Current through Register Vol. 48, No. 38, September 20, 2024
a) Except as
provided below, a person must not cause or allow the concentration of mercury
in any effluent to exceed the following level, subject to the averaging rule
contained in Section 304.104(a).
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CONSTITUENT
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CONCENTRATION mg/L
|
|
Mercury
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0.0005
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b) It
is an exception to subsection (a) if all of the following conditions are met:
1) The discharger does not use mercury; or,
the discharger uses mercury and this use cannot be eliminated; or, the
discharger uses mercury only in chemical analysis or in laboratory or other
equipment and takes reasonable care to avoid contamination of
wastewater;
2) The effluent mercury
concentration is less than
0.003 mg/L, as determined by
applying the averaging rules of Section
304.104(a);
3) The discharger is providing the best
degree of treatment consistent with technological feasibility, economic
reasonableness, and sound engineering judgment. This may include no treatment
for mercury; and
4) The discharger
has an inspection and maintenance program likely to reduce or prevent an
increase in the level of mercury discharges.
c) It is an exception to subsection (a) if
all of the following conditions are met:
1)
The discharger is a publicly owned or publicly regulated sewage treatment
works;
2) The discharger does not
use mercury; or, the discharger uses mercury only in chemical analysis or in
laboratory or other equipment and takes reasonable care to avoid contamination
of wastewater;
3) The effluent
mercury concentration is less than
0.003 mg/L, as determined by
applying the averaging rules of Section
304.104(a);
provided, however, that daily averages may exceed
0.006 mg/L 30% of the
time;
4) The discharger has
enforceable ordinances or contract provisions by which it limits the use of
mercury by dischargers and the discharge of mercury into its sewage
system;
5) The discharger's
limitations on the use and discharge of mercury to its sewage system are at
least as stringent as those provided in 35 Ill. Adm. Code
307.1102;
6) The discharger has a surveillance program
with a reasonable likelihood of determining sources of mercury discharged to
the sewage system;
7) The
discharger takes all lawful steps to eliminate known mercury discharges to the
sewage system that contribute to levels exceeding those allowed by 35 Ill. Adm.
Code 307.1102; and
8) The
discharger reports all known violations of 35 Ill. Adm. Code
307.1102 to the
Agency.
d) When it issues
a permit, the Agency may consider applying the exceptions of this Section to
determine compliance with this Section. The Agency may impose permit conditions
necessary or required to assure continued application of an exception. When
subsection (b) applies, the Agency may impose an effluent limitation in the
permit which allows discharge of a concentration of mercury greater than
0.0005 mg/L but not more than
0.003 mg/L.
