Canterbury Regional Council is encouraging rural residents with septic tanks to check their wastewater system for any signs of damage following September's earthquake.
The council's environmental protection manager, Brett Aldridge, says he's aware of about a dozen or so cases where tanks have popped up out of the ground, but he says its hard to know exactly what kind of damage has happened below ground.
Residents should check whether septic tank levels are lower than they should be, tell-tale patches of green on the grass, or get a professional to do a pressure test on the lines.
Mr Aldridge says any claims to the Earthquake Commission must be lodged before 4 December to be eligible for cover.
As well as septic tanks, Mr Aldridge is urging people to check their underground hydrocarbon storage tanks.
He says dairy effluent ponds in the quake area will be given priority when the Council carries out its routine monitoring season.