(a) General Requirements.
(1) In order to control sediment pollution of water resources, the developer, owner, operator or person(s) responsible for the development area shall use conservation planning and practices to maintain the level of conservation established by the standards outlined in Section 1399.05(b) hereof.
(2) These standards outlined herein are general guidelines and shall not limit the right of the City to impose additional, more stringent requirements, nor shall the standards limit the right of the City to waive individual requirements.
(3) Erosion and sediment control practices used to satisfy the standards outlined herein shall meet the specifications in the latest edition of the Division of Soil and Water Conservation, Ohio Department of Natural Resources technical guidance document entitled, "Rainwater and Land Development, Ohio's Standards for Stormwater Management Land Development and Urban Stream Protection," or specifications in other erosion and sediment control manuals, or other accepted practices, receiving prior City approval. Reasonable modifications and variations to standard details and/or specifications will be considered by the Administrator provided that the proposed modification meets the basic requirements of this regulation. Justification shall be provided, upon submission of erosion and sediment control plans for review and approval, for rejecting each practice outlined in 1399.05(b) hereof, based on site conditions.
(b) Standards and Criteria.
(1) Sediment deposition caused by accelerated stormwater runoff over a development site or by accelerated erosion due to the sloughing or sliding of surface soil that has been exposed by grading, dumping, stockpiling or any other excavation-related earth disturbances shall be retarded and confined to within the boundaries of the development site, during site development.
(2) Timing of Sediment-Control Practices: Sediment control practices shall be functional throughout earth-disturbing activities. Sediment Ponds (including sediment basins and traps) and perimeter controls intended to trap sediment shall be implemented as the first step of grading and within seven days from the start of grubbing. They shall continue to function until the upslope development area is permanently stabilized.
(3) Stabilization/Non-structural Practices: Control practices shall preserve existing vegetation where attainable and disturbed areas shall be re-vegetated as soon as practicable after grading or construction. Such practices may include: temporary seeding, permanent seeding, mulching, matting, sod stabilization, vegetative buffer strips, phasing activities (to minimize denuded areas), and protection of trees.
A. Stabilization of Disturbed Areas. Disturbed areas must be stabilized as specified in the following tables below. Permanent and temporary stabilization are defined in Section 1399.01:
TABLE 1: Permanent Stabilization
Area requiring permanent stabilization | Time frame to apply erosion controls |
Any areas that will lie dormant for one year or more | Within seven (7) days of the most recent disturbance |
Any areas within 50-feet of a stream and at final grade | Within two (2) days of reaching final grade |
Any other areas at final grade | Within seven (7) days of reaching final grade within that area |
TABLE 2: Temporary Stabilization
Area requiring temporary stabilization | Time frame to apply erosion controls |
Any disturbed areas within fifty (50) feet of a stream and not at final grade | Within two (2) days of the most recent disturbance if the area will remain idle for more than 14 days |
For all construction activities, any disturbed areas that will be dormant for more than 14 days but less than one year, and not within 50 feet of a stream | Within seven (7) days of the most recent disturbance within the area For residential subdivisions, disturbed areas must be stabilized at least seven (7) days prior to transfer of permit coverage for the individual lot (s). |
Disturbed areas that will be idle over winter | Prior to the onset of winter weather |
When seasonal conditions prohibit the application of temporary or permanent seeding, non-vegetative soil stabilization practices such as mulching and matting shall be used, until such time as conditions permit seeding.
B. Permanent Stabilization of Conveyance Channels. The person or persons who are undertaking land disturbing activities shall employ special measures to stabilize channels and outfalls and prevent erosive flows. Measures may include seeding, dormant seeding (as defined in the latest edition of the Rainwater and Land Development Manual, by the Ohio Department of Natural Resources and the Ohio EPA), mulching, erosion control matting, sodding, riprap, natural channel design with bioengineering techniques or rock check dams.
(4) Structural Practices: Structural practices shall be used to control erosion and trap sediment from all sites remaining disturbed for more than fourteen (14) days. Such structural practices shall store runoff allowing sediments to settle and shall divert flows from exposed soils or otherwise limit runoff from eroding exposed areas of the site. Such practices may include, among others, sediment traps, sediment basins, silt fences, earth diversion dikes, check dams, and storm drain inlet protection:
A. Settling Ponds: Concentrated stormwater runoff from denuded areas flowing at rates which exceed the design capacity of sediment barriers shall pass through a sediment-settling pond. The pond's storage capacity shall be a minimum of sixty-seven (67) cubic yards per acre of total contributing drainage area with a minimum 48-hour drain time. Settling ponds, by definition, include sediment basins and traps. For common drainage locations that serve an area with ten (10) or more acres disturbed at one time, a temporary (or permanent) sediment settling pond must be provided until final stabilization of the site. The applicant may request approval to use alternative controls if it can demonstrate the alternative controls are equivalent in effectiveness to a sediment pond. It is recommended for drainage locations serving less than ten (10) acres, smaller sediment basins and/or sediment traps should be used. To the extent practicable, and without causing adverse effect to adjacent properties, the off-site contributory area to settling ponds should be minimized or eliminated, using diversion berms around the perimeter of the site disturbed area.
B. Sediment Barriers: Sheet flow runoff from denuded areas shall be intercepted by sediment barriers. Sediment barriers, such as sediment fences, 12-inch diameter sediment barriers or diversions directing runoff to settling ponds, shall protect adjacent properties and water resources from sediment transported by sheet flow.
1. Silt fence. When intended to provide sediment control, silt fence shall be placed on a level contour. This criteria is not intended to preclude the use of other effective sediment barriers designed to control sheet flow runoff. The relationship between the maximum drainage area to silt fence for a particular slope range is shown on the table below.
Maximum drainage area (in acres) to 100 lineal feet of silt fence | Range of slope for a particular drainage area (in percent ) |
0.5 | < 2% |
0.25 | 2% but < 20% |
0.125 | 20% but < 50% |
2. Diversions. Storm water diversion practices shall be used to keep runoff away from disturbed areas and steep slopes where practicable. Such devices, which include swales, dikes or berms, may receive storm water runoff from areas up to ten (10) acres.
C. Storm Sewer Inlet Protection: All storm sewer inlets which accept water runoff from the development area shall be protected so that sediment-laden water will not enter the storm sewer system without first being ponded and filtered or otherwise treated to remove sediment unless prior approval is granted by the City and/or the storm sewer system drains to a settling pond. All inlets receiving runoff from drainage areas of one acre or more will require a sediment settling pond.
(5) Stream Protection. Structural practices shall be designed and implemented on site to protect all adjacent streams, from the impacts of sediment runoff. If a stream channel must be disturbed, the environmental impacts of the disturbance shall be minimized. Furthermore, if a stream channel must be disturbed, the site owner shall provide notification to the City of Groveport, at least 48-hours prior to any such work. In the event work is necessary within or across a stream, the following controls shall be implemented.
A. Mitigation measures shall be undertaken to stabilize disturbed areas and repair damages to the stream channel and adjacent bank area immediately after the disturbance is completed.
B. Streams including channel-bed and banks shall be re-stabilized immediately after in-channel work is completed, interrupted, or stopped. To the extent practicable, construction vehicles shall be kept out of streams. Where in-channel work is necessary, precautions shall be taken to stabilize the work area during construction to minimize erosion.
C. If a wet channel must be crossed by construction vehicles regularly during construction, a temporary stream crossing shall be provided.
(6) Construction Access Routes. Measures shall be taken to prevent soil transport onto surfaces or onto public roads where runoff is not checked by sediment controls.
(7) Sloughing and Dumping.
A. No soil, rock, debris, or any other material shall be dumped or placed into a water resource or into such proximity that it may readily slough, slip, or erode into water resources, unless such dumping or placing is authorized by the City or its representatives and when applicable, the U.S. Army Corps of Engineers, for such purposes as, but not limited to, construction of bridges, culverts, and erosion control structures.
B. Unstable soils prone to slipping or landsliding shall not be graded, excavated, filled or have loads imposed upon them unless the work is done in accordance with a qualified professional engineer's recommendations to correct, eliminate, or adequately address the problems.
(8) Cut and Fill Slopes: Cut and fill slopes shall be designed and constructed in a manner which will minimize erosion. Consideration shall be given to the length and steepness of the slope, soil type, upslope drainage area, groundwater conditions, and slope stabilization.
(9) Stabilization of Outfalls and Channels: Outfalls and constructed or modified channels shall be designed and constructed to withstand the expected velocity of flow from a post-development, ten-year frequency storm without eroding.
(10) Establishment of Permanent Vegetation. A permanent vegetation shall not be considered established until ground cover is achieved which, in the opinion of the Administrator, provides adequate cover and is mature enough to control soil erosion satisfactorily and to survive adverse weather.
(11) Disposition of Temporary Practices: All temporary erosion and sediment control practices shall be disposed of within thirty days after final site stabilization is achieved or after the temporary practices are no longer needed, unless otherwise authorized by the approving agency. Trapped sediment shall be removed or permanently stabilized to prevent further erosion.
(12) Maintenance: All temporary and permanent erosion and sediment control practices shall be designed and constructed to minimize maintenance requirements. They shall be maintained and repaired as needed to assure continued performance of their intended function until all up slope areas they control are permanently stabilized. The person or entity responsible for continued maintenance and inspection of permanent and temporary erosion controls shall be identified to the satisfaction of the Administrator.
Procedures in the plan shall provide that all erosion and sediment controls on the site are inspected (by the owner or the owner's representative) at least once every seven (7) calendar days and within twenty-four (24) hours after any storm event greater than 0.5 inch of rain per twenty-four (24) hour period, to ensure that sediment and erosion control devices are functioning properly. Repairs and/or maintenance shall be made to control practices within three (3) days of the inspection. If an inspection reveals a control practice is not providing the intended function and needs replaced with a more appropriate control, then the Erosion and Sediment Control Plan shall be amended; the new control must be installed within ten (10) days of the inspection.
Recordkeeping: Records shall be developed and maintained by the owner/operator or the owner's site representative in a manner that is compliant with the Ohio EPA's General NPDES permit for construction activity (see OEPA NPDES Construction General permit- Part III.G.2.i.). These records shall be made available upon request by either the City or the Ohio EPA.
(13) To the maximum extent practicable, soil loss shall be minimized through the use of Best Management Practices (BMP's), as referenced within the latest edition of the Division of Soil and Water Conservation, Ohio Department of Natural Resources technical guidance document entitled, "Rainwater and Land Development, Ohio's Standards for Stormwater Management Land Development and Urban Stream Protection", or referenced within other design manuals, determined to be acceptable by the City.
(14) Underground utility line construction involving dewatering operations: To the extent practicable, sediment-laden effluent from dewatering operations and effluent discharged from dewatering operations to surface-lands and/or surface-waters, shall be controlled by structural practices to filter and trap sediment, such that the erosion and sedimentation resulting from dewatering operations, does not affect flowing streams and lands on or off-site.
(c) Off-site Drainage Facilities for Sediment Control. At the City's discretion, the City may allow surface water runoff and associated sedimentation to be discharged into drainage facilities off the site of development only if each of the following conditions are met:
(1) It is not practicable to completely manage runoff and sedimentation on the site in a manner that meets the performance standards and design standards of this regulation;
(2) The off-site drainage facilities and channels leading to them are designed, constructed and maintained in accordance with the requirements of this regulation;
(3) Adverse environmental impacts from the site of development will be minimized.
(4) A request to use off-site drainage facilities and all information related to these proposed drainage facilities should be made a part of the developer's application.
(Ord. 19-005. Passed 2-25-19.)