kane county stormwater technical guidance manual - Kane County, IL

§ T300(g) Limitation on Site Disturbance
The limitation on site disturbance is in recognition of the need to prevent
erosion in preference to controlling sediment. Site disturbances shall not
exceed 20 acres at any one time unless it is to balance cut and fill, for which a
maximum of 40 acres may be disturbed at any one time. The Administrator
has considerable flexibility to vary the maximum area of disturbance based on
site or project specific conditions, or in recognition of a particularly effective
plan with aggressive and effective implementation. The amount of area open
to erosion at any one time poses a risk for delivery of sediment downstream
and the risk needs to be minimized consistent with the requirements of getting
the project constructed.
The plan for limiting disturbance should be fully developed with both the
applicant and the contractor and may not be finalized until a permit is issued
but before construction. It should also be flexible to meet the challenges of
Kane County weather patterns in the prime construction season.
Certain areas will be disturbed repeatedly, such as utility corridors and haul
roads. These areas are not exempt from sediment and erosion control, but
when defined on a plan or in the field, do not become subject to the limitation
on disturbed area.
Areas such as sedimentation basins and detention/retention facilities are also
exempt from the area limitations.
Outside the normal spring and fall planting seasons, temporary stabilization
may be accomplished by hydroseeding with heavy mulch. Multiple
treatments may be necessary to adequately stabilize the site. The use of
erosion control blankets with or without seed also meet the requirements.
Permanent stabilization requires the placement of seed or sod. In the case of
dormant season seeding the use of erosion control blankets or heavy
mulching with permanent seeding satisfies the requirement. The use of
heavy mulch may require multiple treatments depending on weather
conditions and dislodgment protection.
§ T300(h) Erosion and Sediment Control Plan Requirements
Figure 16 illustrates the minimum components necessary for an erosion and
sediment control plan sheet. The plan should clearly detail all phases of site
construction and the erosion and sediment control practices to be installed.
All permanent stabilization is to be shown on a separate plan sheet using
practices shown in Table 8.
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