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Home My WebLink About2016-10-04 Operation and Maintenance Plan DTO SPR MOD III NN�� I��IrIl0�Il01/�% OPERATION AND MAINTENANCE PLAN FOR. WEST MILL REDEVELOPMENT PHASE 1 & 2 PARKING LOT DEVELOPMENT 4W HIGH STREET NORTH ANDOVER, MA 01845 PREPARED FOR: RCG, LLC 17 IVALOO STREET, SUITE 100 SOMERVILLE, MA 02143 PREPARED BY: Civii. DESIGN GROUP, 1.111c 21 HIGH STREET, SUITE 207 NORTH ANDOVER,MA 01845 HORSLEY WITTEN GROUP 90 ROUTE 6A,UNIT#1 SANDWICH,MA 02563 DATE: JULY 2015 REVISED: SEPTEMBER 2016 N '�f�l f111�(iia�1111N11111fu1ff%!!`"` TABLE OF CONTENTS Page 1.0 INTRODUCTION 2 2.0 RESPONSIBILTY FOR OPERATION AND MAINTENANCE 3 3.0 MAINTENANCE/INSPECTION SCHEDULE AND TASK 3 3.1 Conveyance Structures 4 3.2 Pretreatment Practices 4 3.3 Stormwater Treatment Practices 5 3.4 Routine Maintenance 7 3.5 Invasive removal 7 4.0 LONGTERM POLLUTION PREVENTION PLAN 9 5.0 ESTIMATED OPERATION AND MAINTENANCE BUDGET 11 APPENDICES Appendix A: Inspection Forms Appendix B: Site Plans West Mill Redevelopment 1 Horsley Witten Group,Inc. North Andover, MA July 2015 H:\Projects\2014\14077 RCG LLC-West Mill North Andover\Reparts\Storrrvmter\O&M\141124-4&M Plan-14077.doc WEST MILL REDEVELOPMENT STORMWATER OPERATION AND MAINTENANCE PLAN 1.0 INTRODUCTION All stormwater management and controls are to be operated and maintained appropriately during regular operation of the site in the post-construction period. The Property Owner and/or Property Management Company is to provide, inspect, and maintain all stormwater management and controls. The following document provides the operation and maintenance (O&M) requirements for the permanent stormwater management system for West Mill Redevelopment the stormwater controls identified in the plan provided in Appendix A, will be inspected regularly to prevent deficiencies in the effectiveness of the systems due to sediment build-up, damage, or deterioration. Permanent stormwater controls are to be operated and maintained appropriately during the regular operation of the site in the post-construction period as well as during the construction phase of the project. West Mill Redevelopment 2 Horsley Witten Group,Inc. North Andover,MA July 2015 H:\Pr0iects\2014\14077 RCG UC-West Mill North Andover\Reports\Storin�•iater\O&M\141124-Q&M Plan-14077,60c 2.0 RESPONSIBILITY FOR OPERATION AND MAINTENANCE Owner: RCG LLC Contact: Responsible party to be designated by RGC The owner is responsible for the continuous operation and maintenance of the stormwater BMPs and associated drainage areas. 3.0 MAINTENANCE/INSPECTION SCHEDULE AND TASKS The maintenance objective for these practices includes maintaining the hydraulic and pollutant removal capacity of the systems and maintaining healthy native, vegetative cover. This section describes the required O&M measures for each site. Also included is a plan showing the location of the items to be inspected and maintained, as well as a specific O&M checklist that Maintenance Staff will use during inspections. During the six months immediately after construction, all BMP retrofit practices should be inspected monthly as well as after precipitation events of at least 1.0 inch to ensure that the system is functioning properly. The following activities are recommended during the first six month after construction: • Inspection of flume inlet, swale, sediment forebay weir, and side slopes for erosion gullying. Repair/re-vegetate as necessary. • Proper grass seed establishment and satisfactory growth. Additional loam and overseeding may be required within the first 6 months to correct bare spots and thin growth, • Watering as required to establish and maintain grass. • Loam and seed any void areas or washouts along the bioretention bed caused by precipitation runoff. Thereafter, inspections shall be conducted twice annually (spring and fall) and after major storm events, which are those greater than or equal to the 1-year, 24-hour precipitation event (-2.5" in Essex County). The following tasks are recommended as specified or as needed basis and broken into four main categories as identified on the attached O&M Site Plan. West Mill Redevelopment 3 Horsley Witten Group,Inc. North Andover, MA July 2015 H:\Projects\2014\14077 RCG LLC-West Mill North Art(lover\Reitarts\5tormwater\O&M\141124-O&M Plart-14077.doc 3.1 Drainage Conveyance Structures (Inflow/Outflow) • Flume Inlet • Overflow Structure • Sidewalk Trench Grates • Spillways • Diversion Structures • Inline Drain • Underdrains • Drainage Pipes All drainage conveyance structures should be inspected and twice annually (spring and fall) and after major storm events to monitor for proper operation, collection of solids, litter and/or trash, and structural deterioration. The structures should be cleaned annually, or when the depth of sediment exceeds one half the depth from the bottom of the invert, and repaired when required. Flume Inlets, in particular, should be inspected for sediment build-up at entrances, which may cause blockage and re-direction of flow away from the applicable facility. Accumulated sediment shall be removed and disposed of properly. All drainage inlets, catch basins, drain manholes, and oil-water/grit separators will be inspected at least twice annually (spring&fall) to monitor for proper operation, collection of solids, litter and/or trash, and structural deterioration. The structures will be cleaned annually or when the depth of sediment exceeds one half the sump depth, and repaired when required. Sediments shall be removed by clam-shell or vacuum-truck; they will not be removed by flushing. Proprietary traps and filters associated with practices shall be maintained as recommended by the manufacturer. Collected sediment will be disposed of properly in a pre-approved off-site location. 3.2 Pretreatment Practices Sediment Forebay: The swale and sediment forebay function as pretreatment for the primary practice. A general inspection and maintenance of the swale and forebay shall be conducted twice annually (spring and fall) and after major storm events. Maintenance work consists of the following: • Removal of any trash and/or debris. • Removal of sediment when buildup is greater than or equal to 2 inches. Sediment should be removed by hand or shovel in both linear sediment forebay (Type 2) and typical sediment forebay(Type 1). Any plants damaged or removed during sediment removal should be replaced with the same plant genus and species as shown on Sheet C-14 of the Construction Plans. Sediment shall be disposed of off-site in a pre- approved location. • Correction of any side slope erosion gullying, animal burrowing or slope slumping, and replanting as necessary. • Correction of any erosion along the bottom of the swale, particularly near the sidewalk trench grate. Repair with appropriate material. • Correct any settling of the weirs/check dams between the sediment forebay and the primary treatment area. Ensure that weirs/check dams are level. Correct any erosion that has occurred around the edges of the weir. West Mill Redevelopment 4 Horsley Witten Group, Inc. North Andover, MA July 2015 F1:\Projects\2014\14077 RCG I.1.0-West Mil€North Andovet'\Reports\Stornnvater\b&M\141124-O&M Plan-14077.doc • Remove and replace vegetation as necessary, using the appropriate species as shown on Sheet C-14 of the Construction Plans. 3.3 Stormwater Treatment Practices A stormwater treatment system should be regularly inspected to ensure proper performance and to prevent deficiencies in the effectiveness of the systems due to sediment build-up, damage, or deterioration. The following operation and maintenance provisions should be provided: Filtering Systems Bioretention Areas General maintenance of the bioretention area falls under landscaping practices. A general inspection and maintenance of the bioretention area shall be conducted twice annually (spring and fall) and after major storm events. Maintenance work consists of the following: • Removal of any trash and/or debris. • Correction of any side slope erosion gullying, animal burrowing or slope slumping, and replanting as necessary. • If standing water is observed in the bioretention 48 hours after a storm event, the top 6 inches of the bioretention soil/mulch area shall be roto-tilled or cultivated to breakup any hard-packed sediment, and replenished with mulch and replanted. The underdrain system shall be snaked and/or flushed. Replant with species as shown on Construction Plans. • In a worst-case scenario, the entire filter bed may need to be re-installed. Upon failure, excavate bioretention soil, rake the pea gravel to loosen, inspect underdrain trench to determine if it has been compromised, repair as necessary, replace soil, replant, and mulch. Plant maintenance is critical to the function of the bioretention area and should include the following: • Cut back grasses, sedges, and rushes annually in the spring. • Remove and replace vegetation as necessary, using the appropriate species as shown the Construction Plans. If at least 50 percent vegetation coverage is not established after two years, a reinforcement planting should be performed. When replacing a plant, place the new plant in the same location as the old plant, or as near as possible to the old location, The exception to this recommendation is if plant mortality is due to initial improper placement of the plant (i.e., in an area that is too wet or too dry) or if diseased/infected plant material was used and there is risk of persistence of the disease or fungus in the soil. The best time to plant is in early to mid-fall or early to mid-spring. Plants should be planted as soon as possible after purchase to ensure the best chance of survival. If possible, new plants should be approximately the same size as those that are being replaced. If surrounding plants have already become well established, care may need to be given to the new plants to ensure successful growth. • Plant Thinning: Separation of herbaceous vegetation rootstock should occur when over-crowding is observed, or approximately once every 3 years. West Mill Redevelopment 5 Horsley Witten Group,Inc. North Andover,MA July 2015 H:\Projects\2014\14077 RCG LLC-West Mill North Andover\Reports\Stortnwatcr\O&M\141124-O&M Plan-14077.doc • Mowing: Mowing of the bioretention area is NOT necessary or recommended. By design, plants in bioretention areas are meant to flourish throughout the growing season, leaving dry standing stalks during the dormant months. When mowing near bioretention areas, either use a mulching blade, or point the mower away from the bioretention area. Fresh grass clippings are high in nitrogen and should not be applied to bioretention areas, as they will compromise the facility's pollutant reduction effectiveness. • Weeding: Weeding should be limited to invasive and exotic species, which can overwhelm the desired plant community. However, native non-invasive volunteer species are often desirable, as they add to the diversity of the plant community. Non-chemical methods (hand pulling and hoeing) are preferable; chemical herbicides should be avoided. • Fertilizing: Proper selection of plant species and support during establishment of vegetation should eliminate the need for fertilizers and pesticides. • Watering: Watering is necessary during the first few weeks after planting, and during drought conditions. During drought conditions, plants should be watered a minimum of every seven to ten days. Mulching: Replace mulch every two years, in the early spring. The previous mulch layer should be removed, and properly disposed of, or roto-tilled into the soil surface. Mulch layers should not exceed 3" in depth. Avoid blocking inflow entrance points with mounded mulch or raised plantings. Once a full groundcover is established, mulching may not be necessary. All barren areas within the extents of the facility shall be replenished with mulch and re-vegetated to the original design standards. Bioretention Maintenance Schedule ..... General Maintenance Task Frequency Time of the Year Min. twice annually(spring Site Inspection and fall) & after major storm Spring thru Fall events. Min. twice annually (spring Debris removal and fall) & after major storm Spring thru Fall events. Min.twice annually(spring and fall) or when sediment is Sediment removal > 2" in sediment forebay; April Ensure sediment does not cause blockage of flume inlet Plant Maintenance Task Frequency Time of the Year Plant Cutting/Thinning Annually Early Spring Weeding As needed April-October West Mill Redevelopment 6 Horsley Witten Group, Inc. North Andover, MA July 2015 H:\Projects\2014\14077 RCG LLC-West Mill Narth Andover\Reports\Stormiadater\O&M\141124-O&M Plan-14077.doc Watering Drought conditions only July-August Plant Replacement As required Spring or Fall preferred Fertilizing Should not be required Mulch Maintenance Task Frequency Time of the Year Remove & replace existing Once every two years or as April mulch required Min. 2x per year& after Re-mulch void areas major storm events as July& November needed Filter Bed Maintenance Task Frequency Time of the Year Tilling As needed If standing water does not drain after 48 hours If standing water does not Soil Media Replacement As needed drain after tilling (see above) Snow Removal Not required Not required 3.4 Other Routine Maintenance Other routine maintenance should include removal of trash and litter from paved and perimeter areas, and street sweeping a minimum of once per year after the spring thaw. The pipes draining the project should be inspected annually for proper operation. Specific considerations when maintaining the parking lots, roadway surfaces, and grounds are as follows: • Pet Waste Removal: Pet waste should be picked up and disposed of properly to reduce bacteria levels in stormwater. • Snow Removal: Plowed or shoveled snow piles should not block the flume inlet structure or be placed in the bioretention area. Note that snow removal is NOT recommended in the bioretention area. • De-Icing: When de-icing compounds are necessary for the parking lot and sidewalk, the least harmful chemicals should be used. Excessive salting of the parking lot/sidewalks should be avoided. Use of large amounts of sand should also be avoided, since it may obstruct the conveyance system. Ice removal is NOT recommended in the bioretention area. 3.5 Invasive Removal Proposed Management Techniques for Phragmites The Applicant proposes an on-site integrated control program to address the small population of Phrogmites adjacent to Osgood Pond (see below for location).This area will be managed using the "cut and drip" method during the months of July and August following tasseling to control the spread of this species within the resource areas. Application of glyphosate by a Licenses Pesticide Applicator in MA using a hand sprayer will follow two to three weeks after West Mill Redevelopment 7 Horsley Witten Group,Inc. North Andover, MA July 2015 W\Projects\2014\14077 RCG LLC-West MR1 North Andover\Reports\Stormv�ater\0&M\141124-0&M Plan-14077.doc cutting the plant to a height of six inches. This may be required for more than one growing season. Repeated cutting of remaining Phrogmites stems will be continued as necessary to eliminate the plant from this area. Use of herbicide shall be limited to the invasive removal area below. Monitoring of Mitigation Areas The Applicant proposes to monitor the Mitigation Areas over the course of the first two growing seasons, in a schedule similar to that typically required for BVW replication areas (i.e., twice annually). Initial monitoring of the restoration area may be more frequent during the grow-in period, such as following initial planting and seeding, and after the first month of the growing season to inspect newly installed plantings. Monitoring activities should include an assessment of the relative success of the restored area,the health and vigor of the plantings, and provide recommendations for replacement of any dead or dying vegetation. Annual monitoring reports should be submitted to the North Andover Conservation Commission and MA DEP. OSGOODPOND APPROWMATEINVASIVE ~�— .p REMOVALAREA EE E r r / r 106 Oo w� 3 .. �' � �T,r�� .•�+—h ..ram" West Mill Redevelopment 8 Horsley Witten Group,Inc. North Andover,MA July 2015 H:\ProjectsN2014\14077 RCG LLC-West Mill North Andover�Reports\Stormtvater\O&M\141124-O&M Plan-14077.doc LONG-TERM POLLUTION PREVENTION PLAN Long-term pollution prevention measures implemented at the each project site will further reduce pollutants in stormwater discharges after construction, The following practices will be employed on an on-going basis. Spill Prevention and Control Measures To minimize the risk of spills or other accidental exposure of materials and substances to stormwater runoff, the following material management practices will be used throughout the project: • An effort will be made to store only enough products required for operation and maintenance of the facility. • All materials stored on-site will be stored in a neat, orderly manner in their appropriate containers and, if possible, under a roof or other enclosure. • Products will be kept in their original containers with the original manufacturer's label. • Substances will not be mixed with one another unless recommended by the manufacturer. • Whenever possible, the maximum amount of a product will be used before disposing of the container. • Manufacturers' recommendations for proper use and disposal will be followed. • The site superintendent will be issued the O&M to ensure proper use and disposal of materials, To reduce the risk associated with hazardous materials used on the site, the following practices will be used: • Products will be kept in original containers unless they are not resealable. • Original labels and material safety data sheets will be retained and kept on-site;they contain important product information. • If surplus product must be disposed of, manufacturers' or local and state recommended methods for proper disposal will be followed. Materials or substances listed below may be present on-site for operation and maintenance: • Materials List: o Concrete o Cleaning Solvents o Fertilizers o Wood a Asphalt o Tar o Petroleum Based Products o Adhesives o Paints (enamel and latex) o Sealants The following product-specific practices will be followed on-site: Petroleum Products-All on-site vehicles will be monitored for leaks and receive preventative maintenance to reduce the chance of leakage. Petroleum products will be West Mill Redevelopment 9 Horsley Witten Group,Inc. North Andover,MA July 2015 I I:\Projects\2014\14077 RCG LLC-West Mill North Andover\Reports\5tormvrater\O&M\141124-Q&M Plan-14077.doc stored in tightly sealed containers which area clearly labeled. Any asphalt substances used on-site will be applied according to the manufacturers' recommendations. • Fertilizers—Fertilizers shall be slow release, low-nitrogen types (< 5%) and phosphorous free, and shall not be used within 25 feet of a resource area. Fertilizers used will be applied only in the minimum amounts recommended by the manufacturer. Once applied,fertilizer will be worked into the soil to limit exposure to stormwater. Products will be stored in a covered shed. The contents of any partially used bags of fertilizer will be transferred to a sealable plastic bin to avoid spills. • Paints—All containers will be tightly sealed and stored indoors when not required for use. Excess paint will not be discharged to the storm and/or sewer system but will be properly disposed of according to the manufacturers' instructions or state and local regulations. • Concrete Trucks—Concrete trucks will not be allowed to wash out or discharge surplus concrete or drum wash water on the site. Lawn/Landscaping Maintenance Lawn and landscaping maintenance will be conducted with minimal use of fertilizers and pesticides to protect the nearby wetland and water resources. Fertilizers utilized for landscaping and lawn care shall be slow release, low-nitrogen types (< 5%) and phosphorous free, and shall not be used within 25 feet of a resource area. Pesticides and herbicides shall not be used within 100 feet of a wetland resource area. Fertilizer will be applied a maximum three times during the growing season, and pesticides will be applied sparingly, as needed,following the manufacturer's directions for application. Any fertilizer/pesticide that lands on paved surfaces such as sidewalks and/or parking areas will be swept up and removed immediately to prevent it from entering the storm drain network. Geese will be discouraged from foraging on the lawn areas to reduce nutrient and bacteria inputs from their droppings. Pet Waste Management Residents will be encouraged to pick up after their pets with signage along lawn areas. Solid Waste Management An enclosed dumpster with a lid will be provided on-site for solid waste management at the site during facility operations. Snow Management/Removal Plan Plowed snow collected from the roadway and parking area will be not be directed to the stormwater management system. Winter road salt and/or sand will not be stored on-site and will be used minimally as necessary for safe driving conditions at the site. Snow storage areas shall be those identified on the Operation and Maintenance figure, If the identified locations are insufficient, snow will be transported to appropriate alternate locations on the property as required. Pavement Sweeping Schedules The roadway and parking area will be swept annually after spring snowmelt. West Mill Redevelopment 10 Horsley Witten Group, Inc. North Andover, MA July 2015 H:\Projects\2014\14077 RCG LLC-West Mill North Andover\Re pot ts\Stormvinter\O&M\141124-0&M Plan-14077.doc Illicit Discharges No sewer pipes or floor drains will be connected to the drainage network. All wastewater will be connected to in approved locations. Personnel Training All contracted personnel retained for work on site will be given a copy of this Plan and will receive training in applicable practices and implementation to prevent pollutants from entering the stormwater system. 4.0 ESTIMATED OPERATION AND MAINTENANCE BUDGET The estimated average annual operating and maintenance budget for the proposed system is shown below: Bioretention Areas/Bioswales (10): $10,000 Source: Center for Watershed Protection (CWP) ($1,000/each) Catch Basins and Drain Manholes: $3,400 ($200/basin) Source: Massachusetts Highway Department Other Routine Maintenance: $2,000 Removal of trash and litter Annual street sweeping Pipe network/outfall inspections Total: $15,400 West Mill Redevelopment 11 Horsley Witten Group,Inc. North Andover, MA July 2015 HVrojects\2014\14077 RCG LLC-West(Aill North A;iclover\Reports\stormvaater\O&M\14tl24-O&M Plan-14077.do[ APPENDIX A Inspections Forms Bioretention Areas operation and Maintenance Checklist West Mill Redevelopment North Andover, Massachusetts Date: Time: Inspector: Location: Maintenance Maintenance Item Description Required? i 1. Conveyance Structures' Inspect annually and after major storm events(I.-yr storm or greater) Flume.Inlet::. Sidewalk Trench Grate Overflow Structure Remove all trash, debris, and sediment from all structures Debris Cleanout annually or when sediment buildup is half the depth from the invert to the bottom, as applicable.* Remove sediment from flume inlet regularly or when a Manholes/Diversion build-up is noticed that impacts inflow. If inlet becomes Structures/Outlets blocked,the Bioretention area will not receive the proper flow. Check for settling gullying or erosion. Ensure spillway is Emergency Spillways level. Repair as necessary if damaged or settling. Return to design grades. 2. Sediment Forebay—Inspect annually and after major storm events(1-yr.storm.or greater) Debris Cleanout Remove all trash and debris from the swale and forebay. Sediment/Organic Debris Sediment build-up shall be removed and properly disposed Removal of when build-up is greater than or equal to 3 inches.* Side Slopes Repair as necessary if signs of erosion gullies,animal burrowing, or slumping are observed. River Stone Look for areas of erosion in the swale, particularly near the sidewalk trench grate. Repair/replace stone as necessary. Boulder Walls Ensure that walls have not settled. Check for areas of erosion or water seepage. Repair as necessary III-established, dead or severely diseased plants will be Vegetation Maintenance removed and replaced annually. See Sheet LA-1 of Construction Plans for appropriate species. laiht i*i e Item ' '; Description' Requei Qda e ADS Water Quality Unit Per manufacturers recommendations. See Appendix D. 3. BioretentionArea—Inspect at least bi-annually and:after major storm events the first year;then annually '. and after major storm events(Z-yr storm or greater) Debris Cleanout Remove all trash and debris from the surface of the bioretention system. Side Slopes Repair as necessary if signs of erosion gullies, animal burrowing, or slumping are observed. If standing water is observed in the bioretention area 48 Sediment/Organic Debris hours after a storm event,the bottom 6 inches shall be Removal rototilled or cultivated to breakup any hard-packed sediment,and replenished with mulch.* Monitor the bioretention soil for proper pH, erosion,and aeration. Well-aged (minimum 6 months),shredded hardwood mulch shall be replaced bi-annually as needed, Vegetation Maintenance/ and ill-established, dead or severely diseased plants will be Replacement removed and replaced annually. See Sheet LA-1 of Construction Plans for appropriate species. Grasses, sedges,and rushes should be cut back annually in the spring. Water Draining properly Ensure standing no standing water for more than 48 hours. If standing water check cleanouts for clogging or aerate. 4. Routine Grounds Maintenance'--Inspect annually Debris Removal Remove trash from perimeter areas. Pavement Sweeping Sweep parking lot minimum once a year after spring thaw. Contributing drainage area Contributing drainage area stabilized Drainage Network Ensure proper operation. *Sediment shall be disposed of offsite in a pre-approved location. Comments: Actions to be Waken: Bioswale Operation and Maintenance Checklist West Mill Redevelopment North Andover, Massachusetts Date: Time: Inspector: Location: Maintenance Maintenance Item Description.; Requireci� 1 Conveyance Structures;-Inspect annually and aftermalor storm events.(1-yr storm or greater) Flume Inlet. . Sidewalk Trench Grate Overflow Structure Remove all trash, debris, and sediment from all structures Debris Cleanout annually or when sediment buildup is half the depth from the invert to the bottom, as applicable.* Remove sediment from flume inlet regularly or when a Paved Drainage Flume build-up is noticed that impacts inflow. If inlet becomes blocked, the facility will not receive the proper flow. Look for areas of erosion at bottom of inlet. Check for clogging and debris accumulation on outlet Outlet Structures grates or in bottom of outlet structure. Repair as necessary. Check for settling gullying or erosion. Ensure spillway is Emergency Spillways level. Repair as necessary if damaged or settling. Return to design grades. 2. Sediment.Forebay—Inspect annually and after major storm. events( -yr storm or greater) Debris Cleanout Remove all trash and debris from the Swale and forebay. Sediment/Organic Debris Sediment build-up shall be removed and properly disposed Removal of when build-up is greater than or equal to 3 inches.* Side Slopes Repair as necessary if signs of erosion gullies, animal burrowing, or slumping are observed. III-established, dead or severely diseased plants will be Vegetation Maintenance removed and replaced annually. See Sheet LA-1 of Construction Plans for appropriate species. Boulder Checkdams No evidence of flow going around structures. No evidence at downstream toe `MALA aintenance Maintenance Item Descriiptlon Required? 3. Bioswale-Inspect at least bi-annually and after major storm events the first year;then annually and after major storm.events(i-yr storm or greater) Debris Cleanout Remove all trash and debris from the surface of the bioretention system. Side Slopes Repair as necessary if signs of erosion gullies,animal burrowing, or slumping are observed. if standing water is observed in 48 hours after a storm Sediment/Organic Debris event,the bottom 6 inches shall be rototilled or cultivated Removal to breakup any hard-packed sediment, and replenished with mulch.* Vegetation Maintenance/ Mow twice per year minimum (4"-6"grass height) Replacement Water Draining properly Ensure standing no standing water for more than 48 hours. If standing water check cleanouts for clogging or aerate. 4. Routine Grounds Maintenance Inspect annually Debris Removal Remove trash from perimeter areas, Pavement Sweeping Sweep parking lot minimum once a year after spring thaw. Drainage Network Ensure proper operation. Contributing drainage area Contributing drainage area stabilized *Sediment shall be disposed of offsite in a pre-approved location. Comments: Actions to he Taken: r APPENDIX B Site Plans it I� r _ s In ��- lo D 0. U` 0. t-- yg r w� Z' _ Lu of 0 r 7 rs w x r eaanematl z 1 -- ,uNuw¢cawc.r �'(lFan � fo*cwx LEGEND wmA I �� I � j, � eauv smucxunr El -C---A .4EID 77777Ag3c If 81ORETENTION AREA r III 5 ' ivI I NOTES: OEWILNT / i. i raAOKr t Y A SNOWAPPROPRIATE OFF SITE LO RE A71ON AS REATE.QUIRED. SNOW WILL BE TRANSPORTED TO APPROPREA7E OFF SITE LOCATION AS REOUtRED. 2.FLOWED OR SHOVELED SNOW STORAGE SHOULD NOT BLOCK THE FLUME h g K I I iumn INLET STRUCTURE OR BE PLACED IN THE BIORETENTION AREA NOTE THAT SNOW REMOVAL IS NOT RECOMMENDED 3N THE BICRETENTION AREA. 3.PLOWED SNOW COLLECTED FROM THE ROADWAY AND PARKING AREA WILL BE NOT BE MRECTEb TO THE STORMWATER MANAGEMENT SYSTEM.WINTER ROAD SALT ANDIOR SAND WILL NOT BE STORED ON41TE AND WILL BE USED MfNIMALLY a,'A �.��ava` AS NECESSARY FOR SAFE DRIVING CONDITIONS AT THE SITE a GRAPHIC SCALE .w«.,.., m o +o m u eo f '\� I i 14077 SINCH•20 FEET � 4 �n 0' 1 -rf•r + ttt `-/�J � � OVERFLOW _OUTLET BIQRETENTION AREA //Ifs/jj BIO RETENTION F # '// • / AREAS ENT j 'FORE EBARY <x XC If 71 SNOW STORAGE;Xntrx\/ AREAS FLUME� Cx -,�_;' ��a_—i. OVERFLOW v ! JN_LET BiORETENTION AREA 9 r Ilk ! * OUTLET ExiS,Z5 NOTES' BU:LD;NG SNOW LINEAL SEDIMENT r 1. SNOW STORAGE AREAS ARE I r�r .. i'rr SNOW STORAGE ,�= APPROXIMATE. SNOW WILL BE i - ! 1 STORAGE FOREBARY ' . TRANSPORTED TO THE APPRd?�R'ATE AREA OFTSI'.E LCCAMON AS REQUIRED. '—' j I�ij rif AREA I I r # 2. PLOWED OR SHOVELED SNOW STORAGE SHOULD NOT BLOCK THE FLU ME INLET STRUCTURE OR BE 'fir/r'r1 �c PLACED AN THE BIORETENTION AREA. NOTE THAT SNOW REMOVAL IS NOT U 7, AREA.RECOMMENDED IN THE BtdRETENTIdN I Glr� 44 I I PLOWED SNOW COLLECTED FRO THE ROADWAY AND PARKING AREA ?' ,, WILL NOT BE DIRECTED TO THE .`�.' t - r . - �s I STORMWATER MANAGEMENT SYSTEM. WINTER ROAD SALT AND/OR SAND WILL NOT BE STORED ONSTE ANIIri� �i WILL BE USED MINIMALLY AS ` �`ff'il'=i NECESSARY FOR SAFE ORN€NGrr. � CONDITIONS AT THE SITE. ff ' .�l l Y , ROG LLC 40 4 20 44 SQ CIVILDEsiGV 17 IVALOO STREET I�o—T FOR COVSTRU£TIC)A� GROUP LLC SOMER4ILLE, MA 02143 5„� > OPERATIONS AND PWkINTENANCE I ® PLAN GRAPHIC SCALE IN FEET cas�x,n o WEST MILL PARKING LOT I vaunt.+>roo�Ta,xn u:rss NORTH ANDOVE.R, MA PLAN -_ n:9%H?ao,vm e4^wxs-av?i 01845 f DATE: 09/28/2016 COG 15001