Chlorine safe and effective if dose is right, says expert

Thursday August 15, 2019 Written by Published in Health
India-based John Koruthu shares his chlorine experience in Rarotonga in the 1980s. 19081418 India-based John Koruthu shares his chlorine experience in Rarotonga in the 1980s. 19081418

Chlorine can be an efficient water disinfection in Rarotonga, says a food technologist.

But John Koruthu says the chemical must be used in right dosage in order to be safe.

Koruthu, who used to work for the Kia Orana Foods Corporation in the 1980s, says they used chlorine in the now defunct manufacturing firm.

He says proper dosage of chlorine was used to disinfect water used for production of citrus and pawpaw juice drinks. The water was dechlorinated before it was put into the processing plant.

“It is universal fact that chlorine is the cheapest disinfectant and 4 parts per million in drinking water is considered as safe,” says Koruthu, now back in India.

However he says the dosage depends on viable microbes such as coliform bacteria.

Read more: Letters: ‘Chlorination kept us healthy’

“Before they start using chlorine in water, they should get the water tested to implement a tailor-made treatment procedure.”

Local water authority To Tatou Vai last month revealed their latest tests of Rarotonga’s water supply has detected very high counts of Escherichia Coli (E.coli) bacteria – an indicator of dangerous contamination.

Of 40 samples tested, 33 contained E.coli and 21 of these had high or very high counts, the report says.

To Tatou Vai says this is proof that disinfection is needed for clean drinking water on the island.

“E.coli is an indicator that there is faeces in the water. If there are faeces then it is likely that there will be pathogens in the water as well,” To Tatou Vai said. “The only acceptable level of E.coli in drinking water is zero.”

Koruthu, who worked as food technologist under the Agriculture Ministry here, says the Kia Orana Foods Corporation used water from the local intakes for the production of soft drinks.

“At the intake the company had a collection tank and we use to chlorinate the water at 10 ppm level. Whenever we needed the water, we collected it in flocculation tank at the factory and the chlorine level is maintained to 10 ppm by adding stock solution of calcium hypochlorate through dosing pump along with other chemicals like Alum.

“Then it is passed through a sand filter followed by passing through a carbon filter to dechlorinate the water. Before it is pumped to the processing hall, we check the water to make sure that it is chlorine free.”

Koruthu says he did not experience any water-borne illnesses during his stay in Rarotonga from 1982 to 1987. He says there is a need to disinfect the local water supply to avoid any potential health risks.

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