Water from the Waikato River is being sent to Australia for tests after slightly elevated levels of arsenic were detected in treated drinking water.
While these levels remain within safety limits, authorities aim to determine why treatment plants are struggling to filter out the arsenic effectively. The testing process is expected to take about a month.
Recent results showed arsenic levels between 0.0189 and 0.0256 milligrams per litre, which fall within the usual range for the river. However, the acceptable maximum for treated water is 0.01 milligrams per litre, meaning some treated samples exceeded this limit.
Scientists believe the issue may involve arsenic in its “arsenic 3” form, which is harder to remove during water treatment.
The seasonal variation of arsenic levels is not uncommon, often rising in spring and peaking in summer. However, Waikato Regional Council and water treatment experts are investigating why the usual filtration methods are less effective right now.
Despite the concern, health officials reassure residents that slightly elevated arsenic levels for short periods are unlikely to harm human health. Measures are underway to improve water treatment processes, including installing advanced filtration systems in some plants.
