Old, abandoned wells can be a hazard for safety as well as water quality. That's why Pembina Valley Conservation District manager Cliff Greenfield says it's important to seal up any unused wells.

"Basically the overburden, you know, the earth, protects the groundwater, and anything that happens on the surface is sort of filtered out by the time the water filters down through the ground and gets into our water table and our aquifers," Greenfield explains. "Having a well is just a direct connection that anything that's happening on the surface, any bacteria, chemicals, anything like that can get directly into the aquifer and into the water table."

That's why it's also important for wells still in use have good, solid lids that can keep things like grass and spiders out.

Aside from the concern of water contamination, it's important for the safety of people and animals that wells are covered and/or sealed.

"It's horrible to think about somebody falling down an abandoned well," Greenfield says.

But he adds old wells aren't uncommon.

"I think everybody has a story (about an old well)," he says. "You know, somebody was driving in an area and all of a sudden the wheel went down and they realized that must've been an old farm site and a well appeared. Or they were looking in the backyard and a goat disappeared (because) it went down this abandoned well."

Greenfield says old wells need to be sealed properly because it's not enough to simply fill the hole with dirt.

"What happens there is the dirt hits the water table, and it bridges at that point, and over the years with freeze and thaw, water going up and down, that hole magically appears again, maybe 40 years later," he explains.

Greenfield also says it's not sufficient to fill an old well with rocks, because this won't stop pollution from potentially contaminating the aquifer.

He says the provincial government has guidelines for sealing old wells.