Salinity & Selenium

High levels of salt and selenium naturally occur in the soils of the Colorado Basin’s Grand Valley, as well as the Uncompahgre Valley in the neighboring Gunnison Basin. These elements are carried into the river when water applied to the land percolates through these soils and returns to the river. High salt levels reduce the productivity of agriculture downstream, and high selenium levels are unhealthy for fish and waterfowl.

The Salinity Control Program (CRBSCP) is a cooperative effort of the seven Colorado River Basin states, the federal government and Basin water users to limit increases in river salinity. Irrigation improvements and vegetation management reduce water available to transport salts. Point sources, such as saline springs like Glenwood Hot Springs are also controlled. The program, a long term interstate and interagency public/private partnership effort, is carried out to reduce the amount of salts in the river and its associated impacts in the Basin. The combined efforts of the Program have resulted in the control of an estimated 772,627 tons of salt per year. This salt reduction results have decreased damages to about $88 million/year.

Salinity Control Projects in the Colorado Basin include:

You can find more information on selenium and selenium control measures on this Gunnison Basin Selenium Management page.

In conjunction with the removal of salts from the Colorado River basin, selenium is also removed. Reductions in selenium concentrations in the lower Colorado River have resulted in attainment of the chronic and acute selenium standards on the lower Colorado River from the Gunnison River to the Colorado-Utah state line. This portion of the river was first identified on the state’s 303(d) List as impaired for selenium in 2004 and remains critical habitat for the endangered species, the Colorado pikeminnow and razorback sucker.

Two federal laws, the Clean Water Act (CWA) and the Safe Drinking Water Act (SDWA), were established to ensure the quality of Americans’ drinking and surface waters. Under the SDWA, EPA sets standards for drinking water quality and oversees the states, localities, and water suppliers who implement those standards (EPA, 2014). Under the CWA, the statute employs a variety of regulatory and non-regulatory tools to reduce direct pollutant discharges into waterways, finance municipal wastewater treatment facilities, and manage polluted runoff. The Colorado Department of Public Health and Environment (CDPHE) – Water Quality Control Commission (WQCC) and Water Quality Control Division (WQCD) are responsible for developing specific state water quality policies in a manner that implements the broader policies set forth by the Legislature in the Colorado Water Quality Control Act. The WQCC adopts water quality classifications and standards for surface and groundwaters of the state, as well as various regulations aimed at achieving compliance with those classifications and standards and the WQCD protects and restores water quality for public health and environment through the development and enforcement of permits.

Several regulations have been established to protect the beneficial uses (public water supplies, domestic, agricultural, industrial and recreational uses, and the protection and propagation of terrestrial and aquatic life), of Colorado’s water bodies. Two specific surface water regulations identify narrative and numeric limits for waters within the Colorado Basin, Regulation No.33, covering the Upper Colorado River Basin and North Platte River Basins, and Regulation No. 37, covering the Lower Colorado River Basin. These regulations are revisited on a triennial basis by the WQCC to ensure site-specific standards protect identified beneficial uses. Another regulation, Regulation No. 93, establishes Colorado’s List of Water-Quality-Limited Segments Requiring Total Maximum Daily Loads (“TMDLs”) and Colorado’s Monitoring and Evaluation List (M&E List). The list of Water-Quality-Limited Segments Requiring TMDLs fulfills requirements of section 303(d) of the federal Clean Water Act which requires that states submit to the EPA a list of those waters for which technology-based effluent limitations and other required controls are not stringent enough to achieve water quality standards,. The M&E List includes a list of those water bodies where there is reason to suspect water quality problems, but there is also uncertainty regarding one or more factors, such as the representative nature of the data. Water bodies that are impaired, but it is unclear whether the cause of impairment is attributable to pollutants as opposed to pollution, are also placed on the M&E List. This M&E List is a state-only document that is not subject to EPA oversite. Both lists have been compiled and included as part of the nonconsumptive needs evaluation as part of this BIP and depicted on the figures within the Regional Breakdown section.