Can rural homes use the same water over and over? A UAA project aims to see

Inside a tiny blue-roofed shed in Anchorage is a toilet, shower, sinks and a machine that can both wash and dry clothes. They're all linked by pipes to a neighboring shipping container, which itself is installed among a jungle of tubes and wires that snake along the sides of the walls.

The water leaves dirty and returns to the shed clean — or at least that's the goal of Aaron Dotson, a civil engineering associate professor at the University of Alaska Anchorage and his team of students running the state-backed experiment. The experiment aims to bring in-home running water and sewage disposal systems to rural Alaska.

"We sent people to space, we can make reused water at your house," a hopeful Dotson said Friday, standing in a lab amid soap, deodorant, noodles, detergent and other items crushed and mixed by his team to create dirty water and test their system's filtration system.

The effort to potentially revolutionize life in rural Alaska by recycling used water has not come without challenges. The latest: bubbles.

Automating appliances

Dotson's team is one of three still participating in the Alaska Water and Sewer Challenge, initiated in 2012 by the state's Department of Environmental Conservation to find better and more affordable ways to bring running water and sewage disposal systems to rural villages and the thousands of homes that still use a 5-gallon honey bucket, lined with a plastic bag, as a toilet.

It is also hoped that whatever comes from the challenge can replace large central pipe and truck systems that are expensive and difficult to maintain, and used in some rural communities.

"We could keep doing it the same way, but the fact is we're just running out of money to do it," said Bill Griffith, facility programs manager for the state's Department of Environmental Conservation.

The state has whittled down the number of teams competing in the challenge over the years. Today, three remain: UAA; national engineering firm, Dowl; and Alaska engineering firm, Summit Consulting. The teams have entered phase three: testing. Over the next nine or so months they will determine if their in-home systems can withstand daily use.

For Dotson, this means creating an invisible family of four who live in the shed on UAA's campus, connected to the shipping container that treats the used water. At set times each day, his team has automated the toilet to flush, the sinks and shower to turn on and the machine to wash and dry clothes. It's supposed to mimic regular use by a family.

In one day, the bathroom sink is scheduled to turn on two dozen times with water running between 30 seconds and a minute. The toilet flushes 16 times. Five times a day, the shower runs for four to five minutes.

Dotson and the students muddy the water for each occasion. Water laced with traces of ground-up beef, berries and salmon travels down the kitchen sink's drain. Urea, salt and other components are added to water to mimic urine. Soap and dust mix into the water that goes down the shower, bathroom sink and laundry drain.

The goal is to repeatedly treat the water and send it back into the home, Dotson said. The state challenge requires the systems to provide at least 15 gallons of usable water per person each day.

Grey water and black water

In the Anchorage shed, the dirtied water travels through initial filters and then into the nearby shipping container, moving through an insulated, flexible corridor that connects the two structures. Some water from the toilet and the kitchen sink, considered "black water," filters into one large tank, while the rest, "grey water," filters into a second.

Treating black water isn't very common. The other two teams are not attempting to do it, the DEC's Griffith said. Dotson said his team wants to waste less water and save money by avoiding hauling away additional soiled water.

His team still sends part of the toilet water away for disposal. They are using a separating toilet that collects urine in the front and feces in the back. Feces filter into a keg, a step up from the honey bucket because it can be sealed, Dotson said. When the keg becomes two-thirds full, the water turns off, signifying it must be replaced.

"It's kind of like honey bucket generation 2," Dotson said. "The keg has been lasting us — approximating the normal use of a home — about four days."

Under his team's plans, people will still have to haul water, just less than they normally do. The hypothetical family will bring 2 gallons of drinking water into its home each day. That goes into a separate tank and through its own filtration system, eventually coming out of a skinny faucet attached to the sink specifically for consumption.

To feed the rest of the appliances, the family would need to bring 3 gallons of water into the home each day. Because it's reused several times, those three gallons are the equivalent of 58 gallons, according to Dotson.

After use, the black water and grey water go through the same treatment process — the black water just goes through it one additional time, Dotson said.

Inside the shipping container, the water is pumped from large holding containers into long tubes. The water filters through a spiral-wound membrane with holes so small it can remove salt. Then, it's treated with ultraviolet lights to kill microorganisms, Dotson said.

"The black water has to migrate two times. The grey water migrates once," he said. "We're trying to wring out all of the bad stuff in the water and keep the clean stuff."

Friday marked the end of the team's second week of testing and it had run into bubbles.

Bubble invasion

Bubbles invaded Dotson's system last week, created by the soap in dirty water and the soap's molecules sneaking through the filtration system into what was supposed to be the clean end product.

"We're fighting with bubbles," Dotson said Thursday. The holding tank had filled with about 3 feet of bubbles, he said. "This needs to be solved before it ever goes into someone's house."

On Friday, the system wasn't running on its typical, automated schedule. The team had shut it down as it tried to figure out how to get rid of the suds. Dotson, having what he called a "faculty moment," used a red marker to draw on a whiteboard attached to the shipping container to explain how the soap made it through the membrane.

"We had a vision of how it would work. It has an issue. We need to revisit it," Dotson said.

Dotson said his team is going to look into using air to create bubbles before the water goes into the filtration system, then scraping the bubbles out. By evening, the team had found a protein skimmer, like one that can be found in a saltwater aquarium, to create and remove bubbles.

Will people use it?

One of the big questions Dotson and his students repeatedly discuss is if their system is something people would want in their homes. Dotson said the number of tubes and wires on the walls would be cut significantly if automation is turned off.

Still, the system requires homeowners to buy into it and work to keep it up and running. Griffith said that's one of the challenges.

"I know one of the toughest things is going to come up with something that we think is going to be accepted and maintained by end users," he said. "We always knew that was going to be hard."

Each of the teams are partnered with rural villages to talk about needs and receive input on the systems being developed. Dotson is partnered with Kipnuk and Koyukuk. Dotson said he has heard that what people most want is a flushing toilet.

The DEC has cost targets for the systems. Each system must cost less than $160,000 and monthly costs should not exceed $135. It is estimated by the state that $40 of the monthly costs will go toward community co-ops developed to assist with the new water and sewage systems, including with cleaning filters and picking up waste, Dotson said.

Griffith said by the time the Water and Sewer Challenge is finished, he expects that between $5 million and $7 million will be spent, a mix of state and federal money.

"I think that's money well spent," he said. Village-wide systems cost many times that.

Dotson said a handful of questions still remain about how the system will work in communities. Potentially, multiple households could hook up to one shipping container filled with filtering equipment. It's likely, he said, that the state or federal government would chip in for the capital costs.

The Water and Sewer Challenge is a long-running experiment. The next phase, field system development and testing, is scheduled for 2018 to 2020. At the phase's conclusion, systems that show sustainable and durable improvement will be further refined, according to the DEC.

Dotson said he has no financial interest in the project, and would rather see the idea "go into the wild" and have other organizations pick it up, tweak it and learn from it.

"I don't think there's any such thing as a silver bullet," he said. "But what I do think is there are options out there to make life better."