Mabton eyes high-tech sewage treatment plant

A year after Mabton made headlines by accidentally dumping 370,000 gallons of raw sewage into the Yakima River, the city is talking about becoming a model of environmental stewardship.

Plans are still under discussion, but the city of 2,300 residents is considering a new wastewater system that would incorporate the latest green technology.

"We're trying to make sure we check out all our options," said City Councilman Mario Martinez.

The city has until November to submit a design for an expanded and renovated plant to the state Department of Ecology, which will enable it to apply for grants to help foot the bill.

Meanwhile, the city already has invested "tens of thousands" of dollars in maintenance and small upgrades to the plant, including more ultraviolet lights to destroy bacteria and improvements to the computer system, said Mayor Angel Reyna.

Since the spill, nine water samples narrowly violated allowable thresholds, according to state Department of Ecology statistics, a track record state officials are happy with.

"I would characterize this as vastly improved," said Donna Smith, the water quality enforcement officer with the Ecology Department, in an email.

In contrast, sampling violated requirements 183 times between January 2009 and the spill.

Engineers with Gray and Osborne Inc. of Yakima are working on a design for the new plant, while a second firm may offer some innovative environmental ideas.

City Councilman Mario Martinez asked the firm 2020 Engineering of Bellingham, Wash., to work with Gray and Osborne to come up with ways to lighten the load on the new facility. One way would be to install low-volume toilets in residents' homes. Another would be filtering wastewater organically through wetlands.

Those ideas sound expensive, Martinez said, but they may help the city qualify for special funding from the U.S. Environmental Protection Agency, Martinez said.

Original estimates put the cost of the improvements between $5 million and $6 million, which could cause utility rates to more than double to $74 per month, Martinez said.

"Can our residents really afford that big of a jump at one time?" he said.

The sewage spill took place on April 16, 2010, after a power failure caused a computer malfunction, sending untreated wastewater into the Yakima River. It was the largest municipal mishap in Eastern Washington in at least 20 years, Ecology Department officials said.

In October, the city received a $35,000 Community Block Grant from the state to help pay for $80,000 worth of design work.

* Ross Courtney can be reached at 509-930-8798 or rcourtney@yakimaherald.com.