- Always use sewage pumpouts, Porta-potti dump stations or
mobile pumpout services.
Washington State Parks Pumpout Station Information
- Do not discharge treated or untreated sewage in the
water. However if you must discharge, current regulations
only allow for discharges from Type I or Type II Marine
Sanitation Devices (described
- Discharge of untreated sewage is illegal within three
nautical miles of shore.
- Boats with an onboard toilet are required to have a U.S.
Coast Guard certified marine sanitation device (MSD),
preferably a Type III holding tank. (See chart below)
- Bring portable toilets ashore for proper waste disposal.
- Use onshore restroom facilities when at dock.
To report sewage spills and other pollution, call the U.S.
Coast Guard at 800-424-8802 and Washington Emergency Management
Division at 800-OILS-911.
Types of Marine Sanitation Devices (MSDs) and Treatment Systems
Treats sewage before
discharge by chopping or macerating. May add
disinfectant chemicals. Disintegrates solids before
discharging into water.
Discharge must meet certain health standards for
bacteria content; must not show any visible floating
Only allowed on vessels smaller than 65 feet in
Being phased out of use
on larger vessels. Only allowed if equipment was on
vessel before Jan. 1978.
Provides higher level
of treatment than Type I. Treats sewage by
biological means before discharging. Separates
solids for incineration or pumpout.
Effluent is cleaner than Type I, but contains
greater level of chemicals.
Usually requires more space and power than Type I.
Usually installed on
larger vessels only.
Does not allow the
discharge of sewage. Includes re-circulating,
incinerating MSDs and holding tanks.
Holding tanks are the most common kind of Type III
MSD used on recreational boats. Waste is stored
until it can be pumped out to a reception facility.
Holding tank waste is not treated even if
odor-reducing chemicals are added.
Allows for “Y-valve” to
discharge directly overboard while outside the three
nautical mile limit along Washington's outer coast.
All inland waters of Washington state which includes the
Strait of Juan de Fuca and Puget Sound are considered Washington