- Reclamation
- Upper Colorado Basin
- Colorado River Basin Salinity Control Program
- Paradox Valley Unit
Paradox Valley Unit
The Paradox Valley Unit is currently operating at a reduced injection rate of 115 gallons per minute (67% of past operations) following a successful injection test throughout calendar year 2024 to determine operability of the injection well and injection zone at reduced rates. The PVU removed 62,913 tons of salt in 2024, which is up from 53,257 tons of salt from 2023.

In 2025, the injection test period will continue until Reclamation's Technical Services Center has gathered enough seismic data to make a recommendation on permanent operations. Reclamation will continue to closely monitor seismicity while maintaining operational status. If unfavorable conditions are observed, the injection test will be suspended until it is deemed safe to continue.
Background

The Paradox Valley Unit was constructed to assist in meeting the objectives and standards of the Federal Water Pollution Control Act of 1948 (P.L. 80-845) and the Colorado River Basin Salinity Control Act of 1974, as amended and supplemented (P.L. 93-320). The Salinity Control Act authorizes the construction, operations, and maintenance of works in the Colorado River Basin to control the salinity of water delivered to users in the United States and the Republic of Mexico.

The PVU is located along the Dolores River in western Montrose County, approximately 50 miles southwest of Grand Junction, Colorado, and 10 miles east of the Colorado-Utah border. Its purpose is to extract naturally occurring brine groundwater in the Paradox Valley, thereby preventing it from entering the Dolores River, which is a major tributary of the Colorado River.
Saline concentrations of this natural brine groundwater have been measured in excess of 250,000 milligrams per liter—that's about eight times saltier than seawater—and have contributed up to 200,000 tons of salt per year to the Colorado River system. The PVU was designed to prevent the natural salt load from degrading the water quality of the main stem of the Colorado River. Salt removal provides substantial benefits such as improved water quality, increased life of municipal and industrial infrastructure, and increased crop yields for all downstream water users in the Colorado River Basin.
Environmental Impact Statement
Because the existing brine injection well is nearing the end of its useful life, the Bureau of Reclamation investigated alternatives for disposing of the brine. Reclamation prepared and released a Final Environmental Impact Statement. Alternatives analyzed in the FEIS included a new injection well, evaporation ponds, zero liquid discharge technology, and no action.
After weighing the benefits and impacts of the alternatives analyzed in the FEIS, the Bureau of Reclamation has identified the no action alternative as the preferred alternative. The no action alternative achieves the best balance among the various goals and objectives outlined in the FEIS, including:
- optimizing costs;
- minimizing adverse effects on the affected environment;
- minimizing the use of nonrenewable resources;
- consistency with Bureau of Land Management Resource Management Plans;
- and being in the best interest of the public, including considerations of health and safety.
The no action alternative will be implemented after the current injection well is decommissioned.
New technically, environmentally, and economically viable alternatives may be investigated in the future to continue salinity control at Paradox Valley.
For those wishing to view the FEIS and supporting technical documents please visit our Document Library - Environmental Impact Statements and Records of Decision page.
Other Paradox Valley Unit Documents
Paradox Valley Seismic Network Annual Reports
- 2023 Annual Report Paradox Valley Seismic Network Link is to a PDF file
- 2022 Annual Report Paradox Valley Seismic Network Link is to a PDF file
- 2021 Annual Report Paradox Valley Seismic Network Link is to a PDF file
- 2020 Annual Report Paradox Valley Seismic Network Link is to a PDF file
- 2019 Annual Report Paradox Valley Seismic Network Link is to a PDF file
Published Papers
Geophysical Journal International - December 2014
Induced seismicity constraints on subsurface geological structure, Paradox Valley, Colorado
Geophysical Journal International - October 2014
Maximum magnitude estimations of induced earthquakes at Paradox Valley, Colorado, from cumulative injection volume and geometry of seismicity clusters
Journal of Geophysical Research: Solid Earth - June 2014
Geological structure of the Paradox Valley Region, Colorado, and relationship to seismicity induced by deep well injection
Seismological Research Letters - June 2014
The 24 January 2013 ML 4.4 Earthquake near Paradox, Colorado, and Its Relation to Deep Well Injection
Bulletin of the Seismological Society of America - April 2005
Deep-Injection and Closely Monitored Induced Seismicity at Paradox Valley, Colorado
Other Documents
- Technical Memorandum No. 86-68330-2024-10 – Event Relative Location and Updated Earthquake Catalog Paradox Valley Seismic network Link is to a PDF file - August 2024
- Technical Memorandum No. 86-68330-2024-8 – Analyses of the Fall 2020 Seismicity Swarm Link is to a PDF file - August 2024
- Technical Memorandum No. 86-68330-2024-7 – Development of a New Velocity Model for the Paradox Valley Area Link is to a PDF file - August 2024
- Technical Memorandum No. 86-68330-2023-2 – Geomechanical and Flow Modeling of the 2022 Injection Test and Future Injection Scenarios Link is to a PDF file - July 2024
- Paradox Valley Seismic Network Status Report Link is to a PDF file - December 2021
- Technical Memorandum 86-68330-2020-07 – Analysis of the March 4th, 2019 MW 4.5 Earthquake and Its Aftershocks Paradox Valley Unit, Colorado Link is to a PDF file - July 2020
- Technical Memorandum 85-833000-2017-15 – Integrated Subsurface Geologic Model, Paradox Valley, Colorado Link is to a PDF file - June 2018
- Technical Memorandum 85-833000-2017-14 - Compilation of Well Data in the Vicinity of Paradox Valley, CO Link is to a PDF file - July 2017
- Technical Memorandum TM-85-833000-2017-10 – Trends of Induced Seismicity and Pressures Following the 2013 Change in Injection Operations at the Paradox Valley Unit, Colorado Link is to a PDF file - July 2017
- Technical Memorandum TM-85-833000-2016-16 – Identification of Deformation in Paradox Valley using InSAR Link is to a PDF file - Dec. 2016
- Paradox Valley Unit Brine Crystallization Technology Assessment Link is to a PDF file - September 2016
- Estimates of Dissolved-Solids Load of the Dolores River in the Paradox Valley Link is to a PDF file (1988 through 2009)
- The ML 4.4 Earthquake of January 24, 2013: Report and Earthquake Catalog Link is to a ZIP file
- Evidence for Far-Field Reservoir Pressurization: Report and Injection Data Link is to a ZIP file
- Considerations in Raising the Maximum Allowable Surface Injection Pressure at Paradox Valley Link is to a PDF file - November 2015
- Paradox Salinity Control Well No. 1 Permit Reauthorization Link is to a PDF file - August 2011
- Overview of PVU-Induced Seismicity (1996 - 2009) and Implications for Future Injection Operations Link is to a PDF file - December 2009
- An Axisymmetric Coupled Flow and Deformation Model... Link is to a PDF file (Roeloffs & Denlinger) - August 2009
- Summary Report for Paradox Valley Link is to a PDF file - June 2008
- Paradox Valley - Phase 3 & 4 Technical Memoranda Link is to a PDF file - June 2008
- Paradox Valley - Phase 2 Technical Memoranda Link is to a PDF file - April 2008
- Paradox Valley - Phase 1 Technical Memoranda Link is to a PDF file - February 2008
- Report of Operations Link is to a PDF file - August 2001
- Final Supplemental Definite Plan Report and Environmental Assessment Link is to a PDF file - May 1997
- Report of Evaluation of Injection Testing for Paradox Valley Injection Test No. 1 Link is to a PDF file (Envirocorp) - June 1995
- Final Geological Well Report Link is to a PDF file (Clarence Harr) - November 1988
- Area of Least Resistance to Fluid Movement and Pressure Rise Link is to a PDF file (Bremkamp & Harr) - September 1988
- Geophysical Interpretation of Seismic Data - Paradox Valley Unit Link is to a PDF file (Katz & Carroll) - July 1984
- Geophysical Interpretation - Seismic Data - Paradox Valley Unit Link is to a PDF file (Bremkamp et al.) - 1984
- OTS Analysis Report Link is to a PDF file - December 1983
- OGS Associates Report - Concerns Involving Paradox Valley Deep Disposal Well Project Link is to a PDF file - July 1983
- Williams Brothers Engineering Company Final Report Link is to a PDF file- April 1982
- Final Environmental Impact Statement Link is to a PDF file - March 1979
- Definite Plan Report Link is to a PDF file - September 1978
- Definite Plan Report Appendix A Link is to a PDF file - September 1978
- Definite Plan Report Appendix B Link is to a PDF file - September 1978
- Feasibility Study of Brine Disposal by Deep Well Injection Link is to a PDF file (Frank P. Turner) - November 1975
For more information please contact:
Kim Weimer, Facility Maintenance Tech
Paradox Valley Field Office
Bureau of Reclamation
P.O. Box 20
Bedrock, CO 81411
(970) 859-7214
kweimer@usbr.gov