Upgrading and Retrofitting Water and Wastewater Treatment Plants” is a new MOP from WEF. Upgrading and retrofitting represents the single largest investment that a public or private utility will make. The tricky aspect of upgrading and retrofitting a treatment plant is that during the upgrade process the rest of the plant must operate with no process upsets and meet permitting guidelines.Written by a set of industry experts who have significant years of experience in this area. It is a practical MOP geared to avoid pitfalls, cost overruns, and permit violations.