(A) Applicability. All clearing, grading, stripping, excavating and filling which is subject to the permit requirements of this chapter shall be subject to the applicable standards and requirements set forth in this section.
(B) Responsibility. The permittee shall not be relieved of responsibility for damage to persons or property otherwise imposed by law, and the village or its officers or agents will not be made liable for the damage, by:
(1) The issuance of a permit under this chapter;
(2) Compliance with the provisions of that permit or with conditions attached to it by the village;
(3) Failure of the village officials to observe or recognize hazardous or unsightly conditions;
(4) Failure of the village officials to recommend denial or to actually deny a permit; or
(5) Exemptions from the permit requirements of this chapter.
(C) Site design requirements.
(1) Onsite sediment control measures, as specified by the following criteria, shall be constructed and functional prior to initiating clearing, grading, stripping, excavating or fill activities on the site.
(a) For disturbed areas draining less than one acre, filter barriers (including filter fences, strawbales or equivalent control measures) shall be constructed to control all offsite runoff specified in referenced handbooks. 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 disturbed areas draining more than one but less than five acres, an equivalent control measure shall be constructed at the downslope point of the disturbed area.
(c) For disturbed areas draining more than five acres, a sediment basin or equivalent control measure shall be constructed at the downslope point of the disturbed area.
(d) Sediment basins and sediment traps shall provide for both detention storage and sediment storage. The detention storage shall be composed of equal volumes of “wet” detention storage and “dry” detention storage and each shall be sized for the two-year, 24-hour runoff from the site under maximum runoff conditions during construction. The release rate of the basin shall be that rate required to achieve minimum detention times of at least ten hours. The elevation of the outlet structure shall be placed such that it only drains the dry detention storage.
(e) The required sediment storage volume may be calculated using the Universal Soil Loss Equation or from Figure 6-20 in the Green Book.
(2) Conveyance channels, because of the presence of concentrated flows typically having high velocities, warrant special consideration. Diversion channels, which are intended to route offsite flows away from disturbed areas, should be constructed as soon as possible in the construction process.
(a) For grades up to 4%, seeding in combination with mulch, erosion blanket or an equivalent control measure shall be applied. Sod or erosion blanket or mat shall be applied to the bottom of the channel.
(b) For grades of 4% to 8%, sod or an equivalent control measure shall be applied in the channel.
(c) For grades greater than 8%, rock, riprap or an equivalent control measure shall be applied, or the grade shall be effectively reduced using drop structures.
(3) Disturbed areas shall be stabilized with temporary or permanent measures within three calendar days following the end of active disturbance, or redisturbance, consistent with the following criteria:
(a) Appropriate temporary or permanent stabilization measures shall include seeding, mulching, sodding and/or non-vegetative measures; and
(b) Areas having slopes greater than 12% shall be stabilized with sod, mat or blanket in combination with seeding, or equivalent.
(4) Land disturbance activities in stream channels shall be avoided, where possible. If disturbance activities are unavoidable, the following requirements shall be met:
(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 restabilized within 48 hours after channel disturbance is completed, interrupted or stopped;
(c) Whenever channel relocation is necessary, the new channel shall be constructed in the dry and fully stabilized channel before flow is diverted; and
(d) Temporary stream crossings of intermittent and perennial streams used only for and during construction shall be designed to convey a two-year flood (minimum) or other flood event approved by the village or its designee without overtopping unless a more frequent design event is allowed by the village or its designee. The entire crossings shall be designed to withstand hydrodynamic and erosive forces up to the base flood event without washing out. Ephemeral streams may be crossed at temporary at-grade crossings provided that the crossing point is stabilized with materials resistive to the erosive forces produced by runoff from upstream drainage areas, and the design is approved by the village or its designee. Temporary stream crossings shall be removed upon completion of construction activities. All temporary stream crossings shall be completely removed and the stream restored to its preconstruction condition upon completion of construction. Restoration shall incorporate appropriate vegetation consistent with the adjacent existing vegetation prior to construction or in accordance with a restoration plan approved by the village or its designee.
(5) Storm sewer inlets and culverts shall be protected by sediment traps or filter barriers that meet acceptable design standards and specifications that will not cause flooding in public streets.
(6) 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 or drainage channel. Filter barriers, including straw bales, filter fence or equivalent, shall be installed immediately on the downslope side of the piles. Soil storage piles cannot be located in areas subject to frequent inundation.
(7) If dewatering 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.
(8) 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.
(9) All the temporary and permanent erosion and sediment control practices must be maintained and repaired as needed to assure effective performance of their intended function. The permittee or his or her designee must inspect the sediment and erosion control measures weekly and after half an inch or greater of rainfall. Repairs and modifications will be reviewed by the village or its designee.
(10) All temporary erosion and sediment control measures shall be disposed 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 should be permanently stabilized to prevent further erosion and sedimentation.
(11) The condition of the construction site for the winter shut down period shall address proper sediment and erosion control early in the fall growing season so that slopes and other bare earth areas may be stabilized with temporary and/or permanent vegetative cover. All open areas that are to remain idle throughout the winter shall receive temporary erosion control measures including temporary seeding, mulching and/or erosion control blanketing prior to the end of the fall growing season. The areas to be worked beyond the end of the growing season must incorporate soil stabilization measures that do not rely on vegetative cover such as erosion control blankets and heavy mulching.
(12) All run off from disturbed areas onsite must pass through sediment control facilities.
(D) Handbooks adopted by reference. The standards and specifications contained in the “Illinois Urban Manual” and the “Illinois Procedures and Standards for Urban Soil Erosion and Sedimentation Control” (the Green Book) cited in § 157.04, are hereby incorporated into this division (D) and made a part hereof by reference for the purpose of delineating procedures and methods of operation under site development and erosion and sedimentation control plans approved under § 157.04. In the event of conflict between provisions of the manuals and this chapter, the ordinance shall govern.
(E) Maintenance of control measures. All soil erosion and sediment control measures necessary to meet the requirements of this chapter shall be maintained periodically by the applicant or subsequent land owner during the period of land disturbance and development of the site in a satisfactory manner to ensure adequate performance.
(F) Inspection. The village shall make periodic inspections and shall notify the permittee wherein the work fails to comply with the erosion control plans or the site development plans as approved.
(G) Special precautions.
(1) If at any stage of the grading of any development site the village or their designee determines by inspection that the nature of the site is such that further work authorized by an existing permit is likely to imperil any property, public way, stream, lake, wetland or drainage structure, the village or their designee may require, as a condition of allowing the work to be done, that such reasonable special precautions be taken as is considered advisable to avoid the likelihood of the peril. SPECIAL PRECAUTIONS may include, but shall not be limited to a more level exposed slope, construction of additional drainage facilities, berms, terracing, compaction or cribbing, installation of plant materials for erosion control, and recommendations of a registered soils engineer and/or engineering geologist which may be made requirements for further work.
(2) Where it appears that storm damage may result because the grading on any development site is not complete, work may be stopped and the permittee required to install temporary structures or take such other measures as may be required to protect adjoining land or the general public safety. On large developments or where unusual site conditions prevail, the village may specify the time of starting grading and time of completion or may require that the operations be conducted in specific stages so as to insure completion of protective measures or devices prior to the advent of seasonal rains.
(H) Amendment of plans. Major amendments of the site development or erosion and sedimentation control plans shall be submitted to the village and shall be processed and approved or disapproved in the same manner as the original plans. Field modifications of a minor nature may be authorized by the village by written authorization to the permittee.
(Ord. 766, passed 10-20-2004)