The Power of Information

National Drinking Water Database

Selenium (total) in Maryland

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 Maryland

22 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
1Fahrney-Keedy Home and Village
Boonsboro, MD
2501 of 38.33 ppb
(0 to 25 ppb)
2Town of Mount Airy
Mount Airy, MD
8,6313 of 86.35 ppb
(0 to 25 ppb)
3Delmarva Mobile Home Park
Ocean City, MD
621 of 15 ppb
(5 ppb)
4St Martins BY The Bay
Berlin, MD
1201 of 13 ppb
(3 ppb)
5San Mar Children's Home
Boonsboro, MD
511 of 12 ppb
(2 ppb)
6Jensen's Hyde Park Mobile Home Park
Southington, MD
3781 of 12 ppb
(2 ppb)
7Town of Hurlock
Hurlock, MD
2,1501 of 12 ppb
(2 ppb)
8Clifton ON The Potomac
La Plata, MD
6671 of 32 ppb
(0 to 6 ppb)
9Town of Rock Hall
Rock Hall, MD
1,7501 of 21 ppb
(0 to 2 ppb)
10Town of Darlington
Millersville, MD
2501 of 21 ppb
(0 to 2 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 Maryland

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

Violation TypeNumber of Violations
Failure to monitor regularly11