International Standard Units for Water and Wastewater Processes is an international reference for units of expression that are readily comparable for all design, operation, and performance factors in water and wastewater treatment. Published jointly by WEF, AWWA, and IWA, the updated 4th edition of WEF Manual of Practice no. 6 continues its goal to establish units of expression that are universally understandable and readily comparable for all design, operation, and performance factors. The manual is written for engineering professionals familiar with water and wastewater treatment concepts, the design process, and the regulatory basis for water and wastewater control. 
International Standard Units for Water and Wastewater Processes reflects current design practices of water and wastewater engineering professionals and focuses on particular sectors of the water and wastewater industry including: units used with water treatment systems, standard units for water and wastewater conveyance systems, units used with wastewater treatment systems, units used with facilities associated with the support of treatment systems, and units used with water reuse systems.   
Co-Published with WEF / AWWA