(A) Soil erosion and sediment control-related measures are required for any land disturbance activity regulated by this chapter.
(B) The following requirements shall be met:
(1) Soil disturbances shall be conducted in such a manner as to minimize erosion. Areas of the development site that are not to be graded shall be protected from construction traffic or other disturbance until final seeding is performed. Soil stabilization measures shall consider the time of year, site conditions and the use of temporary or permanent measures.
(2) Properties and channels adjoining development site shall be protected from erosion and sedimentation. At points where concentrated flow leaves a development site, energy dissipation devices shall be placed at discharge locations and along the length of any outfall channel as necessary to provide a non-erosive velocity of flow from the structure to the watercourse so that the natural physical and biological characteristics and functions are maintained and protected.
(3) Soil erosion and sediment control features shall be constructed prior to the commencement of excavating or mass grading.
(4) Disturbed areas shall be stabilized with temporary or permanent measures within 14 calendar days following the end of active hydrologic disturbance, or redisturbance, consistent with the following criteria or using an appropriate measure as approved by the village:
(a) Appropriate temporary or permanent stabilization measures shall include seeding, mulching, sodding and/or nonvegetative measures.
(b) Areas or embankments having slopes greater than or equal to 3H:1V shall be stabilized with staked-in-place sod, mat or blanket in combination with seeding.
(c) Erosion control blanket shall be required on all interior detention basin side slopes between normal water level (or basin bottom for dry basins) and high water level.
(d) The 14-day stabilization requirement may be precluded by snow cover or where construction activity will resume within 21 days from when the active hydrologic disturbance ceased, in which case stabilization measures do not have to be initiated on that portion of the site by the fourteenth day after construction activity temporarily ceased, given that portion of the site has appropriate soil erosion and sediment controls.
(5) Land disturbance activities in streams shall be avoided, where possible. If disturbance activities are unavoidable, the following requirements shall be met:
(a) Where stream construction crossings are necessary, temporary crossings shall be constructed of non-erosive material.
(b) The time and area of disturbance of a stream shall be kept to a minimum. The stream, including bed and banks, shall be restablized within 48 hours after channel disturbance is completed or interrupted.
(6) Soil erosion and sediment control measures shall be appropriate with regard to the amount of tributary drainage area as follows:
(a) Disturbed areas draining greater than 5,000 square feet but less than one acre shall, at a minimum, be protected by a filter barrier (including filter fences, straw bales or equivalent control measures) to control all off-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) Disturbed areas draining more than one but fewer than five acres shall, at a minimum, be protected by a sediment trap or equivalent control measure at a point downslope of the disturbed area.
(c) Disturbed areas draining more than five acres, shall, at a minimum, be protected by a sediment basin with a perforated filter riser pipe or equivalent control measure at a point downslope of the disturbed area.
(d) 1. Sediment basins shall have both a permanent pool (dead storage) and additional volume (live storage) with each volume equal to the runoff amount of a two-year, 24-hour event over the on-site hydrologically disturbed tributary drainage area to the sediment basin.
2. If the detention basin for the proposed development condition of the site is used for sediment basin, the above volume requirements will be explicitly met. Until the site is finally stabilized, the basin permanent pool of water shall meet the above volume requirements and have a filtered perforated riser protecting the outflow pipe.
(7) All storm sewers that are or will be functioning during construction shall be protected by an appropriate sediment control measure.
(8) If dewatering services are used, adjoining properties and discharge locations shall be protected from erosion. Discharges shall be routed through an effective sediment control measure (e.g., sediment trap, sediment basin or other appropriate measure).
(9) All temporary soil erosion and sediment control measures shall be removed within 30 days after final site stabilization is achieved or after the temporary measures are no longer needed. Trapped sediment and other disturbed soil areas shall be permanently stabilized.
(10) A stabilized mat of aggregate underlain with filter cloth (or other appropriate measure) shall be located at any point where traffic will be entering or leaving a construction site to or from a public right-of-way, street, alley or parking area. Any sediment or soil reaching an improved public right-of-way, street, alley or parking area shall be removed by scraping or street cleaning as accumulations warrant and transported to a controlled sediment disposal area.
(11) Earthen embankments shall be constructed with side slopes no steeper than 3H:1V. Steeper slopes may be constructed with appropriate stabilization as approved by the village.
(12) Stormwater conveyance channels, including ditches, swales and diversions, and the outlet of all channels and pipes shall be designed and constructed to withstand the expected flow velocity from the ten-year frequency storm without erosion. All constructed or modified channels shall be stabilized within 48 hours.
(13) Temporary diversions shall be constructed as necessary to direct all runoff from hydrologically disturbed areas to the appropriate sediment trap or basin.
(14) Soil stockpiles having greater than 100 yards of soil and remaining in place for more than seven days shall not be located in a flood-prone area or waters of the United States. Soil stockpile locations shall be shown on the soil erosion and sediment control plan and shall have the appropriate measures to prevent erosion of the stockpile.
(15) Soil erosion and sediment control BMPs shall be designed and constructed per the requirements contained in the Illinois Urban Manual, 2002 (or current edition).
(Ord. 07-02, passed 4-16-2007)