Atlantic City Mua

What it means: Cyanide in drinking water originates primarily from industrial discharges — metal plating, steel manufacturing, and certain mining operations — and from leaching of road salt formulations that contain ferrocyanide compounds. It can also enter from improper disposal of industrial waste. Natural background levels are negligible. It is measured as free cyanide.

Health effects: Acute high-dose cyanide exposure interferes with cellular oxygen use and can cause rapid deterioration of the central nervous system, including headache, dizziness, and in severe cases, loss of consciousness. Chronic exposure at lower levels is associated with thyroid dysfunction and nerve damage. Most drinking water violations pose chronic rather than acute risk.

Limit: 0.2 mg/L (200 ppb)

What it means: The Interim Enhanced Surface Water Treatment Rule (IESWTR), finalized in 1998, strengthened protections for systems serving 10,000 or more people by tightening turbidity limits and requiring Cryptosporidium removal. It was an intermediate step between the original SWTR and the Long-Term Enhanced SWTRs.

Health effects: Violations indicate failure to meet treatment technique requirements that reduce exposure to Cryptosporidium, Giardia, and other microbial pathogens. Cryptosporidium poses the greatest risk to immunocompromised individuals, infants, and the elderly, and can cause severe or fatal illness in vulnerable populations.

Limit: Treatment technique — no numeric MCL; compliance means meeting turbidity limits (0.3 NTU in 95% of monthly samples) and Cryptosporidium removal benchmarks