(1) A
user may not introduce into a POTW any pollutants which cause pass through or
interference. These general
prohibitions and the specific prohibitions in (2) of this rule apply to all
non-domestic sources introducing pollutants into a POTW whether or not the
source is subject to other national pretreatment standards or any national,
state, or local pretreatment requirements.
(2) In addition, the following pollutants may not
be introduced into a POTW:
(a) pollutants which create a fire or explosion
hazard in the POTW, including wastestreams with a closed cup flashpoint of less
than 140ºF or 60ºC using the test methods specified in 40 CFR 261.21;
(b) pollutants which will cause corrosive
structural damage to the POTW, but in no case discharges with pH lower than
5.0, unless the works is specifically designed to accommodate such discharges;
(c) solid or viscous pollutants in amounts which
will cause obstruction to the flow in the POTW resulting in interference;
(d) any pollutant, including oxygen-demanding
pollutants (BOD, etc.) , released in a discharge at a flow rate and/or pollutant
concentration which will cause interference with the POTW;
(e) heat in amounts which will inhibit biological
activity in the POTW resulting in interference, but in no case heat in such
quantities that the temperature at the POTW treatment plant exceeds 40ºC
(104ºF) unless the department, upon request of the POTW, approves alternative
temperature limits;
(f) petroleum oil, nonbiodegradable cutting oil,
or products of mineral oil origin in amounts that will cause interference or
pass through;
(g) pollutants which result in the presence of
toxic gases, vapors, or fumes within the POTW in a quantity that may cause
acute worker health and safety problems; and
(h) any trucked or hauled pollutants, except at
discharge points designated by the POTW.
(3) A user has an affirmative defense in any
action
brought
against it alleging a violation of the general prohibitions established in
(1) (a) of this rule and the specific prohibitions in (2) (c) -(g) of this rule if
the user demonstrates that:
(a) it did not know or have reason to know that
its discharge, alone or in conjunction with a discharge or discharges from
other sources, would cause pass through or interference; and
(b) (i) a local limit designed to prevent pass
through or interference or both of them was developed in accordance with (4) of
this rule for each pollutant in the user's discharge that caused pass through
or interference, and the user was in compliance with each local limit directly
prior to and during the pass through or interference; or
(ii) if a local limit designed to prevent pass
through or interference or both of them has not been developed in accordance
with (4) of this rule for the pollutant or pollutants that caused the pass
through or interference, the user's discharge directly prior to and during the
pass through or interference did not change substantially in nature or
constituents from the user's prior discharge activity when the POTW was
regularly in compliance with the POTW's MPDES permit requirements and, in the
case of interference, applicable requirements for sewage sludge use or
disposal.
(4) (a) POTW's
developing POTW pretreatment programs must develop and enforce specific limits
to implement the prohibitions listed in (1) and (2) of this rule. Each POTW with an approved pretreatment program
shall continue to develop these limits as necessary and effectively enforce
these limits.
(b) All other POTW's shall, in cases where
pollutants contributed by user(s) result in interference or pass through, and
such violation is likely to recur, develop and enforce specific effluent limits
for industrial user(s) , and all other users, as appropriate, which together
with appropriate changes in the POTW treatment plant's facilities or operation,
are necessary to ensure renewed and continued compliance with the POTW's MPDES
permit or sludge use or disposal practices;
(c) Specific effluent limits may not be developed
and enforced without individual notice to persons or groups who have requested
such notice and an opportunity to respond.
(5) Where specific prohibitions or limits on
pollutants or pollutant parameters are developed by a POTW in accordance with
(3) of this rule, such limits are deemed pretreatment standards for purposes of
75-5-304, MCA, of the Montana Water Quality Act.
(6) If, within 30 days after notice of an
interference or pass through violation has been sent by the department to the
POTW, and to persons or groups who have requested such notice, the POTW fails
to commence appropriate enforcement action to correct the violation, the
department may take appropriate
enforcement
action.
(7) The board hereby adopts and incorporates by
reference 40 CFR 261.21 (characteristics of ignitability) (July 1, 1991) .
Copies of these materials are available from the Department of Environmental
Quality, PO Box 200901, Helena, MT 59620-0901.