Int. J. Environ. Res. Public Health 2009, 6 181 After the extent of the radioactive contamination of the Techa River became known, countermeasures were implemented to limit doses to the local population, initial prohibitions on water use and evacuation beginning in 1951 along the upper part of the river. Hydrological engineering works such as damming the upper reaches of the river were performed, and wells were dug to supply newly constructed water pipelines. All villages on the upper part of the river, less than 78 km from the site of contamination release (7,500 people), were evacuated between 1953 and 1961 [1]. The effectiveness of the evacuation was however limited, since the riverside village populations had already received their main external and internal radiation dose prior to evacuation. In addition, a sanitary-protection regime was established where the Techa floodlands near villages were fenced-off to prevent the use of river water for drinking and domestic purposes. Fishing, breeding waterfowl and the use of floodlands for cultivation and pasture were abandoned [15]. Restrictions on the use of the Techa and its river water were also introduced along downstream parts of the river in 1956. Some of these restrictions are still in place in the area, including bans on drinking river water, fishing and bathing in the river, access to the river banks and use of riparian pasture for grazing animals. However, no strict control of countermeasures is visibly enforced and several local people are still believed use the Techa River and the riverbank areas to some extent. After the Kyshtym accident in 1957, several protective measures were put into action in order to reduce population doses: 10,200 people were evacuated from the most contaminated sites at different times after the accident. Some foodstuffs and fodder were discarded and a sanitary control zone was established. In addition, the use of lakes for potable water and fishing was prohibited, pasture and grassland was put under control and the state farms had to change their production profile [15]. Contamination from dried-out radioactive Karachay sediments in 1967 mainly affected areas within the 1957 EURT. Between 1967 and 1971, remediation work was carried out to fill in shallow areas of the lake and to re-cultivate the area surrounding it. The surface area of the lake was reduced from 0.51 km2 in 1962 to 0.15 km2 in 1994, and this reduction process was planned to continue until the lake was completely filled. At a JNREG meeting in Oslo, November 2005, Russian authorities presented plans to reduce discharges from Mayak PA; according to these plans, discharges to R9 should cease in 2009. 1.4. Contamination Levels in Groundwater, Reservoir Water and River Water Filtered water samples collected from two boreholes in the vicinity of Lake Karachay in 1994 exhibited levels of 4,200 Bq l-1 60Co and 8,800 Bq l-1 90Sr at depths below 50 m [2], 137Cs levels being below 2 Bq l-1 at this site. Activity concentrations were considerably lower at a borehole 4 km south of the lake, with maximum levels of 270 Bq l-1 60Co and 68 Bq l-1 90Sr; data from the regular monitoring of this second borehole showing a steady increase in 90Sr levels over the period 1989-1994 [1]. Surface waters sampled from the Mishelyak River, Reservoirs 10 and 11, the by-pass channels and Techa River in 1994 exhibited highest activity concentrations in Reservoir 10 (up to 14 kBq l-1 90Sr, approximately 100 Bq l-1 137Cs and 2 Bq l-1 60Co), with activity levels decreasing in Reservoir 11 (up to 2.4 kBq l-1 90Sr, 1.5 Bq l-1 137Cs and <0.1 Bq l-1 60Co) [1]. Reported concentrations of radionuclides in Techa River water, which primarily receives water from the reservoir cascade via filtration of water through the dam from Reservoir 11 and overland drainage flow from the reservoir by-pass channels, have been relatively constant between the Asanov