Experimental Wetland

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Bullard Regulating Wetlands Pilot

The City of Goodyear, U.S. Bureau of Reclamation (Reclamation) and the City of Phoenix are testing a "green solution" to a regional water challenge - how to dispose of salty waste water. Plants that normally grow well in salty conditions have been put to work taking salt out of the water in which they grow. A small artificial wetland has been set up at Bullard Water Campus to test whether these plants take enough salts out of brine waste to meet water quality standards. If the pilot is successful, water treated in the wetlands may be put into the Gila River bed in the future.

Native plants grow in bins to test wetland ability to improve water quality.



How does the Bullard Regulating Wetland work?



The City pumps salty waste water (brine concentrate) generated by its reverse osmosis treatment at Bullard Water Campus into a set of outdoor tanks. Native wetland plants that tolerate salt grow in the tanks. As water flows through the tanks, metals and salts are absorbed by the plants and deposited in tank sediments.

City and Reclamation staff will monitor water flows, water quality and plant growth for a year. Salt levels in the plant's tissue will be measured to see how much salt they store. Treated water will be transmitted to the 157th Avenue Water Reclamation Facility throughout the pilot.

If salt levels in the treated water drop far enough after a year of operation, the City will then request permission from the Arizona Department of Environmental Quality to conduct a second, larger scale test. Blends of reclaimed water and the treated concentrate from Bullard Wetlands would be run through a second wetland at the 157th Avenue Water Reclamation Facility to see whether water quality improves further.


Three square rush, cattails, and salt grass are the most effective in removing salts so far.

Where does all the salt come from?


An array of reverse osmosis membranes used to remove salt from ground water

All drinking water sources used in Central Arizona contain high natural levels of salts. The ground water that is our water source in Goodyear is very salty.

The City uses reverse osmosis to reduce salt concentrations in ground water to make the water safe for drinking. Reverse osmosis forces water through a very fine membrane which acts like a filter to the salt. Reverse osmosis also produces waste water with a much higher concentration of salt than untreated ground water. The City’s water treatment produced 151 million gallons of brine concentrate in 2009.

Why would this be a “green solution”?

  • Wetlands brine treatment would reduce the volume of salt entering the water reclamation facility.

    • This will lower the salt content in reclaimed water. More landscaped facilities may be willing to use reclaimed water with lower salt content.

    • Every gallon of potable irrigation replaced by one gallon of reclaimed water would save 1.17 gallons of groundwater.

    • Lower salt content would reduce facility operating costs through improved efficiency.


Gila River habitat through southwest Goodyear can be restored with high quality effluent.

  • Wetlands brine treatment will save energy.

    • Wetlands brine treatment would require less energy than other disposal alternatives for brine.

    • Replacing 1,000 gallons of potable irrigation water with reclaimed water will save 3.1 kWh of electricity per 1,000 gallons of water.

  • The treated water could eventually help restore life in the Gila River bed by providing some year-round flow.

Is the pilot working?

Six months after initial measurements, results are encouraging in some bins. In Bin 4, several undesirable elements have been reduced; some by 30%, and others as much as 99%. Other bins are not yet as promising, but the work continues.

Photos this page courtesy of Tom Poulson, Bureau of Reclamation and Jerry Postema, City of Goodyear.