“As groundwater contamination problems go, the stuff leaking from septic systems isn’t terribly sexy” — John Fleck

Septic system
Septic system

From the Albuequerque Journal (John Fleck):

That, says University of New Mexico engineering professor Bruce Thomson, is precisely the problem.

“It’s groundwater contamination that’s happening all around us, and we’re not paying any attention,” said Thomson, an expert in treating human waste who delights in describing his academic specialty as “turd mechanics.”

Septic systems drain away household waste into settling tanks, with the water spilling out into drain fields and the natural filtration of the soil doing the cleanup work. But when they don’t work – because homes are packed too closely together, or the systems are old or poorly maintained, contamination can result. The key problem is nitrates, which can render water dangerous to infants…

The Carnuel neighborhood, located in Tijeras Canyon, is a good example of the problem that septic systems can cause. Homes in the area depend on wells for their water and use septic tanks to dispose of their waste. Measurements of water quality taken in the area show the problem, Thomson said. The higher up the hill you are, the lower the levels of nitrates. But for residents downstream from the clusters of septic systems, the contamination from uphill neighbors has left well water of questionable quality.

It’s a classic example of what economists would call an “externality” – when the actions of one person impose costs on someone else.

“You have an area where the groundwater is essentially undrinkable because of contamination from septic systems,” Hart Stebbins said of Carnuel. When that happens, taxpayers are often on the hook for coming in and helping fix the problem by providing piped-in clean water. That is what is happening in Carnuel, where the Albuquerque Bernalillo County Water Utility Authority is now building a water distribution system extension to serve the community.

More water pollution coverage here.

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