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HomeMy WebLinkAbout20200205 Kaydeross Ave East Subdivision 2nd Engineering Response 8-3-20 THE CAPITAL DISTRICT OFFICE Ghaz, n Civil Engineers 547 River Street Land Surveyors Planners Troy, NY 12180 COMPANIES® Environmental&Safety Professionals P: 518.273.0055 or 888.539.9073 Landscape Architects Proud to be Employee Owned Transportation Planners&Engineers www.chazencompanies.com August 3, 2020 Ms. Susan Barden,AICP Principal Planner City of Saratoga Springs Planning Office 474 Broadway Saratoga Springs, NY 12866 Delivered via email: susan.barden@saratoga-springs.org Re: City Designated Engineer Services for Subdivision application—2nd Submittal Kaydeross Ave East Conservation Subdivision 227 Kaydeross Avenue East, City of Saratoga Springs, Saratoga County, New York City Project No. PB# 17.006.1 Chazen Project No. 32004.03 Dear Susan: The Chazen Companies (Chazen) have completed our review of the following materials received: • Comment Response Letter dated 07/14/2020; • Stormwater Pollution Prevention Plan, prepared by The LA Group, dated 07/10/2020; • Engineer's Report, prepared by The LA Group, dated 07/10/2020; • Buoyancy Calculations, prepared by The LA Group, dated 07/10/2020 and; • Site drawings entitled "Kaydeross Avenue East Conservation Subdivision", dated 07/10/2020, prepared by The LA Group, unless noted otherwise, consisting of the following sheets: o Cover Sheet o 5-1 Subdivision Map o S-2 Subdivision Map o L-1.0 Existing Conditions o L-2.0 Conservation Analysis o L-3.0, 3.1, 3.2 Site Clearing, Erosion & Sediment Control Plan o L-4.0, 4.1,4.2 Site Layout Plan o L-5.0, 5.1, 5.2 Site Grading and Drainage Plan o L-7.0 Road/Utility Profile &Sections o L-8.0, 8.3, 8.4, 8.5 Site Utility Details Following are our observations/comments. Comments follow the original numbering in our letter dated June 26,2020.Comments that have been satisfactorily addressed are not repeated; new comments/clarifications are presented in bold. New York: Hudson Valley• Capital District• North Country• Westchester Tennessee: Nashville• Chattanooga Oregon: Portland Chazen Engineering, Land Surveying& Landscape Architecture Co. DPC(NY) • Chazen Engineering Consultants, LLC(TN/OR) Kaydeross Avenue East Conservation Subdivision—PB17.006.1—2nd Submittal Review August 3,2020 Page 2 of 4 General: 2. The Management Plan indicates that the open space lands will be owned by the owners of Lot 1 and Lot 15, and are proposed to be managed by the City of Saratoga Springs. A maintenance agreement between the City and the property owners will need to be established if the City is willing to accept management responsibilities. The applicant stated that their attorney has discussed this with the City and maintenance responsibilities will be resolved prior to final approval. Subdivision Plans 4. Please provide a boundary and topographic survey map signed and sealed by the licensed land surveyor. The applicant stated that a signed/sealed boundary and topographic survey map will be provided with final approved drawings. 9. Please detail the proposed septic system layout on the plans, showing the laterals, septic tank and distribution box locations for each lot with dimensions. The applicant has indicated that a detailed septic system design will be provided when building permits applications are submitted. A subdivision should not be approved without proof that all lots can accommodate a septic system. Since the septic systems proposed are alternative mound systems,we recommend that at a minimum the applicant be required to submit the detailed design of the system for Lot 8,the narrowest and steepest lot. If they can accommodate the typical house on this lot they should be able to accommodate systems on the remaining lots. If acceptable to the City,we do not object to deferring the submission of the detailed septic system designs for lots 1—7 and 9 to 14 in conjunction with building permit applications. 10. Indicate the proposed invert elevations of all septic system components along with top of concrete and the finished grades over each component. The applicant has indicated that final design for the septic systems will be submitted with the building permit application. See additional comment number 9 above. 16. In accordance with the NYSDOH Appendix 75-A Wastewater Treatment Standards and the New York State Design Standards for Intermediate Sized Wastewater Treatment Systems (Design Standards), Section B.4.b, two percolations tests should be performed within the limits of each proposed sewage treatment system. Additional percolation tests should be performed in accordance with these standards. The applicant has indicated that two percolation tests will be performed as part of the final design of the septic system and provided with the building permit application. See additional comment number 9 above. Kaydeross Avenue East Conservation Subdivision—PB17.006.1—2nd Submittal Review August 3,2020 Page 3 of 4 17. In accordance with Section E.2 of the Design Standards, conventional soil-based treatment systems should be avoided if the percolation rate is slower than 60 mpi.The soil tests provided indicate a percolation rate of"greater than 60 mpi". Please indicate the actual percolation rates on the plans to clarify if the percolation rate is slower or faster than 60 mpi. If the percolation rate is slower than 60 mpi, a conventional soil-based treatment system would not be suitable. Provide design calculations providing appropriate application rates based on soil testing to justify the size of each septic system for on each lot. It appears that the septic system areas shown accommodate seven (7) 60-ft laterals at 6-ft on center. The applicant has indicated that the percolation rate is slower than 60 mpi in these locations and that additional percolation tests will be performed once the final locations of the systems are determined. See additional comment number 9 above. 18. Test pit results indicate seasonally high water between 16 inches and 42 inches. Please show proposed finished grade at each septic system location to ensure the required separation to groundwater is satisfied, and that the proposed mound system can fit on the site while maintaining required property line setbacks. The applicant indicates that the final design plans for the septic systems will be submitted with the building permit application. See additional comment number 9 above. 25. Due to seasonally high groundwater conditions throughout the site, a geotechnical investigation shall be performed to evaluate whether the standard pavement section is suitable for these conditions or if a greater than standard pavement section is required. The applicant has indicated that a geotechnical investigation will be performed, and recommendations will be included in the final plans. Please submit the geotechnical investigation for review. 26. Based on the profile, it appears that portions of the proposed road will be cutting into the seasonally high groundwater elevations. As such, dewatering provisions for constructing roadways and utilities in these conditions shall be detailed on the plans. In order to minimize deterioration of the road due to freeze/thaw conditions, additional provisions such as perimeter drains will need to be installed. The applicant has indicated that a geotechnical investigation will be performed, and recommendations will be included in the final plans. Please submit the geotechnical investigation for review and revise the plans to include perimeter drains where needed. SWPPP 31. The proposed pocket ponds do not show the required aquatic bench with plantings. Please revise the design accordingly. The applicant has indicated that since the permanent pool is less than 4-ft, an aquatic bench is not required. Aquatic benches are a required element for all wet ponds since they provide the majority of treatment by preventing erosion, slowing water movement through the pond, hold or convert pollutants, and enhance pollutant uptake and promote evapotranspiration. Kaydeross Avenue East Conservation Subdivision—PB17.006.1—2nd Submittal Review August 3,2020 Page 4 of 4 The NYSSMDM states that the perimeter of all deep pool areas(4 feet or greater) shall be surrounded by two benches, an aquatic bench and a safety bench.An exception is only given for safety benches when side slopes above the water surface are 4:1 or flatter. Since the current design provide side slopes of 4:1 a safety bench is not required. Please revise the plans accordingly. In order to expedite and simplify the review of revised materials we would appreciate if the next submission be accompanied by a response letter that describes the revised materials and how our comments were/were not integrated. If you have any comments, questions or need additional information, please do not hesitate to contact this office at 518-273-0055. Sincerely, 4;Litio (---Th. Jessica Brown, P.E. Project Engineer cc: James J. Connors, P.E. Chazen Jennifer Nechamen, P.E. Chazen File Z:\projects\32000-32099\32004.xx C Saratoga Springs Master\32004-03_KayderossAveEastConserv_sub_PE-20200205\2nd submittal\sent\32004-03_KayderossAveEastConserv_sub PB20200205 Submittal-2.docx