Historic mining activities in the Oquirrh Mountains in southwest Salt Lake County led to the creation of two groundwater plumes in the principle aquifer of southwest Salt Lake County (Contaminated Zones Map). The two groundwater plumes contain elevated concentrations of sulfate and total dissolved solids (TDS) above the State of Utah primary drinking water standards.
The Zone A acid plume (core of Zone A) also contains metals above the State of Utah primary drinking water standards. Since 1986 the State of Utah has been involved in addressing the investigation and implementation of response actions to address both plumes of groundwater contamination.
In 1986 the State of Utah filed a natural resource damage (NRD) claim against Kennecott Utah Copper Corporation (now Kennecott Utah Copper LLC) for mining influences to the principle aquifer of the Southwest Salt Lake Valley.
In 1995, the State of Utah, Kennecott, and the Salt Lake Valley Water Conservancy District (now the Jordan Valley Water Conservancy District, or JVWCD, then an intervening plaintiff) reached an accord under which Kennecott agreed to complete certain CERCLA remedial response actions, establish a Trust Fund (NRD Trust Fund) with the State of Utah as beneficiary in an amount equated to the physical damage to the influenced aquifer, and to begin extractions on the then entitled Zone A acid plume to facilitates its containment. The terms of the accord were captured under the 1995 Natural Resource Damage Consent Decree.
In 2004 the State of Utah Natural Resource Damage Trustee (NRD Trustee) accepted a project proposal from Kennecott and the JVWCD after a lengthy public outreach effort. The proposal intended to make use of the Trust Fund to fund the construction and completion of two reverse osmosis treatment plants to address the treatment of groundwater extracted from the Zone A and Zone B plumes influenced by elevated sulfate and TDS. Under the 2004 Three Party Agreement, the NRD Trustee accepted the project proposal, after issuance of a Findings and Conclusions determination. Under the 2004 Three Party Agreement, Kennecott and the JVWCD agreed to:
Kennecott—Construct and operate (in compliance with federal and State regulations) a reverse osmosis treatment plant to produce 3,500 acre-feet of municipal quality water (drinking quality water) from the direct treatment of the Zone A sulfate plume. The treated water is to be delivered to the JVWCD for provision at a reduced rate to the four affected municipalities and subsequently the affected public.
JVWCD—Construct and operate (in compliance with federal and State regulations) a reverse osmosis treatment facility to provide municipal quality water from the direct treatment of the Zone B sulfate plume, or to provide the equivalent volume to be produce by treatment (3,500 acre-feet per year) from other available sources.
The JVWCD also agreed to construct and operate a reverse osmosis treatment facility to treat and produce a volume of municipal quality water that makes up for the water lost during the reverse osmosis treatment process. The volume to be produced is equivalent to 1,235 acre-feet per year. The JVWCD obligation under the agreement is to offer these volumes of treated water to the affected municipalities for sale.
Since 2004, the NRD Trustee has continued to oversee the response action by Kennecott and the JVWCD pursuant to the terms of the 1995 Natural Resource Damage Consent Decree and 2004 Three Party Agreement. In 2009, the three parties amended the 2004 Three Party Agreement. For further information on current and past activities, please consider the following topic links:
- 2009 Amendment
- Kennecott Annual Progress Reports
- JVWCD Construction and Testing Activities
- Great Salt Lake Advisory Council
- NRD Trustee Stakeholder Forum
- Proposed Jordan Valley Water Conservancy District UPDES Permit to Discharge to Great Salt Lake
Coordination with CERCLA (Superfund) Program at U.S. EPA Region 8
The NRD Trustee has and continues to coordinate response actions under the NRD project with the U.S. EPA Region 8. Both authorities have actively pursued the remediation of the Zone A and Zone B plumes, and thus have endeavored to coordinate their response actions to ensure a successful remediation of the mining influenced groundwater. Please go to Operable Unit—Southwest Jordan Valley Groundwater Plumes on the CERCLA (Superfund) Projects page for more information.
NRD Document Repository
UDEQ supports an online document repository, in which a number of the NRD project documents are maintained for public review.
For more information or questions about the ongoing NRD response action performed by Kennecott or the JVWCD, please contact: