For decades, Great Salt Lake shorebirds have been harbingers of the chemicals contaminating Utah’s inland sea.
And soon, mallards — and more specifically their eggs — may be the gatekeepers of a $74 million water-reclamation project.
Private scientists will monitor the ducks’ nests every year to determine the impact of a pipeline dumping 1.5 million gallons a day of wastewater — the byproduct of a public-private partnership between Kennecott Utah Copper and the Jordan Valley Water Conservancy District — on the lakebed.
Now, after more than a decade, the 21-mile pipeline’s final stage is in sight: building a 1,000-foot extension that will spew water from two new reverse-osmosis plants straight into the lake.
The concentrations of trace minerals in the wastewater worry environmentalists and lake lovers alike.
The water agency and mining company’s plan to clean up two contaminated groundwater plumes at the south end of the Salt Lake Valley essentially removes chemicals from underground aquifers fouled over decades of mining and dumps them in the briny lake at a time when chronic low water levels undermine its capacity to absorb pollution. At risk are the lake’s flocks of migratory aquatic birds, which absorb selenium from the brine shrimp, brine flies and other tiny organisms that inhabit the lake and surrounding wetlands.
“If you don’t have a place to dump the concentrate, then you haven’t accomplished a single thing on behalf of the environment. It is possibly worse to dispose of concentrated toxins … into a precarious ecosystem — which is precisely what you are doing here,” Ivan Weber, a Salt Lake City environmental consultant, wrote to the U.S. Environmental Protection Agency.
But the cleanup has to happen. The plumes are slowly making their way to the Jordan River and, eventually, the lake. And EPA scientists concluded in March that the project would not result in “significant impacts.”
That finding freed up $1 million in federal grants to pay for the final piece of pipeline, according to Shazelle Terry, water-quality manager for the Jordan Valley district. “We want to make sure we aren’t causing unintended consequences,” Terry said. But “that plume was making its way to the Jordan River anyway. All we are doing is speeding up a natural process.”
Tailings to treatment • In 1988, Kennecott and state air-quality watchdogs reached a settlement that established a remediation fund to manage groundwater contamination.
For about 100 years, company miners dumped tailings directly onto the ground or into evaporation ponds at the western edge of Salt Lake County. Through the years, the minerals and heavy metals in that waste leached into groundwater, leaving two 50-square-mile plumes with thousands of acre-feet of tainted water.
A decade ago, the company and the water district tapped the cleanup fund to build two nondescript water-treatment plants — one in South Jordan, the other in West Jordan.
Jordan Valley district has sunk eight wells 800 feet down into “Plume B” and pipes the contaminated water a few miles downhill to the new plant at its West Jordan headquarters on the Jordan River around 8200 South.
Kennecott has been cleaning Plume A with a similar plant since 2006. Jordan Valley’s plant went on line in 2013.
In reverse osmosis, which is commonly used in desalinization, water is squeezed under intense pressure through membranes that block all dissolved solids.
The West Jordan plant pumps the groundwater into the plant in silver pipes. After two stages of filtering, it concentrates the contamination by a factor of five into a waste stream that exits the plant in brown color-coded pipes and is pumped to Kennecott’s Magna tailings pond.
For every four gallons of pure water, or “permeate,” the process produces one gallon of “concentrate.”