Water Quality

Definition

The quality and safety of water for human use and consumption. 

Water is one of our most important natural resources and is vital to life in all forms. Water has many direct and indirect uses that have health implications, and it is estimated that 10 percent of the global disease burden is attributable to unsafe drinking water and lack of proper sanitation, causing millions of deaths each year (1). Contamination of water bodies and underground aquifers by biological, chemical or radiological agents affects water quality, having potentially severe impacts on the health of people and the environment where treatment systems are unavailable.

In the U.S., drinking water safety has improved substantially with the passage of the Clean Water Act and the Safe Drinking Water Act, which tasked the Environmental Protection Agency to regulate water quality at its sources and regulate contaminants in drinking water with strict standards, respectively (2). The maximum contaminant levels for drinking water were developed to determine the highest amount of a contaminant that people consume without long-term risks from cancer, organ damage, circulatory system disorders, nervous system disorders and reproductive systems disorders (3). These drinking water regulations — combined with other state and federal laws — ensure water quality is protected and that drinking water from public treatment systems is safe for human consumption.

However, these laws do not apply to private wells. It is the responsibility of — and strongly recommended that — private well owners and users maintain and periodically test their wells for contaminants. In Colorado, water quality concerns are more frequently associated with private water systems, such as private wells or small water systems that are not part of the state's regulatory program.

Within Jefferson County, many mountain residents rely on private wells and septic systems for water supply and wastewater treatment. These residents should be aware of naturally occurring and man-made groundwater contaminants that can sometimes be present in well water, especially nitrates and bacteria. Some mountain areas of the county also have naturally high fluoride levels and high natural radiation levels due to the presence of uranium or other minerals in the rocks surrounding the groundwater. Testing is strongly recommended to determine to if levels of these contaminants are within safe ranges.

Other water quality impacts are related to human activities and land uses, including proliferation of impervious pavement in urban areas. In these areas, water runs off impervious surfaces when it rains or snows, carrying debris and chemicals into streams, rivers and other water bodies. Runoff has been directly associated with environmental impacts such as erosion, sediment transport, flooding, loss of biodiversity, aquifer depletion, algal blooms and water quality degradation (4).

Implications and Data for Jefferson County

Community Health Needs Assessment Focus Group Findings

Pollution and its effect on human health and water quality was a concern across focus group participants. Concerns centered around water quality and quantity.

Participants in the focus group held in Indian Hills expressed the most concerns regarding this factor, due to development pressures which they fear will overstress current water supplies. They expressed concerns about pollution from sources such as herbicides, nitrates from animal waste and chemicals in recycled asphalt seeping into the water. One person stated that “[w]ater safety and development. . . is my number one concern up here.”

Numerous participants had concerns around the perceived safety of soils and water near the former nuclear weapons production facility at Rocky Flats. One resident commented that they were hesitant to enter certain bodies of water due to stories they had heard about pollution, while others specifically mentioned uranium and lead as contaminants. 

Community Health Needs Assessment Key Informant Interview Findings

Key informants cited access to clean water as an issue for some underserved areas of the community, such as people living around 50th Street and Sheridan Boulevard, as well as parts of Federal Boulevard.

The table below shows the most common contaminants that are tested for in Jefferson County public water systems between 1999 and 2018. The accepted level of contaminants that is considered to be safe and the number of times a public water system reported those levels were above the standard. Total trihalomethanes (TTHMs), radium and uranium levels from 1999-2018 are shown in more detail in the charts found below the table.

Source: CDPHE, https://www.colorado.gov/pacific/coepht/public-drinking-water-data

Source: CDPHE, https://www.colorado.gov/pacific/coepht/public-drinking-water-data

Notes: Only community water systems that reported a maximum tested uranium value above the EPA standard (30 ug/L) in at least two different years are shown here. Mountain WSD is separated from the other water system (shown below) due to the scale difference in uranium levels. Data was not available for Ken Caryl West Ranch and Homestead water systems in 2018.

The Colorado Department of Public Health and Environment (CDPHE) provides grants to water districts each year around the state to help them reduce their levels of radioactive elements in drinking water. Mountain Water Systems District in Jefferson County is an example of the effectiveness of these programs in reducing the amount of uranium in the public's water.

Source: CDPHE, https://www.colorado.gov/pacific/coepht/public-drinking-water-data

Source: CDPHE, https://www.colorado.gov/pacific/coepht/public-drinking-water-data

Notes: Only community water systems that reported a maximum tested radium value above the EPA standard (5 pCi/L) in at least two different years are shown here. Note the split in the scale to show the maximum value recorded in 2002.

Since 2016, no water systems reported radium levels above the EPA standard in Jefferson County.

Source: CDPHE, https://www.colorado.gov/pacific/coepht/public-drinking-water-data

Notes: Only community water systems that reported a maximum tested total trihalomethanes (TTHMs) value above the EPA standard (80 ug/L) in at least two different years are shown here. 

In 2018, one water system reported total trihalomethanes (TTHMs) levels above the EPA standard in Jefferson County.

Harmful Algal Blooms (HAB) are becoming more of a problem in Colorado as temperatures and pollution increase. To see what Colorado is doing about this, click on the image below. 

Source: CDPHE, https://www.colorado.gov/pacific/cdphe/harmful-algae-blooms

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Reference List


1. Meinhardt, P. (2017). Water quality and water-related disease. Oxford University Press. May 2017. Retrieved from: http://www.oxfordbibliographies.com/view/document/obo-9780199756797/obo-9780199756797-0052.xml

2. Environmental Protection Agency (2018). Drinking Water Contaminants-Standards and Regulations. Retrieved from: https://www.epa.gov/dwstandardsregulations

3. Environmental Protection Agency (2018). Drinking Water Regulations. Retrieved from: https://www.epa.gov/dwreginfo/drinking-water-regulations

4. Centers for Disease Control and Prevention. (2009, October 15). Water Quality. Retrieved from: https://www.cdc.gov/healthyplaces/healthtopics/water.htm

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Data Sources


EPA Environmental Justice Screening and Mapping Tool: https://ejscreen.epa.gov/mapper/

CDPHE: Colorado Department of Public Health and Environment, Colorado Environmental Public Health Tracking: https://www.colorado.gov/pacific/coepht/public-drinking-water-data

CDPHE: Colorado Department of Public Health and Environment: https://www.colorado.gov/pacific/cdphe/harmful-algae-blooms

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Published on July 17, 2018

Updated on March 10, 2020