Section 306.402  Restricted Status

a)         Restricted status means the Agency's determination that a sewer has reached hydraulic capacity or a sewage treatment plant has reached design capacity and, as a result, additional sewer connection permits may no longer be issued without causing a violation of the Act or regulations.

b)         The Agency may place a sewage treatment plant on Restricted Status when any of the following conditions exist, as shown by Agency field inspections, operational reports, records of permits issued, or other information:

1)         Hydraulic overloading of the treatment plant as determined by a comparison of the permitted design capacity of the plant with the actual average monthly flows measured at the plant during the three low-flow months in the preceding 12-month period, adjusted to include all outstanding (permitted but not connected) permits issued by the Agency, or other information on hydraulic loading of the plant available to the Agency (i.e., water pumpage, recent development, demographic and meteorological data, etc.);

2)         Organic overloading of the treatment plant as determined by the comparison of the permitted design capacity of the plant with the actual average monthly loadings in the preceding 12-month period, adjusted to include all outstanding (permitted but not connected) permits issued by the Agency, or other information on organic loading of the treatment plant available to the Agency (i.e., water pumpage, recent development, demographic and meteorological data, etc.);

3)         Continuing violation of effluent limitations established by the treatment plant's National Pollutant Discharge Elimination System (NPDES) permit.  Determining a violation of effluent limitations must be made according to the sampling, testing, and averaging procedures specified in the NPDES permit;

4)         Operational neglect resulting in frequent bypassing of any treatment unit or units; or

5)         An Illinois Pollution Control Board decision finding a violation of Section 12(a) of the Environmental Protection Act [415 ILCS 5/12(a)].

c)         The Agency may place sanitary sewers and lift stations on Restricted Status to prevent overflows as prohibited under Subpart C.  Restricted Status may be imposed upon confirming overflows in the form of basement backups, overflows of sanitary sewer manholes, or sanitary sewer overflow devices.

d)         All combined and sanitary sewers and lift stations are subject to Restricted Status when they become hydraulically overloaded, meaning unable to accommodate the following flows:

1)         Combined sewers and lift stations serving combined sewers must be able to handle 350 percent of the average daily flow (based on best available information) before overflowing.

2)         Interceptors serving both combined sewers and sanitary sewers must be able to accommodate 250 percent of the average daily dry weather flow (based on best available information) from the sanitary sewers tributary to them and 350 percent of the average daily dry weather flow from the combined sewers tributary to them before overflowing.

(Source:  Amended at 47 Ill. Reg. 4641, effective March 23, 2023)