Waukesha Water Transition Project

Jacobs prepared the first ever water diversion with return flow application under the Great Lakes – St. Lawrence River Basin Water Resources Compact (Compact) and oversaw the permit approvals, transition from groundwater to Lake Michigan water, and design of treatment improvements and monitoring for returning treated wastewater to the Lake Michigan tributary. 

How’d we do it? Read on…

From a dwindling water supply…

For a U.S. state home to 15,000 lakes, including two of the world's largest lakes as borders, it may come as a surprise that water supply is a challenge for our clients in Wisconsin.

In the southeastern portion of the state though, Waukesha Water Utility (Waukesha) was faced with a steadily declining groundwater supply and naturally occurring, carcinogenic radium contamination. To find an alternative water supply for the 70,000 people who rely on its service, Waukesha needed to act. So, in 2001, they turned to Jacobs to investigate water supply alternatives and design interim radium removal treatment facilities.

As part of Waukesha’s Future Water Supply Study, we found that the Great Lakes – in particular, Lake Michigan – were the most reliable, sustainable source of high-quality water for the future. This finding started Waukesha on the path toward seeking a sustainable water supply from the Great Lakes; however, bi-national regulations – which eventually became the Compact – for managing Great Lakes water were in development at the time. It was unclear whether Waukesha, which is in a county that straddles the Great Lakes Basin, would meet the criteria being defined in those regulations. 

Ratified in 2008 by the U.S. and Canada – to protect and manage the Great Lakes – the Compact prohibits diversions out of the Great Lakes basin, except under limited exceptions, one of which allows diversions to communities within counties that straddle the Great Lakes surface water divide. Under this exception Waukesha was allowed to pursue its Application for a Lake Michigan Supply with Return Flow (Application). 

From 2003 through 2016, Jacobs completed numerous projects and studies in support of Waukesha’s Application to use and return Great Lakes water. The Application development itself involved water supply and treatment and return wastewater flow alternatives screening, feasibility analysis and life-cycle cost development.

Innovative work that supported the Application includes: 

• Delivered first municipal water conservation plan compliant with Wisconsin Administrative Code Chapter NR 852 Water Conservation and Water Use Efficiency and the Compact. 
• Implemented a first-of-its-kind process compliant with Wisconsin Administrative Code NR 854 Water Supply Service Area Plan and the Compact, to evaluate water supply alternatives that considers environmental, economic, public health, implementation and sustainability impacts.
• Developed a first-of-its-kind return flow discharge management plan to optimize environmental benefits and mitigate flooding potential.
• Pilot tested, designed and constructed high-rate radium removal treatment at select Waukesha groundwater wells to comply with drinking water radium regulations on an interim basis.
• Pilot tested, designed and operated water quality and corrosion control testing to provide safe drinking water during and after the water transition.

… to a resilient solution for tomorrow

On June 21, 2016, after 15 years of developing a sustainable water supply alternative, the Council of Great Lakes State Governors unanimously approved Waukesha’s Application to use and return Great Lakes water under the Great Lakes Compact. This historic decision marks the first time a city located outside the Great Lakes basin received approval from all eight Great Lakes governors to receive and return Great Lakes water. Waukesha’s application was subjected to unprecedented public and regulatory scrutiny and is regarded as the most vigorous test of the Great Lakes Compact law to date. Jacobs’ technical work and documentation contributed significantly to this success. 

Waukesha’s transition from groundwater to Great Lakes water was completed over a two-week period in October 2023, marking 20 years since the initial water supply alternative investigation. This transition was the result of extensive studies into water chemistry and the distribution system water quality including the development of an innovative transition flushing program that minimized the mixing of the two separate water supplies. Perhaps most critical though: Customers are not only receiving a more sustainable drinking water supply, it’s also higher quality. The new water continues to have low levels of lead and copper, greatly reduced hardness, and radium is almost totally eliminated.

Transitioning from an unsustainable and contaminated groundwater supply to a sustainable Great Lakes water supply provided a net environmental benefit to the Great Lakes. Through the project, it’s estimated that two billion gallons of water will be used by customers, treated through the clean water plant, and returned to Lake Michigan through the Root River annually. The return flow meets stringent water quality requirements and enhances the fish habitat and flows in the Root River, especially during periods of drought. In fact, an environmental analysis showed a net environmental benefit to the Great Lakes Basin. 

Our planners, engineers and scientists work with our clients like Waukesha Water Utility every day to solve water challenges with customized, innovative solutions and new ways of thinking. We recognize that water challenges are complex and interconnected, and that the old ways of managing the water cycle in silos cannot keep pace with the issues we all face. Viewing all water as a resource and developing integrated, holistic solutions, like this transition project, provides comprehensive benefits for our communities, providing them with the water resources they need to be healthy and flourish.