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HomeMy WebLinkAbout1993-04-12 Wetland Restoration & Construction Control Plan DEF SUB { ETLANos y 4 RESERVATION NC, Wetland Restoration and Construction Control Plan Stevens Crossing Oegood Street North Andover, Massachusetts 01845 March 2, 1993 Prepared for Rogers Park Realty Trust 733 Turnpike Street Suite 209 North Andover, Massachusetts 01845 By Wetlands Preservation, Inc. 569 North Street Georgetown, Massachusetts 01833 569 North Street 47 Newton Road 126 Wildcat Road Goorgetowo, MA 01833 Plaistow, NH 03865 Barrington, NH 03825 [508)352-7903 (603)382-3435 (603) 664-7645 Wetland Restoration and construction Control. Flan Stevens Crossing` Osgood Street North Andover, MA 1.0 Introduction The following report provides specifications for erosion and sediment control .-..,-measures:,, ,the control of construction act ivit ie a-and—restorat ion of off site wetlands which will be temporarily impacted due to the construction of a sewer line crossing of the Cochichewick Brook for the Stevens crossing subdivision located on Osgood Street in North Andover, Massachusetts. Specifications for both on site and off site erosion and sediment control measures associated with this limited project crossing and site development which will be undertaken to maintain water quality and prevent sedimentation of wetlands during and after construction are provided. These specifications are based on the proposed sewer line as shown on Sheets 4, 5 and 8 of the 40 scale Special Permit and Definitive Plan prepared for Rogers Park Realty Trust by Merrimack Engineering Services, Inc. dated January 30, 1993. 2.0 Wetland Impact Area Descriptions Sewer Stations 600+70 to 601+70 The wetland resource area directly associated with the brook, between Sewer Station 600+70 and Sewer Station 601+70, has a substrate which is a combination of mineral and organic soils, all of which are considered hydric. y ! f The installation of the sewer line is confined to the side slopes of the existing road fill between Sewer stations 600+70 to 601+70 and on to Road station 11+00, except for 40t feet of impact to the actual stream bed, which has a substrate of deep very fine textured alluvial sediments. The depth of fill over hydric soils varies with the location of the sewer line along the road side slope and generally increases closer to the road. The removal of this fill overburden will expose very poorly drained mineral soils beneath. The organic surface layer of the flatural soils has been compressed by the deposition of road fill. similar very poorly drained mineral soils predominate at the toe-of-elope of the road fill, in the area along wetland flags A4 - A8, These soils will behave very similar to organic soils during excavation of the sewer line trench by virtue of their very fine sandy texture, organic matter content and saturated consistency. These very poorly drained mineral soils typically possess 8 to 15 inches of sapric organic muck over one to several feet of fine' and very fine sandy alluvial sediments which possess a high percentage of organic matter. Very poorly drained organic soils- tend to lie further from the existing road in the backwaters of the brook and typically have 161 inches of highly decomposed muck over one to several feet of fine and very fine sandy alluvial sediments which possess a high percentage of organic matter. The underlying material is very coarse textured sandy and gravelly material with a large percentage of small cobbles. 2 t 1 The organic and mineral soils have both been directly disturbed by the construction of Osgood Street and indirectly by construction of the bridge and the ensuing changes in the flow characteristics and channel of the brook. The changes in flow have altered the manner in which alluvial sediments are deposited and organic matter is accumulated. Although the construction of the road and bridge have altered its flow attributes, the brook continues to influence the morphology of all hydric soil types in this area. Vegetation found in the area between Sewer Station 600+70 and Sewer Station 601+70 includes ash (Fraxinus app. ) , black cherry (Prunus serotina) , elm (Ulmus sp. ) and spruce (Picea sp. ) in the tree stratum. The shrub stratum consists of red panicled (Cornus foemina) and red osier (Cornus stolonifera) dogwoods, Northern arrowwood (Viburnum recognitum) , tartarian honeysuckle (Lonicera tatarica) and red maple (Acer rubrum) . Additionally, the road fill side slope has multiflora rose (Rosa multiflora) and some staghorn sumac (Rhos typhina) . The herbaceous stratum has purple loosestrife (Lythrum salicaria) , sensitive fern (Onoclea sensibilis) and skunk cabbage (Symplocarpus foetidus) . The road fill side slope has red panicled dogwood, goldenrod (Solidago sp. ) and sedge (Carex sp. ) species in the herbaceous stratum. Wild grape (Vitis op. ) can be found in the liana stratum. Observations of soils and vegetation were made near wetland flag A7. No portions of this site fall in a rare or endangered species habitat zone as listed by the 1992 Edition of the Atlas of Estimated Habitats of State-listed Rare Wetland Wildlife, South Groveland Quadrangle. (See Figure 1. ) 3 Road Stations 11+30 to 13+00 The entire length of the sewer crossing from Road Station 11+30 to Sewer Station 604+70 (at Road Station 13+00t) will be installed within the buffer zone. More specifically the installation will take place within the side slopes of the road fill from Osgood Street which cover the natural hydric soils of the former wetland resource area to a depth of 1 to 2 feet (average) . The wetland resource area in close proximity to the installation of the sewer line in the buffer zone between Road Stations 11+30 and 13+00 has a substrata of poorly drained mineral soils. These soils are considered hydric. The soils of the wetland and the buffer zone have been disturbed by the construction of Osgood Road and the access road to North Andover High School. The hydrology of this area has also been altered as there is no culvert under the access road to the high school. The vegetation in the nearby wetland resource area includes species which also frequent the road fill where the construction will take place. The tree and shrub strata are absent in this area. The shrub stratum includes Northern arrowwood, elm, elderberry (Sambucus canadensis) , witherod (Viburnum cassinoides) , tartarian honeysuckle and multiflora rose. The herbaceous stratum is composed of purple loosestrife, goldenrod, aster (Aster op. ) , curled dock (Rumex crispus) , evening primrose (Oenothera biennis) and meadowsweet (Spiraea latifolia) . The liana stratum is composed of wild grape. Observations of soils, vegetation and hydrology were made in the area near wetland flag B2. 4 t } Road Station 30+60 Between Road Stations 9+50 and 31+20 the sewer line will either be .installed within the road side slopes or underneath the road. The vegetation and soils to either side of the crossing of a stone culvert beneath the road at Station 30+60 have not been examined because no permanent direct impacts are being proposed. However, the crossing involves the potential for sedimentation of down stream wetlands so erosion and sedimentation control measures planned for this area are discussed in the next section and in the construction sequence as well. 3.0 Erosions and Sedimentation Controls Erosion Controls In addition to customary erosion and siltation control measures such as hay bale and silt screen barriers, various other management practices will be employed to maintain water quality and minimize damage to wetlands by sedimentation. These measures include a permanent sedimentation/detention pond for construction and post-construction stormwater control, dewatering filter devices, check dams, clay trench dams and a pump discharge diffuser. Additionally, work on the sewer line will not commence before July so as to avoid high stream flow conditions in the spring. Hay bale and silt screen barriers will be securely installed as per the site plans prior to the commencement of any site work. Silt fencing will be backed by a row of hay bales. Hay bales will be double staked and silt fence will be dug in as per site plan detail drawing. The erosion control barrier will be inspected after installation to insure that all sources of erosion will be controlled and will be adjusted as necessary. 5 Sedimentation Detention Pond The sedimentation/detention pond is designed to provide control of both sedimentation and stormwater runoff flow rates during construction activities and is intended to offer detention after construction efforts are complete. The pond will be constructed prior to commencing site development activities or simultaneous to the installation of drainage utilities. The pond will have a 100 year ponding elevation of 127.0 and an overflow elevation of 127.5. The pond outlet invert at 123.7 will be fitted with an elbow and a two foot vertical overflow pipe added. The vertical overflow will be constructed of perforated plastic or metal pipe wrapped with hardware cloth and filter fabric to increase detention and siltation removal during construction. The extension pipe and elbow will be backfilled with crushed stone for stabilization and additional sediment trapping. This apparatus will be removed after construction is complete and any areas of bare soils within the detention pond will be stabilized. The outlet pipe from the sedimentation pond will have a short rip-rap apron where it exits the pond to disperse the flow. The accumulation of the sediment in the pond will be monitored during site construction and removed if the depth exceeds 12 inches. Any side slopes altered as a result of sediment removal will be loamed and reseeded. Dewaterina Filters Dewatering filter devices will be used to treat water pumped from the trenches during installation of the sewer pipe (see Figure 2) . Two such filters will be constructed near the proposed sewer manhole at Sewer Station 600+70 (see Sheet 8) and one will be constructed to the east of the stone wall in the open space 6 opposite Road Station 30+25 (see Sheet 4) . Sufficient materials will be kept onsite for maintenance purposes and construction -of back up filters as necessary. The dimensions of the dewatering filters will be approximately 10 feet by 20 feet. They will involve dug in silt fence backed by double staked hay bales on the outside and will have 6 inches of crushed stone or mulched hay in the bottom. In the event that secondary dewatering filters are needed at either location, they will be constructed no closer than 5 feet to the existing filter. Stream Flow and channel Protection The sewer is proposed to cross through Cochichewick Brook to the south and to pass beneath a stone culvert to the north. To control stream flow conditions and to protect the existing channels at each location, temporary check dams will be fabricated using plywood, timbers and sand bags and employed to suspend flow at the bridge and at the stone culvert during construction activities. ,Additional flash boards will be added to the outlet structure from Stevens Pond to temporarily suspend flow during construction of the sewer while working in the brook. Pumps will be used to draw down any excessive stream flow and bypass the construction area. Care will be taken to avoid downstream pump discharge scouring, and if necessary, a pump discharge diffuser will be utilized to disperse flow from the pump that will be used to draw down the brook. The flash boards, check dam and pump will be removed when work in the brook is finished, at which time the stream bed will be restored and erosion control barrier will be rearranged to isolate the remainder of the excavation north of the wing wall from the brook. 7 } 1 Clay trench dams will be utilized to eliminate the propensity of the sewer trench to act as a conduit for drainage to or from wetlands. Clay will be placed in the sewer trench before backfilling between the manhole at Sewer Station at 600+70 and the wetland boundary, and opposite Road Stations 11+00, 11+30t, 13+00±, 30+50t and 30+70t. 4.0 Restoration Specifications After construction is complete, the dewatering filters will be removed and the area will be restored and seeded with turf grass mix similar to that of the remaining lawn at the North Andover DPW. Remaining dewatering filter areas will be removed and seeded with conservation mix. Upland slope areas will be seeded with an aggressive slope stabilizing mix such as NH Slope 44 at the recommended application rate of 60 pounds per acre (refer to attached seed specifications) . All areas will be restored immediately after completion of the sewer installation. Remaining areas of wetland disturbance associated with the sewer trench or erosion control will be loamed and seeded with a 1:1 mixture of switchgrass and redtop. switchgrass (Pa.azcum virgatum) 1:1 mix seeded on exposed soil surfaces at an application rate redtop of 50 lbs./acre. (Agrostis alha) 5.0 Construction Monitoring As part of the site construction work, the owner will retain a wetland scientist to oversee construction activities. The oversight provided will include monitoring of construction activities, erosion control devices, planting of plant stock and reports to the North Andover Conservation Commission (NACC) documenting the restoration of the area. 8 Statue reports will be provided following construction and planting of the area and as requested thereafter until compliance is achieved and a Certificate of Compliance is attained. The reports will document any corrective actions required to attain appropriate compliance. Photographs will also be furnished to document the progress and to provide a basis for determining compliance. 6.0 Construc.tion Sequence Wetland CrossingStation 600+70 to 601+70 Notify wetland scientist and NACC of construction schedule prior to commencement of construction. - Install siltation fence and hay bale barrier as per site plan. Hay bales to be double staked. Siltation fence edge to be buried 6 inches. - Construct dewatering filter devices on adjacent DPW land. Siltation fence to be buried 6 inches. Hay bales to be double staked. Additional materials for maintenance purposes and for construction of an additional filter to be available onsite. - Mobilize heavy machinery, flash boards, lumber, trench box, pumps, hose, 3/4 inch plywood, timbers and sand bags to site. - Construct check dam upstream of bridge using plywood, timbers and sand bags. Leave a partial opening to be closed when construction commences. - Prepare pump discharge diffuser using plywood and timbers. - Cut flash boards to length for damming outlet of Stevens Pond. - Place trench box and begin excavation for sewer manhole at Station 600+00. Begin dewatering trench into filter devices. - Install sewer pipe and sewer manhole at station 600+70. - Install flash boards to dam Stevens Pond outlet. 9 t -- Close off opening in check dam at bridge. - Install pump upstream of bridge. Run hose to pump discharge diffuser. W Excavate sewer pipe trench to manhole at Station 601+70 stockpiling any topsoils in waiting trucks. Install steel ductile pipe between 5MH 600+70 and 601+70. Install clay trench dams on each side of wetland crossing between Sewer Station 600+70 and the wetland boundary and opposite Road Station 9+50. - Restore stream bed and extend erosion control to isolate stream bed excavation area from remainder of installation at eastern wing wall. Remove erosion control in stream channel. -- Enclose disturbed wetland area in erosion control. Slowly remove check dam. - Slowly remove flash boards from pond outlet. - Continue installing remainder of sewer line to Road Station 11+00±. Install clay trench dam opposite Road Station ll+00±. Backfill surface of trench with stockpiled topsoil and restore original grade. Repair guard rail and side walks. Seed entire disturbed area with grass seed mix. Monitor soil stability and remove silt fence and break up hay bales upon approval of NACC. Road Stations 11+30 to 13+00 - Notify wetland scientist and NACC of construction schedule prior to commencement of construction. - Install siltation fence and hay bale barrier as per site plans. -- Place trench box and begin excavation for ductile iron sewer pipe and sewer manhole at Station 604+70. 10 Add additional hose as necessary and dewater to filters on DPW lawn. Install clay trench dam in sewer lane opposite Road Stations 11+30± and 13+00±. Backfill trench and loam and seed with conservation mix upon completion of installation. Culvert Crossing at Road station 30+60 - Notify wetland scientist and NACC of construction schedule prior to commencement of construction. - Construct dewatering filter device in the field opposite Road Station 30+25. Additional materials for additional filter to be available nearby. - Install check dam of plywood, timbers and sand bags on upstream opening of stone culvert. - Install erosion control barrier across down stream opening of stone culvert. - Begin excavation of stone culvert for sewer line. - Begin dewatering into filter devices. - Install sewer line and repair stone culvert as necessary after construction is complete. - Install clay trench dams at Road Stations 30+50 and 30+70. -- Remove check dam when construction is complete and seed any disturbed wetlands. - Remove down stream erosion control barrier and seed disturbed wetlands. Adams, Roger and Bailey Squares - Notify wetland scientist and NACC of construction schedule prior to commencement of construction. 11 i r Establish erosion and sediment control barriers as per site plan. silt fence to be dug in and backed by hay bales. Hay bales to be double staked. Conduct inspection of erosion control barriers with NACC. Adjust or extend barrier as needed. - Construct erosion and sediment control pond. Install perforated extension pipe and wrap with hardware cloth and filter fabric. Backfill with crushed stone. Place rip-rap apron at outlet. Install subsurface utilities and begin project build out. - Monitor pond sediment and remove when accumulated depth exceeds one foot. Seed all exposed upland soils with grass seed upon completion. Monitor soil stability and remove silt fence and break up hay bales upon approval of NACC. 12 1 l New Hampshire Slope 44 Species % Composition creeping red fescue 42% perennial rye 33% alsike clover 8% bi.rdsfoot trefoil 8% redtop 8% Application rate: 60 lbs, per acre 13 IIAI Of (SINATIO RAIITATS 0UIH GR0VELAND QUAD Of STATI-1ism tAtt tl•LTLAMOS Wi )TI Ise oily la reftsosct 1s (it ketisals floleelita Act ts0e1011sas 1111 GMI ill MUatsl Iletit►ve A Laloatttel Species froSrsa Ysseeciasetls OI►hlot sl fislerleo i MiliHit '+ I It Ml)Dix<Im'.:.•'' IAft 'IiY'fit' moll w,. i � \ 1 •1�"1,;Yti�t�'9Y lit ... '•.� i. loll �1l;6 ' ;... �►.' f F1,51fitt SIT- t. �t' ••l,tlt,llll t �� S `i _ r 1 It,l •' \ , \ co#iieL erk \ tAIISH !=1 Pom Seale 'l.bQ,001 (1� inch + 5,000 feJ) 1991 EDITION ' See tasty Isles Mops to lecollo sllaceit sioalrtaSlti FIGURE 1 • ETLANOS •,RESERVATION INC. STEVENS CROSSING Osgood Street . r North Andover, MA i -071A PLAN (NO SCALE) S14y` �540—:. SECTION "A • A " ENO SCALE ) FIGURE 2 Dewatering Filter 569 North Street 47 Newton Road 126 Wildcat Road Georgetown, MA 01833 Plaistow, NH 03865 Barrington, NH 03825 (508)352-7903 [603] 382-3435 (603)664-7645