(A) All users are subject to state standards and requirements as defined in 35 Ill Adm. Code (IAC) 307. Specifically, the standard for discharge of mercury is as follows:
(1) Mercury (35 IAC 307.1102)
(a) Except as provided below, no person shall cause or allow the concentration of mercury in any discharge to a publicly owned or publicly regulated sewer system to exceed the following level, subject to the averaging rule contained in 35 IAC 304.104(a):
CONSTITUENT | STORET NUMBER | CONCENTRATION (mg/1) |
Mercury | 71900 | 0.0005 |
(b) It shall be an exception to division (A)(1)(a) if the discharge is to a publicly owned or publicly regulated sewer system which is required to meet a limitation less stringent than the 0.0005 mg/l mercury concentration in which case the discharge limitation shall be the same as that applicable to the publicly owned or regulated sewer system to which it discharges.
(c) It shall be an exception to division (A)(1)(a) if all 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; and,
2. The discharge mercury concentration is less than 0.003 mg/l, as determined by application of the averaging rules of 35 IAC 304.104(a); and,
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 to prevent an increase in the level of mercury discharges.
(d) The discharge of wastes from medicinal or therapeutic use of mercury, exclusive of laboratory use, shall be exempt from the limitations of division (A)(1)(a) if all the following conditions are met:
1. The total discharge is less than 227 g (one-half pound) as mercury (Hg) in any year;
2. This discharge is to a public sewer system; and
3. The discharge does not, alone or in conjunction with other sources, cause the effluent from the sewer system or treatment plant to exceed 0.0005 mg/l of mercury.
(e) No person shall cause or allow any discharge of mercury to a publicly owned or publicly regulated sewer system which, alone or in combination with other sources, causes a violation by the sewer treatment plant discharge of the Water Quality Standard of 35 IAC 302 for mercury applicable in the receiving stream.
(f) For purposes of permit issuance, the IEPA may consider application of the exception of division (A)(1)(b) or (c) of this section to determine compliance with this section. The IEPA may impose permit conditions necessary or required to assure continued application of the exception. When division (A)(1)(b) or (c) of this section applies, the IEPA may impose an effluent limitation in the permit which allows the discharge of a concentration of mercury greater than 0.0005 mg/l but not more than 0.003 mg/l.
(Ord. 2020-06-18, passed 6-15-2020)