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EWG's Tap Water Database — 2021 UPDATE

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City of Longmont

EWG's drinking water quality report shows results of tests conducted by the water utility and provided to the Environmental Working Group by the Colorado Department of Public Health & Environment, as well as information from the U.S. EPA Enforcement and Compliance History database (ECHO). For the latest quarter assessed by the U.S. EPA (January 2021 - March 2021), tap water provided by this water utility was in compliance with federal health-based drinking water standards.

Utility Details

  • Longmont, Colorado
  • Serves: 87,850
  • Data available: 2013-2019*
  • Source: Surface water
  • * 2013 testing is for chemicals in EPA's Third Unregulated Contaminant Monitoring Rule (UCMR-3) only.

Contaminants Detected

8

EXCEED
EWG HEALTH
GUIDELINES

14 Total Contaminants

  • Legal does not necessarily equal safe. Getting a passing grade from the federal government does not mean the water meets the latest health guidelines.
  • Legal limits for contaminants in tap water have not been updated in almost 20 years.
  • The best way to ensure clean tap water is to keep pollution out of source water in the first place.

Legal ≠ Safe

EWG Health Guidelines fill the gap in outdated government standards.

The federal government’s legal limits are not health-protective. The EPA has not set a new tap water standard in almost 20 years, and some standards are more than 40 years old.

Contaminants Detected

Bromodichloromethane

Potential Effect: cancer41x EWG'S HEALTH GUIDELINE
THIS UTILITY2.46 ppb
EWG HEALTH GUIDELINE0.06 ppb
NO LEGAL LIMIT
DETAILS
X

Bromodichloromethane

more about
this contaminant

Bromodichloromethane, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Bromodichloromethane and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.

Bromodichloromethane was found at 41 times above EWG's Health Guideline.

EWG Health Guideline

0.06 ppb or less

This Utility

2.46 ppb

National Average

5.79 ppb

State Average

6.38 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
ppb = parts per billion

Health Risks

The EWG Health Guideline of 0.06 ppb for bromodichloromethane was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.

Pollution Sources

water treatment icon

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Chloroform

Potential Effect: cancer81x EWG'S HEALTH GUIDELINE
THIS UTILITY32.6 ppb
EWG HEALTH GUIDELINE0.4 ppb
NO LEGAL LIMIT
DETAILS
X

Chloroform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Chloroform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy.

Chloroform was found at 81 times above EWG's Health Guideline.

EWG Health Guideline

0.4 ppb or less

This Utility

32.6 ppb

National Average

15.5 ppb

State Average

18.4 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
ppb = parts per billion

Health Risks

The EWG Health Guideline of 0.4 ppb for chloroform was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.

Pollution Sources

water treatment icon

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Chromium (hexavalent)

Potential Effect: cancer2.1x EWG'S HEALTH GUIDELINE
THIS UTILITY0.0428 ppb
EWG HEALTH GUIDELINE0.02 ppb
NO LEGAL LIMIT
DETAILS
X

Chromium (hexavalent)

more about
this contaminant

Chromium (hexavalent) is a carcinogen that commonly contaminates American drinking water. Chromium (hexavalent) in drinking water may be due to industrial pollution or natural occurrences in mineral deposits and groundwater. Read more about chromium (hexavalent).

Chromium (hexavalent) was found at 2.1 times above EWG's Health Guideline.

EWG Health Guideline

0.02 ppb or less

This Utility

0.0428 ppb

National Average

0.484 ppb

State Average

0.0959 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2013-2019.
ppb = parts per billion

Health Risks

The EWG Health Guideline of 0.02 ppb for chromium (hexavalent) was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer.

Pollution Sources

industry icon

Industry

naturally occuring icon

Naturally Occurring

Filtering Options

reverse osmosis icon

Reverse Osmosis

ion exchange icon

Ion Exchange

Dichloroacetic acid

Potential Effect: cancer42x EWG'S HEALTH GUIDELINE
THIS UTILITY8.38 ppb
EWG HEALTH GUIDELINE0.2 ppb
NO LEGAL LIMIT
DETAILS
X

Dichloroacetic acid

more about
this contaminant

Dichloroacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.

Dichloroacetic acid was found at 42 times above EWG's Health Guideline.

EWG Health Guideline

0.2 ppb or less

This Utility

8.38 ppb

National Average

7.97 ppb

State Average

8.3 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
ppb = parts per billion

Health Risks

The EWG Health Guideline of 0.2 ppb for dichloroacetic acid was proposed in 2020 by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk.a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.

Pollution Sources

water treatment icon

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Haloacetic acids (HAA5)†

Potential Effect: cancer199x EWG'S HEALTH GUIDELINE
THIS UTILITY19.9 ppb
EWG HEALTH GUIDELINE0.1 ppb
LEGAL LIMIT60 ppb
DETAILS
X

Haloacetic acids (HAA5)

more about
this contaminant

Haloacetic acids are formed when disinfectants such as chlorine are added to tap water. The group of five haloacetic acids regulated by federal standards includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid.

Haloacetic acids (HAA5) was found at 199 times above EWG's Health Guideline.

EWG Health Guideline

0.1 ppb or less

This Utility

19.9 ppb

Legal Limit

60 ppb

National Average

17.1 ppb

State Average

18.5 ppb
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
ppb = parts per billion

Health Risks

The EWG Health Guideline of 0.1 ppb for the group of five haloacetic acids, or HAA5, was defined in a peer-reviewed scientific study by EWG and represents a one-in-a-million lifetime cancer risk level. This health guideline protects against cancer.

Pollution Sources

water treatment icon

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Haloacetic acids (HAA9)†

Potential Effect: cancer400x EWG'S HEALTH GUIDELINE
THIS UTILITY24.0 ppb
EWG HEALTH GUIDELINE0.06 ppb
NO LEGAL LIMIT
DETAILS
X

Haloacetic acids (HAA9)

more about
this contaminant

Haloacetic acids are formed when disinfectants such as chlorine are added to tap water. The group of nine haloacetic acids includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid, which are regulated as a group by the federal government (HAA5); and bromochloroacetic acid, bromodichloroacetic acid, chlorodibromoacetic acid, and tribromoacetic acid.

Haloacetic acids (HAA9) was found at 400 times above EWG's Health Guideline.

EWG Health Guideline

0.06 ppb or less

This Utility

24 ppb

National Average

23.7 ppb

State Average

22.2 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2021.
ppb = parts per billion

Health Risks

The EWG Health Guideline of 0.06 ppb for the group of nine haloacetic acids, or HAA9, was defined in a peer-reviewed scientific study by EWG and represents a one-in-a-million lifetime cancer risk level as . This health guideline protects against cancer.

Pollution Sources

water treatment icon

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Total trihalomethanes (TTHMs)†

Potential Effect: cancer210x EWG'S HEALTH GUIDELINE
THIS UTILITY31.5 ppb
EWG HEALTH GUIDELINE0.15 ppb
LEGAL LIMIT80 ppb
DETAILS
X

Total trihalomethanes (TTHMs)

more about
this contaminant

Trihalomethanes are cancer-causing contaminants that form during water treatment with chlorine and other disinfectants. The total trihalomethanes group includes four chemicals: chloroform, bromodichloromethane, dibromochloromethane and bromoform.

Total trihalomethanes (TTHMs) was found at 210 times above EWG's Health Guideline.

EWG Health Guideline

0.15 ppb or less

This Utility

31.5 ppb

Legal Limit

80 ppb

National Average

29.7 ppb

State Average

29.1 ppb
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
ppb = parts per billion

Health Risks

The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level.

Pollution Sources

water treatment icon

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Trichloroacetic acid

Potential Effect: cancer111x EWG'S HEALTH GUIDELINE
THIS UTILITY11.1 ppb
EWG HEALTH GUIDELINE0.1 ppb
NO LEGAL LIMIT
DETAILS
X

Trichloroacetic acid

more about
this contaminant

Trichloroacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.

Trichloroacetic acid was found at 111 times above EWG's Health Guideline.

EWG Health Guideline

0.1 ppb or less

This Utility

11.1 ppb

National Average

6.62 ppb

State Average

7.54 ppb
NO LEGAL LIMIT
The state and national averages were calculated using the averages of the contaminant measurements for each utility in 2017-2019.
ppb = parts per billion

Health Risks

The EWG Health Guideline of 0.1 ppb for trichloroacetic acid was proposed in 2020 by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk.a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.

Pollution Sources

water treatment icon

Treatment Byproducts

Filtering Options

carbon filter icon

Activated Carbon

reverse osmosis icon

Reverse Osmosis

Includes chemicals detected in 2017-2019 for which annual utility averages exceeded an EWG-selected health guideline established by a federal or state public health authority; chemicals detected under the EPA's Unregulated Contaminant Monitoring Rule (UCMR 3) program in 2013 to 2015 (and subsequent testing when available), for which annual utility averages exceeded a health guideline established by a federal or state public health authority; chemicals detected under the EPA's Unregulated Contaminant Monitoring Rule (UCMR 4) program in 2017 to 2020 (and subsequent testing when available), for which annual utility averages exceeded a health guideline established by a federal or state public health authority.

† HAA5 is a contaminant group that includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid. HAA9 is a contaminant group that includes the chemicals in HAA5 and bromochloroacetic acid, bromodichloroacetic acid, chlorodibromoacetic acid and tribromoacetic acid. TTHM is a contaminant group that includes bromodichloromethane, bromoform, chloroform and dibromochloromethane.


Other Contaminants Tested


Chemicals tested for but not detected from 2014 to 2019:

1,1,1-Trichloroethane , 1,1,2-Trichloroethane , 1,1-Dichloroethane , 1,1-Dichloroethylene , 1,2,3-Trichloropropane , 1,2,4-Trichlorobenzene , 1,2-Dibromo-3-chloropropane (DBCP) , 1,2-Dichloroethane , 1,2-Dichloropropane , 1,3-Butadiene , 1,4-Dioxane , 1-butanol , 17-beta-Estradiol , 2,4,5-TP (Silvex) , 2,4-D , 2-methoxyethanol , 2-propen-1-ol , 4-Androstene-3,17-dione , Alachlor (Lasso) , Aldicarb , Aldicarb sulfone , Aldicarb sulfoxide , Alpha-hexachlorocyclohexane , Atrazine , Benzene , Benzo[a]pyrene , Bromochloromethane , Bromoform , Bromomethane , Butylated hydroxyanisole , Carbofuran , Carbon tetrachloride , Chlordane , Chlorodifluoromethane , Chloromethane , Chlorpyriphos , Chromium (total) , cis-1,2-Dichloroethylene , Cobalt , Dalapon , Di(2-ethylhexyl) adipate , Dibromoacetic acid , Dibromochloromethane , Dichloromethane (methylene chloride) , Dimethipin , Dinoseb , Diquat , Endothall , Endrin , Equilin , Estriol , Estrone , Ethinyl estradiol , Ethoprop , Ethylbenzene , Ethylene dibromide , Germanium , Heptachlor , Heptachlor epoxide , Hexachlorobenzene (HCB) , Hexachlorocyclopentadiene , Lindane , Methoxychlor , Molybdenum , Monobromoacetic acid , Monochloroacetic acid , Monochlorobenzene (chlorobenzene) , Nitrate & nitrite , Nitrite , o-Dichlorobenzene , o-toluidine , Oxamyl (Vydate) , Oxyflurofen , p-Dichlorobenzene , Pentachlorophenol , Perfluorobutane sulfonate (PFBS) , Perfluoroheptanoic acid (PFHPA) , Perfluorohexane sulfonate (PFHXS) , Perfluorononanoic acid (PFNA) , Perfluorooctane sulfonate (PFOS) , Perfluorooctanoic acid (PFOA) , Permethrin , Picloram , Polychlorinated biphenyls (PCBs) , Profenofos , Quinoline , Simazine , Styrene , Tebuconazole , Testosterone , Tetrachloroethylene (perchloroethylene) , Toluene , Toxaphene , trans-1,2-Dichloroethylene , Tribufos , Trichloroethylene , Vanadium , Vinyl chloride , Xylenes (total)

City of Longmont compliance with legally mandated federal standards:

  • From April 2019 to March 2021, City of Longmont complied with health-based drinking water standards.

Information in this section on City of Longmont comes from the U.S. EPA Enforcement and Compliance History Online database (ECHO).

LEARN MORE ABOUT THIS UTILITY

Water Filters That Can Reduce Contaminant Levels

ContaminantActivated Carbonactivated carbonReverse Osmosisreverse osmosisIon Exchangeion exchange
CONTAMINANTS ABOVE
HEALTH GUIDELINES
Bromodichloromethane
Chloroform
Chromium (hexavalent)
Dichloroacetic acid
Haloacetic acids (HAA5)
Haloacetic acids (HAA9)
Total trihalomethanes (TTHMs)
Trichloroacetic acid
OTHER CONTAMINANTS
DETECTED
Chlorate
Di(2-ethylhexyl) phthalate
Fluoride
Manganese
Nitrate
Strontium

Take Action

Contact Your Local Official

One of the best ways to push for cleaner water is to hold accountable the elected officials who have a say in water quality – from city hall and the state legislature to Congress all the way to the Oval Office – by asking questions and demanding answers.

LEARN MORE

Filter Out Contaminants

Check out our recommendations for filters to protect your water against the detected contaminants.

EWG’S WATER FILTER GUIDE