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The Annual Water Quality Report Explained

Every year around this time residents receive Roxborough Water and Sanitation District’s (RoxWSD or the District) Annual Water Quality Report, also known as the Drinking Water Consumer Confidence Report (the Report). Publication of this Report is mandated by the EPA’s Clean Water Act and is intended to provide residents with a summary of the quality of their drinking water. Because there are detailed regulations governing the Report, the text we are required to use can seem technical and be difficult to understand. In this blog, I’ll do my best to explain what it all means.

First, let’s review the community’s water supply. RoxWSD is fortunate to have a permanent surface raw-water supply from the mountains west of the District. It starts as snow at the highest elevations that is collected in various reservoirs upstream of Strontia Springs Reservoir, which is located at the top of Waterton Canyon. From Strontia the water travels through tunnels to Rampart Range Reservoir near Roxborough State Park and transmission pipelines to the Larry D. Moore Water Treatment Plant, located off Roxborough Park Road.  Because we share a source water supply with the City of Aurora and Denver Water, the community benefits from those larger utilities’ source water protection programs and monitoring.  For the residents/businesses in Chatfield East, Chatfield Estates, and Titan Road Industrial Park, we work collaboratively with the Centennial Water and Sanitation District, and the Report you receive reflects data and information we receive from them.

Next let’s address some frequently asked questions.

Is our community’s drinking water regularly tested? Yes. RoxWSD routinely monitors constituents in the drinking water according to federal and state law. The table in the Report shows the monitoring results for 2019. Bottom line, RoxWSD complied with all drinking water regulations in 2019.

  • Reviewing the table in the Report, the first contaminant of concern is Total Coliform, which is a measure of potential bacterial contamination that is naturally present in the environment. This is a pass/fail test done monthly – if you find it you fail – and RoxWSD passed every month.
  • The next category is Turbidity, which is a measure of the particulates in the water that can come from soil runoff. The limit maximum allowed is 1, and we are required to be below 0.3 95% all of the time. The highest measured in RoxWSD was 0.24.
  • Next are three different measurements of naturally occurring radionuclides that are only monitored periodically. RoxWSD’s next scheduled monitoring is in 2020 and will be reported in next year’s Report.
  • Lead and Copper are next. Lead has gotten a lot of attention since the situation in Flint, MI. There is no lead in RoxWSD’s drinking water, but in older communities it can leach into the water from lead pipes.  Because the Roxborough community didn’t exist before 1972, we have no lead pipes, but some faucets and other fixtures can have lead solder or brass fittings that can also leach lead.  In 2019 RoxWSD monitored 60 homes two times for lead and copper. Both lead and copper have an Action Level (AL) and a Goal (ALG).  The requirement is that the 90th percentile of the monitoring of all homes be below the AL, and the District was in compliance.
  • The drinking water is also regulated for Chlorine and Chloramines. A disinfection residual must be maintained in the distribution system to keep the water safe. RoxWSD uses chloramination to maintain that disinfection residual. The maximum residual allowed is 4 parts per million (ppm), and RoxWSD’s results were an average of 1.9 ppm with a range of 0.94 minimum to a 2.73 maximum.
  • Haloacetic Acids (HAA5) and Total Trihalomethanes (TTHM) are disinfection byproducts that can result from the reaction of chlorine used in disinfection with the naturally occurring dissolved organic matter in water. The standards, known as the Maximum Contaminant Limits or MCL, are 60 and 80 ppb, respectively, as a running annual average, and the RoxWSD results ranged from 4.3-12.6 ppb with an average of 8.5 ppb for HAA5, and 10.9-20.9 ppb with an average of 15.07 ppb for TTHM.
  • Total Organic Carbon, which is naturally present in all water, is regulated by a Compliance Factor that is a minimum of 1.0 as a running annual average, and RoxWSD’s running annual average for 2019 is 1.28.
  • Next are a number of metals that can be present in water from a number of sources some of which are naturally occurring, and others are the result of human activity such as agriculture, mining and refineries. The table in the Report shows the MCL or standard and the results of the RoxWSD monitoring, all of which are well below the MCL.
  • Finally, there is a secondary drinking water standard for Sodium. A secondary standard means the contaminant does not have a health impact but can affect the taste and odor of drinking water. Sodium is naturally occurring because of erosion and the standard is 10000, and the RoxWSD result was 29.3.

Are there contaminants in drinking water? All drinking water, including bottled water, may contain trace contaminants. The presence of contaminants does not necessarily mean a health risk, but if you have a compromised immune system, we encourage you to consult with your health care professional. You can also call the EPA Safe Drinking Water Hotline at 1-800-426-4791.

Why does drinking water sometimes contain contaminants? The sources of drinking water (both RoxWSD’s tap water and bottled water) include rivers, lakes, streams, ponds, reservoirs, and springs. As water travels, it dissolves naturally occurring minerals and can pick up substances resulting from the presence of animals, plants or from human activity. These contaminants can include:

  • Microbial contaminants such as viruses and bacteria from human activity, livestock and wildlife. RoxWSD uses ultraviolet light (UV) as the primary disinfectant at the water treatment plant and chloramination to maintain a disinfection residual in the distribution system to treat these contaminants.
  • Inorganic contaminants such as salts and metals, which can be naturally occurring or result from activities such as mining or farming.
  • Pesticides and herbicides that can come from agriculture.
  • Radioactive contaminants which can be naturally occurring or result from mining activities.

Because RoxWSD’s water starts as snow melt in the Rocky Mountains, it is considered moderately hard with a total hardness as calcium carbonate (CaCO3) typically just below 100 mg/L in the finished water.  While hardness isn’t regulated, we do monitor it monthly. RoxWSD’s water also has trace amounts of naturally occurring, harmless minerals, such as iron and manganese, which can adhere to the inner walls of pipelines during the winter when usage is low.  This is what can cause discolored water at times and is why we flush the system every spring.  If you notice discolored water, please call us and we’ll get a crew out to flush the pipes in your neighborhood.

To ensure tap water is safe to drink, EPA prescribes regulations that limit the amounts of certain contaminants in water provided by public water systems like RoxWSD.

How can I learn more about the drinking water in Roxborough? If you have questions about the Report or you water service, please contact the District at (303) 979-7286, and we’ll be happy to answer your questions.  We want you to be informed about your water and confident in its safety. Click here to view the Drinking Water Consumer Confidence Reports.

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