(A) Generally. The preparation of soil erosion and sediment control plans shall follow the principles outlined in the Illinois Procedures and Standards for Urban Soil Erosion and Sedimentation Control, excepting Chapter Six published by the Urban Committee of the Association of Illinois Soil and Water Conservation Districts. The design criteria, standards and methods shall be prepared in accordance with the requirements of this chapter and the standards and specifications contained in Illinois Urban Manual prepared for the Illinois Environmental Protection Agency by the U.S.D.A. Natural Resources Conservation Service, which standards and methods are hereby incorporated into this chapter by reference. In the event of conflict between the provisions of said manuals and of this chapter, this chapter shall govern.
(B) Erosion and sediment control design requirements. New developments or redevelopments shall comply with § 114.042 and meet the following.
(1) Control measures shall be constructed to control runoff from the property to such an extent possible that sediment is retained on-site.
(2) Temporary on-site control measures required shall be constructed and functional prior to initiating clearing, grading, stripping, excavating or fill activities on the site.
(3) Disturbed areas shall be stabilized with permanent measures within seven calendar days following the end of active disturbance, or re-disturbance consistent with the following criteria:
(a) Appropriate permanent stabilization measures shall include seeding, mulching, sodding, with non-vegetative measures as a last resort; and
(b) Areas having slopes greater than 33% shall be stabilized with sod, mat or blanket in combination with seeding or equivalent.
(4) All temporary and permanent erosion and sediment control practices must be maintained and repaired as needed to assure effective performance of their intended function.
(5) All temporary erosion and sediment control measures shall be disposed in a proper manner within 30 days after final site stabilization is achieved with permanent soil stabilization measures. Trapped sediment and other disturbed soils resulting from the disposition of temporary measures shall be permanently stabilized to prevent further erosion and sedimentation.
(6) Site development requirements. On-site sediment control measures, as specified by the following criteria, shall be constructed as specified in the referenced handbooks, and functional prior to initiating clearing, grading, stripping, excavating or fill activities on the site.
(a) For new developments or redevelopments less than one acre, or for a tract of land where a single-family dwelling is being erected and less than 10,000 square feet of impervious surface is being developed, filter barriers (including filter fences, straw bales or equivalent control measures) shall be constructed to control all on-site runoff. Vegetated filter strips, with a minimum width of 25 feet, may be used as an alternative only where runoff in sheet flow is expected.
(b) For new developments or redevelopments more than one acre but less than five acres, a sediment trap designed in accordance with the IEPA Standards and Specifications for Soil Erosion or equivalent control measure shall be constructed at the downslope point of the disturbed area.
(c) For new developments or redevelopments greater than five acres, a sediment basin or equivalent control measure shall be constructed at the downslope point of the disturbed area.
(d) Sediment basin and sediment trap designs shall provide for both “dry” detention and “wet” detention sediment storage. The detention storage shall be composed of equal volumes of “wet” detention storage and “dry” detention storage and each shall be sized as regulated in §§ 114.020 through 114.025. The release rate of the basin shall be that rate as regulated in §§ 114.020 through 114.025. The elevation of the outlet structure shall be placed such that it only drains the dry detention storage.
(e) The sediment storage shall be sized to store the estimated sediment load generated from the site over the duration of the construction period with a minimum storage equivalent to the volume or sediment generated in one year. For construction periods exceeding one year, the one-year sediment load and a sediment removal schedule may be substituted.
(f) The alteration of sinkholes by filling, grading or excavation is prohibited, including an area within 25 feet from the rim.
(g) To the extent possible or as otherwise regulated in this chapter all desirable trees eight inches in diameter and larger shall be protected for their present and future value for erosion protection and other environmental benefits. Trees that have been selected for preservation shall be marked prior to the beginning of any clearing, grading, stripping, excavation or filling of the site. A no construction zone shall be established and marked at the perimeter of the drip line of each tree which is to be preserved.
(7) Stormwater conveyance channels, including ditches, swales, and diversions, and the outlets of all channels and pipes shall be designed and constructed as regulated in §§ 114.020 through 114.025. All constructed or modified channels shall be stabilized within 48 hours, consistent with the standards as required in the IEPA Erosion Control Manual Standards and Specifications for Soil Erosion and Sediment Control.
(a) Construction vehicles shall be kept out of the stream channel to the maximum extent practicable. Where construction crossings are necessary, temporary crossings shall be constructed of non-erosive material, such as riprap or gravel.
(b) The time and area of disturbance of stream channels shall be kept to a minimum. The stream channel, including bed and banks, shall be stabilized within 48 hours after channel disturbance is completed, interrupted or stopped.
(9) Storm sewer inlets and culverts shall be protected by sediment traps or filter barriers meeting accepted design standards and specifications.
(10) Soil storage piles containing more than ten cubic yards of material shall not be located with a downslope drainage length of less than 25 feet to a roadway, drainage channel or sinkhole. Filter barriers, including straw bales, filter fence or equivalent, shall be installed immediately on the downslope side of the piles.
(11) If de-watering devices are used, discharge locations shall be protected from erosion. All pumped discharges shall be routed through appropriately designed sediment traps or basins, or equivalent and shall not be deposited into a sinkhole.
(12) Each site shall have graveled (or equivalent) entrance roads, access drives and parking areas of sufficient length and width to prevent sediment from being tracked onto public or private roadways. Any sediment reaching a public or private road shall be removed by shoveling or street cleaning (not flushing) before the end of each workday and transported to a controlled sediment disposal area.
(1993 Code, § 114.38) (Ord. 2000-09, passed 8-16-2000) Penalty, see § 114.999