Water is safe to use at Chiang Rai Central Prison, the Department of Corrections said in an effort to address concerns about potential lead contamination in the nearby Kok River.
The department issued a statement on Monday to address recent media reports suggesting that the prison's 4,000 inmates may be at risk from cancer due to potential lead contamination in the Kok River, which has allegedly spread into the prison's water supply.
The department said the prison's water comes from a surface water supply system built according to standards set down by the Department of Water Resources, as well as a groundwater system, since the prison lies outside the service area of the Provincial Waterworks Authority. The prison also conducts annual water quality monitoring.
Following reports of discoloured water in the Kok River in early April, the Chiang Rai Office of Natural Resources and Environment collected water samples from the area for laboratory analysis.
The test results showed that heavy metal levels, including lead, in the prison's water were within safe limits. Lead levels did not exceed 0.05 milligrammes per litre -- the national safety threshold.
Nevertheless, the prison has initiated a three-phase plan to improve water quality.
As part of a short-term measure, the prison has replaced water filter cartridges and added sediment filters to improve water quality immediately. Large water tanks have been installed throughout the prison. It is also coordinating with the Provincial Waterworks Authority (PWA) to purchase clean drinking water for inmates and is currently testing blood samples taken from inmates to check for any signs of contamination.
For medium-term plans, the facility will separate the plumbing systems for surface water and groundwater. Surface water will be used for general use, while groundwater -- filtered to meet safety standards -- will be used for drinking and cooking.
A long-term strategy has been devised where the department has proposed to the provincial governor that the PWA extend its service coverage to include the prison. This expansion would benefit not only the prison but also nearby communities by providing cleaner, safer water.
The Department of Corrections is currently allocating funds to equip the prison with a reverse osmosis water filtration system.