DERR-2024-007717

NRD Trustee – Comment Response Summary – Response to Common Comment No. 4 4-1
SOUTHWEST JORDAN VALLEY GROUNDWATER CLEANUP PROJECT
STATE OF UTAH NATURAL RESOURCE DAMAGE TRUSTEE

COMMENT RESPONSE SUMMARY
AUGUST 31, 2004

Response to Common Comment No. 4 – Sulfate Plume Treatment

Several comments were received regarding the technology selected to treat sulfate-contaminated
groundwater. Some comments suggested further study of other technologies. The Trustee
believes that reverse osmosis (RO) is a proven, viable, and economic technology that is consistent
with the Consent Decree. This technology was selected after consideration of numerous
alternatives. The Trustee’s approval of the project as proposed does not preclude the future
adoption of new or improved treatment technologies that would benefit the project.

The use of RO technology to treat the sulfate-contaminated water has been well documented and
demonstrated to be a reliable method of water treatment. As part of the CERCLA Remedial
Investigation and Feasibility Study (RI/FS), Kennecott evaluated over 40 different remediation
technologies, combinations of technologies, and alternatives. An evaluation of these technologies
was presented in the Feasibility Study for Kennecott Utah Copper South Facilities Groundwater
Plume, dated March 16, 1998 – Version B. This document is available from the DEQ. During
the RI/FS evaluation, a number of the technologies, which have been recommended by
commenters, were evaluated and eliminated from further consideration due to technical,
economic or environmental considerations. RO was pilot tested and determined to be the best
method to achieve the desired results and satisfy the remedy selection criteria listed under
CERCLA and the Consent Decree.