18 AAC 83.335 - Whole effluent toxicity monitoring for POTWs and other designated dischargers

(a) An applicant for a permit under 18 AAC 83.330 shall submit information on effluent monitoring for whole effluent toxicity, including an identification of any whole effluent toxicity tests conducted during the four and one-half years before the date of the application on any of the applicant's discharges or on any receiving water near the discharge.

(b) An applicant under 18 AAC 83.330 shall submit to the department, in compliance with (c) - (g) of this section, the results of valid whole effluent toxicity tests for acute or chronic toxicity for samples taken from each outfall through which effluent is discharged to surface waters, except for combined sewer overflows, if the applicant

(1) has a design flow rate greater than or equal to one million gallons per day;

(2) has an approved pretreatment program or is required to develop a pretreatment program; or

(3) is required to comply with this section by the department, based on consideration of the following factors:

(A) the variability of the pollutants or pollutant parameters in the POTW effluent based on chemical-specific information, the type of treatment plant, and types of industrial contributors;

(B) the ratio of effluent flow to receiving stream flow;

(C) existing controls on point or non-point sources, including total maximum daily load calculations for the receiving stream segment and the relative contribution of the POTW;

(D) receiving water characteristics, including possible or known water quality impairment, and whether the POTW discharges to a coastal water or a water designated as an outstanding natural resource water; and

(E) other considerations, including the history of toxic impacts and compliance problems at the POTW that the department determines could cause or contribute to adverse water quality impacts.

(c) When an applicant under 18 AAC 83.330 has two or more outfalls with substantially identical effluent discharging to the same receiving water segment, the department may, on a case-by-case basis, allow the applicant to submit whole effluent toxicity data for only one outfall. The department may also allow an applicant to composite samples from one or more outfalls that discharge into the same mixing zone.

(d) An applicant under (b) of this section that is required to perform whole effluent toxicity testing must provide

(1) results of a minimum of four quarterly tests for a year, from the year preceding the permit application; or

(2) results from four tests performed at least annually in the four and one half year period before the application, if the results show no appreciable toxicity using a safety factor determined by the department.

(e) An applicant under (b) of this section must conduct tests with no less than two species, including fish, invertebrate, or plant, and test for acute or chronic toxicity, depending on the range of receiving water dilution. Unless the department directs otherwise, an applicant shall conduct acute or chronic testing based on the following dilutions:

(1) acute toxicity testing if the dilution of the effluent is greater than 1000:1 at the edge of the mixing zone;

(2) acute or chronic toxicity testing, if the dilution of the effluent is between 100:1 and 1000:1 at the edge of the mixing zone; acute testing may be more appropriate at the higher end of this range (1000:1), and chronic testing may be more appropriate at the lower end of this range (100:1);

(3) chronic testing if the dilution of the effluent is less than 100:1 at the edge of the mixing zone.

(f) An applicant required to perform whole effluent toxicity testing under (b) of this section shall provide

(1) the number of chronic or acute whole effluent toxicity tests that have been conducted since the last permit reissuance;

(2) the results using the form provided by the department, or test summaries, if available and comprehensive, for each whole effluent toxicity test conducted under this section for which the information has not been reported previously to the department;

(3) for whole effluent toxicity data submitted to the department within four and one-half years before the date of the application, the dates on which the data were submitted and a summary of the results; and

(4) any information on the cause of toxicity and written details of any toxicity reduction evaluation conducted, if any whole effluent toxicity test conducted within the past four and one-half years revealed toxicity.

(g) For purposes of the whole effluent toxicity testing required by this section, an applicant must conduct testing using methods approved under 40 C.F.R. Part 136, adopted by reference in 18 AAC 83.010; however, an applicant for a facility in this state is exempt from the chronic toxicity testing methods under 40 C.F.R. Part 136, and shall instead perform chronic toxicity testing in accordance with the methods specified by the department under 18 AAC 70.030.

Notes

18 AAC 83.335

Eff. 7/29/2006, Register 179; am 11/10/2007, Register 184

Authority:AS 44.46.020

AS 46.03.010

AS 46.03.020

AS 46.03.050

AS 46.03.100

AS 46.03.110