Current through Register Vol. 48, No. 38, September 20, 2024
a) 35
Ill. Adm. Code
304.105
provides that no effluent may cause or contribute to a violation of a water
quality standard but Section
304.103
provides that it is not the intent of 35 Ill. Adm. Code 304 to clean up
contamination caused by upstream sources or incidental traces of contaminants.
If a discharge contains a toxic substance solely due to its presence in intake
water from the same water body receiving the discharge, the Agency may
determine there is no reasonable potential for that discharge to cause or
contribute to an exceedance for that substance and therefore not establish a
WQBEL in the permit. Agency application of such intake credits will be
restricted to the following conditions:
1)
100% of the water comprising the discharge is withdrawn from the same body of
water that receives the discharge.
2) The permitee does not contribute any
additional mass of the identified intake toxic substance to its
discharge.
3) The permitee does not
alter the identified intake pollutant chemically or physically in a manner that
would cause adverse water quality impacts to occur that would not occur if the
substance were left in the water body.
4) The discharge does not result in an
increase above the intake concentration at any applicable point below the
discharge outside a mixing zone unless such increase does not cause an
excursion above the applicable water quality standard, criteria or
value.
5) The timing and location
of the discharge would not cause adverse impacts to occur that would not occur
if the substance were left in the water body.
b) If the source water contains a pollutant
at a concentration in excess of an applicable water quality standard, criteria
or value and there is some net addition of that parameter due to activities or
operations of the permittee or source tributary to the discharge, the Agency
will restrict intake credits to the following circumstances:
1) The Agency will establish permit limits
allowing no greater discharge than the concentration and mass present in the
intake water as a "no net increase limit".
2) Intake credit will only be allowed for
that portion of intake pollutant loading present in source water withdrawn from
the same body of water receiving the discharge. If any of the intake pollutant
is removed through a water treatment process prior to utilization by the
permittee, intake credit will be restricted to the concentration and mass
emerging from the water treatment process.
3) Any permits incorporating "no net
increase" provisions must include notice to the permittee that current federal
guidance prohibits allowance of such limits after March 23, 2007. The permit
need not include an expiration date at the time of issuance but must give fair
warning that continuation in future permit renewals is questionable due to
anticipated federal requirements. The sunset of "no net increase" allowances
after March 23, 2007 is mandated in USEPA's Water Quality Guidance for the
Great Lakes System, 60 FR 15366, March 23, 1995. The preamble to this guidance
contains a commitment from USEPA to reconsider this requirement by March 23,
2002 with the possibility of extending or deleting this deadline.
4) If a facility's treatment system under
proper operation and maintenance results in removal of the intake pollutant of
concern to a discharge level that is below the level in the intake water, the
Agency will establish effluent limits that reflect the lower mass and
concentration of the pollutant achievable and feasible by such
treatment.
5) The issuance of a
permit incorporating "no net increase" provisions shall not affect or modify
the requirement of 35 Ill. Adm. Code 304.103, that effluent standards in 35
Ill. Adm. Code 304 must be complied with without subtracting background
concentrations, except that compliance with those standards is not required
when effluent concentrations for the facility in excess of the standard result
entirely from evaporation or incidental traces of materials not utilized or
produced in the activity.
c) When, pursuant to 35 Ill. Adm. Code
352.425(a), the Agency declines to establish a WQBEL that would otherwise be
warranted under other provisions of this Part, the permit shall contain
requirements sufficient to demonstrate that the terms of subsection (a) of this
Section are being maintained. Appropriate permit requirements may include
influent, effluent and ambient monitoring, and a reopener clause authorizing
modification or revocation and reissuance if new information demonstrates that
intake credit is no longer justified.
