Lee Chalmers never dreamed her home in Quispamsis, N.B. was sitting on a problem, saying she bought her home long after the plumbing was switched over to municipal sewage.

Chalmers received quite a shock when she went to sit outside on her patio and discovered a large hole.

"I was coming out to my patio to sit in one of my chairs, I was just on the edge of the hole, I could see it was at least three feet in diameter," said Chalmers. "I was lucky, I was just on the edge, as opposed to stepping over top. The ground in a three-feet-diameter had completely given in."

Chalmers said an old septic tank had never been properly emptied or filled in.The wooden planks that served as a cover, finally rotted through.

"I guess over time, with moisture, it got rotten and caved in, and broke apart," said Chalmers.

Gary Losier is the town engineer for Quispamsis. He said he's heard many other similar stories of people finding old septic systems in their yards.

"Somebody's out mowing the lawn, they're in that area, they put a foot through, or the mower goes through," said Losier. "Or they see a sinkhole they've never seen before."

Losier said more than 1,000 homes in Quispamsis were transferred to a municipal sewage system around 1976.

"You could have homes that are 36, 37 years old that have septic fields and septic tanks in their yard, they may be connected to municipal sewer and don't know they have septic tanks in their yards," said Losier.

Chalmers said she'll have to pay out of pocket to have the tank drained and then filled in. She'll also have to pay to get her patio fixed.

She said she hopes her own story raises some awareness about this kind of potential problem for people in her area.