Christchurch's Yaldhurst residents are concerned over a quarry's plans to expand in the area.

Road Metals has purchased two properties on West Coast Road.

It's understood the company's offered a good deal, giving residents permission to stay in the house rent free for up to two years.

Anna Youngmamn lives in the area.

She says she doesn't want to go public, but is speaking out because she's worried if she doesn't...it will be too late.

"My neighbours have encouraged me...I don't like being the face of Yaldhurst but that's what I've been christened."

"We are really personally affected. It's just happening all around us."

The two sites purchased are near the Paparua Prison, where the company is based.

Both properties are 10 acres in size.

Managing director Murray Francis says he won't discuss the specifics of the agreement between the company and home owners, but to clarify - it wasn't the company that made the first move.

"The seller approached us in both cases."

The Christchurch City Council and Environment Canterbury have approved applications from the company for quarrying activity to take place on both sites.

Work has already begun.

Ms. Youngman says residents are concerned about their health, with fears of dust building up, as well as the possibility of water contamination.

Murray Francis says those fears are completely unfounded.

"I would dare anyone to come back to me and give me one example where quarrying has affected drinking water."

"There is no known example in New Zealand."

He says the level of dust will also be controlled.

Earlier this week, the same residents spoke out about a separate quarry in the area, which was slapped with an abatement notice after it dug too far into the ground.

It sparked fears thousands of residents may have been exposed to contaminated drinking water.

However, tests completed by Environment Canterbury have given no indication of that to be the case.

Anna Youngman says she had no confidence in Environment Canterbury's ability to make sure both quarries place it safe.