NORTH BATTLEFORD, Sask. -- The Saskatchewan city of North Battleford says so far things are looking good but a precautionary drinking-water advisory remains in effect.

The city's 14,000 residents have been told to boil all water used for drinking, cooking or for brushing teeth for at least one minute.

City manager James Puffalt says the city flushed out the main lines of the F.E. Holliday water treatment plant and bacterial testings are "clean."

However, he says the advisory will remain until place "until further assurances and water quality testing" confirms the safety of the drinking water supply.

He also says residents are asked to continue conserving water because the water treatment plant is only operating at 60 per cent capacity and they need to make sure there's enough water on hand to fight a fire if one breaks out.

The advisory was issued after an operational error on Tuesday resulted in about 8,000 litres of partially treated water being spilled into clean water at one of North Battleford's filtration plants for six minutes.

Alarms went off and the facility was shut down.

A precautionary drinking-water advisory is issued if there's potential for a contaminant. It does not mean any unwanted substance or organism has been found.

The city believes the partially treated water was caught within the water treatment plant before it got into the drinking supply.