By Peak Johnson
East Chicago, IN, is having persistent problems with its drinking water.
Already, the city implemented a chemical, sodium hexametaphosphate, in order to control corrosion in lead pipes, though some experts think it could be doing more harm than good.
Records obtained by the Northwest Indiana Times, show that the Indiana Department of Environmental Management (IDEM) “approved the change in chemicals in May 2009, when it issued a permit for construction of the city’s new water filtration plant.”
However, sodium hexametaphosphate can actually increase lead release, according to Marc Edwards, a professor of civil and environmental engineering at Virginia Tech. Edwards said that “using sodium hexametaphosphate might have been worse than conducting no corrosion control at all.”
Edwards added that East Chicago’s plan before taking on sodium hexametaphosphate was not very strong either.
Now, the Times is reporting that East Chicago “increased the amount of orthophosphate it adds to water in October, after the U.S. Environmental Protection Agency notified the Indiana Department of Environmental Management (IDEM) it found low or no orthophosphate levels at two homes in the Superfund site.”
Orthophosphate is a chemical added to water to control corrosion of lead pipes and “is being pulled through lines to create a protective scale that can prevent releases of lead and copper.”
However, due to reduced water use in the area, the use of orthophosphate may be rendered ineffective.
“Dead-end water lines near railroad tracks, the relocation of more than 1,000 from a public housing complex and the loss of the city’s second-largest water customer could result in lower water flows,” per the Times. “Lower water flows means less orthophosphate … is being pulled through lines to create a protective scale that can prevent releases of lead and copper.”
The EPA found low levels of the chemical during a pilot study at the Superfund site, but stated later that the results gathered “and the city’s monthly operating reports showed high lead levels were likely to be systemwide.” The agency found lead levels above its 15 ppb action level at 18 of the 43 homes tested.
EPA officials have said that the water sampling “was more robust than testing required under the federal agency's Lead and Copper Rule, which East Chicago has been in compliance with since 1993.”
The Times reported that “up to 90 percent of East Chicago’s water lines could be lead; EPA recommended residents should assume they have lead lines and use a certified water filter.”
Edwards said that “results from EPA’s pilot study, the city’s monthly operating reports and knowledge of water chemistry indicate EPA was correct to assume high lead levels likely are a systemwide problem.”
In addition to recommending that East Chicago increase their orthophosphate levels, IDEM also added that it has strengthened its testing.
"The city is currently monitoring for orthophosphate in the Superfund area and has a target orthophosphate residual of at least 1 mg/L," the department said. "Each resident that has their tap sampled for lead and copper is notified of their results via the lead consumer notice."
Edwards said the latest target orthophosphate residual might not be high enough.
To read more about lead remediation efforts visit Water Online’s Drinking Water Contaminant Removal Solutions Center.
Image credit: "dripping pipe :)" Keir Martin © 2010 used under an Attribution 2.0 Generic license: https://creativecommons.org/licenses/by-sa/2.0/