Tapcensus

Hexachlorobenzene violations in Maryland

3 active public water systems in Maryland had a Hexachlorobenzene violation in the past three years, 1 of them in the latest quarter of EPA's data. What Hexachlorobenzene is and why it matters.

Health effects: Chronic exposure to hexachlorobenzene is associated with liver damage, skin lesions, and neurological effects. EPA classifies it as a probable human carcinogen (Group B2). It can be transferred to infants through breast milk. Reproductive and developmental toxicity have been observed in animal studies.

Systems with a Hexachlorobenzene violation

Latest quarter first, then largest first
SystemServesStatusRules violated, 3 yrUnresolved
Town of Perryville
Cecil County 		4,413 4 0
City of Rockville
Montgomery County 		52,000 2 0
City of Havre de Grace
Harford County 		14,000 3 0
About this data

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