Tech Tip: Waste Management

When we take off on our boats for a local cruise or to anchor among the Channel Islands, we must remember to respect and protect the surrounding natural environment and our fellow boaters as well. This means following a set of laws and best practices regarding sanitation.

 

Bilge

The rule with emptying bilges is easy enough to put in words but far more difficult to follow. No oil overboard means precisely that. So why can’t we use soap to break up oil in the bilge and pump it overboard the way we toss out a stale cup of coffee? And why does the U.S. Coast Guard call soap a “dispersant”?

When soap breaks up oil, it does not chemically convert it into a less harmful substance. All the soap does is break up, or disperse, the oil into tiny droplets, forming an emulsion. In short, the oil is still oil. While it is true that diesel and gasoline eventually evaporate, they can still cause extensive harm to aquatic life while they are floating on the water’s surface.  Heavier petroleum distillates, such as motor oil, also gradually evaporate, but in saltwater they first emulsify to form a thick sludge that gunks up beaches, reefs and boat hulls. Evaporation after that point can take many years.

If your bilge contains oil or fuel, place oil-absorbing mats in the bilge to soak up the residue. The white mats have an affinity for oil, allowing you to pump the remaining water safely out of the bilge once all the oil has been removed. Even more effective is a BioSok Oil and Fuel Absorber from Johnson Pump, which biodegrades petroleum residue in the bilge, allowing you to pump the bilge into open water after the oil or fuel sheen has disappeared. To keep bilge odor under control, use a tank deodorizer, such as West Marine Exterminodor, available in one-gallon plastic jugs. Four ounces of this additive treats a 20-gallon tank.

 

Gray Water

Small amounts of food waste dumped offshore through gray water from cruising yachts have a negligible effect on the ocean’s health. Mangrove leaves, coconuts and careless land animals have been dropping into the oceans for eons and are all part of the ecological process.

Inside a protected, crowded harbor, though, a high concentration of organic waste causes eutrophication, a process by which bacteria and algae deplete the water of dissolved oxygen as they multiply and break down the waste. As a consequence, fish and crustaceans die through paralysis and asphyxiation, particularly at greater depths.

The destruction wrought by eutrophication in portions of Long Island Sound and Los Angeles Harbor, to say nothing of our lakes and rivers, was front-page news in the 1960s and 1970s. Lake Erie, once known as the “Dead Sea of North America,” saw the spread of Aphanizomenon flosaquae algae, which resembles green paint floating on the water. In recent years, owing to greater controls of urban water run-off and a ban on phosphorous-based dish soaps in more than a dozen states, the health of Lake Erie, along with U.S. ports and coastal waters, has gradually been improving.

When using the galley sink, filter out as much solid waste as possible before allowing the water to drain into an anchorage. Also, avoid the use of phosphorous-based soaps, at least while your vessel is in an anchorage or harbor. On many larger yachts, the sinks, showers and washing machine drains are connected to a large holding tank, which can be pumped out offshore or at a dockside pump facility in the same manner as a toilet holding tank.

 

Marine Toilets

Late-generation boats with marine sanitation devices also have built-in holding tanks that are emptied at designated pump-out facilities. If your boat was built without a holding tank, then you must close the outlet seacock, remove the handle and stow it away from the head. If you are aboard an older boat without a holding tank within three miles of the coast, close the toilet discharge seacock and store the handle in a drawer.

Whether you choose to adhere to the letter and spirit of the law regarding human solid waste is up to you. If you have second thoughts, think of your own health and that of your passengers. You certainly would not want them swimming near a boat with a toilet discharging directly into the water. As for urine, it is probably harmless in limited amounts, even in a small harbor. Most of the male sailors I know urinate directly into the ocean while under sail (remember your harness, mates).

Solid waste, however, is quite a different matter. Human feces, unlike bird or fish effluent, contains highly infectious coliform bacteria. Far offshore, macerated waste discharged into the water is exposed to intense UV light and is then broken down by microorganisms. However, common sense tells us not to dump fecal sewage into coastal waters. Just for the record, USCG regulations forbid discharging toilets within three nautical miles of the coast. Use your holding tank as designed and empty it in accordance with the law.

An alternative solution for toilet waste is composting toilets. The toilet bowl on this device has separate portals for urine and feces in the bowl, requiring men and ladies alike to sit in order to urinate. Liquid waste is collected in a separate tank for disposal, while fecal waste is allowed to dry and decompose in its own tank. A cup of peat moss may be added to provide extra biological material to aid in the decomposition process. After a few weeks of collecting and composting, the solid waste may be deposited at a pump-out facility.

The Air Head, manufactured by EOS Design in Westbrook, Mass., is a completely self-contained apparatus with its own holding tank and a ventilation system to dry out waste. A bit smaller than a standard land toilet, the Air Head can be used regularly by two people for a whole month before necessitating disposal.

Other manufacturers of similar systems include Biolet of Fresno, Ohio, Nature’s Head of Van Buren, Ohio and Sun-Mar of Tonawanda, N.Y. Composting may not work for everyone, but it seems better than sailing with 20 gallons of sloshing sludge and risking a disconnected hose or ruptured tank beneath the v-berth.

By preventing the illegal dumping of illegal waste in our coastal waters, we help to ensure a cleaner, safer environment for coastal and marine flora and fauna, and for ourselves as well.