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HomeMy WebLinkAbout05/02/2018 - Stormwater Pollution Prevention Plan (SWPPP) and Construction Sequencing Plan - - 1210 Osgood Street HANCIOC K' ----­­­­­---................. ,ASSOC'LATES STORMWATER POLLUTION PREVENTION PLAN AND CONSTRUCTION SEQENCING PLAN Project: 1210 Osgood Street North Andover Client: Princeton Properties, Inc. NRP Group, Inc. Operator: NRP Group, Inc. SWPP Coordinator: Brenden Gilmore NRP Group, Inc. Cell Phone 978-735-2490 Plan Ref.: Erosion and Sediment Control Plan 4/20/18 Prepared by Hancock Associates. Date: 05-02-18 During the initial stages of site work, permanent stormwater measures as designed and detailed within the approved site plans and final project permitting are not applicable. This SWPPP is intended to cover the initial retaining wall, site preparation and stabilization construction operations required to reach reasonably level and stable construction grades close to finish grades.This SWPPP has been developed in coordination with the General Contractor, NRP Group, Inc. insuring all facets of site and building construction are considered.This plan has been developed to insure the initial stages of site clearing and earth movement are done in a manner that will protect the surrounding resource areas. We feel once the walls are build and final grades achieved, potential for sedimentation will be dramatically decreased and more standard measures can be implemented.The SWPPP coordinator will have day to day responsibility for implementation of the plan, have daily interaction with the sub-contractors and have the power to dictate certain and necessary measures to insure protection of the resource areas. This document should be considered part of the approval of the North Andover Conservation Commission, any change will require input and approval of the Conservation Agent and/or full commission. Best management practices (BMP)for erosion and sedimentation control are silt fence, hay bales,filter fences, hydro seeding, and phased development. Many stormwater BMP technologies (e.g., infiltration technologies) are not designed to handle the high concentrations of sediments typically found in construction runoff and must be protected from construction-related sediment loadings. Construction BMP's must be maintained.The fact that the project design utilizes modular retaining walls is being used as an integral part of the control of erosion and sedimentation toward the surrounding environs. In developing the construction sequencing for the proposed project, certain measures will be implemented to minimize impacts which erosion and sedimentation could have on surrounding areas. This section addresses items that involve proper construction techniques, close surveillance of workmanship, and immediate response to emergency situations.The developer must be prepared to provide whatever reasonable measures are necessary to protect the environment during construction and to stabilize all disturbed areas as soon as construction ends. The purpose of this document is describe the anticipated temporary and permanent soil erosion and sediment controls and construction sequencing that will be used during the initial "Pad Ready" project construction activities. Temporary control measures will be all those devices and practices design to reduce, mitigate or eliminate soil erosion and sediment control during active construction activities, prior to final project stabilization and site occupancy. Permanent control measures will be all those devices and practices designed to reduce, mitigate or eliminate soil erosion and sediment control when construction is completed, the site is occupied and all designed/approved stormwater infrastructure is in place and functionally operable. The main function and purpose of temporary erosion control practices is to prevent soil from uncontrolled migration into existing natural resources, including streams, brooks, ponds and wetlands. As such, the project anticipates implementing the above mentioned BMP's in the following sequence/purpose: Sequence Purpose BMP Passive cleaning of construction equipment Stabilized Construction Entrance(s) 1 entering and exiting the site Perimeter surface containment and filtration Perimeter silt fence,staked hay bales and 2 devices crushed stone check dams 3 Localized point source filtration device Catch Basin silt sacks Structural element—see approved plans Large segmental block retaining wall 4 Intended to provide a definitive separation from both construction activities and final land use(s) from existing natural resources Redirect,channelize and control surface Diversion swales and interior sedimentation 5 stormwater energy/volume within disturbed and basins with pond skimmers,as appropriate active construction zones 6 Centralize,manage and minimize potential point Stockpile stabilization and perimeter source soil migration or erosion stockpile controls 7 Temporary surface stabilization Hydro-seeding,mulch and crushed stone In addition to the above tangible temporary erosion control practices,there are additional good housekeeping practices that can be performed on a regular basis in order to minimize, reduce or eliminate soil erosion during active construction practices. These practical and common sense practices area as follows: A. Collect, store and monitor all onsite waste materials in a closed device, such a dumpster, barrel or waste receptacle commensurate with waste materials composition. B. Remove all stored waste from site on a routine basis,so as not to allow materials to accumulate and potentially spill beyond reasonable containment or confinement devices. C. Provide and maintain onsite sanitary waste units, having a regularly scheduled cleaning and disposal program. D. Provide and maintain an onsite spill prevention plan as well as spill clean-up kit. E. Provide regularly scheduled training and information sessions for all persons onsite, including visitors of long durations. F. Provide and monitor centralized personal vehicle, as well as construction equipment storage areas, including a first alert program notifying the SWPPP monitor of any known leaks, spillage or apparent visual defects requiring repairs. G. Do not permit any vehicle maintenance or repairs onsite H. Do not permit any bulk fuel or petroleum storage onsite I. Limit all chemical storage onsite to typical household volumes as usual and customary for normal cleaning activities. J. Implement a weekly street sweeping program of all hard surfaces within the construction activities zone of influence,which may or may not entail offsite activities. K. Implement a trucking inspection station that observes and monitors heavy trucking activities to insure trucks entering or exiting the site are utilizing their load tarps/coverings and are sufficiently clean so as not to transport unnecessary materials or debris on or off the active construction site. Pre-Construction Sequencing 1. Survey and flag wetlands buffer areas 2. Install wetlands signage and markings 3. Install erosion control measures per requirements- straw waddle, erosion control fence, etc 4. Schedule site inspections with Conservation Commission agent for pre-construction walk-thru 5. If necessary, make modifications outlined during pre-construction walk-thru prior to actual construction start. Construction Sequencing Phase 1 Phase 1 of the construction sequencing is the area tributary to the "1" series wetlands flags at the southeast corner of the site and partial tributary to the "2 series wetlands flags related to the retaining wall (only) at the northwest of the property identified behind building D .This area will be worked prior to any other work performed on site outside of mobilization and the setting of construction trailers. 1. Clear and grub vegetation only; (1) nthe area of the erosion control line, (2) proposed temporary sediment basin 1-1, (3) sediment basin 1-2, (4) proposed retaining wall R-5, R- 4, and R-2. Note- Erosion control will be install at perimeter of subject property prior to items 2-4 being cleared and grubbed. 2. Install construction entrance per plan. 3. Construct sediment basin 1-1, relocated sediment basin 1-2 and diversion swale 4. Begin wall installation for poured-in place wall R-4/R-5 5. Begin and install coursing at retaining wall R-2.Wall construction will run continuously through phase 1. 6. Place wall R-4/R-5 7. Proceed with clearing and grubbing of remaining area within Phase 1. 8. Backfill retaining wall R-4/R-5 9. Stabilize all areas down gradient of the wall and loam and seed embankment. 10. Maintain and modify as necessary the diversion swales and sediment basins as fill and wall operations proceed. Phase 2 Phase 2 includes the area in tributary to the "2" and "3" series wetlands. 1. Clear and grub vegetation in the area of the proposed erosion control line, retaining wall R-1 and all areas identified in the ESC plan as Phase 2. 2. Start construct sediment basin 2-11 2-2 and diversion 3. Begin wall installation for two to three courses and construct sediment basins and diversion swales behind walls as shown on detail in referenced plan. 4. Begin fill operation and advance walls higher. 5. Stabilize all areas down gradient of the wall with loam and seed. 6. Maintain and modify as necessary the diversion swales and sediment basins as fill and wall operations proceed. Phase 3 Phase 3 includes the area in tributary to the "3" series wetlands. 1. Clear and grub vegetation in area Phase 3 as identified in the ESC plan. 2. Begin fill operation and advance walls higher. 3. Construct sediment basin 2-3 and diversion 4. Maintain and modify as necessary the diversion swales and sediment basins as fill operations proceed. Phase 4 Phase 4 includes the balance of the site as this area is defined to the retaining wall and frontage of Osgood Street. 1. Clear and grub of phase 4 will take place during phase 2. 2. Begin wall installation for two to three courses 3. Begin fill operation and advance walls higher. 4. Maintain and modify as necessary the diversion swales and sediment basins as fill and wall operations proceed Inspection s The SWPPP Coordinator shall be primarily responsible to insure stormwater inspections are scheduled, performed and recorded. Stormwater observations or inspections may be performed by trained personal only, usually assigned members of the SWPPP team or their assigned agent(s). All stormwater BMP's shall be inspected or observed on a regularly scheduled basis, in accordance with the specific practice or after every major storm event defined as one inch in a twenty—four hour period. In general, the purpose of stormwater BMP inspections/observations is to verify the normal operations of installed erosion control measures in accordance with approved plans/permits. All measures should be found to be in good functional condition. The following inspection schedule shall be used as a guide only, as additional observations may be required depending on construction schedule, adverse weather and actual site conditions: BMP Observation Schedule Stabilized Construction entrance/entrance geometry,stone size,depth and Daily Entrance(s) cleanliness Perimeter silt fence,staked hay bales and crushed stone check Installation&condition,silt deposit or erosion Daily dams Catch Basin silt sacks Installation&condition,silt or debris deposits Bi-Weekly Large block retaining wall Installation&condition,stability Daily Stability,turbidity,inlet/outlet controls,silt or debris Diversion swales and interior deposits.Sediment ponds should be drained if more than sedimentation basins with pond half full in advance of a pending storm event. Draining Weekly skimmers,as appropriate shall be done in a controlled manner to insure turbid water is not discharged to the surrounding environment. Stockpile stabilization and Stability, perimeter controls, riels,soil migration,siltation Daily perimeter stockpile controls Hydro-seeding,mulch and Vegetative growth,stability,riels, material migration, crushed stone siltation Bi-Weekly In the event installed BMPs are compromised, damaged, missing or otherwise not functioning properly, the observation representative shall immediate complete a Correction Action Log (see appendix) in addition to the Observation Log, as well as verbally notify the appropriate construction representative responsible for stormwater measures corrective actions. Additionally, it will be encouraged to augment all SWPPP inspections/observations with photographs, videos or plan mark-ups, as applicable. Proper, sufficient and adequate stormwater observations/inspections logs records are critical to the resulting maintenance activities. All inspection/observation reports/logs are to be kept on site, as required by the construction manager/superintendent, typically within the project office(s). Duplicate copies shall be distributed to the Owner, Operator and applicable agencies, as specified in the project approvals. Landscaping Maintenance The SWPPP Coordinator shall be primarily responsible to insure stormwater maintenance activities are identified and recorded with the project specific Observation or Correction Action Log(s), as applicable. Additionally, the SWPPP Coordinator or his/her assigned agent(s) shall immediately verbally notify the appropriate construction representative responsible for stormwater measure maintenance, as well as follow up with written notification. BMP maintenance notification shall be specific to the applicable stormwater measure. Stormwater BMP maintenance shall be performed by the site contractor who installed the practice or assigned agent(s) by the construction manager/superintendent. All Stormwater BMP maintenance shall be performed in accordance with the approved plans/permits and manufacturer specification,whichever is more stringent.Similar to stormwater observations, maintenance activities, including BMP replacement or augmentation shall be performed by trained professionals. The following maintenance schedule shall be used as a guide only, as additional maintenance may be required depending on construction schedule, adverse weather and actual site conditions: BMP Maintenance Schedule Regrade—backdragorsimilar(trafficdependent) Daily Stabilized Construction Refresh stone material(traffic dependent) Weekly Entrance(s) Replace(traffic dependent) Monthly Perimeter silt fence,staked hay bales and crushed stone check Remove silt deposit, Fill erosion/riels,adjust placement Bi-Weekly Remove& replace blinded or damaged practice (as needed) dams Remove silt or debris deposits Bi-Weekly Catch Basin silt sacks Remove& replace blinded or damaged practice (as needed) Large block retaining wall Installation&condition,stability Daily Diversion swales and interior Remove silt or debris deposits Weekly sedimentation basins with pond Clean&clear inlet/outlet devices (as needed) skimmers,as appropriate Fill, re-grade,stabilize & re-establish practice Stockpile stabilization and perimeter stockpile controls Supplement and replace as necessary to contain sediment. Weekly Hydro-seeding,mulch and Any areas that are completed and can be stabilized should As needed crushed stone be immediately treated. If necessary,the SWPPP Coordinator shall be primarily responsible to maintain the integrity of the project SWPPP, including all edits, revisions and alterations. Landscaping Landscaping shall occur as soon as practical to provide permanent stabilization of disturbed surfaces. 2. If the season or adverse weather conditions do not allow the establishment of vegetation, temporary mulching with straw, wood chips weighted with snow fence or branches, or other methods shall be provided. 3. A minimum of 4 inches of topsoil shall be placed and its surface smoothed to the specified grades. 4. The use of herbicides is strongly discouraged. 5. Hydro seeding is encouraged for steep slopes. Application rates on slopes greater than 3:1 shall have a minimum seeding rate of 5-Ibs/1000 SF. A latex or fiber tackifier shall be used on these slopes at a minimum rate of 50 lbs. of tackifier per 500 gallons of water used. Training The SWPPP Coordinator shall be primarily responsible to create, implement and manage the SWPPP training program. The SWPPP training program will be developed to educate and inform individuals about the project specific SWPPP. This education program will include project awareness of project permit approvals, contracts, SWPPP applicability, purpose, responsibility, implementation and maintenance. There shall be two (2) levels of SWPPP training. The first and less invasive will be SWPPP awareness training, applicable to all full time persons actively working within the project limits, including management and ownership. The second level will be more in depth and focus on the purpose, use, implementation and maintenance of the project specific SWPPP. All individuals who receive second level training are required to sign the certification form, indicating they are certified by the SWPPP Coordinator and are eligible to perform SWPPP team duties, as assigned by the SWPPP Coordinator. SWPPP Training Certification "I certify under penalty of law, that I have been trained and have reviewed this APEX Center SWPPP document and all attachments, including appendices. I understand and acknowledge personal responsibility to implement, monitor, observe and maintain the project specific intended purpose of this SWPPP document and its supplemental information, including approved plans and permits. I accept potential future SWPPP duties and responsibilities, as assigned by the SWPPP Coordinator, if called upon to do so in accordance with the standard forms and documents provided herein. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing SWPPP violations." Name: Date: Title: Signature: Corporate Certification (NRP Group, Inc.—Owner/Operator) "I certify under penalty of law, that this SWPPP document and all attachments were prepared under my direction or supervision,in accordance with a system designed to assure that qualified personnel properly gathered and evaluated the information submitted herein. Based on my inquiry of the person or persons who manages the system, or those persons directly responsible for gathering the information, the information submitted is, to the best of my knowledge and belief, true, accurate, and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations." Name: Date: Title: Signature: APPPENDIX The purpose of this section is to provide supplemental information. • Construction General Permit • Inspection Log, Corrective Action Log, Annual BMP Maintenance Log • SWPPP Plan