The Fresno City Council on Thursday hired a pair of nationally recognized experts to make sure that the problems with discolored water plaguing the city’s Northeast Surface Water Treatment Plant don’t happen when a new treatment facility opens in southeast Fresno in 2018.
Since January, the city has received between 1,500 and 2,000 complaints from residents and is targeted by at least one lawsuit over rust-colored water – and in some cases, lead above acceptable levels set by the U.S. Environmental Protection Agency. The complaints are from people living in homes with galvanized pipes and in neighborhoods that receive water from the northeast treatment plant.
Vernon Snoeyink, professor emeritus of civil and environmental engineering at the University of Illinois at Urbana-Champaign, and Marc Edwards, a civil and environmental engineering professor at Virginia Tech, will conduct laboratory experiments using samples of galvanized pipes collected from Fresno homes and water from Pine Flat and Millerton lakes.
Edwards’ research team at Virginia Tech was given a $150,000 contract, while Snoeyink and his current affiliate, Water Quality & Treatment Solutions Inc. of Los Angeles, landed a $200,000 contract.
Tommy Esqueda, public works director, said Edwards will perform static lab tests by immersing different samples of pipe for extended periods in samples of water with varying adjustments to pH, alkalinity and corrosion-control chemicals.
The combinations of water chemistry that show the least degree of corrosion and release of zinc from the galvanized coating inside the pipes will be applied by Snoeyink in what Esqueda called “pipe loop tests,” in which water is recirculated through the pipes on a continuous basis.
This study will use real-world pipe and real-world water. That’s something that wasn’t done in the 1998 treatability study (for the northeast treatment plant).
Thomas Esqueda, Fresno public utilities director
The most promising combination of pH, alkalinity, phosphates and other additives will represent the treatment strategy to be used initially at the Southeast Surface Water Treatment Plant. That process will be adjusted as necessary depending on how galvanized plumbing in residents’ homes reacts to the treated water.
Earlier this year, the city broke ground on the new $159 million treatment plant near Armstrong and Olive avenues. When it opens in late 2018, that plant is expected to produce 54 million gallons of water a day, with the ability to expand production to 80 million gallons daily.
Because the Fresno Irrigation District’s Enterprise Canal is the source of water from Millerton and Pine Flat lakes for both plants, the treatment strategy determined by Edwards and Snoeyink will also be used at the Northeast Surface Water Treatment Plant.
That facility was built at a cost of about $32 million and opened in mid-2004. But within months of starting operation, residents in the area began complaining about discoloration in the water. The number of complaints exploded earlier this year after social media posts indicated that problems were more widespread than even many of the affected homeowners had previously believed.
Snoeyink and Edwards were initially hired by the city earlier this year to help Fresno understand the water chemistry conditions associated with complaints of red, brown or yellow-tinged water at homes with galvanized iron plumbing.
The 1998 study conducted in anticipation of developing the northeast plant had, in fact, predicted the potential for discoloration from galvanized pipes because of the differences between surface water and the pumped groundwater that was previously the sole source of drinking water for the city.
I wouldn’t say the (1998) report was inherently flawed. I think it reflects the naivete of the time that we thought we understood something we really didn’t.
Marc Edwards, engineering professor from Virginia Tech
In August, Edwards described the 1998 study as “state of the art for the time.” But, he added, galvanized pipe is one of the most unpredictable plumbing materials in which to assess the potential for corrosion. As a result, Edwards said, the study likely gave the plant’s operators a level of “false confidence” that they could handle whatever resulted.