Tuesday, April 7, 2020


I have read carefully about 2/3 of the report and skimmed the rest. To say that it is long winded, detailed etc. is an understatement. I'm not totally convinced that it is superior to all the Region of Waterloo Annual Reports (i.e. Waterloo, Kitchener, Cambridge & four Townships). The reason is that it is very difficult to get the big picture or even to find the various specific data one is looking for. Yes much of the Region of Waterloo's data is far too thin without details as to why wells are shut down, why so many Method Detection Limit's are so high (particularly glyphosate), why other wells out of use for years continue to be considered part of the water system etc.. Anyhow here goes regarding Guelph's water supply and system.

It is broken down into the Guelph System and the Gazer Mooney Subdivision System. The second one consists of a total of about 200 people and uses the same water that is used throughout Guelph. There are 21 groundwater wells and a shallow groundwater collection system called the Arkell Springs Glen Collector System. This system consists of trenches that are occasionally inundated with water from the Eramosa River. Boy that's a new one to me. River water generally is much dirtier in every sense than groundwater but perhaps introducing it and then filtering it directly through sands and gravels is less expensive than Kitchener's ridiculously expensive Mannheim Treatment System which treats Grand River water.

The City has a Lead Reduction Plan that perhaps is superior to other municipalities. They offer a subsidy of up to 75% for homeowners to remove the lead pipes running from the municipal water lines into their homes. That is an excellent idea.

Besides the usual sodium hypochlorite to treat for bacteria the City also uses Ultraviolet Light (UV) for the previously mentioned groundwater Collection System as well as the Carter Wells (1 & 2) and the Arkell Wells (1,6,7,8,14 & 15). UV is usually used for raw water that may have excessive bacteria or other contaminants (NDMA or perhaps TCE). Hence surface water or groundwater under the direct influence (GUDI) of surface water is a candidate for this additional treatment. There were a few relatively minor Adverse Water Quality Incidents during 2019.

As to be expected there were a few issues with bacteria in the raw water including 4 E.Coli and 78 Total Coliform. Heterotrophic Plate Counts (HPC) had occasional maximum Coliform Unit counts that were very high namely in the Distribution System (280 cfu/ml) and the Point of Entry HPC (1300 cfu/ml).

As with other nearby cities (Kitchener, Waterloo, Cambridge), Trichloroethylene (TCE) is an issue in a few Guelph wells namely the Membro and Emma wells and possibly one other. While below the drinking water standard it still should not be in our drinking water at any measurable concentration.

Generally Volatile Organic Chemicals (VOC) on pages 53-56 look very good. The trouble is that on later Tables dichloroethylene, TCE, Xylenes, Ethyl Benzene show up although not in this Table (Table 23). Also they are below the drinking water standards. Of course the usual listing of Trihalomethane (THM) chemicals show up albeit well below the drinking water standard. This includes chloroform, bromodichloromethane, bromoform, and dibromochloromethane. The overall levels of THMs and Haloacetic Acids (HAA) are as good or better than many in the Region of Waterloo reports.

Sodium while technically above the Aesthetic Objective is nevertheless much better in Guelph than throughout the Region of Waterloo.

Overall despite the difficulty and time required to find the good stuff in this report, I would suggest that on a comparative basis Guelph water isn't any worse than Region of Waterloo water and in fact might be a little better. As with most other systems I have studied there are issues with bacteria in the raw water which requires too much chlorine and accompanying by-products of disinfection. There are also issues with low level solvents and just like the Region of Waterloo, there is virtually no mention of asbestos piping in the Guelph water system. That error of omission concerns me in that I wonder what other contaminants are in our drinking water that are either unintentionally or intentionally being ignored.

No comments:

Post a Comment