Marine Sanitation Devices (MSDs) | US EPA
What is an MSD? Electro Scan (foreground) and Thermopure-2 (background) type I marine sanitation devices. For purposes of the CWA, an MSD is " any equipment for installation on board a vessel which is designed to receive, retain, treat, or discharge sewage, and any process to treat such sewage. " 33 U.S.C. 1322 (a) (5) (PDF) (10 pp, …