject property boundary. Engineering does not have enough information on how the drainage ditch functions, responsibility, etc. The applicant must provide additional information as well as an easement (if applicable) prior to site plan approval. It is our understanding that this is the old “Walton Ditch” which was once used for irrigation but is no longer used for irrigation and instead is used for stormwater. This ditch originally conveyed irrigation water from Farmers Canal through central areas of the Bozeman Solvent Site. It is our understanding that the headgate from Farmers Canal was removed as part of the S 19th Ave. improvements, and therefore steady irrigation flows are no longer observed in the ditch, and the current primary transport is only stormwater (Record of Decision of Bozeman Solvent Site, MDEQ, August 2011). It is possible that a portion of this ditch adjacent to the project site was or is lined in order to reduce the possibility of groundwater mounding related to the Bozeman Solvent Site. Per email discussion with the City of Bozeman, it is the City’s understanding that the ditch is classified as an urban waterway and does carry stormwater runoff. There is infrastructure connected to this waterway as can be seen on the City’s GIS data. An image from the City’s GIS data is shown below. Per discussions with the ditch company, the ditch is abandoned from an irrigation standpoint. Alicia Paz-Solis May 25, 2022 Page 3 of 10 The current project does not propose to discharge directly to this ditch, mainly due to the fact that the ditch is on the high side (south side) of the site and therefore getting water to it is difficult. 4. BMC 38.410.060.C - The applicant must provide a drainage easement for the proposed stormwater features. The proposed stormwater infrastructure is privately owned and maintained and does not receive any runoff from City owned areas. All stormwater runoff will be retained on-site. An easement for the stormwater infrastructure on-site is not required. Stormwater 1. BMC 38.540.020.M - The applicant must identify snow storage areas for the parking area. Snow removal storage areas must be sufficient to store snow accumulation on site. Such areas shall not cause unsafe ingress/egress to the parking areas, shall not cause snow to be deposited on public rights-of-way, shall not include areas provided for required parking access and spaces, and shall not be placed in such a manner as to damage landscaping. Snow storage areas have been shown on the site plan drawings. 2. DSSP Section II.A.4 - Water Quality: The applicant must include a drainage plan with post-construction stormwater management controls that are designed to infiltrate, evapotranspire, and/or capture for reuse the post-construction runoff generated from the first 0.5 inches of rainfall from a 24-hour storm preceded by 48 hours of no measurable precipitation. For projects that cannot meet 100% of the runoff reduction requirement, the remainder of the runoff from the first 0.5 inches of rainfall must be either: a. Treated onsite using post-construction storm water management control(s) expected to remove 80 percent total suspended solids (TSS); b. Managed offsite within the same sub-watershed using post-construction storm water management Alicia Paz-Solis May 25, 2022 Page 4 of 10 control(s) that are designed to infiltrate, evapotranspire, and/or capture for reuse; or c. Treated offsite within the same subwatershed using post-construction storm water management control(s) expected to remove 80 percent TSS. A drainage plan has been provided as part of the Stormwater Design Report. The drainage plan has been completed to meet requirements of the DSSP for water quality. 3. DSSP Section II.C - Water Quantity: The applicant must provide on-site detention with release rates limited to predevelopment runoff rates. Retention ponds must be sized based on a 10-year, 2-hour storm intensity. Stormwater infrastructure has been sized adequately to fulfill requirements of the DSSP as described in the Stormwater Design Report. 4. DSSP Section II.B.3 - Storm Drainage Plan: The storm drainage plan must include a description of the ultimate destination of stormwater runoff from the project and an evaluation of its impact on downslope facilities and water quality. Please refer to the Stormwater Design Report provided with the Site plan submittal. All stormwater runoff will be retained on-site. 5. The stormwater facility cannot be within the water and sewer easement boundaries. As shown on the site drawings, a curb inlet is proposed to be located along the west portion of the site. The curb inlet will be piped via underground pipe to storm manholes that eventually direct all stormwater to the underground infiltration system. The extents of the proposed 30-foot easement, located on the west end of the property, do not encompass any of the stormwater infrastructure. Water Rights 1. BMC 38.410.130.A.1 - Water rights: The applicant must contact Griffin Nielsen with the City Engineering Department to obtain a determination of cash-in-lieu of water rights (CILWR). CILWR must be paid prior to site plan approval. The response from the City regarding a preliminary determination of cash-in-lieu of water rights (CILWR) has been provided with the Site Plan Application. CILWR will be paid prior to site plan approval. Water and Wastewater 1. BMC 38.410.070 and DSSP Section V.A and V.B - Prior to a determination of adequacy the applicant must provide an estimate of the peak-hour sanitary sewer demand as well as the average and max day demands of domestic water usage for the proposed site development. The estimates must be certified by a professional engineer. Alicia Paz-Solis May 25, 2022 Page 5 of 10 Sewer demand estimates have been provided with this Site plan submittal. 2. DSSP Section V.A - A water design report must be prepared by a professional engineer for the proposed project. The water distribution system must be designed to meet the maximum day demand plus fire flow and the peak hour demand. A water design report has been provided for the development per the DSSP and City standards. The new system has been designed to meet maximum day demands and peak hour demands. 3. DSSP Section V.A.6.a - A line serving more than one building or intended to serve more than one building or facility is designated a water main. Water and sewer main extensions are planned for the site, as shown on the civil drawings submitted. Services will stub off each main to serve each building. 4. DSSP Section V.A.6.f - All service connections shall be uniform size from the service line tap to the building structure or structures unless otherwise approved or required by the Water Superintendent. The proposed water and sewer service configuration is shown on the civil drawings and provides uniformity to the buildings. Transportation 1. BMC 38.220.080.A.2.g - Traffic Generation: The applicant must submit a peak hour trip generation value to the City to determine whether a traffic impact study is required Peak hour trip generation values have been calculated and provided to the City. An email waiver of the traffic impact study requirements has been submitted with this application. The trip generation numbers are as follows. Land Use Size ITE Land Use Code Average Daily Traffic (ADT) AM Peak-Hour Trips PM Peak-Hour Trips Entering Exiting Entering Exiting Duplex 4 units 210 38 1 2 2 2 Triplex 6 units 220 44 1 2 2 1 2. BMC 38.400.090.D.2 - Table 38.400.090-1 provides the minimum distance between public and/or private accesses and intersections. Drive access for the proposed parking lot must align with the drive accesses across the street, or be at least 40 feet apart. Alicia Paz-Solis May 25, 2022 Page 6 of 10 Drive accesses are shown on the civil site plan and do meet the requirement to be at least 40 feet apart. a. The applicant must show all adjacent drive accesses with future site plan or subdivision submittals. b. As presented, we do not see adjacent access or streets shown on the plan. Adjacent drive accesses are shown with the site plan. Environmental 1. The project is within the original contamination area of the Bozeman Solvent Site. The property is underlain by an aquifer contaminated with perchloroethylene (PCE). No irrigation wells may be installed on this property. The applicant must abide by institutional controls defined in the City of Bozeman agreement with Montana DEQ and the associated permitting for work within the boundaries of the contamination source. No irrigation wells are proposed. This project will abide by all institutional controls defined by the City and MDEQ. We have discussed the project with Kate Fry, Senior Project Officer at MDEQ, who has indicated that this project is acceptable, and further information from Kate Fry is attached to the site plan submittal or is forthcoming. 2. Resolution 4356- The applicant must complete and submit the Trench/Excavation Ventilation Permit for the Bozeman Solvent Site Area for any trenching and excavation activities in the area around the contamination source. The permit form is attached. A trench/excavation ventilation permit has been provided with the submittal. 3. The applicant must ensure that Bozeman Solvent Site groundwater monitoring wells remain in place and functional upon completion of construction. Existing groundwater monitoring wells located on the south end of the site are not disturbed or impacted with the development. They will remain functional upon completion of construction. 4. The applicant shall confirm that the Declaration of Restrictive Covenants for Lot 2 (adjacent property to the south) including no construction or development of any kind may occur on the surveyed portion of the property during the time that the residual source area is undergoing active treatment is not applicable to the subject property. Per our discussions with Kate Fry at MDEQ, there are no restrictive covenants that impact this development. A letter from MDEQ is attached or is forthcoming. Engineering Advisory Comments: 1. The applicant may contact the Engineering Department to receive a copy of easement templates. Alicia Paz-Solis May 25, 2022 Page 7 of 10 Easement templates have been received from the City. Draft easements for the 10-ft. utility easement and 30-ft. water and sewer easement have been included with this submittal. 2. DSSP Fire Service Line Standard: The applicant must prepare plans and specifications for any fire service line in accordance with the City’s Fire Service Line Policy. The plans must be prepared by a Professional Engineer and be provided to and approved by the City Engineer prior to initiation of construction of the fire service or fire protection system. The applicant must also provide Professional Engineering services for construction inspection, post-construction certification and preparation of mylar record drawings. Fire service plans, and domestic services 4” or larger, must be a standalone submittal, separate from the site plan submittal. City of Bozeman applications for service must be completed by the applicant. Fire service plans will be submitted with the infrastructure submittal. Draft fire service information is provided. 3. City of Bozeman Resolution 5076, Policy 1: The applicant must provide and file with the County Clerk and Recorder's office executed Waivers of Right to Protest Creation of Special Improvement Districts (SID’s) on City standard form for the following: a. Street improvements to 15th Avenue between Main Street and Durston Road including lighting, signalization, paving, curb/gutter, sidewalk, and storm drainage. b. Street improvements to Main Street between 19th Avenue and 7th Avenue including lighting, signalization, paving, curb/gutter, sidewalk, and storm drainage. c. Street improvements to Beall Street between 19th Avenue and 15th Avenue including lighting, signalization, paving, curb/gutter, sidewalk, and storm drainage. d. Intersection improvements at 15th Avenue and Beall Street including lighting, signalization/channelization, paving, curb/gutter, sidewalk, and storm drainage. e. Intersection improvements at 15th Avenue and Main Street including lighting, signalization/channelization, paving, curb/gutter, sidewalk, and storm drainage. f. Intersection improvements at 15th Avenue and Durston Road including lighting, signalization/channelization, paving, curb/gutter, sidewalk, and storm drainage. g. Intersection improvements at Beall Street and 19th Avenue including lighting, signalization/channelization, paving, curb/gutter, sidewalk, and storm drainage. h. Intersection improvements to Main Street and 19th Avenue including lighting, signalization/channelization, paving, curb/gutter, sidewalk, and storm drainage. i. Intersection improvements to Main Street and 11th Avenue including lighting, signalization/channelization, paving, curb/gutter, sidewalk, and storm drainage. j. Intersection improvements to Main Street and 7th Avenue including lighting, signalization/channelization, paving, curb/gutter, sidewalk, and storm drainage. A draft of this Waiver of Right to Protest has been provided with the Site Plan Application. This document will be filed with the County Clerk and Alicia Paz-Solis May 25, 2022 Page 8 of 10 Recorder. The document filed must specify that in the event an SID is not utilized for the completion of these improvements, the developer agrees to participate in an alternate financing method for the completion of the improvements on a fair share, proportionate basis as determined by square footage of property, taxable valuation of the property, traffic contribution from the development, or a combination thereof. The applicant must provide a copy of the filed SID waiver prior to the site plan approval. West Beall Street Townhomes – Landscape and Irrigation Conceptual Plan Advisory Comments See response to landscape and irrigation advisory comments below. The Water Conservation Division strives to promote outdoor water-use efficiency and best practice of landscape and irrigation installations. The following best practice recommendations to the West Beall Street Townhomes conceptual plan are provided to guide the project towards maximizing landscape health and resiliency while minimizing outdoor water consumption. Adhering to these recommendations is not required to receive plan approval. 1. The landscape design plan should indicate the total landscaped area (ft2) and landscaped area of all turf grass areas. 2. Each hydrozone should be on a separate irrigation zone based on the vegetation’s water demand. Grouping plants with similar watering needs will reduce over or under watering the vegetation. 3. Drought tolerant and water-wise landscaping can use approximately 75% less irrigation water than turf grass. The plant schedule should maximize the installation of drought tolerant landscaping and minimize the use of Kentucky bluegrass, especially within areas surrounded by pavement and/or parking spaces. It is recommended to install native seed mix and/or drought tolerant plants/shrubs in these areas. 4. Landscape plans should include topsoil depth specification of 4”- 6” (after grading) to allow for proper root depth growth and assist with plant and turf grass resiliency. 5. Specify that perennials, shrubs, and trees will be irrigated using low flow drip irrigation technology that will directly target the roots. Drip irrigation uses approximately 75% less water when compared to overhead spray irrigation. 6. Multi-spray, multi-trajectory (rotary) nozzles can reduce water loss from evaporation and wind drift by up to 50%. Specify the installation of water efficient sprinkler nozzles (multi-spray, multi-trajectory nozzles or ‘rotary nozzles’) if overhead irrigation is to be used within turf grass lawn areas. To save money and water - check out the City’s sprinkler nozzle rebates for new construction! 7. When programmed properly, weather based irrigation controllers can reduce outdoor water use by 25%. Specify the installation of a weather based irrigation controller that can automatically adjust the watering schedule according to local weather events. To save money and water - check out the City’s WaterSense® Alicia Paz-Solis May 25, 2022 Page 9 of 10 weather based irrigation controller rebates for new construction! 8. Rain sensors can reduce outdoor water use by approximately 10%! Specify the installation of a rain/freeze sensor, which overrides and turns off the irrigation system when a certain amount of rain has fallen. When the sensor dries, it opens the connection to allow the system to resume normal operations. To save money and water - check out the City’s rain sensor rebates for new construction! 9. Overhead sprinkler heads should be installed upright in the ground and ~2”-4” from any paved surface, especially curbs, to minimize sprinkler head damage from snowplows and lawn care equipment. This will also help to minimize future pavement obstruction of the sprinkler head which can occur as the ground settles over time. 10. After installation, sprinkler heads should be adjusted to throw the proper distance and direction in order to minimize water waste via run-off and achieve head-to- head coverage. Please refer to the landscape and irrigation plans attached with the Site plan submittal. Sincerely, WGM Group, Inc. Gary Fox, PE PROJECT ENGINEER