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HomeMy WebLinkAbout1996-07-25 Notice of Intent Prelim Subdivision r2-,Ac,Q Town of North Andover' t "ORT" Q OFFICE OF �c<,<�79 ,,�HeL COMMUNITY DEVELOPMENT AND SERVICES l' p 146 Main Street % North Andover, Massachusetts 01845 WILLIAM d.SCOTr �sSACHUSti� Director January 7, 1997 Mr. Phil Christiansen Christiansen & Sergi 160 Summer Street Haverhill, MA 01830 RE: NOTICE OF INTENT- Settler's Ridge Subdivision (DEP #242-847). Dear Phil: The North Andover Conservation Commission (NACC) and this Department conducted field inspections at the above referenced property on December 28", and January 4th respectively. Our goal was to make an educated decision regarding the Riverfront Act and view the proposed detention pond, wetland replication area and roadway crossing. RIVERFRONT ACT: The following sources of data were analyzed as a means of effectively characterizing on-site streams: 1. USGS Topographic Map (Lawrence Quadrangle); 2. U.S. Geological Survey Data; 3. Soil Conservation Service Maps; 4. North Andover Wetland Maps; 5. F&W National Wetland Indicator Maps 6. FEMA FIRM Maps; 7. Aerial Photographs. Factors considered were: 1. Was the stream depicted on the above referenced sources and, if so, was it characterized as intermittent or perennial? Was a floodplain associated with the waterbody?; 2. What is the relative size of the watershed contributing to this stream? 3. What is the primary source of hydrology "driving" this stream? Small culvert and/or groundwater seeps? BOARD OF APPEALS 688-9541 BUILDING 688-9545 CONSERVATION 688-9530 HEALTH 688-9540 PLANNING 688-9535 4. Were dated photographs and/or affidavits submitted by the applicant justifying intermittent flows?; 5. What is the potential for a warm water fishery? Cold water fishery? Entomological evidence? 6. Nature of upstream, downstream and bordering wetland resource areas?, After a careful review of these sources and weighing the merit of each source independently my recommendation to the NACC is that the_stream is intermittent and thus not subject to protection under_the_Riverfront Act. If so desired, I am more than willing to forward my documented findings to your attention for review. STORMWATER MANAGEMENT POLICY; The following sources of data have been reviewed for compliance with DEP's "Stormwater Management Policy" (dated 11/18/96): 1. Notice of Intent Application (dated 12/96); 2. Drainage Report(dated REV 9/23/06); 3. Wetland Replication Plan (not dated); 4. Stormwater Management Form (not dated). I have conducted a preliminary review of the proposed stormwater management system and the comments which follow detail outstanding issues which warrant additional information or clarification. Coler and Colantonio, Inc., the Town's drainage consultant, has yet to review the proposal in detail but it is understood that a review letter will be forwarded to the applicant and this Department prior to the anticipated 1/22/96 public hearing. Standard #2 -Post Development Peak Discharge Rates: 1. The applicant's objective reads "mitigate storm drainage flows such that there will be no increase in the peak rate of runoff at any point on the parcels boundary..." Was the downstream end of the intermittent stream used as the control point or was it the sum of Areas Al through A3? Multiple control points? Please clarify. 2. Page 12 of the North Andover Wetland Regulations requires that the mean annual storm event be evaluated for impacts from proposed alterations. It appears as though analysis was performed for the 2, 10 and 100 year storm events and reduced post development runoff rates were calculated. Please perform a similar analysis for the 1 year storm event. 3. I understand that pipe sizes were designed for a 10 year storm but it is not clear to me if larger storm events are conveyed towards the proposed detention pond. Is "overflow" directed towards the detention pond? \y 6 Standard #3 -Rechuarge to Groundwater: Recharge potential of wetlands varies according to numerous factors, including wetland type, geographic location, season, soil type, water table location and precipitation Under some conditions, the groundwater system may receive some recharge from wetlands. However, wetland soils are typically less permeable than soils associated with groundwater recharge areas, so recharge from wetlands will be less than from other areas (i.e. the buffer zone). Most wetlands occur where water is discharging to the surface from the groundwater system. The small culvert which discharges into the intermittent stream and bordering vegetated wetland is a secondary source of hydrology for this wetland resource area; a more important factor, or primary source, is the groundwater flow which seeps from the sides of the surrounding topography. This may be referred to as a "groundwater recharge source". Under existing conditions wetland vegetation extends far up slope to the high point of the property but soils remain indicative of an upland environment (high chromas w/ few redoximorphic features). These soils are classified by SCS as "well drained"; this assertion was verified in the field with seasonal groundwater elevations observed at 24". Throughout the buffer zone it can be inferred that groundwater is not at or near the surface long enough during the growing season to result in hydric soil conditions but just long enough to provide suitable conditions for wetland vegetation. Spicebush, northern arrow-wood and highbush blueberry are notorious for climbing up slope and are indicative of intermittent or fluctuating hydrologic conditions. Standard #3 of the "Stormwater Management Form" requires that the applicant justify groundwater recharge. As a primary Best Management Practice (BMP) you have proposed a "sump" in a "wet extended detention area"; how do you infiltrate or recharge the groundwater supply if a 4' cut is proposed into the water table (top 24" versus 6.5' pond excavation)? The proposed sump is already in the groundwater and would likely take groundwater away. This appears to contradict the policy. Where is the justification for this design? Wouldn't the detention pond have to be constructed above the water table (i.e. fill versus cut) and act as a retention pond? Can a detention pond remove suspended solids (refer to Standard #4) and recharge groundwater at the same time? How is the total impervious surface (64,010 square feet) mitigated? How is post development recharge quantified? A "water quality swale" is also proposed as a recharge mechanism. It is my opinion that the proposed swale is too steep and will likely carry runoff via lateral surface flow rather than through infiltration as intended. Furthermore, the proposed sub drain parallel to the roadway intercepts groundwater and directs it into a closed system and then a wet pond (i.e. pipes to storm drain to wet pond). How is this recharging the groundwater? Are the deep sump catch basins at least 4' deep as required? r The ability of the surrounding buffer zone to recharge the groundwater supply is vital to the downstream vegetated wetland and intermittent stream. Absent this recharge it is my professional opinion that the performance standards are not satisfied and the wetland will be negatively impacted. I see no evidence of adequate groundwater recharge. Please scrutinize my findings and re-design accordingly. The NACC will not waiver from this performance standard. Standard #9 - Operatiosl/Mainten ante Plan: You have noted on your application that this plan has been submitted. I am not in receipt of said document; was it forwarded to DPW? Planning Board? Please send a final copy to this Department for review and subsequent approval. Your anticipated cooperation is appreciated and I look forward to assisting the applicant through the permit application process. I understand and appreciate that fact that the Riverfront Act and Stormwater Management Policy are new concepts to the applicant and the NACC but regardless, a thorough review and earnest attempt to comply is warranted. I am more than willing to make myself and Coler and Colantonio, Inc. personnel available for a meeting and project review. If you have any questions or concerns please do not hesitate to contact me. Thanking you in advance. Sincerely, 00000k �")&001, Michael D. Howard Conservation Administrator cc: NACC DEP-NERO Kathleen Colwell,Town Planner William Scott,Director CD&S Tom Zahriouko Steve D'Urso file i TARA LEIGH DEVELOPMENT CORP. ® dNSTRUCTION �rq R Thomas D.Zahoruiko,President 185 Hickory Hill Road Noah Andover,MA 01845 Tel: (508)687-2635 Pax: (508)689-2310 North Andover Conservation Commission, Planning Board, and Dept. of Public Works 146 Main Street North Andover, MA 01845 June 9, 1997 Re: Settlers Ridge Road Construction Progress Report and Monitor Week Ending June 7, 1997: 1. Level spreading swale hydroseeded 2. Entrance area retainer begun 3. Subdrain installed from ST3+00 to cul-de-sac 4. Detention pond shaped 5. Final redressing of replication area 6. Riprap installed on South side of Wetland crossing area 7, Shoulder shaping nearly complete Work Planned for Week of June 9- June 14, 1997: (weather permitting) Finish retainer at entrance Complete detention pond and outlet structures Complete subdrain to entrance area Finish all sewer inverts Riprap North side of wetland crossing Complete gas main and service stub installation Regrade gravel installation Begin gravel installation Post ConCom Bonds on a few lots If you have any questions, please contact me at the address and telephone n tile. hornas D. Z rulko, Pres. Tara Leigh Development Corp.