Homepage Utility Main navigation Implementing Machine Learning Process Controls at Water Resource Recovery Facilities advancing the science of water Topic Hub See our portfolio of research in this area ShortChain PFAS Investigation of treatment alternatives Request for Proposals Project funding opportunities Cyanobacteria Cyanotoxins Learn more from our experts Topics of Focus Biosolids In the United States alone billions of gallons of water are treated each day at water resource recoveryfacilities. Once the water is clean a different challenge remains determining what to do with the solids that are removed during the treatment process. The resulting mixture is often a unique semisolid blend of organic and inorganic materials trace elements chemicals and even pathogens so there is no across the board solution for handling and processing the combinations of constituents that may be present. Because these solids are often rich in nutrients like nitrogen and phosphoruswhich also happen to be the perfect ingredients for promoting healthy soil and plant growthmany facilities have turned to land application.