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Maintenance of King St Brook Diversion Channelr Submitted to: Proponent: Prepared By: NOTICE OF PROJECT CHANGE EOEA NO. 12453 MAINTENANCE OF THE KING STREET BROOK DIVERSION CHANNEL NORTHAMPTON, MASSACHUSETTS 0 X frfj ,5 SECRETARY OF ENVIRONMENTAL AFFAIRS Attn: MEPA Unit 251 Causeway Street, 9th Floor Boston, MA 02114 -2150 CITY OF NORTHAMPTON Department Of Public Works 125 Locus Street Northampton, MA 01060 BAYSTATE ENVIRONMENTAL CONSULTANTS, INC. 296 N. Main Street East Longmeadow, MA 01028 SEPTEMBER 2001 September 7, 2001 Secretary of Environmental Affairs Attn: MEPA Unit 251 Causeway Street, 9th Floor Boston, MA 02114 -2150 Re: Notice of Project Change EOEA No. 12453 Maintenance of the King Street Brook Diversion Channel, Northampton, Massachusetts. Dear EOEA: Enclosed please find a Notice of Project Change for the above referenced project. An Environmental Notification Form (ENF) was previously reviewed for this project, and the MEPA Certificate required that an Environmental Impact Report (EIR) be completed for the proposed full project scope. At this time, funding necessary to proceed with preparation of the EIR document have not been secured by the Proponent; however, funding is in place for the construction of the sedimentation basin, which is a small component of the previously reviewed overall project. Construction of the sedimentation basin is a project component that will lead to immediate flooding relief and is not a significant factor in the thresholds which led to either the need to prepare an ENF or and EIR. For the sedimentation basin alone, no MEPA threshold is met or exceeded. With regards to project segmentation, the change in project scope has not been proposed to avoid meeting or exceeding ENF Thresholds. The Proponent is well aware that to accomplish the full project scope, as previously reviewed, the EIR document must be prepared and reviewed under MEPA. The proposed sediment basin will not result in below threshold impacts for the remaining segments of the previously reviewed maintenance program; therefore, the change in scope does not circumvent the MEPA Regulations, 301 CMR 11.00, and the thresholds established therein. The Proponent is seeking to appropriate the necessary funding for the EIR in the near future and will complete MEPA review of those portions of the project which exceed thresholds, consisting of the excavation of sediments from 1,630 linear feet of King Street Brook Diversion Channel and 565 feet of a tributary from the Carlon Drive detention basin.. As the representative for the Proponent, BEC has submitted the NPC Form to describe the proposed changes to the previously reviewed project scope. The ENF plan set has been revised and enclosed as a reference document. If we can be of further assistance, please contact our office at your earliest convenience. Very truly yours, BEC, Inc. Daniel M. Nitzsche Enviroiunental Scientist encl. NPC Form with Support Documents cc: See Revised Distribution List Secretary of Environmental Affairs _Septenzber: 2001 Page 2 of 2 Project Name: Maintenance of the King Street Brook I Diversion Channel EOEA 12453 Street: Off State Street and Norwottuck Rail Trail, Municipality: Northampton Watershed: Connecticut Universal Tranverse Mercator Coordinates: UTM NAD 83 meters X: 6 94 463 Y: 46 89 044 Latitude: 42° 32' 93" N Longitude: 72° 62' 77" W Status of project construction: 0 %complete Proponent: Department of Public Works Street: 125 Locus Street Municipality: Northampton State: MA Zip Code: 01060 Name of Contact Person From Whom Copies of this NPC May Be Obtained: Daniel M. Nitzsche Firm /Agency: BEC Inc. Street: 296 North Main Street Municipality: East Longmeadow State: MA Zip Code: 01028 Phone: (413) 525 -3822 Fax: (413) 525 -8348 E -mail: dnitzsche @b e c.com �i NPC r-- r H r P n U Commonwealth of Massachusetts Executive Office of Environmental Affairs MEPA Office Notice of Project Change The information requested on this form must be completed to begin MEPA Review of a NPC in accordance with the provisions of the Massachusetts Environmental Policy Act and its implementing regulations (see 301 CMR 11.10(1)). In 25 words or less, what is the project change? The project change involves a reduced project scope that includes the construction ofa sediment basin and no MEPA threshold is met or exceeded by the proposed project change. See full project change description beginning on page 3. Date of ENF filing or publication in the Environmental Monitor: Was an EIR required? Yes ❑No; if yes, was a Draft EIR filed? ❑Yes (Date: was a Final EIR filed? ❑Yes (Date: was a Single EIR filed? Yes (Date: Have other NPCs been filed? ❑Yes (Date(s): No No No ®No For Office Use Only Executive Office of Environmental Affairs MEPA Analyst: Phone: 617 -626- If this is a NPC solely for lapse of time (see 301 CMR 11.10(2)) proceed directly to May 2001 Summary of Project Size Environmental Impacts Previously reviewed Net Change Currently Proposed LAND Total site acreage 4.3 3.8± AC 0.5± AC. Acres of land altered N/A 0.06± AC 0.06± AC Acres of impervious area 0.05± AC 0 0.05± AC Square feet of bordering vegetated wetlands alteration 2000± S.F. 310 S.F. 1230 S.F. perm. 460 S.F. temp. Square feet of other wetland alteration N/A N/A N/A Acres of non -water dependent use of tidelands or waterways N/A N/A N/A STRUCTURES Gross square footage N/A N/A N/A Number of housing units N/A N/A N/A Maximum height (in feet) N/A N/A N/A TRANSPORTATION Vehicle trips per day N/A N/A N/A Parking spaces N/A N/A N/A WATER/WASTEWATER Gallons /day (GPD) of water use N/A N/A N/A GPD water withdrawal N/A N/A N/A GPD wastewater generation/ treatment N/A N/A N/A Length of water /sewer mains (in miles) N/A N/A N/A "ATTACHMENTS SIGNATURES" on page 4. Not Applicable PERMITS FINANCIAL ASSISTANCE LAND TRANSFER List or describe all new or modified state permits, financial assistance, or and transfers not previously reviewed: Not Applicable Are you requesting a finding that this project change is insignificant? (see 301 CMR 11.10(6)) ❑Yes ®No; if yes, attach justification. Are you requesting that a Scope in a previously issued Certificate be rescinded? fYes El No; if yes, attach the Certificate Are you requesting a change to a Scope in a previously issued Certificate? ❑Yes ®No; if yes, attach Certificate and describe the change you are requesting: 2 r� J Under the Massachusetts Wetlands Protection Act (MA WPA) and as regulated under the City of Northampton Wetland Protection Ordinance the proposed work will impact Bordering Vegetated Wetlands (BVW) and Bank resource. The proposed resource area impacts are in compliance with the performance standards outlined in 310 CMR 10.55 (BVW) and 310 CMR 10.54 (Bank). L_) Does the project change involve any new or modified: 1. conversion of public parkland or other Article 97 public natural resources to any purpose not in accordance with Article 97? EYes No 2. release of any conservation restriction, preservation restriction, agricultural preservation restriction, or watershed preservation restriction? Yes No 3. impacts on Estimated Habitat of Rare Species, Vernal Pools, Priority Sites of Rare Species, or Exemplary Natural Communities? nYes No 4. impact on any structure, site or district listed in the State Register of Historic Place or the inventory of Historic and Archaeological Assets of the Commonwealth? ❑Yes ®No; if yes, does the project involve any demolition or destruction of any listed or inventoried historic or archaeological resources? ❑Yes ❑No 5. impact upon an Area of Critical Environmental Concern? ❑Yes No If you answered 'Yes' to any of these 5 questions, explain below: PROJECT CHANGE DESCRIPTION (attach additional pages as necessary). The project change description should include: (a) a brief description of the project as most recently reviewed (b) a description of material changes to the project as previously reviewed, (c) the significance of the proposed changes, with specific reference to the factors listed 301 CMR 11.10(6), and (d) measures that the project is taking to avoid damage to the environment or to minimize and mitigate unavoidable environmental impacts. If the change will involve modification of any previously issued Section 61 Finding, include a proposed modification of the Section 61 Finding (or it will be required in a Supplemental EIR). Introduction The City of Northampton through its Department of Public Works (NDPW) is proposing to control sediment loading into the King Street Brook Diversion Channel (KSBDC) by constructing an accessible sedimentation basin in line with the KSBDC, thus augmenting current sediment trapping efforts within the watershed. The proposed work will consist of an excavated pool immediately downstream of the Northampton Bikeway embankment and cross culvert. The quiescent area to be excavated below the flowline of the diversion channel will provide for trapping of suspended sediments and will significantly reduce flooding and drainage impacts to abutting properties. The sediment basin will be accessed from a new ramp to be constructed from the bikeway. The access ramp will assist in preventing the flow of waters from the KSBDC into the Stop Shop detention basin. Regular maintenance of the proposed basin, by removal of the accumulated sediments, will help to preserve the hydraulic capacity of the 4'x4' box culvert by keeping it unobstructed and free of debris. Proposed Work The NDPW is proposing to create an accessible sedimentation basin in line with the KSBDC. This will consist of excavating a pool immediately downstream of the bikeway embankment and cross culvert. The excavated basin will be lined with riprap and provide slope protection at a 2:1 slope to a gabion retaining wall. A ten -foot wide bituminous concrete access ramp will be constructed from the bikeway to the basin at a 12% grade. This ramp will provide access to the basin so that collected sediments can be periodically removed. The ramp will also serve to prevent the flow of waters from the KSBDC into the Stop Shop detention basin. The sediments 3 collected within the basin will be dewatered in place, removed by excavator, and transported to the Northampton Sanitary Landfill by truck to be beneficially reused as daily cover Construction access will be from the bikeway, entering at the end of State Street. Construction of access ramp, I gabion retaining wall, and riprap areas will require the filling of 1230 S.F. of BVW. Impacts are being compensated for by greater than 1:1 wetland replacement. I J A temporary cofferdam with a pump system will be used to dewater the work area when flows are at a minimum. All work shall be conducted during low flow conditions: The contractor shall discontinue construction in the event of a significant storm event where flows exceed the capacity of the pump system. The adjacent land will be graded as specified; all disturbed soils shall receive a minimum of 4" of loam and shall be seeded and mulched to stabilize disturbed soils. Mitigation A 1400 S.F. replacement wetland is being proposed to mitigate the loss of BVW associated with the proposed project. An upland "island" area, to the west of the proposed work, has been selected as the area to replace the lost wetlands. This forested area will be cleared of vegetation and the grade lowered to be consistent with the adjacent wetland. This area will be planted with wetland shrubs, that will provide food and cover for local wildlife populations. The remaining exposed soils will be covered will a New England wetland seed mix. A temporary wetland crossing will be necessary to construct the replacement wetland. A fifteen -foot wide access corridor will be established from the bikeway down to an eight -foot wide strip of BVW, where the temporary crossing will be constructed. The existing vegetation at the crossing area will be cut flush with the ground surface and overlain with two protective layers of geotextile filter fabric. A minimum of eight inches of crushed stone will be place around the 12 -inch temporary culvert. (b) The changed project scope is a significant reduction in the total impact proposed under the ENF application. (c) With regards to 301 CMR 11.10(6): a. The project scope has been reduced and not expanded. No MEPA threshold is met or exceeded by the project change; b. No increase in impact, only a decrease; c. The commencement date would be revised late September 2001; d. The proposed sediment basin is limited to limited to the first 80 linear feet of the King Street Brook, north of the culvert crossing at the bike trail; e. N /A; f. The proposed changes will increase protection of the wetland resource area by reducing sedimentation; and, g. N /A. (d) N/A (a) ATTACHMENTS SIGNATURES Attachments: 1. Secretary's most recent Certificate on this project 2. Plan showing most recent previously- reviewed proposed build condition 3. Plan showing currently proposed build condition 4. Original U.S.G.S. map or good quality color copy (8 -1/2 x 11 inches or larger) indicating the project location and boundaries 5. List of all agencies and persons to whom the proponent circulated the NPC, in accordance with 301 CMR 11.10(7) Signatures: Signa ure or Proponent Guilford Mooring Name (print or type) Northampton DPW Firm /Agency (413) 586 -6950 Phone Phone 7/10 d/ 444 7 4 1, 7 Officer Date Signature o person p ep g NPC (if different from above) Daniel M. Nizsche Name (print or type) Baystate Environmental Consultants, Inc. Firm /Agency 125 Locus Street 296 N. Main Street Street Street Northampton, MA 01060 East Longmeadow, MA 01028 Municipality /State /Zip Municipality /State /Zip (413) 525 -3822 5 ATTACHMENTS for NOTICE OF PROJECT CHANGE Maintenance of the King Street Brook Diversion Channel Northampton, Massachusetts MAINTENANCE OF THE KING STREET BROOK DIVERSION CHANNEL NORTHAMPTON, MA Baystate Environmental Consultants, Inc. East Longmeadow, MA 0.2 0 0.2 Miles LEGEND Q Project Location FIGURE 1- LOCUS MAP USGS Quad Imager, MrSID Forman Scanned by MarsGIS at 250 dots per Inc!: 256 colors. Converted from tiff to .sid format Source dates 1979 EASTHAMPTON MT HOLYOKE QUADRANGLES. fl I, L _J L WETLAND BOUNDARY EXISTING 7A VVALL 4 X 4' BOX CULVERT "11 nre Civil Engineers 298 North Nob, Street BAYSTATE ENVIRONMENTAL CONSULTANTS INC. Environmental Scientists Easi Longmeadow, IAA 01028 KING STREET BROOK DIVERSIONCHANNEL .(TO BE EXCAVATED) WETLAND BOUNDARY--/ STOP SHOP DETENTION POND PROP. RAMP TO ACCESS BASIN FOR' MAINTENANCE PROPOSED SEDIMENTATION BASIN Scale: 1" 40'± .1 AL PI Figure 2 King %or Existing Stop Shop Deterition osin ■IMENTAL INC. al Scientists dow, 88 01028 rook— Existing 4x4'Bo)( Location of Proposed s yd t e imen ation Basin 10 k 11, 1; 11T PROPOSED PLAN FOR <ING STREET BROOK S Scale: 1" 200'± Previously Submitted ENF Narrative Description for King Street Brook Diversion Channel Northampton, MA The City of Northampton through its Department of Public Works (NDPW) is proposing to maintain 1,630± LF of the King Street Brook Diversion Channel (KSBDC) and 565± LF of additional ditch/swale by excavating accumulated sediments to restore hydraulic capacity. The project will also include construction of a sedimentation basin to collect future stormwater sediments and help maintain the function of the KSBDC. Project description plans are included in Appendix C. Currently, sediment and debris constrict the channel downstream of the culvert under the Norwottuck Bike Trail, and King Street Brook and divert flow away from the KSBDC and onto private, developed property. Impacted areas also include the Stop Shop and Carlon Drive detention basins. The proposed action is consistent with historical maintenance of the KSBDC, as described in Appendix D. Project Component 1 involves excavation of the accumulated sediment and debris from the KSBDC. The material to be excavated is composed of fine sands and silt, with a high organic content. Analytical results for two sediment samples showed that the sediments contain elevated levels of PAHs (see Appendix E). The channel will be excavated by approximately 2 feet to attain the approximate elevations that existed on the effective date of the Massachusetts Inland Wetland Protection Regulations, 310 CMR 10.51 -10.60 (April 1, 1983). Project Component 2 will create an accessible sedimentation basin in line with the KSBDC, located immediately downstream of the bike trail embankment and cross culvert. The quiescent area to be excavated below the flowline of the diversion channel will provide for trapping of suspended sediments. The sediments to be excavated are medium to coarse sand. Analytical results for one sediment sample showed that there are elevated levels of PAHs (see Appendix E). A new access ramp to the basin will be constructed that will also prevent the flow of waters from the KSBDC into the Stop Shop detention basin. Project Component 3 is the proposed excavation of a trapezoidal channel from the cleared KSBDC to the outlet of the Carlon Drive detention basin in order to improve drainage in this area. ALTERNATIVES ANALYSIS No Action The No Action alternative will lead to increased occurrences of significant and damaging flooding of the KSBDC upstream of the bike trail and adjacent private land. Diversion of King Street Brook This alternative involves a below grade diversion of King Street Brook away from the Barrett Street marsh and towards the Connecticut River. This option would be extremely costly, requiring significant easements across private land and extensive excavation and construction within highly developed areas. Excavation of the Diversion Channel This alternative is a viable option for restoring the hydraulic capacity of the KSBDC. A concrete weir was constructed in 1997 at Barrett Street to control water levels within the diversion channel. The accumulated sediments and debris have caused the water elevations to be much higher than the weir (see Appendix C). It is proposed to initially excavate the diversion channel starting at an elevation 6" lower than the weir and proceeding upstream at a 0.03% slope. This will provide for nominal channel capacity with the water level at the height of the weir. As indicated in Appendix E, the sediments and organic debris to be removed from the channel are of very low density (77 pcf) and high water content (65% by weight). Immediately downstream of the bike trail culvert, the sediments were found to be more dense and granular in nature, consisting primarily of medium to coarse sands. Excavation of the downstream portions of the channel presents technical challenges due limited access and the character of the low-density materials to be removed. The following excavation i 3 techniques have been considered: Conventional excavation by dragline or excavator: Under this akemative, the materials would be excavated and deposited in a windrow adjacent to the channel. This option was discarded due to the negative environmental effects associated with allowing the sediments to remain in a large mass adjacent to the channel. Conventional excavation by dragline or excavator, with removal of excavated materials: This alternative involves excavation by dragline or excavator, followed by sediment transport to a landfill or other disposal akematives. This alternative requires construction of an access road and was discarded due to the high cost of constructing the access road, impacts to wetlands, and the anticipated difficulty in handling the sediments of high water content. Hydraulic excavation: This methodology utilizes the water within the channel to transport the sediments in a slurry (typically 10 solids) to a dewatering area (belt filter presses or centrifuges). The dewatered sediments would be disposed of and the excess water returned to the channel. Hydraulic excavation requires the waterbody to supply sufficient water to create a slurry for sediment transport. As King Street Brook is intermittent, the technical challenges of this approach render this alternative impractical. Excavation by rotary ditcher: Rotary ditching involves the use of mechanical equipment that simultaneously excavates the sediments and sprays them across the adjacent land surface. The rotary ditcher throws the finely tilled earth 50 feet or more, thus eliminating the need for spoils leveling or removal. The ditcher can be mounted on the arm of a hydraulic excavator, and the channel excavation can proceed with the excavator travelling alongside the channel. This is the preferred methodology for the excavation of the main body of the KSBDC and for the creation of the drainage channel leading to the C'nrlon Drive detention basin. Sedimentation Basin: A sedimentation basin will be constructed under the proposed excavation alternative. Upstream of the bike trail culvert, King Street Brook and its tributary network are relatively steep in gradient and capable of carrying a significant sediment load. Once the flow enters the flat gradient of the diversion channel, the heavier sediments are deposited in the area immediately downstream of the bike trail culvert. This area has been selected as appropriate for an inline sedimentation basin. By providing a basin for the sediments to accumulate below the normal Bowline of the diversion channel, the hydraulic capacity of the bike trail culvert and the brook can be preserved. It is assumed that the granular sediments in this area will be dewatered in place, removed by excavator, and transported to the Northampton Sanitary Landfill for beneficial reuse as daily cover. WETLAND IMPACT AND MITIGATION Soil and Sediment Deposition: Excavation of accumulated sediments within the existing KSBDC ditch and side channel/swale by rotary ditcher will be conducted such that the channel deposits will be evenly broadcast along both sides of the channels. The proposed excavation will re- establish the pre-existing KSBDC drainage channel with a typical cross section of twelve feet wide and two feet deep, with 1:1 side slopes and an average cross-sectional area of 20 square feet. The total in-situ sediment volume to be excavated from the KSBDC is approximately 1,200 cubic yards, and would result in a dry thickness of 0.8 to 0.9 inches if spread evenly across the land surface for 50 feet each side of the channel. The proposed channel to the C'nrlon Drive detention basin has a cross- sectional area of 8 square feet (excavation of 170 cubic yards), yet will result in a depositional area an average of 1" in thickness, due to the higher density of the sediments. The discharge of these sediments is not anticipated to have long-term negative impacts on the vegetation or soil morphology within the depositional areas. Rotary ditching is the methodology preferred by the U.S. Anny Corps of Engineers when ditching is necessary within wetland areas, as the sediments are distributed in a thin layer in surrounding wetlands and low-pressure equipment can be used. Lowering of Water Levels: Excavation of the KSBDC and the side channel/swale to the C Drive detention basin will restore pre-existing hydrology within portions of the marsh area. Due to the low permeability of the soils and limited depth of excavation, broader scale hydrologic effects are anticipated to be minimal. The current water surface level within the diversion channel is approximately at the ground surface, and the proposed excavation will lower water levels by an average of 2 feet. The ellipse equation (Natural Resources and Conservation Service, SCS Field Engineering Manual, 1969), used to gauge this action's zone of influence, is an accepted design methodology for subsurface drains to be used in dewatering of agricultural areas. Calculations performed by BEC indicated that the lateral effects of lowering the water levels will extend for several feet to each side of the channels (See Appendix F). Given the groundwater wicking properties of existing marsh soils and the maximum depression of water levels within the KSBDC, there is not anticipated to be any loss of hydrology that would result in a change from wetland to upland conditions. However, the area adjacent to the ditch may be able to support woody wetland vegetation, which ultimately would provide greater shading to the water flow in the ditch and improve wetland wildlife habitat diversity in the marsh. Wetland Fill: Construction of the sedimentation basin at the culvert outfall will require a wetland fill of approximately 2,000 square feet associated with the construction of the access ramp, gabion retaining wall, and riprap areas. As part of the project, a wetland replacement plan will be developed in consultation with the Northampton Conservation Commission during the project permitting phase. r ARGEO PAUL CELLUCCI GOVERNOR JANE SWIFT LIEUTENANT GOVERNOR BOB DURAND SECRETARY PROJECT NAME PROJECT MUNICIPALITY PROJECT WATERSHED EOEA NUMBER PROJECT PROPONENT DATE NOTICED IN MONITOR SzectWve elice o Jai& 900 t/ga02114 -2119 <9 Printed on Recycled Stock 20% Post Consumer Waste Tel. (617) 626 -1000 April i l 6 2 0 01 Fax (617) 626 -1181 p http /www.magnet.state.ma.us /envir CERTIFICATE OF THE SECRETARY OF ENVIRONMENTAL AFFAIRS ON THE ENVIRONMENTAL NOTIFICATION FORM Maintenance of the King Street Brook Diversion Channel Northampton Connecticut River 12453 Northampton Department of Public Works March 7, 2001 Pursuant to the Massachusetts Environmental Policy Act (G. L. c. 30, ss. 61 -62H) and Sections 11.03 and 11.06 of the MEPA regulations (301 CMR 11.00), I hereby determine that this project requires the preparation of an Environmental Impact Report (EIR) According to the Environmental Notification Form (ENF), the project involves excavation of sediments from 1,630 linear feet of King Street Brook and 565 feet of a tributary from the Carlon Drive detention basin. Both channels are in the Barrett Street Marsh Conservation Area. A rotary ditcher, that throws the material up to 50 feet to the side of the channel, is proposed. A sedimentation basin with an access roadway is proposed at the bicycle path on the upper end of the marsh. The project is subject to review pursuant to Section 11.03 (3)(a) la of the MEPA regulations because it involves alteration of more than one acre of bordering vegetated wetland. It requires a Chapter 91 Waterways permit and Water Quality Certification from the Department of Environmental Protection (DEP), an individual 401 permit from the U.S. Army Corps of Engineers (COE), and an Order of Conditions from the local conservation commission. The project is funded from the Massachusetts Emergency Management EOEA #12453 ENF Certificate April 6, 2001 Agency (MEMA). Because the proponent is seeking financial assistance from the Commonwealth, MEPA jurisdiction extends to all aspects of the project that might have significant environmental impact. The Brook is to'be•opened to a channel 12 feet wide by 2 feet deep, and the tributary from the detention basin channel, to approximately 4 feet wide by 2 feet deep. The channels are heavily vegetated in sections. In addition to clearing the channels, the project will alter a further 188,000 square feet of bordering vegetated wetland (BVW). Approximately 2,000 square feet of BVW will be permanently filled for access to the sedimentation basin. The remaining 186,000 square feet would receive up to one inch of sediment material from the rotary digging process. No wetlands replacement plans have been identified at this time. The proponent should consult with both the DEP and COE as the EIR is prepared. The April, 2000 Functional Analysis of the Hydrology and Hydraulics of Barrett Street Marsh and A Natural History of the Barrett Street Marsh contain useful information for the preparation of the EIR. SCOPE I. Project Description The EIR should fully describe the proposed project and any alternatives developed during the preparation of the EIR, including any alternatives that reduce wetlands impacts. The no -build must be considered for comparative purposes. II. Wetlands Resources The EIR should identify and describe all wetlands resource areas in the project area, including those in the detention basin area and those upstream from the bicycle path. Each resource area should be evaluated for its, significance and each alteration proposed to a resource area should be quantified and evaluated for significance under the Act. All identified environmental impacts should be quantified and available strategies to avoid, or if not able to avoid, mitigate impacts, should be evaluated for effectiveness and feasibility. 2 V. Maintenance Access The EIR should consider if access is needed to the sedimentation basin at ground level, or if maintenance activities could be'performed from the bicycle path. VI. Wetlands Replication If wetlands replication is required for the project, the EIR should identify an acceptable site and include plans for development of the mitigation. VII. Variance If DEP concludes that a variance will be required for the project, the EIR should justify the issuance of the variance. IX. Mitigation The EIR should contain a proposed Section 61 Finding which identifies all mitigation measures,. parties it responsible for their implementation and an implementation schedule. 3 EOEA #12453 III. Invasive Species The EIR should identify areas of invasive species in the current marsh and evaluate their potential change due to the project. IV. Wetlands Vegetation Changes The EIR should evaluate the potential long -term change in wetland characteristics due to the change in water elevation in the wetlands, and due to the deposit of the layer of sediment alone, and with some elevated PAHs, on the marsh. ENF Certificate April 6, 2001 The EIR should follow MEPA regulation 11.07 as modified by this scope and must address the issues raised in the enclosed comment letters. It must be circulated to the following for the MEPA review periods: DEP /Boston DEP /WERO COE MEMA F &WL Connecticut River Basin Team EPA /Ed Reiner NMFS PVRPC Mass Audubon Alexandra Dawson CRWA i j EOEA #12453 Northampton City Council Northampton Conservation Commission Northampton Public Library Ten additional copies must be available on request. April 6, 2001 DATE Comments received DEP 3/29/2001 COE 3/26/2001 EPA 3/19/2001 NHESP 2/27/2001 MHC 2/26/2001 BD /DES /ds ENF Certificate April 6, 2001 4