Do You Know Where Your Flushes Go?

Craig Just (right) examines the bulrushes growing in a test cell of a sub-surface wetland project at the Iowa City waste-water treatment facility.

“Do you know what happens to the stuff you flush down your toilet? Where does it all go?”

Craig Just asks that question as we drive onto the grounds of the Iowa City waste water treatment plant. Of course, I knew we had a waste treatment plant somewhere, but I didn’t really know where. Until today.

If you live in a city, as I do, chances are the waste from your toilet shoots down the sewer pipes to a treatment system somewhere on the edge of the city limits. Out of sight. Out of mind. And too far away for most people to smell.

At a city waste water plant, the effluent goes through various stages of treatment. And, in warm weather months, it may be chlorinated to kill E. coli and other bacteria, then de-chlorinated before running the cleaned water into a river or stream. Solids are separated, then sold to farmers for their fields, or perhaps incinerated. It’s an expensive, but essential process.

If you live in a rural area or a development that isn’t attached to a city sewer system, your bio-waste products are most likely collected in a septic system. There, the water spills into a leach field while the solids build up in a tank. Eventually, the tank fills, and you pay someone to drain it.

But what if you live in one of the small, unincorporated towns that can’t afford a modern waste water system and don’t have a septic system? What happens to everything you flush down your toilets?

It gets dumped — untreated, unfiltered, unsanitized — directly into a nearby river or stream.

Feel like a swim? Me, neither.

Wetlands Water Treatment

Iowa alone has in excess of 600 unincorporated communities without adequate — or, more often, any — waste water treatment systems. Estimates by the American Water Works Association indicate that upgrading these Iowa communities to the same standard as a facility like  Iowa City’s would cost in excess of $1 Billion. (Yep. That’s one Billion dollars. Fat chance of that happening in this economy.)

Just (right) braves the wind and rain to show the group the demonstration test cells. The cells in the foreground are planted with bulrushes; the cells in the background (left) were left unplanted. Each cell is working under different conditions in this experiment. Photo: Joe Hennager

But that may not be the only option, according to Craig Just, adjunct assistant professor of civil and environmental engineering at the University of Iowa.

This is a cold, rainy afternoon, with wind tearing at our umbrellas. Yet Just is cheerfully leaning into the wind to talk with a few members of the recently formed RiverCry group. He explains an alternative waste water system that may be a solution to the problem of raw sewage entering the Iowa River from unincorporated areas.

Just and a team of university students have constructed a micro wetlands site on the grounds of Iowa City’s south waste water treatment plant.

“Wetlands provide natural waste water treatment,” Just says. “If you don’t put too much [nitrogen and phosphorus] in, the system works by itself. It’s a slow process, but an effective one, until the numbers become overwhelming.”

Wetlands work well to purify water and break down nitrogen when humans or other animals live in low density. So Just and his students are experimenting to find a way to speed up the wetlands process to accommodate small, unincorporated communities.

They’ve created eight mini wetlands with subsurface flow to treat small batches of raw waste from the Iowa City sewage system. Though it’s too early to draw conclusions (this is a scientific experiment, after all), the process seems to be working as anticipated. And (as a visitor I appreciate this every bit as much as you might imagine), with the effluent entirely below the surface and a foot-high layer of wood chips on top, there’s no smell.

Still, there’s a problem.

Even If It Works, You Can’t Use It

Even if Just and crew do develop the perfect system, they can’t use it — yet. The Iowa Department of Natural Resources (DNR) prohibits the use of subsurface flow wetlands to treat sewage. But if it works, why not allow it?

“Most subsurface wetlands evaluated [by the DNR] were not using forced aeration,” Just tells the group. Those treatments didn’t meet the DNR’s standards. But in this project, air is pumped through the wetland soil during half the day — a timer turns it on and off automatically. Just explains that the extra oxygen is helpful for one part the process of breaking down nitrogen; a lack of oxygen is necessary for another part.

If the project is assessed to be effective, Just may still have a fight on his hands to get approval for using the system. Asked what happens to the filtered water in his pilot project, he says. “It gets pumped back into the beginning of the waste water cycle here at the treatment plant.” He would be breaking the law if he pumped this cleaned water directly into the Iowa River; remember, the DNR does not approve. (He can’t dump cleaned water into the river, but it’s legal to dump raw sewage? The logic of this escapes us all.)

Just is working to further the project, but there’s just not much funding for something so “unsexy” as applying simple engineering to solve a real-world problem. There’s funding for scientific investigations of a more esoteric nature, but not much for applied science. (This, too, makes little sense to the assembled group.)

“We proposed a test run at an I-80 rest stop,” Just says. Lagoons near the interstate highway treat the wastes from many of these facilities. “We’d like to take what comes out of the lagoons and use our aeration system as the next step in the line.” But that proposal’s future is far from certain.

100 Frames + 2 Wheels = 1 Bicycle

Craig Just explains that phosphorus is a greater problem than nitrogen. Photo: Joe Hennager

One of the great advantages of this aerated subsurface wetland is that it efficiently removes nitrogen from the sewage. But despite the fact that nitrogen levels are high in Iowa’s rivers (due largely to animal waste from CAFOS and fertilizers applied to farm fields), “nitrogen isn’t the biggest problem,” Just tells the group. “What we should be talking about is phosphorous, but there are no limits for phosphorous in the water.”

“Think of it this way,” he says. “If you have 100 bicycle frames and only two wheels, how many bicycles can you build?” He pauses. “Just one.”

As it turns out, our rivers are carrying a phosphorous load equivalent to those 100 bicycle frames, and nitrogen equivalent to the two tires. “We’re working to solve a tire problem when we’ve got a frame problem,” Just says. The key is to reduce the level of phosphorous. But without regulations, it’s not likely to happen.

What Can YOU Do?

Just’s project is only a few months old, and final results are yet to come. But that doesn’t mean we have to sit back and wait to take action, the group agrees. (But then, we’re here because we’re activists. We like the idea of stirring things up to make them better.)

“What can citizens do to improve our water?” one of the group asks Just.

“Vote to support water improvement,” he says. “Get your legislators to support water quality measures and get the DNR to do its job.”

Good advice for everyone, no matter where you live.

But there’s more, too. If you care about water quality — and you will if you don’t have clean water to drink — get involved.

• Look for ecologically minded groups in your area. Join one. Take on local water issues and make an impact with your time, your talents, and if you’re so moved, your wallet.

• Band together to support candidates who care about water quality more than they care about Big Ag or other special interest groups that pollute your waterways. Find out who the “good guys” are in your state and your community. Support them at the grassroots level, because that’s where change begins.

• Learn what you shouldn’t flush. Things like medicines, condoms, sanitary napkins, cigarette butts, chewing gum, dental floss, cat litter … and anything that won’t biodegrade. In short, don’t use your toilet as a trash can.

• Use non-caustic kitchen and bathroom cleaners, like vinegar and baking soda instead of chlorine bleach. Use phosphate-free laundry detergents, as well as natural dish soaps and hand soaps.

• Refrain from chemically fertilizing your lawn so you don’t add to the nitrogen and phosphorous load in your waterways.

If you live in one of those unincorporated areas that flushes your sewage into the river, walk to the water’s edge. But don’t stand upstream of the sewage pipe; stand as close as you can below it. Watch what comes out. Is this the standard you want for your children and grandchildren? For yourself?

Yes, it is costly to install a huge civic waste water plant, but there are less-expensive alternatives. Craig Just is working on one now. But he’s not alone. Check your local universities to see what research they are doing in your area. Actively search for solutions.

One thing we must not waste is time.

Julia Wasson
Blue Planet Green Living (Home Page)