Paradox Valley Unit
Environmental Impact Statement

aerial photo: Paradox Valley Unit
Aerial view of the Paradox Valley Unit


The Paradox Valley Unit (PVU) 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. The PVU extracts naturally-occurring brine groundwater in the Paradox Valley, thereby preventing it from entering the Dolores River. Saline concentrations of this natural brine groundwater have been measured in excess of 250,000 milligrams per liter, which, prior to the PVU, added more than 205,000 tons of salt to the Dolores River annually. The Dolores River is a major tributary to the Colorado River. The PVU is designed to prevent the natural salt load from degrading the water quality of the main stem of the Colorado River.

image: Paradox Valley Location Map

The PVU consists of facilities to intercept shallow brine and inject it into the Leadville geologic formation via a Class V deep injection well. The PVU has been injecting brine since 1996. Approximately 100,000 tons of salt are injected annually; this correlates to about ten percent of the total salinity control in the Colorado River, making the PVU one of the most effective salinity control projects in the Colorado River Basin.

Environmental Impact Statement

The existing brine injection well may be nearing the end of its useful life, so the Bureau of Reclamation (Reclamation) is investigating alternatives for intercepting the brine in order to enhance and protect the quality of water available in the Colorado River for use in the United States and the Republic of Mexico. Reclamation intends to prepare an environmental impact statement (EIS) to identify and evaluate brine disposal alternatives to replace or supplement the existing brine injection well.

Reclamation published a Notice of Intent (NOI) in the Federal Register on September 10, 2012. The NOI announced Reclamation’s intent to prepare an EIS, and initiated the scoping process which will guide the development of the EIS. Formal scoping activities for the EIS extended from September through November 2012.

Based on internal and external scoping, Reclamation’s interdisciplinary team has identified the following alternatives that will be analyzed in the EIS:

  • No Action (future without well and salinity control)
  • Additional Injection Well
  • Evaporation Ponds
  • Brine Crystallization

A draft EIS and a final EIS will be prepared to provide decision makers appropriate information and to inform the public of the proposed action, reasonable alternatives, and the impacts of the alternatives. In addition to scoping of significant issues and alternatives, key activities include analysis of alternatives that support the purpose and need, evaluation of applicable issues, and selection of a preferred alternative. The final decision will be documented in a Record of Decision (ROD) following the final EIS. The ROD will officially present the Department of the Interior’s decision on brine disposal at the PVU.

Questions and comments can be submitted to:

For more information please contact:

Lesley McWhirter, Chief Andy Nicholas, Facility Operations Specialist
Environmental and Planning Group Paradox Valley Field Office
Bureau of Reclamation Bureau of Reclamation
Western Colorado Area Office P.O. Box 20
445 West Gunnison Avenue, Suite 221 Bedrock, CO 81411
Grand Junction, CO 81501-5711 (970) 859-7214 or
(970) 248-248-0608 or  

Environmental Impact Statement Documents

Environmental Impact Statement Related Documents

Last Updated: 2/26/19