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Public water system record

City of Boulder

Serves Boulder and Gunbarrel, Boulder County, CO · 166,080 people served

Federal records show 2 health-based violations and 5 monitoring/reporting issues for City of Boulder in the last ten years. The most serious issue in this window was a resolved Haloacetic Acids (HAA5) violation.

  • CO0107152
  • BOULDER
  • CO
  • 166,080 served

System profile

Source water Surface water
ZIP 80302
EPA system ID CO0107152

Verify this system on EPA ECHO →

Health-based violations, last 10 years
2
Resolved
2
Unresolved
0
Any acute record
No
Monitoring issues, last 10 years
5

Key facts

  • City of Boulder draws water from 4 surface water intakes.
  • Highest measured level in the last 10 years: Haloacetic Acids (HAA5), 0.061 mg/L, federal limit 0.06 mg/L (at or just above the limit), 2017.
  • Record on file since 2010, with 1 health-based violation before October 19, 2016.
  • Lead pipe inventory: 0 lead and 0 unknown out of 28,088 service lines.

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Health-based violations

Since October 2016

Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.

Contaminant Rule family Start date Status Acute
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 0.061 mg/L, federal limit 0.06 mg/L (at or just above the limit)
 220 Jul 1, 2017 Resolved No
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 0.06081 mg/L, federal limit 0.06 mg/L (at or just above the limit)
 220 Apr 1, 2017 Resolved No

Monitoring and reporting issues

Since October 2016

Missed tests or reports, not contaminants found above a limit.

Issue Start date Status
Interim Enhanced Surface Water Treatment Rule
Monitoring and reporting
 Oct 1, 2024 Resolved
Surface Water Treatment Rule
Monitoring and reporting
 Jun 1, 2022 Resolved
Surface Water Treatment Rule
Monitoring and reporting
 Jan 1, 2017 Resolved
Surface Water Treatment Rule
Monitoring and reporting
 Dec 1, 2016 Resolved
Surface Water Treatment Rule
Monitoring and reporting
 Oct 1, 2016 Resolved

Full record since 2010

EPA's records for City of Boulder go back to 2010. Before October 19, 2016 they list 1 health-based violation (1 resolved) and 1 monitoring or reporting violation.

Violations that began in Health-based Monitoring and reporting
2010 to October 18, 2016 1 1
October 19, 2016 to 2019 2 2
2020s 0 2

Most recent health-based violation before October 19, 2016: Interim Enhanced Surface Water Treatment Rule (acute), began January 2010, Resolved.

Show the health-based violation before October 19, 2016
Contaminant Start date Status
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
 Jan 1, 2010 Resolved

What the violations mean

Haloacetic Acids (HAA5)

2 incidents

Haloacetic acid byproducts exceeded the federal limit

Long-term exposure to HAAs may increase cancer risk

Where the water comes from

City of Boulder draws water from 4 surface water intakes. 5 other community water systems and 1 smaller public system such as schools, businesses or campgrounds buy water from City of Boulder. 1 other public water system has an emergency connection to City of Boulder.

Community systems that buy water from it

Annual water quality report

City of Boulder must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.

Systems serving 10,000 or more people must mail or deliver the report to every customer, and from 2027 they must send it twice a year.

Find a posted report with EPA's Consumer Confidence Report search

Testing your own water

To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by Colorado.

Certified drinking water labs by state EPA guidance for private wells