Six of New Brighton’s water supply wells pump water from a groundwater plume containing chlorinated solvents. Those wells serve as both the City’s primary water supply source and as a remediation system to control the migration of the groundwater plume. The solvents in the extracted water are removed to non-detectable concentrations using granular-activated carbon in a Barr-designed treatment plant (known as Water Treatment Plant 1 or WTP1) that was completed in 1992. In 2014, the compound 1,4-dioxane was detected in the treatment plant effluent at concentrations above the health-based value set by the Minnesota Department of Health. For New Brighton to continue using this water in a potable capacity, additional treatment was required to remove the 1,4-dioxane.
Barr designed and operated an eight-month pilot-scale test of alternative treatment technologies, and based on that test, Barr recommended a UV-peroxide advanced oxidation process (AOP) to remove the 1,4-dioxane from New Brighton’s drinking water. Barr specified and assisted in procurement of the water treatment equipment and designed an addition to WTP1 to house the equipment. Barr also designed a 6,000-gallon-per-minute booster station with an interconnection to the city of Minneapolis on the same property, providing a safe interim water supply while the new AOP technology was being installed at WTP1.
Barr used 3D modeling software for piping and structural design. The 3D models and renderings were used extensively for stakeholder review and clash detection for the various engineering disciplines. We also designed extensive upgrades to the existing facility, including backup power supply, controls, lighting, and process piping. Extensive building exterior and interior finish and HVAC upgrades were also completed.