If you enjoy being on the water, you need to know and follow regulations about disposal of human waste in marine environments. Whether you are circumnavigating the globe in a sailing or motor yacht, or floating with friends down a quiet river with a flotilla of canoes, you have an obligation to manage human waste responsibly to prevent unsightly environmental contamination that poses serious health risks to humans, animals and even plants.
Marine sanitation devices are defined by the U.S. Environmental Protection Agency as any device installed aboard a vessel that manages sewage. The only exceptions to treated or untreated wastewater discharge laws laid down by the federal government are special dispensations--few and far between--given to states that apply for and receive them. While boating near shore, in inland waterways, offshore or on inland lakes, you should defer to and follow the federal regulations. The U.S. Coast Guard (USCG) must certify your sewer system; this is typically done prior to installation, but if you have an older system you should contact your local USCG office for certification procedure and requirement information. All boating areas are designated either as "no-discharge" areas--places where under no circumstances are you allowed to release effluvia into the water--or "discharge" sectors where treated wastewater may be released. It is never permissible to discharge untreated waste. It is your responsibility to know the law and maintain a system aboard that has the capacity to work within the parameters of the regulations and your boating plans.
Many smaller and older vessels do not have toilet systems installed, but can accommodate porta-pottys. The same rules that apply with flush toilet systems apply to porta-potty systems. Waste must be treated; there are a number of organic, non-toxic and biodegradable products on the market for both systems that break the sewage down into non-harmful liquid. Per the discharge and non-discharge zone regulations, this treated waste can be dumped overboard or pumped out/flushed at any marina.
Groovers and Catholes
A groover is an ammunition can or other 100 per cent sealable and watertight device used by river runners and wilderness campers as a toilet. Almost all U.S. river system authorities require river runners to pack everything out they pack in; this includes trash, personal items and solid human waste. The U.S. National Park System has a policy of "leave no trace," requiring visitors to park waterways and back country to leave no sign behind they were there. Although the Bureau of Land Management allows "cathole" waste disposal in the back country, they require waste be kept out of water systems and advocate groover use. The U.S. Forest Service and state recreation areas nationwide have similar regulations.