Water in the region of Gillette could become a little harder but with less fluoride after the Madison Pipeline project is complete.

The project is a $217 million effort to stretch a 42-mile-long pipeline that will bring fresh water from the Madison formation well fields north of Moorcroft to Gillette. The pipeline will duplicate the route of the existing pipeline, which will continue to serve Gillette.

It is designed to extend the water supply for growth anticipated for another 50 years.

The preliminary design for the project has been completed, which counts for 10 percent of the total design process, and is slowly on its way toward approval by the city, the Wyoming Water Development Commission, the state Department of Environmental Equality and the state Engineer’s Office.

The city has two sources of groundwater wells now — the Fort Union wells in the immediate vicinity of Gillette and the Madison, which is piped from well fields near Devils Tower.

Fort Union water quality is softer water with a higher concentration of fluoride, said Darin Brickman, project director for Burns & McDonnel Engineering, one of the consultants on the project. Madison water quality is much harder with lower fluoride levels.

City of Gillette Project Manager Mike Cole said the strategy to blend the Madison water with the Fort Union water works to level out the hardness and fluoride counts. But as time goes on, there will be an increased reliance on water delivered from the Madison, which will gradually increase the hardness of the water.

“It’s a trade-off,” he said. “Wyoming regulates for fluorides but they don’t regulate for hardness.”

Primary health drinking water standards and secondary standards for aesthetics will improve with the lower fluoride concentration, Brickman said.

City and state officials, who are partners on the project, are discussing two alternatives to deliver water to Gillette:

? A fully blended system that blends all water at a common spot before anyone in Gillette receives water, so residents receive consistent water quality.

? A partially blended system would not blend water at a common point and have inconsistent water quality throughout the city, but it would be cheaper.

They are leaning toward the fully blended system.

The city and consultants likely will drill the test wells northwest of the existing Madison well fields, said Carl Anderson, project director from Morrison Maierle.

Rather than drilling smaller test wells, the decision was made to drill full-size wells that will become the production wells for the project, he said.

The consultant will finalize the design of the test wells and drill later this fall — the first part to be tackled of a project that will not be completed until 2016 or later.

Print PDF