Harmful Effects of Sewage
Over 100 intestinal pathogens such as viruses, parasites, and bacteria can be found in sewage that may harm humans, wildlife, and drinking water quality. Human sewage from boats can also affect recreational activities, reduce oxygen available to aquatic life, and cause algal blooms (which block sunlight penetration). Vessel sewage is more concentrated than domestic sewage because people on boats use less water for sanitary purposes than those on land.
Keep Boat Sewage Out of the Water
- Always use shoreside restrooms when docked and before casting off. Plan ahead for restroom stops.
- It is against federal and state laws to discharge untreated sewage waste anywhere within the three-mile U.S. territorial limit (lakes, rivers, reservoirs, or coastal water within three miles of shore, the Bay and the Delta). Fines of up to $2,000 can be imposed for illegal discharges.
- Never discharge any sewage, treated or untreated, in a federally designated No-Discharge Area.
- If you have a Y-valve with a through-hull fitting that allows direct overboard discharge, it must be secured in a closed position (using a padlock or non-releasable wire tie) when within the three-mile limit.
- Empty holding tanks at sewage pumpout facilities, or call a mobile pumpout service. For sewage pumpout locations in the Delta, visit the Delta Marina Service section or visit the Department of Boating and Waterways website.
- All boats with installed toilets must have a Coast Guard-approved Marine Sanitation Device (MSD) if operating in U.S. navigational waters.
- Choose MSDs that use a holding tank or a portable toilet. When regularly emptied at a pumpout or dump-station, they offer the best environmental protection.
- Boats without installed toilets should use a portable on-board toilet and empty it at a dump station.
- Avoid holding tank disinfectants and deodorizers that contain chlorine, formaldehyde, quaternary ammonia, or other components that can be harmful to aquatic organisms.
- Learn how to properly operate a sewage pumpout (PDF).
- Learn more about sewage holding tank systems for recreational boats.
- Learn more about boat-to-boat mobile services.
- Learn more about environmental laws associated with sewage.
- Find information on boat sanitation system installation and repair services.