Marine heads and No-Discharge Zones
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How a manual head works, what goes in it, holding tanks and pump-outs, the Y-valve, and the discharge rules — including No-Discharge Zones like Puget Sound.
Sources (10)
- Manual head pump: lifting the handle draws waste from the bowl while water goes into the bowl; pushing down sends waste down the discharge hose — xylem.com
- The joker valve is a duck-billed rubber valve that prevents flushed water and odor returning to the bowl; flush the waste clear to the tank — practical-sailor.com
- Toilet paper is the number-one cause of clogged marine heads; many boats use a lidded bin or allow only a couple of squares — theboatgalley.com
- Type III MSDs are holding tanks that store sewage aboard; holding tanks must be pumped out at an onshore or mobile facility — epa.gov
- Untreated sewage discharge is prohibited within three miles from shore; within three miles only USCG-approved Type I/II devices may discharge; NDZs prohibit treated and untreated discharge — epa.gov
- To comply in an NDZ: close the seacock and remove the handle, padlock it, use a non-releasable wire-tie, or lock the head door (33 CFR 159.7) — epa.gov
- Puget Sound NDZ: all marine waters inward from the New Dungeness–Discovery Island line to the Canadian border, plus Lake Washington and Lake Union (82 FR 11218, 2017) — epa.gov
- A Y-valve directs sewage to the holding tank or overboard; in NDZs or inside the three-mile limit it must be secured (padlock, wire seal or handle removed) — goodoldboat.com
- Hose permeation is a common cause of head odor; test by wrapping a hot damp cloth round the hose, letting it cool and sniffing it — if it smells, replace the hose — raritaneng.com
- Permeation of waste gases through sanitation hose is a major source of head odor — practical-sailor.com
General guidance for recreational boaters — your engine and equipment manuals and local regulations come first.