Washington Administrative Code
Title 173 - Ecology, Department of (See also Titles 197, 317, 372, and 508)
Chapter 173-205 - Whole effluent toxicity testing and limits
Section 173-205-070 - Monitoring for compliance with whole effluent toxicity limits
Current through Register Vol. 24-06, March 15, 2024
(1) A discharge is in compliance with the narrative water quality standard for acute toxicity when the most recent acute toxicity test has shown no statistically significant difference in response between the acute critical effluent concentration and a control.
(2) A discharge is in compliance with the narrative water quality standard for chronic toxicity when the most recent chronic toxicity test has shown no statistically significant difference in response between the chronic critical effluent concentration and a control.
(3) During compliance monitoring, the one hundred percent effluent concentration in an acute test and the acute critical effluent concentration in a chronic test shall be performed in order to assess the attainment of the performance standards in accordance with WAC 173-205-120(1).
(4) Toxicity tests conducted for monitoring for compliance with whole effluent toxicity limits shall meet, as appropriate, the acute or chronic statistical power standards. If a whole effluent toxicity test does not meet appropriate statistical power standard, then the effluent shall immediately be resampled and the toxicity test repeated with the number of replicates increased in order to meet the statistical power standard.
(5) The permittee shall provide the department with all information and records required in the permit in order to evaluate toxicity test results to determine their adequacy for effluent characterization, compliance monitoring, effluent screening tests, or rapid screening tests.
Statutory Authority: Chapter 90.48 RCW and 40 C.F.R. 122.44. 93-20-110 (Order 91-54), § 173-205-070, filed 10/6/93, effective 11/6/93.