Current through Register Vol. 48, No. 12, March 22, 2024
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.