Illinois Administrative Code
Title 35 - ENVIRONMENTAL PROTECTION
Part 372 - ILLINOIS DESIGN STANDARDS FOR SLOW RATE LAND APPLICATION OF TREATED WASTEWATER
Subpart B - SITE SELECTION CONSIDERATIONS
Section 372.240 - Loading Factors on Application Fields
Universal Citation: 35 IL Admin Code ยง 372.240
Current through Register Vol. 48, No. 38, September 20, 2024
a) General
The size of the application area shall be based on the limiting characteristic of the treated wastewater and the site. Balances shall be calculated and submitted for water, nitrogen, phosphorus, and 5 Day Biochemical Oxygen Demand (BOD5). Loading rates must be established for each parameter. The critical loading rate will determine the application area required.
b) Water Balance
1) The water balance for the application site
shall include the applied treated wastewater, runon from adjacent areas,
precipitation, evapotranspiration, permeability, groundwater recharge rate and
effect on water table depth and subsurface tile drainage. The system shall be
designed so that runoff does not occur as a result of treated wastewater
application. Treated wastewater shall not be applied during precipitation
events; however, runoff in response to precipitation is acceptable. The water
balance shall be calculated on a rational basis for each month and exclude the
days on which application cannot occur due to rainfall, frozen or wet ground
conditions, cropping practices, high groundwater conditions or wind in excess
of design conditions.
2) The design
shall provide for alternate wetting and drying periods in order to maintain
aerobic conditions in the topsoil, as well as to maintain a viable cover
crop.
3) The design daily
percolation rate shall not exceed 10% of the minimum soil permeability at the
site. The percolation rate calculations shall exclude the days on which
application cannot occur due to rainfall, frozen or wet ground conditions,
cropping practices, high groundwater conditions or wind in excess of design
conditions.
c) Nitrogen Balance
1) On an annual basis, the total
nitrogen applied in the treated wastewater shall be within agronomic rates and
shall be accounted for by crop uptake, volatilization, denitrification,
adsorption, mineralization and metal precipitation. Any application of chemical
fertilizer must be accounted for in the design.
2) Land application areas shall be managed
according to normal agricultural and horticultural practices, including but not
limited to cultivated farmland with harvest, fallow land, set-aside programs,
pasture land, golf courses, sod farms, urban parks, or forest
preserves.
Disclaimer: These regulations may not be the most recent version. Illinois may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
This site is protected by reCAPTCHA and the Google
Privacy Policy and
Terms of Service apply.