Drinking Water Quality Monitoring Program

Boulder implements a comprehensive source to tap water quality monitoring program.

2023 Drinking Water Quality Report

The City of Boulder is pleased to present the 2023 Drinking Water Quality Report, which summarizes water quality testing results from 2022. Read the Water Report PDF and learn about the city’s efforts to protect our water supply from the impacts of wildfires.

El Gobierno de la ciudad de Boulder se complace en presentar el Reporte de calidad de agua potable de 2023. El reporte resume los resultados de los análisis de la calidad del agua del año calendario 2022. Una copia digital del reporte está disponible en este enlace, que incluye todos los esfuerzos llevados a cabo por la ciudad de Boulder para proteger nuestro abastecimiento de agua del impacto de los incendios forestales.

Water quality samples are routinely collected in the water supply creeks and reservoirs, which include the Middle and North Boulder Creek watersheds, as well as Carter Lake and the Colorado-Big Thompson watershed. Water quality is also monitored at the water treatment plants and throughout the city.

Drinking Water graphic

Important Information about your Drinking Water

The City of Boulder recently discovered a violation of the Colorado Backflow Prevention and Cross-Connection Control regulations. This is not an emergency and does not impact public health. As our customers, you have a right to know what happened and what the city is doing to correct this situation.

Haga clic aqui para leer esta notificación en español.

What happened?

  • State and local regulations require owners of backflow devices to have all devices inspected and tested annually. If a device fails the annual test, property owners are required to repair or replace the device within 120 days.
  • The city identified 16 backflow prevention devices with failed tests that were not repaired or replaced within 120 days. This is about 0.2% of the 7,000+ devices in the city. Of these, 9 have been resolved.

What do you need to do?

  • You do not need to take any action related to your drinking water or seek an alternate supply of drinking water. If this had been an emergency, you would have been notified immediately.
  • The city is not aware of any water contamination due to this violation. City staff collect water quality samples throughout the city on a weekly basis. None of our testing has shown disease-causing organisms in the drinking water, or other reason for concern.
  • Commercial, industrial and multi-family property owners must ensure backflow devices are tested annually and reported to the city.
  • Per state regulations, the city is required to notify the community that: “Uncontrolled cross connections can lead to a back pressure or siphonage event that may allow contaminants or disease-causing organisms to enter the drinking water, which can cause diarrhea, nausea, cramps and associated headaches.”

What is being done?

  • The city has issued notices of violation to property owners to repair or replace and retest the failed devices.
  • Staff have automated tracking systems and are reviewing compliance data more frequently.
  • The city has increased enforcement, including suspension of water service, for property owners who fail to comply prior to the 120-day regulatory deadline.

Learn About or Report Drinking Water Quality

Water quality results

All drinking water, including bottled water, contains substances that do not necessarily pose health risks. The city goes above and beyond regulatory requirements, monitoring for 450+ water quality substances including basic chemistry, nutrients, bacteria, metals, disinfection byproducts, pesticides, pharmaceuticals, personal care products, hormones, and radionuclides. The vast majority of these compounds and chemicals are not detected in drinking water.

Discolored water

  • Running several taps with cold water at full force for a short period may help flush the discolored water out of your system.
  • A general recommendation is to run the taps for five minutes.
  • If the water is not clear, wait for half an hour before running them for five minutes again.

Get in touch

  1. Online request
    • ​​​​​​​Make a request for Drinking Water Quality on Inquire Boulder
  2. Call us
    • If you have additional questions, please call the Drinking Water Program at 303-441-3200.

Common Customer Questions

  • Chlorine Taste and Odor
    The city uses chlorine to disinfect the drinking water. While the city uses the minimum amount necessary to keep drinking water safe, water can have a chlorine taste and odor. Chlorine will dissipate in drinking water if left in an uncovered container in the refrigerator overnight .
  • Rusty Water
    Rusty brown/orange water can be caused by a main break, main replacement, construction activities, fire hydrant use, in-home plumbing, or hot water tanks. These activities can disrupt the water distribution system releasing iron from the pipe walls. Flushing the cold water tap should clear the water.
  • White or Cloudy Water
    The white water is typically caused by small air bubbles, which will dissipate in a few minutes. If the white water is caused by flakes that don't disappear, this may be caused by a deteriorating dip tube in the property's hot water heater.
  • Pink or Black Mildew
    Mildew can form in sinks, showers, toilets or areas with stagnant water. Clean fixtures regularly and fix leaks to reduce mildew and mold growth.
  • Water Hardness
    Average water hardness for Boulder’s water is 42 mg/L, equivalent to 2.4 grains/gallon. Water hardness is determined by naturally occurring minerals, including calcium and magnesium.
  • PFAS
    In 2020, the city proactively participated in a state-sponsored program to test for PFAS and found no detections of PFAS compounds in city drinking water. Learn more about PFAS.