Safe, clean water is important to all Coloradans, whether it’s drinking water for humans and animals, cooking, irrigation, recreation, or for fish and wildlife. Water quality plays a critical role in Colorado given our agricultural heritage and economy, our robust recreation and tourism industry, and limited and valued natural resources. As a headwaters state, we are responsible for finding the appropriate balance between protecting our water resources and expensive financial and regulatory commitments necessary to ensure quality water for Coloradans and our downstream neighbors.

Major Factors Affecting Water Quality
Natural FactorsGeology- Formations with varying amounts of minerals or metals
- Different soil types
- Formations containing naturally occurring radionuclides, such as radon and uranium
Climate- Mountainous areas with considerable snowmelt runoff vs. arid areas with minimal runoff
- Cooler vs. warmer in-stream temperatures
Vegetation- Dense or sparse vegetation of varying types
Wildlife- Fecal bacteria
Wildfires- Erosion
- Sedimentation and ash from burned areas
- Loss of riparian habitat, raising in-stream temperatures
Human-Induced FactorsPoint Source Pollutants- Industrial and municipal wastewater discharges
- Stormwater runoff
- Leaking underground storage tanks
Nonpoint Source Pollutants- Polluted runoff of leaching from areas disturbed by human activity
Structural Changes- Modified stream channels
- Reservoir storage
- Diversion of water from streams
- Drainage of wetlands
Atmospheric Sources- Fuel combustion produces pollutants, such as nitrates that may infiltrate lakes and streams
Source: Table recreated from Water Education Colorado's [WEC] Citizen's Guide to Colorado Water Quality Protection (2013).

Water Quality Legislation

Clean Water Act
Created in 1948, the Federal Water Pollution Control Act was one of the first major pieces of legislation to address water pollution in the US. Growing public awareness and concerns around water pollution led to a variety amendments in 1972, after which the law became commonly known as the Clean Water Act (CWA). These amendments included (US EPA, 2017a):

  • The establishment of the regulatory structure for pollutant discharges into US waters;
  • EPA authority to implement pollution control programs for industry;
  • The criminalization of point source pollution into navigable waters (unless otherwise allowed by an obtained permit);
  • Funding for the construction of sewage treatment plants; and
  • Recognition of the need for planning to mitigate nonpoint source pollution and related problems.

The objective of the CWA is to restore and maintain the chemical, physical, and biological integrity of waters in the US by preventing point and nonpoint pollution sources of pollution.  In addition to funding publicly-owned treatment, the act also serves to maintain the integrity of wetlands. It is one of the United States’ first and most influential modern environmental laws. The EPA coordinates with state governments to fulfill these activities (Copeland, 2016; US EPA, 2017a).

Water Quality Act of 1987
Revisions in 1981 streamlined the funding process for treatment plant construction, enhancing the capabilities of those built under the program. Further amendments made in 1987—known as the Water Quality Act (WQA)—phased out this grants program and replaced it with the State Water Pollution Control Revolving Fund (commonly known as the Clean Water State Revolving Fund), which help to meet water quality needs by building on existing EPA-state partnerships (US EPA, 2017a).

Colorado’s wetlands range from alpine wet meadows to marshes along the Arikaree River. Though they cover less than 3% of the state, wetlands and riparian areas are by far the most ecologically and economically significant ecosystem in the state. Colorado Wetland Information Program (n.d.).

In response to increasing issues around stormwater, the WQA also expanded the definition of wastewater to include industrial stormwater discharges and municipal separate storm sewer systems (also known as MS4s) as point sources, and thus required them to obtain national pollutant discharge elimination system (NPDES) permits (US EPA, 2018b). These permits require regulated municipalities to use best management practices to reduce pollutants to the “maximum extent practicable” (Water Quality Act of 1987, 33 U.S.C. § 1342). Agricultural discharges continued to be exempt, but the WQA created the Nonpoint Source Management Program to provide grants to states, territories and First Nations to support demonstration projects, technology transfer, education, training, technical assistance and related activities designed to reduce nonpoint source water pollution (Water Quality Act of 1987, 33 U.S.C. § 1329).

A wastewater treatment plant in Boulder. City of Boulder (n.d.).

In response to increasing issues around stormwater, the WQA also expanded the definition of wastewater to include industrial stormwater discharges and municipal separate storm sewer systems (also known as MS4s) as point sources, and thus required them to obtain national pollutant discharge elimination system (NPDES) permits (US EPA, 2018b). These permits require regulated municipalities to use best management practices to reduce pollutants to the “maximum extent practicable” (Water Quality Act of 1987, 33 U.S.C. § 1342). Agricultural discharges continued to be exempt, but the WQA created the Nonpoint Source Management Program to provide grants to states, territories and First Nations to support demonstration projects, technology transfer, education, training, technical assistance and related activities designed to reduce nonpoint source water pollution (Water Quality Act of 1987, 33 U.S.C. § 1329).

Additionally, the WQA created a program for the management of biosolids (sludge) generated by publicly-owned treatment works (POTWs). The EPA was required to develop guidelines for usage and disposal of sewage sludge or biosolids, and the agency created an Intra-Agency Sludge Task Force to aid in this task (Water Quality Act of 1987, 33 U.S.C. § 1345).

Safe Drinking Water Act
The Safe Drinking Water Act (SDWA) was enacted in 1974 to protect public drinking water supplies. Under the SDWA, the EPA sets standards for drinking water quality and implements programs to ensure safe drinking water (US EPA, 2017c). The SDWA applies to every public water system in the US—of which there are currently more than 151,000. The Act does not cover private wells (Safe Drinking Water Act of 1974; US EPA, 2017b).

The National Primary Drinking Water Regulations set by the EPA under the SDWA include both mandatory maximum contaminant levels (MCLs) and voluntary maximum contaminant level goals (MCLGs) for contaminants that may cause adverse public health effects. Water standards are organized into six categories: microorganisms, disinfectants, disinfection byproducts, inorganic chemicals, organic chemicals, and radionuclides (US EPA, 1988). To meet these requirements, public water systems are required to monitor water for contaminants, and water samples must be regularly analyzed using EPA-approved testing methods. Regulatory oversight of public water systems is managed by “primacy” agencies—either state government agencies, Indian tribes, or EPA regional offices (US EPA, 2018a).

A variety of amendments have expanded upon the original SDWA:

  • 1986: The National Primary Drinking Water Regulations must also be applied to community and non-transient non-community water systems (US EPA, 1986).
  • 1996: Regulatory and protective activities must be communicated via consumer confidence reports and public right-to-know; the EPA must conduct cost-benefit analyses and strength protections against microbial contaminants; water system operators must be EPA-certified; and small water systems must receive special consideration to ensure they have the managerial, financial, and technical ability to comply with drinking water standards (Government Publishing Office [GPO], 1996).
  • 2005: Fluids or other propping agents (except diesel) used for fracking are exempt from underground injection regulations (Energy Policy Act of 2005, 42 U.S.C. § 1421).
  • 2011: Lead in drinking water must be reduced or eliminated via lead-free plumbing fixtures and fittings (Reduction of Lead in Drinking Water Act, 42 U.S.C. § 300).
  • 2015: Risks associated with algal toxins in drinking water must be assessed and managed by the EPA (US EPA, 2015).
  • 2016: Water infrastructure improvements, necessitated by water contamination crises like that in Flint, MI, shall be supported by a loan program, communicated to the public, and mitigated by a voluntary testing program for water supplies in schools (Grassroots Rural and Small Community Water Systems Assistance Act of 2016, 42 U.S.C. § 300).

Water Quality in Colorado

Statewide surface water and groundwater standards are determined by the Water Quality Control Commission, housed under the Colorado State Department of Public Health & Environment. These standards are used to assess the quality of the state’s waters and for establishing regulatory requirements for activities that may impact water quality. A complete list of regulations can be found here. Private water wells are not regulated by the state of Colorado and homeowners are responsible for testing, interpreting results, and correcting problems with their well’s water quality (CO Dept. of Public Health and Environment).

How do I test my water quality?
Homeowners often have questions about where and how to test their water sources. There is no a generic water test for everything, as each contaminant must be evaluated individually. The Department of Public Health and Environment offers suggestions here, as well as other FAQ here. The Tri-County Health Department provides detailed information on to test your well here.

Experts at Colorado State University have also developed an online assessment tool to interpret the results of your water sample. It is recommended homeowners maintain detailed records of test results in order to track changes in water quality over time.