What is the quality standard for trihalomethanes in drinking water?

What is the quality standard for trihalomethanes in drinking water?

• A. < 0.008 mg/L
• B. < 0.08 mg/L
• C. < 0.0 mg/L
• D. < 0.80 mg/L

Answer: (B)

Total trihalomethanes are disinfectant byproducts formed when chlorine used for disinfection reacts with organic matter in water. The standard set to protect public health is 0.08 mg/L for total trihalomethanes, typically monitored as a running annual average. This 0.08 mg/L limit equals 80 parts per billion, so keeping measurements at or below this level meets the quality standard. The other numbers either imply too strict, too lenient, or unrealistic limits compared to the regulatory value.

Total trihalomethanes are disinfectant byproducts formed when chlorine used for disinfection reacts with organic matter in water. The standard set to protect public health is 0.08 mg/L for total trihalomethanes, typically monitored as a running annual average. This 0.08 mg/L limit equals 80 parts per billion, so keeping measurements at or below this level meets the quality standard. The other numbers either imply too strict, too lenient, or unrealistic limits compared to the regulatory value.