ABOUT US WWTPdesigns.com is an automated, completely FREE, on-line service that rapidly produces preliminary engineering designs for wastewater treatment plants also known as sewage treatment plants. Mustang Engine Builder Program. Unique in the industry, the WWTP Design Generator software which powers our website automatically integrates decisions and calculations from each engineering discipline (process, mechanical, civil, architectural, electrical) to create a custom preliminary design of a wastewater treatment plant (WWTP) including 10+ engineering quality documents. The software, which leverages design know-how from a team of world-renown engineers with hundreds of years’ experience designing WWTPs all over the world, was built for both non-technical (basic inputs) and technical (detailed inputs) users. Simply enter data about a project, and in no time at all you will receive TRUE engineering quality designs for the COMPLETE facility, including mass balance info, flow diagrams, equipment specs, and a full set of architectural drawings. These documents can then be used for planning and permitting, including CAPEX, OPEX, and Geographic Footprint estimation, as well as a basis for starting the detailed design of the WWTP. Two common wastewater treatments include effluent treatment plant (ETP) and sewage treatment plant (STP).