Westlake Water Treatment Systems Help Pennsylvania Borough Meet U.S. Clean Water Act

Jul 05, 2021

The Water Treatment division of Westlake Chemical Corporation, manufacturer of the Accu-Tab® chlorination and CleanSlate® dichlorination systems, published a new case history outlining the key roles its water treatment systems perform within a recently upgraded wastewater processing plant in Southwestern Pennsylvania.

Close to $50 million was invested by the borough in new construction and retrofits to the Combined Sewer Overflow (CSO) complex located in Donora, Penn. The processing plant, run by the Mon Valley Sewage Authority, now better protects surrounding rivers and streams throughout the region from storm sewage run-off contamination.

The Mon Valley project is one of the first in the country to comply with the United States Clean Water Act mandating the reduction or elimination of sewer overflows. It is the largest CSO of its kind in the nation to use Westlake’s solid forms of chlorine and dichlorination chemicals and delivery technologies, which are marketed under the Accu-Tab brand from Axiall Water Treatment, a Westlake business.

Most processing plants in the United States, and the infrastructures that feed them, were built decades ago. As the population and industries grew so did demand loads on these wastewater treatment facilities. Consequently, many are not equipped to process excess wastewater that accompanies heavy rainstorms. This is when overflows typically occur that may result in untreated water being discharged into rivers and streams.

The Accu-Tab chlorination system, which uses United States Environmental Protection Agency (EPA) certified and National Sanitization Foundation (NSF) Standard 60 and 61 listed Accu-Tab White SI calcium hypochlorite tablets and feed equipment, was selected as the primary treatment chlorination chemical based on its low cost and easier maintenance when compared to ultraviolet light systems. The longer shelf-life of Accu-Tab chlorine tablets also made the Accu-Tab system a clear choice over liquid chlorine, which degrades faster. Shelf-life is particularly important because rainstorms are an infrequent occurrence, and the reliable strength of the chlorine to treat the influent water is crucial. At the end of the process, Westlake’s CleanSlate® dechlorination system removes residual chlorine before the water is discharged back into the environment.

“Municipalities and townships that are struggling with how to address their own CSO shortfalls will find valuable information and insights in the Mon Valley project case history. The management at the Mon Valley Sewage Authority and their community took a forward-thinking approach to improving their wastewater processes that not only addressed their current combined sewer processing system needs, but one that also looked many years down the road as well,” said Noel Irizarry, Westlake vice president Chlor-Alkali & Derivatives.


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Westlake Chemical Corporation

Chip Swearngarn

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TX 77056 Houston

United States


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