Current through Register Vol. 24-06, March 15, 2024
(1) If a toxicity
test result fails the compliance test described in WAC
173-205-070, then the permittee
shall take a new sample as soon as possible for retesting and begin additional
monitoring unless the permittee chooses the option in subsection (4) of this
section.
(a) If the noncompliance was with an
acute toxicity limit, the additional monitoring shall be conducted weekly for
four weeks using the same toxicity test as in the failed compliance test or
shall be conducted on the next four discharge events in the case of an
intermittent discharge.
(b) If the
noncompliance was with a chronic toxicity limit, the additional monitoring
shall be conducted monthly for three months using the same toxicity test as in
the failed compliance test or shall be conducted on the next three discharge
events in the case of an intermittent discharge.
(c) This additional monitoring shall be
conducted the same as in effluent characterization and shall determine the
LC50, IC50, or
EC50, as appropriate, and measure compliance with the
permit limit.
(d) If the permittee
believes that the compliance test failure will be identified by the department
as an anomalous test result in accordance with WAC
173-205-070(5)(c),
the permittee may send the department notification with the compliance test
result that the compliance test result might be anomalous and that the
permittee intends to take only one additional sample for toxicity testing and
wait for notification from the department before completing the additional
monitoring required in this subsection.
(i)
The notification must identify the reason for considering the compliance test
result to be anomalous.
(ii) The
permittee shall take the additional sample and retest as soon as possible after
receiving the compliance test result.
(iii) The additional test result shall
replace the compliance test result upon determination by the department that
the compliance test result was anomalous.
(iv) The permittee shall complete all of the
additional monitoring required by this subsection as soon as possible after
notification by the department that the compliance test result was not
anomalous.
(v) If the additional
sample fails the compliance test, then the permittee shall proceed without
delay to complete all of the additional monitoring required by this
subsection.
(e) The
department may determine any compliance test result to be anomalous regardless
of whether it was accompanied by permittee notification that it may be
anomalous.
(f) The department may
notify a permittee to take another sample for toxicity testing because a
compliance test result was anomalous and could not be used to determine
compliance in accordance with this section.
(2) Any permittee failing the compliance test
for a whole effluent toxicity limit shall take all reasonable actions to
achieve compliance including conducting a toxicity identification/reduction
evaluation as defined in WAC
173-205-100.
(3) The discharger shall return to the
original monitoring frequency after conducting the additional monitoring
described in subsection (1) of this section.
(4) The permittee may proceed directly to a
toxicity identification/reduction evaluation and not perform the additional
testing.
Statutory Authority:
Chapter
90.48 RCW and
40 C.F.R.
122.44. 93-20-110 (Order 91-54), §
173-205-090, filed 10/6/93, effective
11/6/93.