Nature calling? Use your head

Sewage discharge — blackwater — contains a variety of pollutants that can impact aquatic ecosystems and endanger humans. Image courtesy Sailors for the Sea Powered by Oceana

By Molly Mulhern
For Points East

OK, I’ll admit it. For many years since we bought our cruising boat here in Penobscot Bay, Maine, we did not use the holding tank. It bugged the heck out of me, especially on those beautiful summer mornings when I heard the head flush and watched the paper and brown matter stream past our hull as I enjoyed coffee in the cockpit.

I hated that complicity, but I did not speak up. And it wasn’t that we didn’t have the solution. Like most of the cruising boats sold here, ours had a Y-valve that, when turned, moved the waste products to an onboard holding tank. Changing our ways amounted to only a turn of the valve.

So why, then, didn’t I use the holding tank? Well, first off, the tank was beneath our bunk in the forepeak. Fear of odoriferous sleeping, a boat that began to smell like an outhouse. And I knew my partner would balk at the request. And I justified our polluting ways, continuously.

A couple of years ago, while in Pulpit Harbor, we rowed over to visit one of our fellow boaters from Camden. We took them a bit by surprise: The male of the pair was just flushing the head as we arrived. I watched the waste material float past our dinghy. “Ah, they don’t use their holding tank, either,” I mused. This was a couple I admired for their cruising, so I felt justified in my ways. And yet it changed my perception of them, not in a good way.

My self-justification didn’t last. While fellow cruisers in our lovely Penobscot Bay were violating both the discharge laws and the larger code of ethics – doing what is right for all, not just oneself – as the years went by I could no longer cruise and dump. Pulpit Harbor, Perry Creek, Isle Au Haut, Buckle Harbor, Buck Harbor – all small, enclosed, beautiful places to spend a night on a boat – and it just wasn’t right for me and my partner to discharge our head into these harbors.

So finally, last season, I insisted we think of the waters we cruise in. I told my partner how awful it feels to know our waste is going overboard, how I could no longer participate in that. Of course, he balked. First, he countered that the Y-valve, after years of disuse, wasn’t really functioning. We investigated and figured out how it worked. His next rejoinder was that it was all going to smell. So we purchased some of the products on the market to control that, and my partner added them, and lots of water, into the tank.

And for the first cruise it worked. Not much smell. We returned to our home berth in Camden, on a windy, swelly day, and I insisted on staying aboard and having the head pumped out, not wanting to have the waste sit until we next came aboard. As we waited for the pump-out boat my mate panicked: He had tried to unscrew the waste-tank deck cover and it wouldn’t budge; it was stuck hard.

Visions of nasty effluent forever stuck aboard swam in his head. But he finally worked it open. And we got pumped out, which took but a few minutes, with no brown matter swimming along the deck and no catastrophes. And I dutifully added odor-control liquid after the pump-out so there would be no odor when we returned to the boat.

And things went well those first few weeks. Then we ran into some trouble. One day, we came back from a trip and didn’t take the time to pump out. Days later, we left the harbor, in a rush to get out for our summer cruise. Mid-cruise, my partner decided that the tank was next to bursting so he discharged it in the middle of Isle au Haut Bay. He had asked my opinion, and I said I hated the thought, but left him with the choice. He had visions of the holding tank – a flexible bag under our bunk – bursting, literally leaving effluent all over the place.

And during those first days of our summer cruise, there was definitely an odor that permeated the head and our forepeak. I remarked that it was an odor one just had to accept: the price of doing the right thing. My partner was not inclined to that kind of acceptance. And I found myself, at times, embarrassed by the odor, or even the prospect of the odor.

My 93-year-old mom came to join us for her annual sail, and, as is our norm, we gave up our bunk in the forepeak for her. The first thing I did was set up her sleeping material on the starboard side, the side not over the holding tank. And then, during the days she sailed with us, I did not switch the valve to the tank. I couldn’t risk the chance that the head and tank would smell while she was aboard. And I hate that I behaved that way. I never talked to my partner about it, but I noticed that he never moved the Y-valve to the tank, either.

And, I suspect, when my partner cruises with others, or alone, he doesn’t use the tank. He doesn’t think using the tank is necessary, even when I outline a theoretical scenario in which every other boat, including cruise ships, are behaving that way. Is it right to think, “Of course others should use their holding tanks, but not me.”

I have read some of the well-known cruising authors decry the need for no-discharge zones. They wish NDZs weren’t there. Do they have some science to justify this wish? None that I have read. They appear to operate on an old salt’s idea that the twice-daily tides will clear our sewage away.

Really? I’m not convinced, and now that our oceans are warming, our discharge heats them up even further. Show me the science, you who dump sewage overboard.

Here’s something to consider. During one of our free pump-outs here in Camden Harbor this past summer, I asked the pump-out operator how busy he was. It was a big race weekend – the Camden Classics Cup – so a lot of boats were in the harbor. He told me that, on one day, they had pumped 900 gallons of sewage. That is a lot of sewage. Now imagine if all of those boats dumped right there. Yuk.

The pump-out fellow told me he likes to ask those who don’t want to pump how they would feel about their children swimming in the harbor. He’s right. Since we’ve started using the holding tank, I now swim off the boat again. I stopped doing this for a while, unable to imagine jumping in where I knew our raw sewage was going. How do I know other boats aren’t still pumping their waste overboard? I don’t, but I sure do hope they aren’t.

So, do we have it figured out? No. Our holding tank is small, so cruising for a full week without emptying it is impossible. And cruising from pump-out to pump-out is hardly enticing: We like to visit spots that are away from amenities. Do I know the right answer? No. My partner figures we just head off “aways” and discharge the tank there.

I am not convinced. This philosophy just seems to be a way to foul the deeper sections of Penobscot Bay. Think how concentrated that sludge is. And what about the treatment material we have put in it? Is that, too, harming the water? The packages say the material is environmentally friendly, but do we accept that as gospel? Dumping our waste while out a little way off seems like the lie of sending off our recycling materials to China; it’s not really dealt with. It’s left to foul someone else’s backyard or home. To that end, this year we’ve updated our cruising boat with a new holding tank and all the lines that run in and out of it.

Simply put, as cruisers, we need to deal with waste management. We need to treat the material safely on board, and learn about what happens when raw waste goes into a harbor or a bay. And we must educate each other on the effects of overboard discharge, and we should hold other boaters accountable when they are seen flushing in a harbor.

Legal and science notes: The Clean Water Act prohibits discharge of raw sewage within three miles of the U.S. coast. Raw sewage is unsightly, and impacts the health of the water. “Sewage-contaminated water can spread diseases and fecal coliform bacteria such as E. coli. Decomposing sewage acts like a fertilizer and causes algae and bacteria to grow, decreasing the amount of light and oxygen in the water available to other aquatic life. Shellfish, such as oysters, mussels, and scallops filter the water, including contaminants and bacteria, which can then infect people who consume them.” – Heather Leba, Alaska Clean Boating Coordinator/Cook Inletkeeper.

Molly Mulhern spent her publishing career at International Marine, North America’s largest nautical publishing company. Currently, Molly is enjoying life as a professional volunteer: chair of the board of The Apprenticeshop in Rockland, Maine; hotline volunteer for a domestic-violence agency; and coach for Girls on the Run. She also dabbles in book editing, writing, and playing with art. And she plans to cycle to Halifax, Nova Scotia, this summer, where she will meet their boat and sail home to Camden, Maine.


Head and holding tank treatments

Source: Tom Burden/West Marine

Holding tank treatments use a variety of methods to mask or eliminate offensive odors created as waste is broken down. They come in four basic formulations.

Chemical treatments are the most popular because they provide the best odor control. Some include chemicals that kill bacteria, but the best chemical treatments deodorize using chemical reactions with odor-causing molecules. They are relatively inexpensive compared to other treatments. Some contain additives that dissolve waste. They can be added to tanks that contain other treatments without cleaning the tank.

Enzyme treatments accelerate the digestion of organic materials in waste and neutralize odors at the same time. Their toxicity is extremely low and they are environmentally friendly. Some help to emulsify paper and sewage. They must be added regularly, work best in well-ventilated systems, but do not work well in hot or cold climates. Enzymes require a tank free of residuals of other treatment products.

Nitrate treatments provide an interesting alternative. Oxygen is vital to bacteria in the process of breaking down organic waste. When little air is present (as in most holding tanks), bacteria derives the oxygen from sulfates in the waste, which produces hydrogen sulfide (stinky!) gas. When nitrates are introduced, they act as nutrients for the bacteria, providing an alternative source of oxygen, which results in the production of nitrogen an odorless gas. Nitrates are environmentally friendly, and are ideal for systems with less ventilation. They speed up the breakdown process and reduce odors. The tank must be free of residuals from other products.

Bio-active treatments contain live aerobic bacteria which break down waste, reproduce and crowd out anaerobic (odor-producing) bacteria. They, too, are environmentally friendly. Like enzymes, bio-active treatments can help in breaking down sewage. Unlike other treatments, they multiply and continue to work long after treatment is complete. However, the microbes require a well-ventilated and residual free holding tank to survive. Although initially expensive, bio-active treatments become more cost effective over time because of bacteria propagation.