Activated Sludge Microorganisms - Discusses and illustrates the organisms in sludge, and what can be learned by microscopic analysis of biological treatment systems for wastewater. Association of Metropolitan Sewerage Agencies , as well as resources for POTW operators.
Topics run from industrial pretreatment to sludge disposal.
The Center for Ecological Pollution Prevention - CEPP conducts workshops, demonstrations, evaluation and public education about ecological wastewater solutions, such as composting toilets and graywater systems. Flush Gordon's Wastewater Page - Introduction to water pollution, wastewater treatment, and water analysis. Useful as an educational resource, with diagrams and many links. Irepolia Environmental studies and analysis center - Conducts research and technology development on wastewater treatment methods. Site is in English and French.