The owners of a Christchurch quarry that residents believe may have contaminated their wells say its operations have remained above groundwater level at all times.
The Winstones quarry in Yaldhurst on the northern edge of the city has been served an abatement notice by Canterbury Regional Council (ECan) but residents say more needs to be done to protect Christchurch's drinking water.
ECan said the quarry, owned by Fletcher Building, failed to stay at least 1 metre above the highest known level of the water table.
GBC Winstone general manager Ian Jones, said the water visible in the quarry was from water used in quarrying operations and from pooling rain water.
He said the company was very aware of its resource consent obligations and was investigating the matters raised by the council.
The council said it had tested 19 wells and found no cause for concern.
Anna Youngman lives across the road from the Winstones' site and said quarrying into the aquifers would have gone unnoticed had residents not laid a complaint with the regional council.
"Winstones are self monitoring it and they've been happy with it. ECan have been happy with them self monitoring.
"Finally ECan went out and the self-monitoring hasn't been successful. Now this water is precious to the whole city of Christchurch and we're in disbelief."
Residents have used a drone to take photos of the operation which they say show areas where groundwater has come to the surface, exposing it to possible contamination.
Ms Youngman said it grated that Winstones was owned by Fletcher Building.
"It just amazes me when Fletcher Building have done so much with the rebuild, and a lot of it has to be redone, and to think they're going to come down here and just contaminate our water. Then once they've finished quarrying they'll go back to wherever and we're left."
Another resident, Annell McDonagh, said to fix the problem, Winstones had been ordered to fill the aquifers back up.
But she had little faith the backfill would be clean and pointed to a neighbouring quarry that had been filled using waste from demolished homes.
"We were at a meeting and I said to Winstones, well 'how often does ECan come in and test the clean fill?' And they said they don't.
"So the next meeting we went to, an ECan person was there and I said 'apparently you don't test the clean fill'. And they said 'no, we look at it'."
Ms McDonagh said she was so worried about what might be getting into her artesian well water she was considering moving to bottled water. And contaminated water was not her only concern.
"On some very strong windy days the dust is piling all around us. We've got children and it's a concern for us and there's older people here but ECan just don't seem to be concerned at all."
Regional council deputy chairperson David Caygill said the council was taking Winstone's breach of its resource consent seriously.
"ECan officers have certainly talked to Winstones recently to reinforce the seriousness with which we view the conditions of their resource consent. These are not trivial matters and we expect compliance with them."
Mr Caygill said the council was being proactive by holding regular meetings with residents but generally acted on concerns around dust and water contamination only when it received a complaint.
"We've got 500 staff but not all of them are engaged in regulatory enforcement. But as we often say to people, if you have a concern, ring our 0800 number because that is the principal means through which we learn what people may or may not be doing."