Red Oak Point

What it means: When a system violates a drinking water standard, it must notify customers promptly: within 24 hours for acute violations (e.g., E. coli), 30 days for non-acute MCL violations, and 1 year for monitoring failures. A violation means the notification was late or missing — not that the underlying water issue is necessarily severe.

Health effects: No direct health risk from the notification violation itself, but delayed notification means customers may have consumed contaminated water without the chance to take protective action (boil water orders, bottled water use).

Limit: No MCL — compliance requires meeting specific notification deadlines

What it means: The 2013 RTCR (effective 2016) replaced the original TCR. It triggers automatic E. coli testing whenever total coliform is found. A single E. coli-positive sample is an acute MCL violation. It also requires systems exceeding 5% total coliform-positive samples to conduct a formal assessment and correct any deficiencies, helping prevent contamination before it escalates.

Health effects: Total coliform bacteria indicate that the disinfection barrier has been breached or fecal contamination is entering the system. E. coli specifically indicates fecal contamination and the possible presence of disease-causing pathogens (norovirus, Salmonella, Shigella, Campylobacter). Illness can be severe in elderly, young children, and immunocompromised individuals.

Limit: Zero E. coli; ≤5% of monthly samples total coliform-positive

What it means: The 1998 Stage 1 Rule was the first comprehensive federal standard for disinfection byproducts. It set MCLs for TTHM and HAA5, added limits for bromate (formed during ozonation) and chlorite (formed during chlorine dioxide treatment), and established maximum residual disinfectant levels (MRDLs) for chlorine, chloramines, and chlorine dioxide. It applies to all community and non-transient non-community water systems that disinfect.

Health effects: See TTHMs (2950) and HAA5 (2456) for their specific health effects. Bromate is a probable human carcinogen (Group B2). Chlorite at elevated levels can cause hemolytic anemia, particularly in infants, developing fetuses, and individuals with certain enzyme deficiencies. Violations indicate the system exceeded one or more of these byproduct or disinfectant limits.

Limit: TTHM: 0.080 mg/L; HAA5: 0.060 mg/L; Bromate: 0.010 mg/L; Chlorite: 1.0 mg/L

What it means: All systems using surface water (rivers, lakes, reservoirs) or groundwater under surface influence (GWUDI) must filter and disinfect. Treatment technique violations mean the system failed to maintain adequate disinfectant residual, exceeded turbidity limits, or lacked required permits. Snowmelt and storm events can raise turbidity and pathogen loads in surface water.

Health effects: Without proper filtration/disinfection: Giardia lamblia (severe diarrhea, cramping), Cryptosporidium (life-threatening for immunocompromised individuals), viruses (hepatitis A, norovirus). Turbidity itself is not a health risk but can shield pathogens from disinfection.

Limit: Treatment technique: turbidity ≤0.3 NTU in 95% of monthly samples; detectable disinfectant residual in 95% of distribution samples