Tapcensus

Thallium violations in Massachusetts

10 active public water systems in Massachusetts had a Thallium violation in the past three years, 2 of them in the latest quarter of EPA's data. What Thallium is and why it matters.

Health effects: Chronic thallium exposure causes hair loss, changes in blood chemistry, kidney damage, intestinal problems, and liver effects. It can also impair the nervous system. EPA has classified thallium as a possible human carcinogen (Group C). The very low MCL reflects its acute toxicity even at small doses.

Systems with a Thallium violation

Latest quarter 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 Thallium, including monitoring and reporting lapses. Rules violated and status in the table are for the whole system, not Thallium 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.