The Power of Information

National Drinking Water Database

Selenium (total) in Montana

Selenium is a naturally occurring element that contaminates water due to mining or petrolum refining, fly-ash from coal-burning power plants, and irrigation of arid farmland soils high in selenium. [read more]

The Most Polluted Communities in Montana

64 water utilities reported detecting Selenium (total) in tap water since 2004, according to EWG's analysis of water quality data supplied by state water agencies

Ranked by highest average Selenium (total) level

RankSystem Population Served Positive test results of total reported tests Average Level
1Spring Tree Ridge
752 of 227 ppb
(4 to 50 ppb)
2New Miami Colony
Conrad, MT
1081 of 215 ppb
(0 to 30 ppb)
3Glendale Colony
Cut Bank, MT
801 of 114 ppb
(14 ppb)
4Hartland Colony
Havre, MT
731 of 210 ppb
(0 to 20 ppb)
5Hillside Colony
Sweetgrass, MT
1351 of 110 ppb
(10 ppb)
6Park Garden Estates
Great Falls, MT
642 of 210 ppb
(10 ppb)
7Blue Grass Water Users Association
Billings, MT
602 of 28 ppb
(8 ppb)
8North Harlem Colony
Harlem, MT
421 of 18 ppb
(8 ppb)
9Town of Dodson
Dodson, MT
1201 of 18 ppb
(8 ppb)
10Sunny Hills Suburban Wua Inc
Glasgow, MT
282 of 26.5 ppb
(6 to 7 ppb)

Health Based Limits for Selenium (total)

Maximum Contaminant Limit (MCL)The enforceable standard which defines the highest level of a contaminant that is allowed in drinking water. MCLs are set as close to health-based limits (Maximum Contaminant Level Goals, or MCLGs) as feasible using the best available analytical and treatment technologies and taking cost into consideration. Source: U.S. Environmental Protection Agency.50 ppb
Maximum Contaminant Limit Goal (MCLG)A non-enforceable health goal that is set at a level at which no known or anticipated adverse effect on the health of persons occurs and which allows an adequate margin of safety. Source: U.S. Environmental Protection Agency.50 ppb
Lifetime health-based limit, non-cancer riskConcentration of a chemical in drinking water that is not expected to cause any adverse, noncarcinogenic health effects for a lifetime of exposure. The Lifetime health-based limit (or Health Advisory, HA) is based on exposure for a a 70-kg adult consuming 2 liters of water per day. Source: U.S. Environmental Protection Agency.50 ppb
EPA Human Health Water Quality CriteriaWater quality criteria set by the US EPA provide guidance for states and tribes authorized to establish water quality standards under the Clean Water Act (CWA) to protect human health. These are non-enforceable standards based upon exposure by both drinking water and the contribution of water contamination to other consumed foods. Source: U.S. Environmental Protection Agency.170 ppb
Drinking Water Equivalent LevelA lifetime exposure concentration protective of adverse, noncarcinogenic health effects, that assumes all of the exposure to a contaminant is from drinking water. Source: U.S. Environmental Protection Agency.200 ppb

Violation Summary for Selenium (total) in Montana

Data from the U.S. Environmental Protection Agency includes the following violations of federal standards in Montana since 2004

Violation TypeNumber of Violations
Failure to monitor regularly21