Loading...
HomeMy WebLinkAbout22ZBA2 Application169 Main Street, 700 Plaza Middlesex Middletown, CT 06457 860.343.8297 | wright-pierce.com August 19, 2022 Town of Montville Zoning Board of Appeals 310 Norwich-New London Turnpike Uncasville, CT 06382 SUBJECT: Cook Hill Tank Replacement Application for Variance 50 Cook Drive, Montville, CT 06382 Dear Chairman MacNeil, On behalf of the Town of Montville Water Pollution Control Authority (WPCA), we request the following application for variance be accepted for site plan review:Cook Hill Tank Replacement Project. Wright-Pierce has prepared this Application for the Cook Hill Tank Replacement Project. The project includes the construction of a new 531,200-gallon glass-fused-to-steel water storage tank at 50 Cook Drive in Montville, CT (the site). The new tank will be constructed adjacent to the existing 590,000-gallon welded steel tank built in 1999 on the same parcel. The existing tank is used by the Town of Montville Emergency Services to support communication equipment and antennas for the Town. The existing tank will remain in place pending a future project to demolish the tank and construct a dedicated antenna tower and equipment building on site. Zoning Variance The parcel is located in the R20 Zone and is subject to the setback requirements of 40-ft Front, 40-ft Rear, 10- ft Side. See attached Zoning Map. The existing tank was constructed at 16-ft front setback and 13-ft rear setback. This application applies for a variance to the front and rear setback requirements for the proposed tank, and for ancillary structures within the side setback. The proposed tank is located on the western side of the parcel, 17-ft from the front property line, 12-ft from the rear, and 12-ft from the western side property line. Ancillary structures consisting of equipment control enclosures, a pole-mounted site light, a hydrant, and a standby generator are proposed along the western side of the property. Site lighting will be shielded to prevent light from shining or reflecting on adjoining properties. Dimensions for these setbacks are shown on the attached Civil C-3 drawing and summarized in the table below. Yard Setback from Property Line to Tank (ft) Setback from Property Line to Ancillary Structures (ft) Front 17.4 11.4 (site light) Side 12 1.7 (site light & hydrant) Rear 12 6 (emergency generator) 8/19/2022 Town of Montville Zoning Board of Appeals Page 2 of 3 Site The parcel is owned by the Town of Montville and is 10,768-square feet (0.2472-acres) in area. The site is accessed by means of a Town-owned easement from the public right-of-way of Cook Drive. The project location is not within a FEMA flood hazard zone, as shown by the attached FIRMette. Additionally, the site was inspected by New England Environmental Services for wetlands or water courses, and none were identified. See the attached letter New England Environmental Services dated March 21, 2022. Finally, the site is located outside the Natural Diversity Data Base preliminary screening area. See attached NDDB map. Stormwater The site is located at the top of a hill and sheds surface water to the east. The existing tank has an overflow pipe that outlets on the east side of the tank for the rare event of over-filling the tank. The proposed tank also has an overflow pipe that outlets at the base of the tank onto a concrete pad extending to a riprap channel approximately 4-ft wide which extends 110-ft towards the eastern property line ending at the small detention basin and level spreader BMP on the east end. This proposed channel will serve not only to direct flows from the rare event of a tank overflow, but also collect surface water runoff and provide detention for approximately 185-cf to address the additional surface water flow increase from the new impervious surfaces. The detention basin has been sized for the 25-yr storm event, as detailed on the attached Civil C-3 drawing and details on the mitigation stormwater controls. The impervious area of the site is increasing by 710-sf with the new water storage tank and ancillary ground- mounted equipment adjacent to the tank. The runoff volume for the existing and proposed conditions under a 25-year design storm are listed in the table below. This net increase in stormwater runoff is 174 cf. For the hydrologic calculations, we utilized HydroCAD modeling software and used the NOAA Atlas, Volume 10, Version 3 rainfall data. The rainfall amount of 6.15 inches was used for the 25-year, 24 hour storm event. Impervious Area (sf) 25-yr Storm Volume (af) 25-yr Storm Volume (cf) 25-yr Storm Peak Discharge (cfs) Pre-Development 710 0.064 2,788 0.61 Post-Development 1,420 0.068 2,962 0.64 Based upon the values below, the groundwater recharge volume is calculated to be 32 cf. This assumes the more conservative NRCS Hydrologic Soil Group of B, which corresponds to the Charlton-Chatfield complex (73E) identified in the attached Web Soil Survey. This volume of 32-cf is less than the volume of the 185-cf detention basin and therefore is satisfactory for the required groundwater recharge volume. 8/19/2022 Town of Montville Zoning Board of Appeals Page 3 of 3 Drainage Area (sf) Impervious Area (sf) I (Impervious Ratio) Groundwater Recharge Depth (D) Groundwater Recharge Volume (cf) Cook Hill Tank 10,148 1,550 0.153 0.25 32 The project will result in the disturbance of less than 1 acre of land; therefore, a Soil and Erosion and Sediment Control Plan is not included in this application. However, erosion and sedimentation controls will be implemented in the final project drawings. Please contact Barry Parfitt, PE of Wright-Pierce at (860) 852-1914 or barry.parfitt@wright-pierce.com with any questions. Sincerely, WRIGHT-PIERCE Barry Parfitt, PE Mariusz Jedrychowski, PE Lead Project Engineer Senior Project Manager barry.parfitt@wright-pierce.com mariusz.jedrychowski@wright-pierce.com Attachments: Variance Application Site Location Map (1” = 1,000’) USGS Topography Map GIS Map Zoning Map Wetlands Inspection Letter NDDB Preliminary Screening Map Stormwater HydroCAD Report FIRMette Map NRCS Web Soil Survey Site Plan (separate attachment) Variance Application Site Location Map (1” = 1,000’) USGS Topography Map PROJECT SITE GIS Map 029-00017.3 Ac 013-00045.3 Ac 010-0002.04 Ac 009-0001.78 Ac 011-0011.18 Ac 001-00024.01 Ac 005-0001.16 Ac 008-0000.86 Ac 006-00A0.92 Ac 003-0000.8 Ac 013-00045.3 Ac 009-0010.25 Ac 006-0000.92 Ac 011-0000.91 Ac Source: Esri, Maxar, GeoEye, Earthstar Geographics, CNES/Airbus DS,USDA, USGS, AeroGRID, IGN, and the GIS User Community, Esri, HERE,Garmin, (c) OpenStreetMap contributors, and the GIS user community Parcel Lines - Ortho Lot and Ac - anno Data shown on this map is provided for planning and informational purposes only. The municipality and CAI Technologies are not responsible for any use for other purposesor misuse or misrepresentation of this map. Cook Water Storage Tank Montville, CT January 25, 2022 ® www.cai-tech.com01412824231 inch = 141 Feet Zoning Map ProjectLocation50 Cook Dr Wetlands Inspection Letter NEW ENGLAND ENVIRONMENTAL SERVICES Wetland Consulting Specialists Since 1983 30 GINA LANE, MARLBOROUGH, CONNECTICUT 06447 richsnarski@gmail.com • 860-918-1970 • www.richsnarski.com March 21, 2022 Mr. Jason P. Berasi, P.L.S. Martinez Couch & Associates, LLC 1084 Cromwell Avenue, Suite A2 Rocky Hill, CT 06067 Re: Cook Drive Montville, Connecticut Dear Mr. Berasi: On February 28, 2022, I inspected the land on Cook Drive in Montville, which is shown on the attached map in red. There are no wetlands or watercourses present in the land outlined in red. If you have any questions, feel free to contact me. Respectively Submitted, New England Environmental Services R. Richard Snarski Professional Wetlands Scientist #1391 Registered Professional Soil Scientist Consulting Botanist RRS/srh NDDB Preliminary Screening Map Cook Tower 79 Elm Street • Hartford, CT 06106-5127 www.ct.gov/deep Affirmative Action/Equal Opportunity Employer February 4, 2022 Mia Jordan Wright-Pierce 169 Main St, 700 Plaza Middlesex Middletown CT 06457 Mia.jordan@wright-pierce.com Project: Cook Hill Water Tower Replacement, 50 Cook Dr, Montville, CT NDDB Determination No.: 202201074 Dear Mia Jordan, I have reviewed Natural Diversity Database (NDDB) maps and files regarding the area provided for the proposed replacement of the Cook Hill Water Tower in Montville, Connecticut. According to our records there are no reported populations of state or federal listed species in the vicinity of this property. We have not visited this site. The result of this review does not preclude the possibility that listed species may be encountered on site and that additional action may be necessary to remain in compliance with certain state permits. Contact NDDB to report the presence of any listed species and for more detailed guidance. This determination is good for two years. Please re-submit a new NDDB Request for Review if the scope of work changes or if work has not begun on this project by February 4, 2024. Natural Diversity Data Base information includes all information regarding critical biological resources available to us at the time of the request. This information is a compilation of data collected over the years by the Department of Energy and Environmental Protection’s Natural History Survey, cooperating units of DEEP, landowners, private conservation groups and the scientific community. This information is not necessarily the result of comprehensive or site-specific field investigations. Consultations with the NDDB should not be substitutes for on-site surveys necessary for a thorough environmental impact assessment. Current research projects and new contributors continue to identify additional populations of species and locations of habitats of concern, as well as, enhance existing data. Such new information is incorporated into the database as it becomes available. Please contact me if you have further questions at (860) 424-3378, or karen.zyko@ct.gov . Thank you for consulting the Natural Diversity Database. Sincerely, Karen Zyko Environmental Analyst Stormwater HydroCAD Report 1S PreDevelopment 2S Post-Development 3R Post-Analysis Point Pre Pre Analysis Point Routing Diagram for Cook_Hill_TankPrepared by {enter your company name here}, Printed 8/11/2022 HydroCAD® 10.00-26 s/n 01135 © 2020 HydroCAD Software Solutions LLC Subcat Reach Pond Link Cook_Hill_Tank Printed 8/11/2022Prepared by {enter your company name here} Page 2HydroCAD® 10.00-26 s/n 01135 © 2020 HydroCAD Software Solutions LLC Area Listing (all nodes) Area (acres) CN Description (subcatchment-numbers) 0.373 79 50-75% Grass cover, Fair, HSG C (1S, 2S) 0.033 98 Existing Tank, HSG C (1S, 2S) 0.016 98 Proposed, HSG C (2S) 0.422 81 TOTAL AREA Cook_Hill_Tank Printed 8/11/2022Prepared by {enter your company name here} Page 3HydroCAD® 10.00-26 s/n 01135 © 2020 HydroCAD Software Solutions LLC Soil Listing (all nodes) Area (acres) Soil Group Subcatchment Numbers 0.000 HSG A 0.000 HSG B 0.422 HSG C 1S, 2S 0.000 HSG D 0.000 Other 0.422 TOTAL AREA Cook_Hill_Tank Printed 8/11/2022Prepared by {enter your company name here} Page 4HydroCAD® 10.00-26 s/n 01135 © 2020 HydroCAD Software Solutions LLC Ground Covers (all nodes) HSG-A (acres) HSG-B (acres) HSG-C (acres) HSG-D (acres) Other (acres) Total (acres) Ground Cover Subcatchment Numbers 0.000 0.000 0.373 0.000 0.000 0.373 50-75% Grass cover, Fair 1S, 2S 0.000 0.000 0.033 0.000 0.000 0.033 Existing Tank 1S, 2S 0.000 0.000 0.016 0.000 0.000 0.016 Proposed 2S 0.000 0.000 0.422 0.000 0.000 0.422 TOTAL AREA Type III 24-hr 25-yr Rainfall=6.15"Cook_Hill_Tank Printed 8/11/2022Prepared by {enter your company name here} Page 5HydroCAD® 10.00-26 s/n 01135 © 2020 HydroCAD Software Solutions LLC Time span=5.00-20.00 hrs, dt=0.05 hrs, 301 points Runoff by SCS TR-20 method, UH=SCS, Weighted-CN Reach routing by Stor-Ind+Trans method - Pond routing by Stor-Ind method Runoff Area=9,191 sf 7.72% Impervious Runoff Depth>3.65"Subcatchment 1S: PreDevelopment Flow Length=152' Slope=0.0050 '/' Tc=22.9 min CN=80 Runoff=0.61 cfs 0.064 af Runoff Area=9,194 sf 15.44% Impervious Runoff Depth>3.86"Subcatchment 2S: Post-Development Flow Length=152' Slope=0.0050 '/' Tc=22.9 min CN=82 Runoff=0.64 cfs 0.068 af Inflow=0.64 cfs 0.068 afReach 3R: Post-Analysis Point Outflow=0.64 cfs 0.068 af Inflow=0.61 cfs 0.064 afReach Pre: Pre Analysis Point Outflow=0.61 cfs 0.064 af Total Runoff Area = 0.422 ac Runoff Volume = 0.132 af Average Runoff Depth = 3.76" 88.41% Pervious = 0.373 ac 11.59% Impervious = 0.049 ac Type III 24-hr 25-yr Rainfall=6.15"Cook_Hill_Tank Printed 8/11/2022Prepared by {enter your company name here} Page 6HydroCAD® 10.00-26 s/n 01135 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 1S: PreDevelopment Runoff = 0.61 cfs @ 12.31 hrs, Volume= 0.064 af, Depth> 3.65" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=6.15" Area (sf) CN Description 8,481 79 50-75% Grass cover, Fair, HSG C * 710 98 Existing Tank, HSG C 9,191 80 Weighted Average 8,481 92.28% Pervious Area 710 7.72% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 22.9 152 0.0050 0.11 Sheet Flow, Grassy Area Grass: Short n= 0.150 P2= 3.46" Subcatchment 1S: PreDevelopment Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 25-yr Rainfall=6.15" Runoff Area=9,191 sf Runoff Volume=0.064 af Runoff Depth>3.65" Flow Length=152' Slope=0.0050 '/' Tc=22.9 min CN=80 0.61 cfs Type III 24-hr 25-yr Rainfall=6.15"Cook_Hill_Tank Printed 8/11/2022Prepared by {enter your company name here} Page 7HydroCAD® 10.00-26 s/n 01135 © 2020 HydroCAD Software Solutions LLC Summary for Subcatchment 2S: Post-Development Runoff = 0.64 cfs @ 12.31 hrs, Volume= 0.068 af, Depth> 3.86" Runoff by SCS TR-20 method, UH=SCS, Weighted-CN, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Type III 24-hr 25-yr Rainfall=6.15" Area (sf) CN Description 7,774 79 50-75% Grass cover, Fair, HSG C * 710 98 Existing Tank, HSG C * 710 98 Proposed, HSG C 9,194 82 Weighted Average 7,774 84.56% Pervious Area 1,420 15.44% Impervious Area Tc Length Slope Velocity Capacity Description (min) (feet) (ft/ft) (ft/sec) (cfs) 22.9 152 0.0050 0.11 Sheet Flow, Grassy Area Grass: Short n= 0.150 P2= 3.46" Subcatchment 2S: Post-Development Runoff Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Type III 24-hr 25-yr Rainfall=6.15" Runoff Area=9,194 sf Runoff Volume=0.068 af Runoff Depth>3.86" Flow Length=152' Slope=0.0050 '/' Tc=22.9 min CN=82 0.64 cfs Type III 24-hr 25-yr Rainfall=6.15"Cook_Hill_Tank Printed 8/11/2022Prepared by {enter your company name here} Page 8HydroCAD® 10.00-26 s/n 01135 © 2020 HydroCAD Software Solutions LLC Summary for Reach 3R: Post-Analysis Point [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.211 ac, 15.44% Impervious, Inflow Depth > 3.86" for 25-yr event Inflow = 0.64 cfs @ 12.31 hrs, Volume= 0.068 af Outflow = 0.64 cfs @ 12.31 hrs, Volume= 0.068 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Reach 3R: Post-Analysis Point Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)0.7 0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.211 ac0.64 cfs 0.64 cfs Type III 24-hr 25-yr Rainfall=6.15"Cook_Hill_Tank Printed 8/11/2022Prepared by {enter your company name here} Page 9HydroCAD® 10.00-26 s/n 01135 © 2020 HydroCAD Software Solutions LLC Summary for Reach Pre: Pre Analysis Point [40] Hint: Not Described (Outflow=Inflow) Inflow Area = 0.211 ac, 7.72% Impervious, Inflow Depth > 3.65" for 25-yr event Inflow = 0.61 cfs @ 12.31 hrs, Volume= 0.064 af Outflow = 0.61 cfs @ 12.31 hrs, Volume= 0.064 af, Atten= 0%, Lag= 0.0 min Routing by Stor-Ind+Trans method, Time Span= 5.00-20.00 hrs, dt= 0.05 hrs Reach Pre: Pre Analysis Point Inflow Outflow Hydrograph Time (hours) 201918171615141312111098765Flow (cfs)0.65 0.6 0.55 0.5 0.45 0.4 0.35 0.3 0.25 0.2 0.15 0.1 0.05 0 Inflow Area=0.211 ac0.61 cfs 0.61 cfs FIRMette Map NRCS Web Soil Survey