Bacteria could lurk in thousands of private wells in Wellington-Dufferin-Guelph, health officials say

Kim Mournahan lives on the banks of the Grand River, and gets her drinking water from a well 100 feet underground. She takes care to follow best practices around wells, but said she hasn't tested hers in years.

"All of us are fine, the water doesn't look a funny colour, it doesn't smell off," she said.

"There's nothing around it to contaminate it."

New numbers going before the Wellington-Dufferin-Guelph (WDG) board of health Wednesday show that most well owners in the area don't test their water every year.

In fact, only about 10 per cent of well owners do — even less than the provincial average of 25 per cent.

But health officials worry that, although well water testing rates are low, contamination rates in the area are high.

Of the local wells that were sampled for testing last year, about 21 percent of them tested positive for bacterial contamination, public health said.

"That's a lot of potential addresses ... that might have significant evidence of bacteria in their well and they don't even know," said Shawn Zentner, manager of environmental health with WDG public health.

The risk of catching an enteric illness from drinking water is five times higher for those with private wells compared to those who drink from a municipal supply, according to public health.

Although people may get accustomed to bacteria in their wells over time, Zentner says it can become a problem for visitors and newcomers, especially if they're young, old or have compromised immunity. 

New system to remind people to test water

Zentner hopes a new, more streamlined system of well water testing rolling out in January will encourage people in the area to test water more often. The system is called WISE, which stands for "Web-based, Interactive, System for your Evidence-based decision making."

Well owners register in the WISE system by filling out nine questions about their well's characteristics. After they're registered, they can print out a testing form from Public Health Ontario, and drop it off along with a sample at a water drop-off location.

Once their results are in, well owners will automatically get an email prompting them to check their results online. They can also sign up for reminder emails about when it's time for their next test.

Zentner said he hopes the email reminders will make people more diligent about testing their water. More than half of those who responded to a recent public health survey on well water said they wanted to test their water more often, but simply forgot. 

The testing system is also free, he said.

"People generally like free things," said Zentner.

The WISE system will automatically inform public health staff if a well comes back positive for contamination.

The system will also create a historical log of past tests. The log is expected to help public health staff assess just how often people need to be testing their individual wells.

In five years, Zentner said he hopes to double or triple the number of households that test their well water regularly.

"The main thing really is to get people who aren't sampling, sampling," he said. "And part of the whole premise of this is to try and make it easier for the public."

In total, there are an estimated 31,000 private, residential wells in WDG, public health said.