The National Water Supply and Drainage Board has responded to allegations leveled against it regarding the quality of a batch of Hydrated Lime imported for water treatment.
Its Chairman has issued a statement in this regard and in the statement, it has been admitted that a laboratory test conducted on 380 tonnes of imported Hydrated Lime has found that the chromium content has exceeded the standard limit of 10mg/kg.
Open bids were invited through national newspapers under “(Contract No.: SUP&MM/CHEM/HL – 05/2022/18)” for the purchase of 1500 tonnes of Hydrated Lime required for water purification. The tender was awarded to Ceegreen Engineering (Pvt) Ltd, the fully qualified and lowest bidder, on 31.07.2024.
Subsequently, a team of officials of the Board participated to conduct quality inspection before shipment with evidence. Since the samples taken at that time were in accordance with the specifications, the shipment was allowed, and accordingly, 380 tons of lime were first brought to Sri Lanka by the contractor and delivered to the Board’s warehouse. When random samples were taken from the same batch as per the procedures followed, it was found that the chromium content of the lime exceeded the 10mg/kg limit specified in the specification.
The statement states that the results of the tests conducted by the board and external laboratories showed that the chromium content was between 11-14 mg/kg, and that the chromium value of the sample taken jointly with the supplier of the lime stock was 11.3 mg/kg.
Meanwhile, internal sources at the Water Supply Board say that the board uses SLS standards for water purification, and that the maximum chromium concentration specified in the SLS standard of 10 mg/kg has been increased to 12 mg/kg a few days ago. Since the chromium value of the sample taken jointly by the supplier and the Water Supply Board is 11.3 mg/kg, it is doubtful whether the chromium value was increased in this way to accept the questionable lime stock based on those results, the sources say.
The change was made by SLS and was not requested by the board, according to a statement issued by the chairman of the Water Supply Board. It is said that the use of Hydrated Lime, which has a high chromium concentration, for water treatment increases the amount of heavy metals in the water, which can cause cancer and kidney diseases.