Illinois Administrative Code
Title 35 - ENVIRONMENTAL PROTECTION
Part 372 - ILLINOIS DESIGN STANDARDS FOR SLOW RATE LAND APPLICATION OF TREATED WASTEWATER
Subpart D - PREAPPLICATION TREATMENT AND STORAGE
Section 372.420 - Storage
Current through Register Vol. 48, No. 38, September 20, 2024
a) Storage Volume
All land application systems must provide adequate storage, with adequacy being determined using either of the following methods, except that those facilities that do not generate wastewater year round must use Method I:
Adequate storage shall be based on a rational design that must include capacity for the wettest year with a 20-year return frequency. The volume provided shall be sufficient to hold flows received during the following periods:
The minimum storage capacity, by volume, shall be capable of storing at least 150 days production of wastewater, at design average flow, except that in southern Illinois areas (defined as all areas south of Interstate 70) a minimum of 120 days storage capacity shall be provided.
b) Design and Construction Requirements
The storage lagoon must be designed and constructed in accordance with 35 Ill. Adm. Code 370, Illinois Recommended Standards for Sewage Works.