²²²Rn at a Groundwater Treatment Plant

Groundwater is a source of drinking water, usually of good quality, but compared with surface water the concentrations of radionuclides of natural origin are higher. A drinking water treatment plant for treating groundwater was monitored. The raw water is aerated, filtered through gravity sand filters and then aerated again. Radium-226 extracted from the raw water is partially retained in the filtration sand. Decay of the accumulated ²²⁶Ra generates gaseous ²²²Rn which is released into the treated water and into the air of the plant hall, especially during the washing of the filters. Radon-222 can pose a health risk to the operating personnel or to the public. The study evaluated the following factors: ²²²Ra and ²²⁶Ra concentrations in the raw and treated water, the amount of ²²⁶Ra accumulated in the filtration sand and the ²²²Rn concentration in the air of the plant. (author)