Can You Drink Tap Water in Boulder?

Yes, Boulder's tap water is generally considered safe to drink as Boulder has no active health based violations of the Safe Drinking Water Act (SDWA) that we are aware of. Other factors such as lead piping in a home, or low levels of pollutants on immunocompromised individuals, should also be considered, however. To find more recent info we might have, you can check out our boil water notice page or the city's water provider website.

According the EPA’s ECHO database, from April 30, 2019 to June 30, 2022, Boulder's water utility, City of Boulder, had 0 violations of the Safe Drinking Water Act. For more details on the violations, please see our violation history section below. The last violation for Boulder was resolved on Sept. 30, 2017. This assessment is based on the City of Boulder water system, other water systems in the city may have different results.

While tap water that meets the EPA health guidelines generally won’t make you sick to your stomach, it can still contain regulated and unregulated contaminants present in trace amounts that could potentially cause health issues over the long-run. These trace contaminants may also impact immunocompromised and vulnerable individuals.

The EPA is reviewing if it’s current regulations around pollutant levels in tap water are strict enough, and the health dangers posed by unregulated pollutants, like PFAS.

Water Quality Report for Boulder Tap Water

The most recent publicly available numbers for measured contaminant levels in Boulder tap water are in its 2020 Water Quality Report. As you can see, there are levels which the EPA considers to be acceptable, but being below the maximum allowable level doesn’t necessarily mean the water is healthy.

Lead in tap water, for example, is currently allowed at up to 15ppb by the EPA, but it has set the ideal goal for lead at zero. This highlights how meeting EPA standards doesn’t necessarily mean local tap water is healthy.

EPA regulations continue to change as it evaluates the long term impacts of chemicals and updates drinking water acceptable levels. The rules around arsenic, as well as, lead and copper are currently being re-evaluated.

There are also a number of "emerging" contaminants that are not currently. For example, PFAS (Per- and polyfluoroalkyl substances), for which the EPA has issued a health advisory. PFAS are called "forever chemicals" since they tend not to break down in the environment or the human body and can accumulate over time.

We recommend looking at the contaminants present in Boulder's water quality reports, or getting your home's tap water tested to see if you should be filtering your water.

Boulder Tap Water Safe Drinking Water Act Violation History - Prior 10 Years

Below is a ten year history of violations for the water system named City of Boulder for Boulder in Colorado. For more details please see the "What do these Violations Mean?" section below.

From July 1, 2017 to Sept. 30, 2017, Boulder had 1 health-based Safe Drinking Water Act violation with the violation category being Maximum Contaminant Level Violation, more specifically, the violation code was Maximum Contaminant Level Violation, Average which falls into the Disinfectants and Disinfection Byproducts Rule rule code group, and the Stage 2 Disinfectants and Disinfection Byproducts Rule rule code family for the following contaminant code: Total Haloacetic Acids (HAA5).

From April 1, 2017 to June 30, 2017, Boulder had 1 health-based Safe Drinking Water Act violation with the violation category being Maximum Contaminant Level Violation, more specifically, the violation code was Maximum Contaminant Level Violation, Average which falls into the Disinfectants and Disinfection Byproducts Rule rule code group, and the Stage 2 Disinfectants and Disinfection Byproducts Rule rule code family for the following contaminant code: Total Haloacetic Acids (HAA5).

From Jan. 1, 2017 to Jan. 31, 2017, Boulder had 1 non-health based Safe Drinking Water Act violation with the violation category being Monitoring and Reporting, more specifically, the violation code was Monitoring of Treatment (SWTR-Filter) which falls into the Microbials rule code group, and the Surface Water Treatment Rules rule code family for the following contaminant code: Surface Water Treatment Rule.

From Dec. 1, 2016 to Dec. 31, 2016, Boulder had 1 non-health based Safe Drinking Water Act violation with the violation category being Monitoring and Reporting, more specifically, the violation code was Monitoring of Treatment (SWTR-Filter) which falls into the Microbials rule code group, and the Surface Water Treatment Rules rule code family for the following contaminant code: Surface Water Treatment Rule.

From Oct. 1, 2016 to Oct. 31, 2016, Boulder had 1 non-health based Safe Drinking Water Act violation with the violation category being Monitoring and Reporting, more specifically, the violation code was Monitoring of Treatment (SWTR-Filter) which falls into the Microbials rule code group, and the Surface Water Treatment Rules rule code family for the following contaminant code: Surface Water Treatment Rule.

Is there Lead in Boulder Water?

Based on the EPA’s ECHO Database, 90% of the samples taken from the Boulder water system, City of Boulder, between sample start date and sample end date, were at or below, 0.0017 mg/L of lead in Boulder water. This is 11.3% of the 0.015 mg/L action level. This means 10% of the samples taken from Boulder contained more lead.

While Boulder water testing may have found 0.0017 mg/L of lead in its water, that does not mean your water source has the same amount. The amount of lead in water in a city can vary greatly from neighborhood to neighborhood, or even building to building. Many buildings, particularly older ones, have lead pipes or service lines which can be a source of contamination. To find out if your home has lead, we recommend getting you water tested.

No amount of lead in water is healthy, only less dangerous. As lead accumulates in our bodies over time, even exposure to relatively small amounts can have negative health effects. For more information, please check out our Lead FAQ page.

Are there PFAS in Boulder Tap Water?

Currently, testing tap water for PFAS isn’t mandated on a national level. We do have a list of military bases where there have been suspected or confirmed leaks. There appears to be at least one military base - Lowry Air Force Base - near Boulder with suspected leaks.

With many potential sources of PFAS in tap water across the US, the best information we currently have about which cities have PFAS in their water is this ewg map, which you can check to see if Boulder has been evaluated for yet.

Our stance is better safe than sorry, and that it makes sense to try to purify the tap water just in case.

Boulder SDWA Violation History Table - Prior 10 Years

What do these Violations Mean?

Safe Drinking Water Act Violations categories split into two groups, health based, and non-health based. Generally, health based violations are more serious, though non-health based violations can also be cause for concern.

Health Based Violations

1. Maximum contaminant levels (MCLs) - maximum allowed contaminant level was exceeded.
2. Maximum residual disinfectant levels (MRDLs) - maximum allowed disinfectant level was exceeded.
3. Other violations (Other) - the exact required process to reduce the amounts of contaminants in drinking water was not followed.

Non-Health Based Violations

1. Monitoring and reporting violations (MR, MON) - failure to conduct the required regular monitoring of drinking water quality, and/or to submit monitoring results on time.
2. Public notice violations (Other) - failure to immediately alert consumers if there is a serious problem with their drinking water that may pose a risk to public health.
3. Other violations (Other) - miscellaneous violations, such as failure to issue annual consumer confidence reports or maintain required records.

SDWA Table Key

For more clarification please visit the EPA's data dictionary.