Residents of Hawea and Arrowtown are being advised that their water will be chlorinated as of today.
Routine and unrelated testing showed elevated coliform counts this morning in both supplies and emergency chlorination is being put in place.
In a statement, the Queenstown Lakes District Council (QLDC) said coliform bacteria are common in the environment (soil or vegetation) and are generally harmless however their presence does indicate the potential that more harmful pathogens could enter the system. The chlorination is therefore a proactive measure.
Chlorination will continue until tests show the supplies are clear.
QLDC said it would keep residents informed on the results of tests.
Cover Photo: Lake Hawea. Nikki Heath / Wanaka Sun