Tapcensus

Selenium violations in Massachusetts

10 active public water systems in Massachusetts had a Selenium violation in the past three years, 2 of them still unresolved. What Selenium is and why it matters.

Health effects: Chronic exposure above the MCL causes selenosis — characterized by hair and nail loss, peripheral neuropathy, fatigue, and gastrointestinal disturbance. Liver damage can occur with prolonged high intake. The margin between nutritional requirement and toxic dose is narrow, making the MCL an important threshold.

Systems with a Selenium violation

Unresolved first, then largest first
SystemServesStatusRules violated, 3 yrUnresolved
Lees Supermarket
Westport · Bristol County 		90 2 0
Stiles and Hart Brick Company
Bridgewater · Plymouth County 		45 2 0
Wannacomet Water Company
Nantucket · Nantucket County 		27,703 7 2
Winchester Water Dept
Winchester · Middlesex County 		22,970 2 0
Scituate Water Division
Scituate · Plymouth County 		19,297 6 2
Hanover Water Dept
Hanover · Plymouth County 		14,984 3 0
Halifax Water Department
Halifax · Plymouth County 		7,575 4 0
M.v. Public Charter School
Tisbury · Dukes County 		150 2 0
Aquinnah Wampanoag
County 		89 5 0
First Congregational Church
Plympton · Plymouth County 		55 5 1
About this data

A system is counted once if any of its violations in the past three years involved Selenium, including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Selenium alone.

Source: the U.S. EPA's Enforcement and Compliance History Online system (ECHO), which publishes the federal Safe Drinking Water Information System. EPA's terms and values are shown as published. The Massachusetts records are from EPA's data refresh of Oct 7, 2026; EPA refreshes this data quarterly, and states report to EPA with a lag of three to six months, so the newest violations may not appear yet. Retrieved from ECHO on Oct 11, 2026.