Wednesday, August 26, 2009
DALLAS -- What would save 250,000 gallons of water a day in the summer and keep Dallas city parks and playing fields lush at the same time?
No curbside bins are needed for this program. Rather, a pipe system that pumps treated wastewater from the city's treatment plant to city parks and school ballfields for watering grass would do the trick.
The proposed project will delay the need for increased water supply capacity at least a decade, Dallas Public Works Director Fred Braun said, deferring the cost of building more water storage.
"It's very costly to build a new reservoir and very environmentally difficult," Braun said. "If anything, dams are being torn down these days."
While the water is not intended for drinking, it would undergo extra filtration and disinfection before use on parks and fields open to the public, Braun said.
Water storage isn't the only issue the city and other areas in the state should be concerned about. An impending shortage of clean, drinkable groundwater is another problem helped with water recycling, said Ron Doughten, the Oregon Department of Environmental Quality's biosolids and water reuse program coordinator.
Rather than using potable water for irrigation of farmland or parks, reclaim programs allow adequately treated water for those uses without posing a threat to public health.
"It really is a good conservation method," Doughten said.
Reclaimed water is broken into four classifications, based on the level of filtration and disinfection it goes through before reuse.
Doughten said the most common use for recycled water is farmland irrigation. Depending on what kind of crop is grown on the land, the treatment disinfection standard is lower than water used on land where human contact is likely, such as parks. Therefore, the city's system will have to include more disinfection. The city also will have to submit a water use plan and comply with DEQ monitoring standards.
The proposal could improve the health of Rickreall Creek as the city decreases the amount of treated water pumped backed into the stream.
For Dallas, the problem is the rush of hot water from showers and baths going into the treatment plant and eventually released raises the temperature of the water, which, in turn affects the health of fish. Diverting water that normally would go back into the creek helps alleviate that problem.
"If we are going to irrigate grass, it's not going to know the difference between 50 degree water and 63 degree water," Braun said. "However, fish will."
Currently the city is completing environmental studies for its project and waiting to hear if it receives federal stimulus grant money for building the water reuse system.
Braun said the city should know about the grant by October. If the money comes through, building will start next summer. If not, construction will be delayed until other funding resources are found.
"Probably in one way or another, we will pursue it," Braun said. "It wouldn't happen as quickly though."