Are you ready to water the lawn with treated sewage?August 17th, 2011 by cdunagan
It seems as if it has taken forever for someone in Kitsap County to put treated sewage to beneficial use, but a demonstration project on Retsil Road in South Kitsap is just around the corner. Check out my story in Saturday’s Kitsap Sun.
Local water experts were contemplating uses for highly treated wastewater even before “low-impact development” became a common phrase for infiltrating stormwater into the ground.
LID has caught on fairly quickly as a method of keeping polluted stormwater from reaching our streams and Puget Sound. The concept got an extra push from new stormwater regulations, which have greatly increased the cost of conventional pipe-and-pond methods of stormwater management.
The less-touted benefit of LID is groundwater recharge, which boosts our long-range water supply.
Kitsap County’s Watershed Management Plan (PDF 147 kb), developed in 2005, estimated that Kitsap County’s sewage treatment plants release 8 million gallons of treated water into Puget Sound each day. That’s enough to increase the base flow of 10 streams by 10 cubic feet per second, raise aquifer levels throughout the county or launch a new industry without touching our drinking water supplies.
“The most significant barriers to recycling wastewater are the cost of infrastructure and additional treatment, as well as public perception,” the report states. “Elected officials in WRIA 15 (the Kitsap Peninsula) have expressed support for public education about reclaimed water.”
The report mentions that highly treated effluent from the Central Kitsap Wastewater Treatment Plant near Brownsville could be used to supplement streamflows in nearby Steele Creek. But more recently Kitsap County and Silverdale Water District have begun working together on a plan to pipe the water into the heart of Silverdale, where it can be used to water ballfields and landscaping.
That’s also the initial plan put forth by West Sound Utility District, as I mentioned in Saturday’s story. Using wastewater for irrigation cuts down on peak demand, which is what drives water utilities to drill new wells. Needless to say, drilling deep wells comes at a tremendous expense — an expense that grows greater as Kitsap County approaches the limits of its groundwater supplies in some locations.
To many people, using reclaimed wastewater seems like a novel idea, especially in an region known for its rain. People remain squeamish about getting anywhere near sewage water, even if it is treated. But I don’t believe it will take long for people to accept the idea of using treated wastewater for irrigation, once they realize it is treated to basically the same level as drinking water.
On the other hand, drinking treated effluent becomes another issue, even though it has been done indirectly for years in many places. If you live in a town on the Mississippi River, your local utility may be drawing water out of the river for your consumption just downstream of where a sewage treatment plant is dumping its effluent.
There are several other places where reclaimed water is mixed with freshwater, such as in a reservoir, then drawn back out for drinking. Ironically, putting the wastewater into a reservoir makes it seem more palatable, even though it probably was cleaner before. Treating the water in the reservoir is essentially treating the wastewater again — although water is just water in the end.
For a description of reclaimed water systems in the U.S. and elsewhere in the world, check out a fact sheet compiled by Queensland Water Commission, Australia: “Water recycling: Examples from other countries” (PDF 592 kb).
A community in Texas made news across the country last week, when reporter Angela Brown of the Associated Press wrote about a new $13-million water-reclamation plant to turn effluent into drinking water, the first to be built in that state. Really, it is nothing new, as Angela herself points out.
What I have not found anywhere so far is a direct use of reclaimed water. That’s what you would get by pumping the highly treated wastewater directly into a municipal water system’s piping network. From a health standpoint, there would be nothing wrong with that, provided the water could be shut off in the event of a problem at the treatment plant. No doubt this kind of direct use will be a little harder to get used to, even in areas where water is scarce.
Alix Spiegel of National Public Radio does a nice job analyzing the psychology behind the aversion to using treated wastewater and why people are more accepting of indirect use. Read or listen to “Why Cleaned Wastewater Stays Dirty In Our Minds .”