This memorandum transmits Office of Water policy and guidance on the interpretation and implementation of aquatic life criteria for the management of metals. This issue covers a number of areas including the expression of aquatic life criteria, total maximum daily loads, permits, effluent monitoring and compliance, and ambient monitoring.

This document is a compendium of scientifically valid and accepted methods that can be used to assess sediment quality and predict ecological impacts...the intent here is to provide the most useful overall measures or predictors of ecological impacts currently in use rather than procedures that may have limited application outside of a particular regulatory framework... parag The information provided in the compendium on the relative strengths and weaknesses of the different assessment methods can provide assistance in selecting the appropriate methods.