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Energy and Environment Cabinet

Division of Water

Division of Water
Whole Effluent Toxicity Testing

The Whole Effluent Toxicity (WET) program is managed by the Surface Water Permits Branch of the Kentucky Division of Water (DOW).  Staff provide technical review of all self-monitoring reports conducted by the regulated community for compliance, as well as Toxicity Reduction Evaluations (TREs).

In 1988 the Kentucky Department for Environmental Protection adopted a strategy to control toxic discharges into waters of the Commonwealth.  This toxics control strategy was implemented by including both chemical-specific and WET limits in Kentucky Pollutant Discharge Elimination System (KPDES) permits issued to major industrial dischargers and major municipal wastewater treatment plants (WWTPs) as well as minor WWTPs with an approved pretreatment program. The WET limits include both acute and chronic levels based on the instream waste concentration. Test organisms include the daphnid, Ceriodaphnia dubia, and the fathead minnow, Pimephales promelas.

The toxics control strategy consists of a two-tiered approach of chemical-specific and WET limits that are implemented through the KPDES program.  The chemical-specific tier is generally well known.  The WET tier was added by the agency because it directly measures toxicity and takes into account the aggregate toxicity in complex effluents and the chemical and physical interactions that can occur.

The DOW currently has approximately 160 industrial and municipal facilities whose permit includes the WET limit.  All these facilities are required to perform self-monitoring for the WET permit condition (usually performed by a consulting laboratory). Our staff reviews all toxicity data reported on discharge monitoring reports (DMRs).  Our job is to verify the quality of the data, ensure proper methods were followed, track compliance and determine enforcement for noncompliance.  The staff has reviewed more than 11,000 toxicity test reports since 1988.  We now average approximately 250 reports per calendar quarter.

In addition to DMR reports, staff will review and make recommendations on TRE plans and quarterly progress reports.  All WET reports should be submitted via the ePortal using the Whole Effluent Toxicity reporting form.  When submitting WET reports, please use the following naming convention: 
Example:  SmithWWTP_KY8675309_11-18-15