"Council is taking an extremely cautious approach in returning to the Makotuku River as Raetihi's water source.
"The installation of a hydrocarbon sensor on a town's water supply like in Raetihi has never been done before in New Zealand."
"We are not willing to switch back to the Makotuku until the new systems have been thoroughly tested and we are satisfied that they are robust enough to withstand a wide range of factors.
"In the case of the hydrocarbon sensor this includes testing it across a range of weather conditions from the current hot and dry conditions to wet and wild all of which affect things such as the river flow, run-off and water turbidity."
"During the last heavy rain fall the hydrocarbon sensor picked-up very low readings measured in micrograms per litre. As streams have natural oil in them that is released from the decay of plant material samples will need to be taken to confirm if the hydrocarbons detected is from the diesel or naturally occurring oils."
Ms Westcott noted that this was positive and demonstrated how sensitive the sensor was at recording oils at very low concentrations.
"It may be, however, that the sensor has been set at too low a level than is required to detect diesel so we will be looking into that.
"We appreciate that the Raetihi community would like to see a return to larger Makotuku River over the current temporary smaller Makara Stream as their water supply as soon as possible but we won't be taking any chances with the health of the community."
