This section is adopted for the purpose of controlling the pollution of public waters by sediment from accelerated soil erosion and accelerated stormwater runoff caused by earth disturbing activities and land use changes connected with developing urban areas. The development of commercial, industrial, residential, recreational, public service or other non-farm projects in the City of Twinsburg shall require a Storm Water Pollution Preven-tion Plan.
(a) General. The work shall consist of temporary and permanent control measures as shown on the Storm Water Pollution Prevention Plan and as directed by the Engineer to control soil erosion and sedimentation through the use of straw or hay bales, sediment traps, sediment basins, silt fences, earth diversion dikes, check dams, storm drain inlet protection grasses and mulches, per the construction plan details of the Ohio Department of Transportation (ODOT) in accordance with Standard Construction Drawing MC 11, and "Rainwater and Land Development Manual". The implementation of soil erosion and sediment control shall also conform to the requirement of the Ohio Environmental Protection Agency (OEPA) under the NPDES Permit Program for the discharge of storm water from construction sites and the erosion and sediment control practices. If conflicts exist regarding the soil and sediment control practices, the more restrictive shall apply.
(b) Erosion Control Procedures. In order to control sediment pollution of watercourses the owner or person responsible for the development area shall use conservation planning and practices to maintain the level of conservation established by the following stan-dards:
(1) Timing of sediment trapping practices. Sediment control practices shall be functional throughout earth disturbing activity. Settling facilities, perimeter controls and other practices intended to trap sediment shall be implemented as the first step of grading and within seven (7) days from the start of grubbing. They shall continue to function until the upslope development area is restabilized. Other erosion control items may be necessary due to environmental conditions.
(2) Stabilization of disturbed areas. Disturbed areas shall have soil stabilization applied within seven (7) days if they are to remain dormant (undisturbed) for more than forty-five (45) days. For areas within fifty (50) feet of any live stream, soil stabilization practices shall be initiated within two (2) days on all inactive, disturbed areas. Permanent or temporary soil stabilization shall be applied to disturbed areas within seven (7) days after final grade is reached on any portion of the site. When seasonal conditions prohibit the application of temporary or permanent seeding, non-vegetative soil stabilization practices such as mulching and matting shall be used.
(3) Settling facilities. Concentrated stormwater runoff from disturbed areas shall pass through a sediment settling facility. Sediment Basins shall be constructed in accordance with ODOT standard construction drawing MC-11 using free draining rock discharge control devices. The temporary sediment basin shall have volume capacities per the "Manual for Lotus Trap Efficiency, Template (TE) Developed by Summit SWCD-USDA Soil Conservation Service and Summit County Engineers" and the contractor shall periodically clean out sediment as needed.
(4) Sediment barriers. Sheet flow runoff from disturbed areas shall be intercepted by sediment barriers. Sediment barriers such as sediment fences, straw bale barriers, or diversion directing runoff to settling facilities, shall protect adjacent properties and water resources from sediment transported by sheet flow.
(5) Stream protection. Streams, including beds and banks, shall be restabilized immediately after in channel work is completed, interrupted or stopped. Where in channel work is necessary, precautions shall be taken to stabilize the work area during construction to minimize erosion. All ditches with grades over 1.5% should have ditch protection applied.
(6) Construction access routes. Measures shall be taken to prevent soil transport onto surfaces where runoff is not checked by sediment controls, or onto public roads.
(7) 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 slopes, soil type, upslope drainage area, groundwater conditions, and slope stabilization.
(8) Stabilization of outfalls and channels. Outfalls and construction of modified channels shall be designed and constructed to withstand the expected velocity of flow from a post development, ten (10) year frequency storm without eroding. Rock channel protection shall be in accordance with ODOT Item 601 and shall be provided at all outfalls.
(9) Establishment of permanent vegetation. A permanent vegetative cover shall be established on disturbed areas not otherwise permanently stabilized. This shall include furnishing of all topsoil, seed, commercial fertilizer, mulch and water and placing all materials on a prepared bed per ODOT Item 659. Permanent vegetation shall not be considered established until ground cover is achieved which, in the opinion of the Engineer, provides adequate cover and is mature enough to control soil erosion satisfactorily and to survive adverse weather conditions.
(10) Inspection and maintenance. All temporary and permanent erosion and sediment control practices shall be inspected at least once every seven (7) days and within 24 hours after any storm event greater than 0.5 inches of rain per 24 hour period. The owner's designated representative shall inspect the practice and direct maintenance and repairs by the contractor to assure continued performance of their intended function.
(11) Preservation and restoration of environmental easement areas (wetlands). Construction activities which cross environmental easement areas shall endeavor to preserve these areas with as little damage to the vegetation and soils as possible. The placement of earth or fill material shall be minimized. Heavy equipment working in the wetlands shall be placed on mats. All temporary fills shall be removed in their entirety. The vegetation and soils shall be restored to conditions prior to construction activities.
The above standards are general guidelines and shall not limit the right of the Municipal Engineer to impose additional, more stringent requirements, nor shall the standards limit the right of the Municipal Engineer to waive individual requirements.
(Ord. 173-2000. Passed 12-17-00.)