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HomeMy WebLinkAbout20191171 Skidmore College Fitness Center LA Group Response 1-14-20 The 1 A GROUP L:resc i�r .n_I•_I-r t _ ri chi r . c P_C January 14 2020 Michael Veitch, Business Manager City of Saratoga Springs 474 Broadway Saratoga Springs, NY 12866 Re: Skidmore College Fitness and Tennis Center Engineering Review—PB#20191171 Dear Mr.Veitch: The LA Group is in receipt of comments from Barton& Loguidice,dated January 7th, 2020.The following are responses to the comments. General Comment 1: The project site is predominantly a disturbed area of tennis courts/turf areas and some undisturbed, wooded site area with a drainage course buffered with mature trees. Response 1: Noted. Comment 2: Existing utilities are close by and able to be connected to. Confirm conditions at existing manhole, bench and steps,see comments below regarding sanitary and storm sewer connections. Response 2: LA Group will confirm the condition of the existing manhole,bench,and steps. Comment 3: Add NYSDEC stormwater permit to question B in Part I of FEAF. Isn't a line extension necessary to serve the new building? Re-consider entry on FEAF D.2.c.iii. Response 3: LA Group agrees with City Planning Staff that NYSDEC's review is ministerial and they are not an involved agent per SEQRA.We will coordinate with Staff per the EAF. No water line extension is needed thus no other revision to the FEAF is needed. Comment 4: How would a fire truck turn-around in front of the new Fitness Center? Increase radius of pavement curves at new tee intersection near new hydrant if necessary. Please clarify. Response 4: Fire access is planned via the fire lane on the west side of the new building where the FDC is located. No large truck access is anticipated in the front. 11� Comment 5: Some unit costs in the cost estimate seem quite low. Examples are concrete sidewalk at$5 per square foot and particularly for heated concrete at$7.50 per square foot. Please clarify and revise. Response 5: LA Group will review and revise unit prices as necessary. lllllllum��,.,. Comment 6: Are any special precautions necessary to take place between construction activity and existing Greenburg Child-Care Center?Are there protective fences,dust control and sound attenuation practices proposed or work scheduled for non-operating times? Response 6: The Greenburgh Center is operated by Skidmore.A six foot chain link fence with fabric will be installed along the along the construction limits near the center. Comment 7: Can some of the mature trees around the existing and newly expanded detention basin be saved? These provide good shade structure and buffering to the drainage course as well as filtering sheet runoff. Response 7: The detention basin was already located to avoid some of the larger more mature trees in this area to the extent practical. Water and Sanitary Sewer Comment 1: Where will a RPZ backflow preventer be located for this project, inside the building? Factor in RPZ and all head losses for fire prevention calculations to verify sprinkler receive adequate pressure. Response 1: The RPZ will be located inside the building and the MEP designer has confirmed head losses from the RPZ were factored into the sprinkler design. Comment 2: Route new 6-inch water main around periphery of proposed bio-retention basin. Response 2: The 6-inch water main will be routed around the east side of the proposed bio-retention basin. Comment 3: Open existing sanitary sewer manhole and assess need to move internal steps if in close proximity to new pipe from the Swing Building. Response 3: LA Group will confirm the condition of the existing manhole,bench,and steps. Stormwater Storm water Pollution Prevention Plan (SWPPP) Comment 1: Include manufacturer's printed maintenance manual for proprietary hydrodynamic separator as appendix and reference in section 6.0. Indicate frequency of pump-outs. Response 1: Contech CDS Inspection and Maintenance Guide will be added to SWPPP and referenced in Section 6.0. Comment 2: In NOI please answer for(7) regarding phasing differs from FEAF. Please clarify. Submit NOI and SWPPOP preparer certification prior to construction and after final approvals. Response 2: NOI answer for(7) has been changed to match FEAF. No phasing. Comment 3: Include concrete washout practice in question 26 of NOI. Response 3: Concrete washout will be added to list of practices in question 26 of NOI. Comment 4: In pre-development model node P-2(existing retention pond) indicates an outlet pipe of 12-inches at 1.86%but survey map shows a 12-inch pipe 10' longer and at 1.56%. Please clarify. Response 4: Node P-2 will be revised to match the site survey with a 61' pipe at 1.56%. Plans L-100 Comment 1: Can some of the trees around the existing and expanded detention basin be retained? If construction access were turned more to the west it seems conceivable. Response 1: The proposed expansion is located to minimize impact to larger trees in this area to the greatest extent feasible. Comment 2: Move the concrete washout practice further away from drainage course and hopefully retain some of the trees near that area. Response 2: Concrete washout will be relocated. Note that the trees will still need to be removed to allow for the construction of the fire access road. L-200 Comment 1: What is top of wall elevation at southeast section of new tennis courts?Will it allow runoff to escape, weeps proposed and detail provided? Is another wall proposed between Greenburg Daycare facility/playground and court access path? Response 1: The top of wall elevation is indicated on Sheet L-300(397.92')and will be designed to allow water to escape. A retaining wall is not proposed between the daycare and court access path. L-300 Comment 1: In northeast Bio-retention Area add two underdrain laterals that tee off main underdrain. Revise detail to use 6-inch and specify perforation pattern with holes all around circumference. Label inverts at capped ends and slope to DI-1. Response 1: Underdrain laterals with inverts and perforation pattern will be added to the plans. Comment 2: Can proposed Hydrodynamic Separator accept the size pipe proposed and proposed flow with existing runoff rates?Show size of pipe and inverts that diverts flow to unit. Show elevations in details and verify unit size selected based on peak WQv flow and bypass rates. Response 2: The Hydrodynamic Separator can accept the 24" pipe proposed and during large storm events excess flow will be diverted to DMH-4 from DMH-3. Information will be added to the SWPPP indicating the approved WQv treatment flow for the hydrodynamic separator. Comment 3: Add in underdrain elevations at capped ends and pipe slopes at southwest bio-retention practice. Response 3: Underdrain elevations will be added to the capped ends. Comment 4: Add in elevation notes for SMP 3 similar to SMP 1 and 2. Response 4: Elevation notes will be added to SMP-3. L-400 Comment 1: Re-route 6-inch water main around bio-retention facility#3 to the east outside 392 contour. Should not be beneath practice. Response 1: The 6-inch water main will be routed around the east side of the proposed bio-retention basin. Comment 2: Verify if steps need to be modified at existing sanitary manhole being connected to east of building addition. Response 2: LA Group will confirm the condition of the existing manhole,bench,and steps. L-500 Comment 1: Add note requiring soil de-compaction with reference to SWPPP appendix so contractor is advised on plan set of needs. Response 1: Decompaction notes will be added to Sheet L-500. L-702 Comment 1: What is surface of dumpster enclosure floor that will receive significant dynamic forces? Detail on plans with apron outside of enclosure on truck side. Response 1: Sheet L-200 indicates that the dumpster pad shall be concrete,with a reference to the concrete pavement detail. Comment 2: Will wooden enclosure be all pressure treated and ultimately painted? PVC material? Response 2: The enclosure will be pressure treated wood,but not painted and no PVC material. L-703 Comment 1: Specify size and depth of rip-rap in detail 4. Pipes larger than 12-inches should be a mix of medium and light rip-rap at least 18-inches in depth. Recommend stabilization fabric instead of filter fabric as underlayment. Response 1: The rip-rap stone size is indicated on the top left portion of detail 4. Size will be modified to also include medium stone fill. Depth of the riprap is included in the section view and proposes a depth of 18"-minimum. It has been our experience that Mirafi 160N is suitable for this application. L-704 Comment 1: Increase pipe size in Bio-retention Area detail to 6-inch and specify perforation pattern. Increase depth of stone layer to 8-inches. 11� Response 1: Comment noted. Comment 2: Show elevations of all piping and rim for Hydrodynamic separator. See previous comments on size of piping and flows tributary to it. Response 2: Elevations will be added to the plans. Comment 3: Specify sand component for bio-retention mix to be ASTM C-33 sand. Response 3: Note 1 of the bioretention area detail will be modified to indicate sand shall be ASTM C-33 sand. Sincerely, 0),...8r, to!, i ii Douglas B. Heller, PE Associate Principal/Civil Engineer dheller@thelagroup.com g:\proj-2016\2016098_skidmore_college_athletic_expansion\2016098_admin\01 correspondence\2.7review_comments\2020-1-7\2020 01-14 comment response Itr..docx