Dissolved Organic Carbon is one of the key water quality components affecting aluminum toxicity and the EPA has taken DOC into account in the newest version of the aluminum criteria. The EPA read through hundreds of comments on the draft aluminum criteria and has made significant improvements over the previous 1988 version that reflect the newest science. The new criteria was only published this month and it will be a while before Colorado and other states fully adopt the new criteria. The EPA has created a tool to help dischargers calculate the aluminum criteria for their site. All you need are the pH, hardness, and DOC concentrations for the receiving water and you can find out the expected new aluminum criteria for your site. So get out there and collect your data now so you can be prepared when the new criteria are implemented in your state. Click here to read the full aluminum criteria document.