Water Quality

Who has the tastiest water in the Rocky Mountains? According to the judges of a taste test at the 2015 Rocky Mountain American Water Works Association annual conference, Castle Rock Water has the best water in the region. Nine municipalities from a three state region competed for the title of best drinking water based on taste, odor and appearance. We're proud to say Castle Rock Water took first place!
Water taste test winners
Water quality reports
Our goal is to provide you with a safe and reliable supply of drinking water. Castle Rock's water quality reports or “consumer confidence reports” are produced annually to describe the overall quality of water from its raw collection and storage to the treated purity at your tap. Learn more about Castle Rock's safe drinking water supply in the 2016 Water Quality Report

If you would like to receive a hard copy, contact us at 720-733-6000 or by email. You may also pick up a copy at 
Castle Rock Water, 175 Kellogg Ct., Castle Rock, CO 80109.

View previous year's reports:

No lead issues in Castle Rock

You may have heard some cities in the United States having issues with lead in their water. However, Castle Rock does not have any such issues.

Lead is not found in the distributed water, but enters the water through contact with plumbing pipes and fixtures within the home. It does this by leaching through the corrosion of pipes, solder, faucets and fittings.

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 and 1986. These homes have been identified because they were built during the time-frame when lead-based solder was more widely used. Since Castle Rock started this sampling back in 1992, there have been no elevated levels of either lead or copper from the random samples collected.

Because Castle Rock Water is a national leader in the water industry, we frequently do more than state and national regulations require. Currently, we are expanding our pool of sample sites and providing in-home testing for select homes built before 1987. We do not anticipate finding any elevated levels of lead and are providing this service as a proactive measure in accordance with Castle Rock Water’s high standards.

If you believe your home might contain lead plumbing materials and would like to participate in the sampling program, please complete the in-home lead testing form and you will be contacted. Residents can also contact the Colorado Department of Public Health and Environment Laboratory Services Division at 303-692-3090 or Colorado.gov/CDPHE where water testing is available for a small fee at any time.

Water appearance

We’re all used to turning on the tap and getting cool, clear water. On rare occasions, we might get discolored water at our homes or businesses. While the causes of this discoloration vary, the water is still usually safe. 

Pipeline disruptions that change the flow direction or the velocity of water in piping systems, both the public system and / or private plumbing, can cause discolored water. Examples of these disruptions include: 

  • Construction activities that require valves to be operated, water to be turned off temporarily or where new taps and mains connect
  • Dead end water mains that are not used very often but are suddenly used at a high rate
  • Electrical outages that impact system pumps or valves
  • Rapid shut-off of faucets or automatic valves in washing machines
  • Rapidly opening or closing fire hydrants or valves
  • Water main breaks


Sometimes, the interior surfaces of water pipes rust or become coated with minerals. When one of the previous disruptions occurs, small pieces of these natural material found in these pipes can be dislodged, causing discoloration or particles in the water. 

Defective or aging plumbing can also lead to discolored water. Pieces of rubber or plastic washers that age and crumble can leave particles in the water. Improperly joined dissimilar materials (such as iron and galvanized, or copper and iron) can accelerate corrosion and turn water red or green for short periods of time when disturbance occurs. Aging pipe can also rust or corrode and then become a potential source of discolored water.


As long as the water has a residual chlorine disinfectant (as Castle Rock Water does), the water should be safe. It can, however, be aesthetically displeasing. Castle Rock Water always checks for disinfectant residual anytime we have a water quality complaint or issue.

What to do

Customers can run the water to flush their system. Typically, this is enough to clear up the water, as the disturbance subsides and the discolored water is flushed out. If the issue does not quickly resolve itself, call 720-733-6000 or email us. We will come to your home or business and work to resolve the issue within a few hours of your call. If the issue is in the distribution system, we will flush fire hydrants in the localized area to remove any discolored water from the system.

While Castle Rock cannot eliminate all of the potential causes of occasional discolored water, we work very hard to minimize them. We are committed to providing you the best and most aesthetically pleasing water possible. 

Water treatment

Currently, most of Castle Rock’s water comes from nonrenewable wells - some as deep as 2,000 feet below ground. In the past, chlorine alone was used to disinfect the water. Renewable water sources that are either surface waters or connected to surface waters (e.g. shallow groundwater along Plum Creek), however, can contain natural organic matter which can cause the formation of disinfection byproducts when disinfected only with chlorine. In May 2013, the Town began treating its water with chloramines, which is a product of chlorine and ammonia. Using chloramines in place of chlorine reduces the likelihood of disinfection byproducts formation and their associated health risks.


While this process will be new to our customers, many municipal and private water providers across the United States and Canada have used this safe, effective disinfectant for more than 90 years. Denver and surrounding communities, for example, have been using chloramine-treated water since 1917, because they have renewable water systems that require this process. 

More information

Learn about the benefits of chloramines, the transition to chloramines and how chloramines affect kidney dialysis treatments and aquatic life