Technical issues affecting the implementation of US Environmental Protection Agency's proposed fish tissue-based...

Area of Science:

• Environmental Science
• Ecotoxicology
• Aquatic Toxicology

Background:

• Current water-based selenium regulations present implementation challenges.
• The US Environmental Protection Agency is transitioning to a fish tissue-based national water quality criterion for selenium.
• Effective implementation requires a comprehensive protocol addressing data acquisition for the new criterion.

Purpose of the Study:

• To discuss key issues affecting the implementation of a tissue-based selenium criterion.
• To outline a strategy integrating water column and tissue-based approaches.
• To propose a combined national water criterion with site-specific fish tissue analysis.

Main Methods:

• Discussion of 11 key implementation issues for a tissue-based criterion.
• Analysis of selenium transport, cycling, and bioaccumulation.
• Proposal of a hybrid monitoring strategy combining water and tissue data.

Main Results:

• A tissue-based criterion necessitates understanding selenium's environmental behavior.
• A phased approach combining a national water criterion with intermittent fish tissue sampling is proposed.
• Site-specific analyses are only required when the fish tissue criterion is exceeded.

Conclusions:

• A comprehensive protocol is essential for the successful implementation of a tissue-based selenium criterion.
• A flexible strategy can balance regulatory needs with discharger costs.
• Intermittent biotic sampling for fish tissue can streamline compliance under the Clean Water Act.