A week of positive results for Covid in the wastewater is a "strong indicator that there may be COVID-19 in the Pahiatua community," health authorities say.
Tests had been carried out on November 15 to 18 with only November 17 having a negative result.
Rob Weir, medical officer of health at MidCentral District Health board said water testing had been undertaken across multiple sites in Tararua.
Anyone with Covid-19 symptoms in the rohe were encouraged to get a test.
A walk in testing station had been set up at 46 Main Street, Pahiatua from 9.30am to 3pm until Thursday afternoon.
Testing was also available at GPs and health providers by appointment.