Thermal Sludge Treatment: Where the Clean Water Act and the Clean Air Act meet

摘要

We all know the Clean Water Act (CWA) governs wastewater effluent from treatment plants and the waterways that receive it. And we know that the Clean Air Act (CAA) regulates air emissions and air quality. But what about sewage sludge that is incinerated and disposed of and, therefore, could affect both air and water? Wastewater treatment managers, engineers, and plan- ners who deal with sewage sludge should keep a copy of both sets of regulations on hand. Both CWA and CAA address sewage sludge treatment, particularly when the processes include drying and combustion technologies. CWA required the U.S. Environmental Protection Agency to establish standards for the use or disposal of sewage sludge. These standards defined minimum national performance requirements for land application, surface disposal, and incineration. Where thermal technologies are used to prepare a pelletized soil amendment or to combust sewer sludge, CAA requirements must also be considered. Given the advances in thermal drying and combustion technologies and the complexity of the requirements that now govern them, it helps to take a closer look at these technologies —and what happens when CWA and CAA intersect.