Drinking Water Quality
The product water from this project will meet or exceed drinking water standards. The water quality and total dissolved solids for the drinking water produced from the Southwest Groundwater Treatment Plant will match the other water supplies delivered by Jordan Valley Water.
By-product Water Quality
The by-product from this project will have a salt concentration higher than drinking water or irrigation water; the total dissolved solids or salt concentration will be less than ocean water and Great Salt Lake water. The by-product water will not contain any hazardous concentrations. A
table showing the projected water quality for the by-product can be seen in the link below, along with some comparisons for key parameters and standards.
Table of Projected Water Quality of By-product
Sulfate - The Contaminant
The contaminant that was introduced to the aquifer by mining activities is sulfate, SO4. Sulfate can cause a laxative effect on humans. Infants and travelers not accustomed to the water are especially susceptible to being affected with diarrhea.
The drinking water sulfate concentration standard to protect human health is 500 mg/L. Milligrams per liter (mg/L) is similar to parts per million (ppm). A link to the Utah drinking water standards is listed below. Sulfate is shown as item no. 17 in Table 200-1.
The EPA drinking water sulfate concentration standard for taste is 250 mg/L. A link to the an EPA reference is listed below. This link provides information on the lower standard and studies on the effects of sulfate in drinking water.
The two plumes of contamination in this project have sulfate concentrations that range from 500 mg/L to over 20,000 mg/L. The western plume (Zone A) sulfate concentrations range from 500 mg/L to over 20,000 mg/L. The eastern plume (Zone B) sulfate concentration ranges from 500 to 1,500 mg/L. Groundwater from the eastern plume has and currently is being pumped and utilized for agricultural irrigation, stock watering, and domestic use by residents deep aquifer water rights. None of this water is being used in municipal water systems where it could be distributed to public or commercial establishments. Kennecott Utah Copper is pumping water from the western plume (Zone A) to complete the objectives of this groundwater project, IE contain the contamination, remediate the aquifer, and provide municipal quality drinking water.
All of the water provided to the public from this project will be treated by Jordan Valley Water Conservancy District or Kennecott Utah Copper to a level that meets the lowest EPA sulfate concentration standard, as well as other water quality goals that Jordan Valley Water has established for itself.
A Great Salt Lake Water Quality Steering Committee and Science Advisory Panel have been organized to establish numeric standards for the Great Salt Lake. The initial focus will be on selenium.
Public concern over the potential of adding more selenium to Great Salt Lake as the result of the Southwest Groundwater Project brought a renewed focus on the need for numeric standards.
Under the Committee’s oversight, a science panel will look at the existing selenium studies on the Lake and conduct additional work where necessary. The committee will consider the science panel’s work, then make a recommendation to the Water Quality Board. If the Board accepts the recommendation, the standard will be sent out for public comment before the action is final.