Wawa's drinking water advisory has officially lifted - 5.5 years after it was put in place.
A notice from the Municipality confirms the advisory issued in November 2014 has now been lifted, after drinking water samples collected quarterly in 2018 and 2019 - as well as 2020 - showed the formerly high levels of trihalomethanes had dropped low enough to meet Ontario Drinking Water Quality Standards.
THMs are a result of organic material (dissolved carbon) reacting with chemicals (like chlorine) used to treat the water.
Since the advisory was issued, the Municipality has undertaken multiple projects to address the issue, most recently - in April - Council approved a plan to use an aluminum sulphate coagulant during treatment.
Kresin Engineering recommended that it only be used on a seasonal basis - during the warmer months, when THM levels are usually higher - monitoring the results to confirm long-term effectiveness.
The Municipality's studies found the coagulant would substantially reduce the THM level - and even reduce the amount of aluminum in the water - though at an expected cost of $15,000 a year.