Well test results provide promise for new drinking water source in Arthur

Water quality considered ‘excellent’ but arsenic levels need attention: report

KENILWORTH – A small test well drilled in 2021 has Wellington North’s water department talking about the potential for a new drinking water source following a recent report on test findings.

Located on township land at the unopened roads of Wells Street and McCauley Road, less than a kilometre north of Domville Street, the well yielded a high flow rate of 27 litres of water per second under a six-day stress test.

Brown water flowing from household taps, caused by excess concentrations of iron and manganese at Arthur’s three existing wells is a common occurrence for Arthur residents. Results from the test suggest concentrations of those metals is lower, which is good news when it comes to what township operations director Matthew Aston called “water aesthetics.”

“I think what we found is a source that has a lot of water that has less iron and manganese than is typical” from Arthur’s other wells, Aston told council on Dec. 5.

However, a concentration of arsenic has been discovered at above half of the maximum allowable concentration, according to a 164-page report from Guelph-based R.J. Burnside and Associates.

Arsenic occurs in the Earth’s crust and is most toxic when in its inorganic form, such as in groundwater, according to the World Health Organization.

Health Canada considers the metalloid chemical to be carcinogenic, and according to the World Health Organization, it can lead to cancers and skin lesions with long-term exposure through drinking water.

The Ontario Drinking Water Standard’s limit is 10 micograms per litre — lowered from 25 in 2018. Results from the well ranged from 6.1 to 7.4 over a six-day test period, according to the Burnside report.

The report recommends the site and notes water quality “is considered excellent,” aside from the arsenic levels, which the report states are likely to be upwards of five micrograms per litre in the area, requiring quarterly sampling and the attention of operations staff.

The report also states the concentration justifies a pumping station design “that will remove or minimize arsenic in the water so that there is no chance for water to exceed” the drinking water standard.

Aston said he’s uncomfortable with the number and insists the arsenic issue can be treated. Exactly how becomes more complicated.

Among several available treatment technologies, the U.S. Environmental Protection Agency lists options such as: filtration, ion exchange, reverse osmosis, electrodialysis and oxidation.

“In every instance, arsenic gets treated a little differently,” Aston said.

“If this is a desired location … then we’ll have to start working with someone like the Walkerton Clean Water Centre to figure out what our treatment train needs to be.”

The Walkerton Clean Water Centre website lists 18 case studies on treating water for arsenic.

Overall, Aston said, “We’re pretty excited about what we found for a water source.

“Certainly it won’t have the discolouration that is prevalent or is seen in Arthur,” he added.

But it will be three to seven years before the water from the well could reach household taps, depending on studies required throughout an environmental assessment process, future council decisions on how to spend tax dollars, and inflation.

“We have to go through the environmental assessment process to see what the best solution is,” Aston told the Advertiser by phone.

The $200,000 environmental assessment, for which council approved a budget request on Dec. 5, will explore alternatives to what’s proposed.

“In a perfect world we would transport water probably from further north into Arthur and that would solve a lot of our problems, but from a cost standpoint that probably isn’t feasible,” Aston explained.

“We can’t presuppose the outcome, but the activity makes sure that we give a good look at options.”

No other locations for a well have been recently tested, though historic well testing records reported to the province were reviewed, Aston said.

“We’ve kind of done a desktop exercise of looking at different locations, but we have not invested the money to do a drill like we did at this location,” Aston said.

The location was also chosen because it’s on the same property where the township envisions a new water tower in the next three to seven years, replacing two existing towers commissioned in 1932 and 1967 that are no longer sufficient to handle future development.

If the test location is supported by studies, the well would likely become Arthur’s primary water source, with those located in southwest Arthur and two kilometres south of Arthur used to complement.

The water could be incorporated into the distribution system to dilute the concentration of iron and manganese from the other wells, possibly reducing discolouration issues.

However, that’s not a “silver bullet” Aston cautioned.

Those living closer to well “7B” will be more predisposed to higher concentrations of manganese, and those closer to wells “8A/B” will have higher concentrations of iron.

Between 2021 and Nov. 30, 2022, the township has spent $105,121 on exploration of the well.