Gray Water Reduction

Clean Regattas

Registration

Running a Clean Regatta

Gray water is the term for all wastewater on board a vessel other than sewage from a marine head. Gray water comes from dish washing, showers, and (the big one) cleaning all parts of the boat, from the hull, to the deck and all the cleats and tackle. Gray water carries detergents, soaps, bleaches as well as organic particles into the lakes and oceans we sail.

The first problem is that the organic particles require bacteria to be broken down. The bacteria require oxygen to do their work. The more gray water that gets flushed into a body of water, the more oxygen the bacteria use, and the less oxygen is available for native species, leading them to die off, particularly in a heavily used area.

The second problem is the phosphates and nitrates carried by detergents and soaps. While phosphorous and nitrogen are both important elements in a healthy aquatic ecosystem, they are required only in small amounts. An influx of these elements (say in a crowded harbor during a regatta or race week), can disrupt a delicate ecological balance, leading to algae blooms and eutrophication. Algae blooms create a mat on the surface of the water, preventing submerged aquatic vegetation from photosynthesizing, and resulting in an overall oxygen decrease, with the same results as described above.

So what can you do as a regatta organizer?

Water Only Wash Downs - As a regatta organizer, you can request or require that no soaps, detergents or other products be used during your event. This is an important step, as a crowded harbor or lake during an event can cause a serious spike in phosphates and nitrates.

Provide access to shoreside facilities for boaters during your event.

Provide, sell or encourage the use of biodegradable and non-toxic cleaning products.

Track Your Success - Before, during and after your event, take water sample near moored and docked vessels to establish baseline levels of phosphates and nitrates in your harbor or lake. This will tell you how effective your measures have been in reducing gray water during your event. Simple test kits can be purchased online at Hach, Amazon, or at most Pet and Aquarium Stores. Contact us if you need help establishing a testing protocol at your site.

What can you do as a boater?

As described above, only use clean water and no soaps to wash down your boat. In some states, gray water is considered sewage and regulated as such, making soap bubbles on the water's surface a reportable pollution offense.

If plain water isn't working on a particular job, use non-toxic cleaning products when necessary.

Use shoreside facilities for dishwashing, showering and laundry whenever possible.

Retain and pumpout your gray water.

Strain and retain all food and organic matter to be disposed of in the trash or composted, rather than washed into your holding tanks or overboard.

As a final note, boats are not the sole-source of phosphates, nitrates and organic matter that can lead to these problems, so it is also important to create stormwater management systems onshore to deal with runoff and non-point source pollution (Link coming soon!)

For more information, contact us, or check out "Boat Green: 50 Steps Boaters Can Take to Save Our Waters" by Clyde W. Ford