THE WELLESLEY WATER SYSTEM - REGION OF WATERLOO ANNUAL REPORTS

This well system consists of the Heidelberg wells, Linwood wells, St. Clements wells and the village of Wellesley wells. The Heidelberg wells consist of two wells, HD1 and HD2 located in the village. To my surprise the gross contamination from the former garage on the main street of Heidelberg has never shown up in the reports however this may have something to do with the fact that numerous chemicals found in gasoline and diesel fuel are not part of the standard 44 chemicals tested for by the Region. Another reason may be that the two drinking water wells fortuitously are located upgradient from the former garage. This of course is no guarantee of safety as the cone of influence from a well that is pumping regularly will draw some downgradient water back to the pumping wells. Bacteria results are excellent in both raw and treated water although a maximum of 27 Coliforms were found via Heterotrophic Plate Count (61 samples) in the Distribution System. That number is higher than what I have read can normally be achieved by municipal water systems (i.e. 10). Both Turbidity and Chlorine maximum levels are fine although there was one Adverse water Quality Incident (AWQI) as the chlorine residual contact time (CT) was found to be zero. This resulted in restoring disinfection, flushing mains and resampling. Obviously something went wrong whether mechanical or human failure.
Sodium and Nitrate levels were also fine in 2019.

The St. Clements system consists of three wells, namely SC2, SC3 and SC4. Bacteria levels in both raw and treated water are zero and the HPC numbers in both treated water and the Distribution System are below 10. Sodium levels are fine although Nitrates are elevated. At the same time Nitrates do not exceed the Ontario Drinking Water Standards (ODWS) nor half the standard. MDLs like the rest of the Region's reports are too high for ten industrial/agricultural chemicals. Both Haloacetic Acids (HAA) and Trihalomethanes (THM) are well below both the standard and half the standard.

The Linwood System consists of wells L1A and L2. Bacteria levels, Turbidity, and chlorine levels in the water are all fine. Sodium is somewhat elevated although not huge as with some other salt contaminated groundwater sources. Nitrates and nitrite levels are both fine. Method detection Limits (MDLs) are too high for at least ten industrial/agricultural chemicals. HAAs are elevated although remain slightly below half the standard (i.e. ODWS). THMs are also a problem as they are not only elevated but very close to half the standard (ODWS) of 100 ppb. I am perplexed to see both high HAAs and THMs when there does not seem to be a bacteria problem with these wells that would require excessive amounts of chlorine.

The Wellesley System consists of wells WY1, WY5 and WY6. There were no AWQI and bacteria levels in both raw and treated water were zero in 2019. The HPC however had a maximum result of 120 Coliforms in the distribution system which is much higher than the recommended value of 10. Perhaps the distribution system needs more regular flushing although I admit that that is merely a guess on my part. Sodium and Nitrate levels are fine and the MDLs are as bad as all the other systems to date. Glyphosate (Roundup) continues to lead with a Method Detection Limit of 25 parts per billion (ppb). HAAs and THMs are both at reasonable levels and are well below even half the standard (ODWS).