T’puram: Water supply in Thiruvananthapuram could be affected if the Aruvikkara water treatment plant cuts production by 15 million litres a day because of operational issues, according to a Kerala Water Authority document. The plant is designed to treat 75 million litres a day (MLD) but has been producing about 90 MLD to meet the city’s demand. KWA has warned that if the problems continue, output may have to be brought down to its designed capacity of 75 million litres a day.The document reveals sludge — the muddy waste separated from water during treatment — has accumulated and caused the sludge mixer to stop working. This has affected the functioning of the lamella plates, which help separate dirt particles from water. The plant is also using considerably more alum, a chemical that helps tiny particles clump together for removal, causing available stocks to deplete rapidly.Moreover, a KWA engineer said turbidity in the incoming water had reached 80–100 nephelometric turbidity units (NTU), increasing the load on the treatment plant. Turbidity measures the cloudiness of water caused by suspended particles. According to a KWA source, higher turbidity can increase the burden on the treatment process and may require adjustments in chemical dosing and more frequent sludge removal.“Desilting is going on“, a source at the executive engineer‘s office said, adding that the sludge had last been cleaned around three months ago.“High turbidity in the incoming water has increased the load on the treatment plant. Desilting is currently under way, as the sludge was last cleaned around three months ago. The plant is producing around 90 MLD to meet Thiruvananthapuram’s water demand,” the source said.The plant’s five-year liability period expired in April 2026. According to a KWA source, the process to award a new annual maintenance contract (AMC) was initiated in April but could not proceed because the bidders did not qualify in the tender process.Meanwhile, a separate tender for one day cleaning work at the plant was called, with bids scheduled to open on Friday. A KWA source said arrangements to carry out the cleaning work were under way and that a final decision was expected on Monday, separately from the main maintenance contract.The operational problems come as the plant continues to produce beyond its designed capacity to meet the capital’s water demand. KWA’s warning that output may have to be restricted to 75 MLD raises concerns over whether the city can absorb a potential reduction of 15 MLD without affecting supply.
