Whirinaki's water supply was chlorinated yesterday and a boil water notice issued after low levels of E coli were found in the network.
Pan Pac Forest Products Ltd was one of 280 Whirinaki properties to receive a boil water notice yesterday afternoon.
The warning will remain in place until further notice, said Hastings District Council water services manager Brett Chapman.
The notices were hand-delivered to all properties yesterday afternoon and the information had been sent to Pan Pac and Contact Energy for sharing with staff.
Pan Pac company secretary Dennis Hall said all staff and contractors were told about the situation yesterday, and the Hastings council had organised for fresh water in 10-litre bladders to be delivered.