1114.09 STORM WATER POLLUTION PREVENTION PLAN

   The SWPPP plan shall contain the following information and drawings:

   (a)    Site Description: A description of the nature and type of construction activity (residential, commercial, industrial, etc.); the total area of the site and of the area that will be disturbed; a calculation of both the pre- and post-construction runoff coefficient; an estimate of impervious area and percent imperviousness created by the construction activity; the name and/or location of the immediate receiving stream or surface water(s) and the first subsequent named receiving water; the extent and description of wetlands or other special aquatic sites at or near the site which will be disturbed or which will receive discharges from disturbed areas of the project; existing soil data; available data describing the quality of any discharge from the site; and a description of prior land use.

      (1)    Construction Schedule: An implementation schedule which describes the sequence of major construction operations (grubbing, excavating, grading, utilities and infrastructure installation) and the implementation of erosion, sediment, and storm water management practices or facilities as they relate to each step of the construction sequence.

      (2)    Site Map: The site map or maps shall contain the following:

         A.    Limits of earth disturbing activity, including associated off-site borrow or spoil areas that are not addressed by a separate NOI and SWPPP;

         B.    Soil types, especially the location of unstable or highly erodible soil;

         C.    Existing and proposed contours, including a delineation of drainage watersheds expected during and after major grading activities, as well as the size of each drainage watershed in acres;

         D.    Surface water locations (springs, wetlands, streams, lakes and water wells) on or within 200 feet of site;

         E.    Existing and planned locations of buildings, roads, parking facilities and utilities;

         F.    Location of all erosion and sediment control practices, including locations of areas likely to require temporary stabilization during the course of development;

         G.    Sediment and storm water managements basins, noting their sediment settling volumes and contributing drainage area;

         H.    Permanent storm water management practices to be used to control pollutant in storm water after construction operations have been completed;

         I.    Areas designated for the storage or disposal of solid, sanitary, and toxic wastes, including dumpsters, cement truck washout pits, and vehicle fueling;

         J.    Location of construction entrances;

         K.    Location of any in-stream activity, including stream crossings. Water ponding facilities should be drawn to scale.

      (3)    Nonstructural Preservation Methods: A description of practices which preserve existing natural conditions as much as feasible (the phasing of operations to minimize the amount of disturbed land at any one time, designated tree preservation areas, etc.)

      (4)    Erosion Controls: Erosion controls must be capable of providing cover over disturbed soils. The SWPPP must provide specifications (seed type, application rates, etc.) for stabilization of all disturbed areas of the site and provide guidance as to which method of stabilization will be employed for any time of the year.

Temporary stabilization must be applied:

         A.    Within seven (7) days of last disturbance on any area that will lie dormant for fourteen (14) days or longer, but less than one (1) year, (in case of a residential subdivision, at least seven (7) days prior to transfer of permit coverage for the individual lot);

         B.    Within two (2) days on any areas within fifty (50) feet of a stream that will remain idle for more than fourteen (14) days; and

         C.    Prior to the onset of winter in those areas that will be idle over winter.

         Permanent stabilization must be applied to any area:

         A.    Within seven (7) days of reaching final grade;

         B.    Within seven (7) days for areas that will lie dormant for one (1) year or more; or

         C.    Within two (2) days of reaching final grade within fifty (50) feet of a stream.

      (5)    Runoff Controls: The SWPPP shall incorporate measures to control runoff flows from disturbed areas to prevent soil erosion by directing the flows from exposed soils and steep slopes. Examples include rock check dams, pipe slope drains, and diversion berms and trenches.

      (6)    Sediment Control: Any site remaining disturbed more than fourteen (14) days must have structural sediment controls. Sediment basins and perimeter sediment barriers shall be implemented prior to grading and within seven (7) days from start of grubbing. Such controls must remain functional until the upslope area is restabilized. No sediment controls shall be placed in a stream. Detail drawings must be provided of all structural control practices. This should include outlet and inlet structures for detention/retention facilities including modifications to those facilities to aid in sediment removal. Installation instructions, such as installing silt fence along the contours and curving it upslope at the ends, must be included. Sediment controls include the following:

         A.    Sediment Settling Ponds - Concentrated runoff and runoff from drainage areas which exceed the design capacity of silt fence or inlet protection shall pass through sediment settling ponds. In addition, all common drainage locations serving ten (10) disturbed acres or more at one time must maintain a sediment pond until final stabilization of the site. Ponds shall be sized at sixty-seven (67) cubic yards per total contributing drainage acre; have a depth less than or equal to five (5) feet; and have the distance between inlet and outlet at least a 2:1 length:width ratio. The SWPPP must include provisions to remove sediment when the pond's capacity is reduced by fifty percent (50%). Sediment settling ponds shall further comply with the provisions of the most recent edition of Ohio EPA General Permit Authorization for Storm Water Discharges Associated with Construction Activity.

         B.    Silt Fence/Diversions - Sheet flow from denuded areas shall be intercepted by silt fence or diversions to protect adjacent property. Silt fence is limited to sheet flow situations and shall be placed on a level contour. The maximum drainage area behind silt fence shall not exceed one half (½) acre per 100 lineal feet of silt fence for less than two percent (2%) slope. For areas of greater slope the maximum drainage area shall be reduced as per the table in the most recent edition of Ohio EPA General Permit Authorization for Storm Water Discharges Associated with Construction Activity. Where the above criteria is exceeded, a diversion directing runoff to a sediment settling pond is indicated.

         C.    Inlet Protection - Unless the storm drain system drains to a sediment settling pond, practices shall be implemented to minimize sediment-laden water entering active storm drain systems. If the permittee chooses not to use structural curb inlet protection, it is imperative that a successful program be maintained utilizing other controls such as silt fence across lot frontage, prompt stabilization. street cleaning, and on-lot construction entrances.

         D.    Stream Protection - Structural practices shall be implemented to protect all adjacent streams from the impacts of sediment laden runoff.

         E.    Trench and Ground Water Controls - A trench or ground water which contains sediment must pass through a sediment settling pond or other equally effective sediment control device. Alternatively, sediment may be removed by settling in place, dewatering into a sump pit, filter bag or comparable practice. Groundwater dewatering which does not contain sediment or other pollutants is not required to be treated prior to discharge. A non-erosive channel must be provided to convey this water from the site. There shall be no turbid discharges to surface waters of the state resulting from dewatering activities.

         F.    Off-Site Traffic - Off-site vehicle tracking of sediments and dust generation shall be minimized.

         G.    Subdivision Lots - Where the SWPPP does not call for a centralized sediment control capable of controlling runoff from multiple lots, a detail drawing of a typical lot showing standard lot erosion and sediment control practices must be provided.

      (7)    Inspections: The SWPPP plan shall contain written statements requiring inspections to be made and recorded at the intervals heretofore stated in Section 1114.08(i).

      (8)    Maintenance: The SWPPP shall contain a description of maintenance procedures needed to ensure the continued performance of controls. Controls must be repaired and maintained as needed to ensure continued performance of their intended function. They must remain functional until all upslope areas are permanently stabilized. Sediment ponds must be repaired/maintained within ten (10) days of inspection. All other controls must be repaired/maintained within three (3) days of inspection. Documentation of when repairs and maintenance occur should become part of the inspection record. Maintenance plans shall be as further delineated in Section 1114.10(i).

      (9)    Post-Construction Storm Water Management: The SWPPP must contain a description of the post-construction facilities that shall be installed during construction of the project, including detailed drawings and notes pertaining to the operation of the facilities. Copies of these plans shall be given by the permittee to the post-construction operator of the facilities upon completion of construction. Design of post-construction storm water facilities shall meet the hereinafter presented requirements.

         (Ord. 48-21. Passed 12-6-21.)