You can’t find a city in the world that doesn’t have to treat its wastewater. Just about every city in the United States has a centralized sewage system, where homes and businesses send their wastewater to be filtered and cleansed at large treatment plants. But in states from Minnesota to Texas, more and more homeowners are opting to keep their sewage close by, and treat it themselves. About one out of every four U-S homes—and one out of every three new homes and commercial buildings—are now using on-site sewage systems. It’s part of a national trend that has ramifications for both water quality and land-use planning.
Most people don’t give much thought to where their wastewater is headed. And they probably don’t want it anywhere near their homes. So it might come as a surprise that nearly all of Austin, Texas, homebuilder Matthew Bailey’s clients are asking him to install a system that keeps their wastewater on their properties.
In the backyard of this house, Bailey is putting in a miniature wastewater treatment plant: a large septic tank that’s the size of a small room. He explains that all the family’s wastewater will flow directly from the house into a set of tanks, where it will be treated with oxygen and chlorine and eventually dissolve into a non-toxic liquid. “And then from there, all the water is distributed to a field, about 140 square meters, that’s located really anywhere on the property. The field in our house is on the front and side of the property.”
Why would someone want to keep all their sewage on their property? In a word, location, location, location.
Bailey says his customers—and many others who are moving to the Austin area—want to live far from the increasingly congested and expensive center of town. “And pretty much every home we’ve done this year, which has been six homes, we’ve had to put these systems in. So we wouldn’t have been able to build without this.”
With an on-site sewage system, Bailey says, homeowners don’t have to live near an existing sewage line. They can build almost anywhere. They also don’t have to pay monthly sewer bills. Developers are happy, too, not to have to build the costly centralized systems that can take decades to pay off.
And according to James McCain, with the Texas Commission on Environmental Quality, on-site systems are as safe for the environment as sewer lines. There are risks, he admits, but he adds, they’re relative. “There’re risks with all development, but what happens when a sewer pipe breaks and goes for six hours before anyone notices it? That incident alone probably adds more sewage to the lake than a small conglomeration of a bunch of failing on-site systems.”
But Bill Priebe, with the Minnesota Pollution Control Agency, isn’t so sure. His state’s on-site sewage program is a bit older than the one in Texas, and he points to pollution problems in some of Minnesota’s many lakes and rivers that could give Texas officials pause. “You can get excessive nutrients, maybe fecal chloroform, that kind of thing showing up in surface waters,” he says, “and there are a variety of sources for those. Some are associated with on-site systems. And we’re trying to come up with ways to manage problems like that so we can bring the water quality back to the designated use standards.”
Back in Austin, James McCain agrees that the older on-site septic tanks do, in fact, pose environmental risks, but he says the new systems have overcome that problem. “Nowadays, you can pretty much deal with most any site. Sometimes it’s expensive, but,” he stresses, “there’s always, always, most of the time, there’s a technological option that will provide environmental protection.”
The Texas Commission on Environmental Quality is so confident of the potential of on-site sewage systems that it is implementing a process for homeowners to maintain their systems on their own, provided they send all the required data to state officials.
McCain expects to see more utility companies across the country encouraging their customers to follow his Commission's lead. The U.S. Environmental Protection Agency has said adequately managed on-site systems are both cost-effective and a viable long-term option for meeting public health and water quality goals, particularly in sparsely populated areas.