Massive Man-made Wetlands System Treats Wastewater

A unique water reuse project uses sedges, rushes and other plants to filter effluent-dominated water.
Massive Man-made Wetlands System Treats Wastewater
The George W. Shannon Wetlands Water Reuse Project was the first of its kind in the United States. Photo courtesy of Tarrant Regional Water District.

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At first glance, the George Shannon wetlands system resembles most other low-lying marshes where water birds roost in old oaks and pelicans wade across shallow ponds. However, the 2,000-acre wetland system in Fairfield, Texas, has a secondary purpose: It slowly converts effluent-dominated water from the Trinity River into an additional 65 million gpd of drinking water that feeds into the Richland-Chambers Reservoir — a significant contribution given prolonged drought in the area.

The George Shannon Wetland Water Reuse Project began as a small 2-acre test facility in the early 1990s, with the largest phase — an additional 1,600 — acres being completed this past October.

The wetland system is operated by the Tarrant Regional Water District (TRWD).

The process explained
Water first travels into one of several large pools, where sediment sinks to the bottom. It then moves through wetland cells, which are essentially shallow ponds that contain vegetation.

“These plants are taking those constituents out of that water and using them for their growth,” says TRWD assistant environmental division director Darrel Andrews in an interview with The Star Telegram. “The soil binds some of those nutrients as well,” he continues. “These act as the filter. That’s what’s removing those nutrients before [the water] gets to the end of the wetland system.”

Phosphorus and nitrates are filtered out over the course of roughly a week before the clear, treated water is fed into the Richland-Chambers Reservoir.  

An effective alternative
Ken Kramer, chairman of the Lone Star Chapter of the Sierra Club — a Texas conservation organization — tells The Telegram that reuse projects will become more common as water providers explore alternatives to reservoirs.

“I think these kind of reuse projects are going to be part of our near-term and long-term water supply strategies,” he says.

The man-made wetland system cost $75 million to construct — far less than traditional filtering infrastructure or the estimated $3.4 billion it would cost to build a new reservoir. Moreover, the system reduces pressure on water utilities that rely so heavily on precipitation in such arid climate.

“This is stepping back from dependence on rainfall,” says David Marshall, TRWD head of engineering, in The Miami Herald.

“With potential climate change or long-term droughts, we’re at risk, whereas these wetlands firm up a tremendous amount of water supply for us.”

The wetlands system was built over a former oil field and provides 1.5 million North Texas users around 30 percent more water than the reservoir would normally hold.

“The wetlands produce 63,000 acre-feet per year, which equals about 56 million gallons a day, so it supports about 343,000 people,” says Marshall.

Wildlife Haven
As a part of the Richland Creek Wildlife Management Area, the wetlands provide a home for more birds, gators, deer, and feral hogs each year.

Come winter, thousands of migratory birds descend on the area as well. Wildlife biologist Matthew Symmank, who presides over the wildlife management area, tells The Telegram, “From our perspective, these wetlands are very beneficial to all sorts of native wildlife.”

Although the wetlands system took almost two decades to complete, all parties involved — even the animals — are enjoying everything it has to offer; foremost, a reliable, sustainable and substantial supply of clean drinking water for an area that’s struggled with drought for years.



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