The Salt Lake County Water Conservancy District has started work on a project officials hope will take the edge off summer water problems in the future.
In November, the district will begin injecting drinking water into two natural, underground reservoirs in Sandy. The purpose is to increase groundwater volume during the winter months when water demand is low in hopes of tapping that same source to meet peak demand during the summer.General Manager David Ovard said the idea for underground storage surfaced in the mid-1980s as the district was scrambling to find new ideas for increasing area water supplies.
Originally the district wanted to build a surface reservoir in the Dimple Dell area but found the ground unsuitable. When the United State Bureau of Reclamation came forward with a proposal to help finance underground storage projects on a test basis, district engineers decided to look a little deeper, about 600 feet underground.
"We submitted a project for consideration, and the BOR has agreed to pay half the capital (construction) costs as well as half the operation and maintenance costs for three years," Ovard said.
The district will inject water into sites near 9800 South and 2300 East and near 9400 South and 2200 East. In both cases, the water will be treated for culinary use before injection.
"This is a high-quality aquifer and we want to be careful that the water quality is not affected," Ovard said. "We will be watching the data closely to see how this water affects the native water, how much of the injected water we can actually recover and how the injection affects other wells in the area."
The EPA, Utah Department of Health, state engineer and the U.S. Geologic Survey will also be keeping close tabs on the project, Ovard said.
The project was made possible by passage of SB71 by the Legislature earlier this year. The bill was needed to provide the district authority to recover the injected water. "Without the bill we could put water in, but we couldn't take it back."
The project, one of 19 such efforts around the West, is expected to cost about $4 million over the three-year test, half of which will come from the BOR. Data from the Salt Lake project will be collected and analyzed along with data from the other projects. That information will then be made available to other water districts interested in pursuing underground storage efforts.
"At the end of the project we'll have to look at the data and determine whether it will make sense to continue," Ovard said.