Frequent Questions

When is a public water system (PWS) required to monitor for beta particles and photon emitters?

Beta particle and photon radioactivity monitoring will be performed only by community water systems (CWSs) designated by the state as "vulnerable" or "contaminated." CWSs (both surface and ground water) designated by the state as vulnerable must collect quarterly samples for beta emitters and annual samples for tritium and strontium-90 at each entry point to the distribution system, beginning within one quarter after being notified by the state. Systems already designated by the state must continue to sample until the state reviews and either reaffirms or removes the designation.

CWSs (both surface and ground water) designated by the state as utilizing waters contaminated by effluents from nuclear facilities must collect quarterly samples for beta emitters and iodine-131 and annual samples for tritium and strontium-90 at each entry point to the distribution system, beginning within one quarter after being notified by the state until the state reviews and either reaffirms or removes the designation (40 CFR 141.26(b)).

Have more questions? Submit a request