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Home My WebLink About1999-02-17 Engineer Review II SPR COLER St C06aL%-TORN � FACSIMILE COVER SHEET To: Kathleen Colwell &Michael Howard Company: Planning Board & Conservation Commission Phone: 978-688-9535/30 Fax: 978-688-9542 From: John C. Chessia Company: Coler & Colantonio, Inc. Phone: 781-982-5400 Fax: 781-982-5490 Date: January 15, 1998 Pages including this cover page: 6 Comments. Please fired the attached review for Commerce Park. cc: .Tim Rand,DPW 978-688-9573 Appledore Engineering,Inc. 603 433-8988 VOLER LANTONIO Z r-Nr'INernme.ANO SCIeNT#�T5 January 14, 1998 Planning Board/Conservation Commission Kathleen Colwell Michael Howard 27 Charles Street North Andover,MA 01845 RE: Wetland Bylaws and Zoning Bylaws Review Commerce Park Dear Ms. Colwell. In response to your request, Coler& Colantonio,Inc.has reviewed the site plans for the above referenced site, The project has been reviewed for conformance with the Zoning Bylaw, Wetlands Protection Bylaw, the DEP Stormwater Management Policy and standard engineering practice, relative to stormwater drainage. We submitted a preliminary checklist, dated December 21, 1998, relative to the Zoning Bylaws site,plan review. We also visited the site on January 4, 1999 to observe existing site conditions. The submittal included the following information: Plans Entitled. "North Andover Commerce Center"Eleven sheets dated December 4, 1998. Prepared by Appledore Engineering Inc. Dated December 4, 1998. Received December 8, 1998. Deports Entitled: • "Drainage Study for North Andover Commerce Center",prepared by Appledore Engineering Inc. Dated December 4, 1998.Received December 8, 1998. • "Geotechnical Investigation for North Andover Commerce Center",prepared by Jaworski Geotech Inc. Dated November 2, 1998.Received January 14, 1999. • "Notice of Intent for North Andover Commerce Center",prepared by Appledore Engineering Inc. Dated December 1998, Received January 14, 199% • Letter of Response-Prepared by Appledore.Engineering,dated January 8, 1999,received January 15, 1999. The site is located old'Clark Street and directly abutting Lawrence Municipal,Airport to its north. The site includes flagged wetlands, streams and ponds at the north and west property boundaries. tot Accord Park Drive 751-982.5400 Norwell, MA 0206 1-1 585 Fax: 781-982-5490 Zoning Bylaw. The plans state that the site is located in the Watershed Protection District. According to the North Andover Zoning Map, only the southwest corner of the site is in the Watershed Protection District. It is anticipated that there will be no impact on the Watershed District due to the proposed development, Therefore,we have not reviewed this project rel ative latrve to the regulations governing the Watershed Protection District, __. Section 6.6)H.)Landscaping, Buffering, Lighting -The Planning Board should review ' `the proposed landscaping. Note that the southerly parking area is located at the roadway layout line and street widening would impact this area. Section 8.1)l I.) The plans should indicate the proposed loading areas and number of �.. b jys. Section 8.3.)S.)v.) Off site contours should be provided to determine the effects of offsite runoff on the proposed drainage system, specifically on the south side of the site. Section 8,4)1.)It is not clear that an impervious screen has been,provided for off-street parking areas. Section 8.4.)4.)It is not clear that the required green space for the westerly parking lot has been provided. Wetland Protection Bylaw.- The North Andover Conservation Commission should review the wetland boundaries. Section III.)4.)A section of the parking lot in the southwest comer of the site, labeled `Annex',lies within a flagged wetland. We anticipate that additional flagging in this area would address this issue. N Section III.)4.)a.)Minor grading for the proposed constructed wetland falls within the 25' No-Disturbance Zone. Section III.) 4,)b.) The edges of the proposed parking lot on the north and west side of the lot fall within the 50' buffer of bordering vegetated wetlands and isolated wetlands. The Conservation Commission should review this design, Section IV.)B.)1-9,) Stormwater Standards: dard I Satisfactorily addressed. tan,dard The lag method of calculating the time of concentration was used. We have discussed the use of the lag method with the Natural Resources Conservation Service. They developed the TR-55 and TR-20 models-and no longer recommend use of the lag method. We do not agree with the ground cover description of Woods-Fair Condition. Based on our site visit, we would estimate the woods to be in good condition. Curve number and time of concentration calculation sheets, consistent with TR-55, should be submitted. The one year 24 hour storm should be modeled. The pipe calculations were modeled for the 25-year storm.R is unclear how the westerly parking area will discharge in a greater than 25-year event. The stage storage elevations and volumes for the proposed constructed wetland are not clear. It appears that pipe used for the outlet structure is modeled as a 36" diameter vs. the 24"diameter pipe indicated on the plans. An emergency spillway designed to pass the 100-year storm should be provided. This spillway should be designed to pass the 100-year storm with the normal outlet plugged. Test pit excavations and soil,borings were performed and logged,however it is not indicated that they were witnessed by a town representative. Groundwater estimations were based upon observed water at the time(November 1998)of excavation.Redoximorphic or mottling identification is indicated by the Soil Conservation Survey as the most accurate method for determining high groundwater elevations.It does not appear that these tests were performed by a soil evaluator as required by the Wetlands By-Law. 59ad9d 3 Recharge systems and calculations were not submitted. Reportedly, on site recharge is not possible due to the high groundwater elevation. Soil evaluations, which indicate these conditions, have not been submitted.The addition of underdrains to the proposed parking lot will drain the groundwater,which is contrary to the recharge requirement. It is possible that the site could not reasonably be designed to provide recharge. Stmdard_4 ,All proposed catch basins should be installed with 4' sumps and,hoods. TSS removal worksheets should be submitted. It likely that the design would comply especially since it is a redevelopment site. tandard 5 Refer to comment on Standard 2 relative to required test pit data for the evaluation the proposed constructed wetland's water quality improvement capabilities. A pocket wetland is defined by the DBP Stormwater Management Policy, as discharging through a hooded broad crested weir. Not applicable, S_lLandard 7 Refer to compliance with standards 1 through 5. lord S Typically reviewed by town staff. S d9 The locations and erosion control procedures for temporary storage of excavated materials should be indicated on the plans. Cleanouts for roof drains should be indicated on the plans. We understand that town staff typically review these plans. J Section IV,)C.)4.))Existing and proposed 100-year flood elevations should be modeled 1 for ponds and wetlands impacted by proposed construction. Section 1V.)C.)6.)b.) The grading is not clear in proximity of the proposed constructed wetland. The side slope of the,proposed wetland is 2.1; it is recommended that the side slope be no steeper than 3.1, Headwall details including bar racks should be submitted. Section IV.)C.)6.)d.) Storage capacity of the proposed constructed wetland may not comply with this section. Test pits consistent with this section should be performed to provide an accurate estimation of the high groundwater elevation. Section VI.)B.)4.)i,)See comment on Section IV.)C.)4.). _... Section VI.)B.)4.)d.) The limits of the existing tree line are unclear. Section VI.)B.)4.)f.)It is not clear that the existing on site gravel ditch, sewer pipes and sewer manholes are proposed to be removed.The discharge points of the existing sewer pipes at the northwest corner of the site are not indicated. All storm drains and sanitary sewer lines,which are to remain, should be verified. Floor drains,if any, Should not be connected to the storm drain.system. Section VI.)B.)5.)g,)The 50' No-Build Zone is not indicated on the existing conditions plan. Section VI.)B.)4.)i.)The plans were submitted at variable scales from I"'=50' to I"=60'. Section VI.)B.)4.)j.) Flows for the easterly wetland& stream areas have not been provided. Geuearal Comments. 1. The town should note the poor condition of Clark Street and the existing flooding problem at the low point of Clark Street, �� 2. The Planning Board and Conservation Commission may want to review any testing regarding soil contamination. Reportedly, a 21 E has been perforrued and is going to be forwarded. 3. Subdivision Regulations Section 7,)A.)2.)a.) Clark Street presently has a variable paved width. It is proposed to create a 24' traveled way by constructing curbs and landscape islands.Note that a 40' traveled way is required in business or industrial zones. The existing layout is a 50' right of way vs. a Wright of way for new industrial zone roadways. 4. The town should note that the proposed private drainage connection across Clark Street between DMH#S and DMH#4 may conflict with the existing utilities in. Clark Street and create maintenance issues. We appreciate the opportunity to assist the Planing Board on this project and hope that this information is sufficient for your needs. We would be pleased to meet with the Board or the design engineer to discuss this project at your convenience. If you have any questions please do not hesitate to contact us. Very truly yours, COLER&COLANTONTO,INC, Johns C. Chessia, P.E. cc: Jim Rand, DPW Appledore Engineering,Inc. jpl/JCC