Operating checks in 1999 involved 500 determinations of total volume alpha activity, and somewhat fewer (458 and 462, respectively) determinations of total volume beta activity and radon-222 volume activity. 55 analyses showed that the total volume alpha activity indication value (IV) set forth by the drinking-water quality standard STN 75 7111 was exceeded. Radon-222 volume activity indication level set out by the standard was exceeded in 8 samples.
These results were used in 2000 to select for monitoring 76 outlets from the water supply system managed by SeVaK. The determinations included total volume alpha and beta activities, radon-222 volume activity and, if an indication value was exceeded, also radium-226 and natural uranium volume activities, on a quarterly basis. The results were evaluated in accordance with the standard STN 75 7111 and the Slovak Health Ministry's regulation 12/2001 on Requirements for Ensuring Radiation Protection which sets forth intervention values for water in public water supply systems as follows: total volume alpha activity 0.2 Bq.l-1, total volume beta activity 0.5 Bq.l-1 and radom-222 volume activity 50 Bq.l-1.
The derived intervention level of total volume alpha activity was exceeded in 36 water samples collected at Turcianska Stiavnicka, Podhradie and Slovenske Pravno run by the Martin Division, and from water sources managed by the Liptovsky Mikulas Division at Liptovsky Hradok (springs Zapac), Liptovska Porubka (wells Kamenista and Kvacany), and also in samples from Istebne (Dolny Kubin Division) and Liptovske Revuce – spring Biele vody (Ruzomberok Division).
The derived intervention level for Rn222 volume activity was only exceeded in the water supply system at Istebne. The situation was solved by installing an airing tower in the Istebne water tank.
Personnel of the State Health Institute's Department of Health Protection against Ionizing Radiation in Banska Bystrica assessed the results of the monitoring and it was agreed to take these steps in 2001:
A. SURLAKOVA - In: Vodohospodarsky spravodajca. - Vol. 44, 20, no. 9(2001), p. 4-5
Information & Contact:
Research Institute of Water Management,
Nabr. arm. gen. L. Svobodu 5,
811 02 Bratislava,
tel.: 00421 (2) 59343111,
fax: 00421 (2) 54415743
Severoslovenske vodarne a kanalizacie, s.p (SeVaK).,
010 23 Zilina
Tel.: 00421 /41/ 764 87