Six of New Brighton’s 11 water-supply wells pump water from a groundwater plume containing chlorinated solvents. The wells serve as the city’s primary water source and are part of a remediation system controlling migration of the groundwater plume. The solvents in the extracted water are removed to non-detectable concentrations via granular activated carbon in a water treatment plant.
In 2014, a contaminant of emerging concern—1,4-dioxane—was detected in treatment-plant effluent at concentrations above the health-based value set by the Minnesota Department of Health. New Brighton quickly shut down the wells and switched to an uncontaminated water supply while the treatment plant was modified to remove 1,4-dioxane.
Barr developed a groundwater model to evaluate the effectiveness of the remediation system's wells at capturing chlorinated solvents and to determine the effects that shutting down this critical system component would have on downgradient users. The model helped refine our understanding of how the chlorinated solvents and 1,4-dioxane move in the groundwater and demonstrated that if the wells were left off line for more than a few years, the water supplies of neighboring cities could be adversely affected. The model also demonstrated how a new well could optimize extraction and shorten the amount of time downgradient users would be affected.
Vice President Senior Hydrogeologist
Vice President Senior Consultant