All drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that the water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the Environmental Protection Agency's Safe Drinking Water Hotline at

1-800-426-4791 or by visiting epa.gov/ground-water-and- drinking-water.

Some people may be more vulnerable to contaminants in drinking water than the general population. Immunocompromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV-AIDS or other immune system disorders, some elderly, and infants can be particularly at risk of infections. These people should seek advice about drinking water from their health care providers. For more information about contaminants and potential health effects, or to receive a copy of the U.S. Environmental Protection Agency (EPA) and the U.S. Centers for Disease Control (CDC) guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and microbiological contaminants call the EPA Safe Drinking Water Hotline at (1- 800-426-4791).

The sources of drinking water (both tap water and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs, and wells. As water travels over the surface of the land or through the ground, it dissolves naturally occurring minerals and, in some cases, radioactive material, and can

pick up substances resulting from the presence of animals or from human activity. Contaminants that may be present in source water include:

• Microbial contaminants: viruses and bacteria that may come from sewage treatment plants, septic systems, agricultural livestock operations, and wildlife.
• Inorganic contaminants: salts and metals, which can be naturally-occurring or result from urban storm water runoff, industrial or domestic wastewater discharges, oil and gas production, mining, or farming.
• Pesticides and herbicides: may come from a variety of sources, such as agriculture, urban storm water runoff, and residential uses.
• Radioactive contaminants: can be naturally occurring or be the result of oil and gas production and mining activities.
• Organic chemical contaminants: including synthetic and volatile organic chemicals, which are byproducts of industrial processes and petroleum production, and also may come from gas stations, urban storm water runoff, and septic systems.

In order to ensure that tap water is safe to drink, the Colorado Department of Public Health and Environment prescribes regulations limiting the amount of certain contaminants in water provided by public water systems. The Food and Drug Administration regulations establish limits for contaminants in bottled water that must provide the same protection for public health.

GW — Groundwater

GW UDI — Groundwater under direct influence of surface water

29. — Consecutive Connection DIST — Distribution System

Water sources and types of water are important to help Castle Rock Water determine the appropriate level of treatment and design the correct type of treatment plant.

Plants treating surface water using flocculation, coagulation, sedimentation, greensand filtration, membrane filtration and disinfection

• Plum Creek Water Purification Facility (PCWPF)

Plants treating groundwater using greensand filtration, or anthracite and silica sand filtration, and disinfection

• Founders Water Treatment Plant (FWTP)
• Meadows Water Treatment Plant (MWTP)
• P.S. Miller Water Treatment Plant (PSMWTP)
• Ray Waterman Regional Water Treatment Facility (RWRWTF)

Possible sources of contamination

Aboveground, Underground and Leaking Storage Tank Sites, Commercial/Industrial/Transportation, High Intensity Residential, Low Intensity Residential, Urban Recreational Grasses, Small Grains, Pasture / Hay, Deciduous Forest, Evergreen Forest, Septic Systems, Road Miles.

The Colorado Department of Public Health and Environment (CDPHE) has provided Castle Rock Water with a Source Water Assessment Report for the Town’s water supply. Through this Assessment Report, the total susceptibility of the Town’s water sources to potential contamination from both discrete and dispersed contaminant sources was determined.

The Source Water Assessment provides a screening-level evaluation of potential

contamination that could occur. It does not mean that the contamination has or will occur. Castle Rock Water can use this information to evaluate the need to improve current water treatment capabilities and prepare for future contamination threats. This can help ensure that quality finished water is delivered to every home. In addition, the source water assessment

results provided a starting point for developing a source water protection plan.

In March 2018, Castle Rock Town Council approved a Source Water Protection Plan to help mitigate risks associated with these potential contaminants. The plan is designed to create awareness of the community’s drinking water sources and the potential risks to surface

water and/or groundwater quality within the watershed; encourage education and voluntary solutions to alleviate pollution risks; promote management practices to protect and enhance the drinking water supply; and provide for a comprehensive action plan in case of an emergency that threatens or disrupts the community water supply. To view the plan, visit CRgov.com/ waterplans. Potential sources of contamination in our

source water area are listed on pages 30-33 in that plan.

For general information or to obtain a copy of the Source Water Assessment, visit https://www.colorado.gov/ cdphe/ccr. The report is located under “Guidance - Source Water Assessment Reports.” Search the table using 118010 - Castle Rock, Town Of. Copies of the report are also available by contacting Castle Rock Water at 720-733-6000.

Please contact Castle Rock

Water to learn more about what you can do to help protect drinking water sources, to ask any questions about this Drinking Water Consumer Confidence Report, to learn more about the water system, or to attend scheduled public meetings. We want you, our valued customers, to be informed about the services we provide and the quality water we deliver to you every day.

Total Manganese

2020

0.013

0.002 - 0.028

14

ppm

0.05

Lead Testing in Castle Rock

Castle Rock Water is required by State and Federal regulations to conduct periodic lead and copper testing. Samples are collected from indoor taps in designated single family homes built between 1982 - 1987. These homes have been identified because they were built during the timeframe when lead-based solder was more widely used. Lead can enter the water through contact with plumbing pipes and fixtures containing lead within the home. It does this by leaching lead and copper from your private plumbing through the corrosion of pipes, solder, faucets and fittings. As part of our treatment process, Castle Rock Water treats the water to minimize, reduce, and eliminate, to the extent possible the potential for this corrosion to occur.

If you have any concerns, or would like your home to be considered for lead testing, contact our Water Quality staff at 720-733-6000 or visit CRgov.com/waterquality. This test is performed at no cost to the homeowner.

Lead in Drinking Water

If present, elevated levels of lead can cause serious health problems (especially for pregnant women and young children). It is possible that lead levels at your home may be higher than other homes in the com- munity as a result of materials used in your home’s plumbing. If you are concerned about lead in your water, you may wish to have your water tested. When your water has been sitting for several hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to 2 minutes before using water for drinking or cooking. Additional infor- mation on lead in drinking water, testing methods, and steps you can take to minimize exposure is avail- able from the Safe Drinking Water Hotline (1-800-426-4791) or at epa.gov/safewater/lead

Terms and Abbreviations

Maximum Contaminant Level (MCL) − The highest level of a contaminant allowed in drinking water.

Treatment Technique (TT) − A required process intended to reduce the level of a contaminant in drinking water.

Health-Based − A violation of either a MCL or TT.

Non-Health-Based − A violation that is not a MCL or TT.

Action Level (AL) − The concentration of a contaminant which, if exceeded, triggers treatment and other regulatory requirements.

Maximum Residual Disinfectant Level (MRDL) − The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants.

Maximum Contaminant Level Goal (MCLG) − The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs allow for a margin of safety.

Maximum Residual Disinfectant Level Goal (MRDLG) − The level of a drinking water disinfectant, below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants.

Violation (No Abbreviation) − Failure to meet a Colorado Primary Drinking Water Regulation.

Formal Enforcement Action (No Abbreviation) − Escalated action taken by the State (due to the risk to public health, or number or severity of violations) to bring a non-compliant water system back into compliance.

Variance and Exemptions (V/E) − Department permission not to meet a MCL or treatment technique under certain conditions.

Gross Alpha (No Abbreviation) − Gross alpha particle

activity compliance value. It includes radium-226, but excludes radon 222, and uranium.

Picocuries per liter (pCi/L) − Measure of the radioactivity in water.

Nephelometric Turbidity Unit (NTU) − Measure of the clarity or cloudiness of water. Turbidity in excess of 5 NTU is just noticeable to the typical person.

Compliance Value (No Abbreviation) – Single or calculated value used to determine if regulatory contaminant level (e.g. MCL) is met. Examples of calculated values are the 90th Percentile, Running Annual Average (RAA) and Locational Running Annual Average (LRAA).

Average (x-bar) − Typical value.

Range (R) − Lowest value to the highest value.

Sample Size (n) − Number or count of values (i.e. number of water samples collected and tested).

Parts per million = Milligrams per liter

(ppm = mg/L) − One part per million corresponds to one minute in two years or a single penny in $10,000.

Parts per billion = Micrograms per liter

(ppb = ug/L) − One part per billion corresponds to one minute in 2,000 years, or a single penny in $10,000,000.

Not Applicable (N/A) – Does not apply or not available.

Level 1 Assessment – A study of the water system to identify potential problems and determine (if possible) why total coliform bacteria have been found in a water system.

Level 2 Assessment – A very detailed study of the water system to identify potential problems and determine (if possible) why an E. coli MCL violation has occurred and/ or why total coliform bacteria have been found in a water system on multiple occasions.