Saint Anthony Village, MN







Construction Materials Testing & Inspection

City Engineering

Drinking Water

Geotechnical Engineering

Grants & Funding


Project Management & Construction Administration

Public Engagement

Landscape Architecture



League of Minnesota Cities 2019 City of Excellence Award

In 2015, the City of St. Anthony Village discovered 1,4-dioxane in its three municipal wells. The wells helped provide over 9,000 residents with drinking water, and the city partnered with WSB to quickly address health concerns related to the contamination. The city’s water treatment plant was outfitted to treat the contaminant with ultraviolet (UV) light and hydrogen peroxide (H2O2) technology. We partnered with the city from initial planning to full operation, providing additional services in grants and funding and community outreach.

The water treatment plant is the first plant in the state of Minnesota to use UV light and H2O2 to treat drinking water. At the beginning of the project, we studied several Environmental Protection Agency (EPA) reports on methods for treating 1,4-dioxane and concluded that the contaminant could be treated with UV light and H2O2. 1,4-dioxane is an organic compound that is not fit for human consumption and can create health concerns. Several modifications were made to the existing water treatment plant to accommodate the change to UV light and H202.

During planning, we identified several options to address the contamination, including constructing new wells and purchasing water from nearby cities. None of the other options were as cost-effective for the city and its residents as treating the contaminant with UV light and H2O2. When added to water, H202 absorbs UV light, producing hydroxyl radicals that break the contaminant down into nontoxic compounds consisting of carbon dioxide, water, and residual chloride.

In addition to its cost-effectiveness, the use of UV light and H202 technology for water treatment offers several auxiliary benefits. The technology destroys and removes 1,4-dioxane from the environment and does not create byproducts that require disposal as hazardous materials. It cleans the aquifer, reducing risk to other users of the aquifer located downstream of St. Anthony Village. The technology is also effective in removing other, more severe contaminants from drinking water.

During construction, the existing water treatment plant remained in full operation with little to no disruption to the previously established water treatment process. The two systems were integrated during a two-day span. The community was kept informed on the project’s progress with a robust communications campaign, spearheaded by the WSB team.

The project lasted 15 months from initial planning to full operation and was completed in July 2017. We offered numerous services over the project’s duration, including geotechnical engineering, construction materials testing and inspection and landscape architecture. The project has won several awards since its completion.

Dozens of other treatment systems across the country have begun to use UV light and H2O2 to remove contamination from more than 250 million gallons of drinking water each day.

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