An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Low - Tech Alternative to Activated Sludge Promises Big Savings

Communities are finding it difficult to finance wastewater treatment plants that will meet more stringent effluent limits. Engineers are seeking low - cost treatment alternatives.

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.