SALT & FERTILIZERS STILL THE MOST COMMON CONTAMINANTS

An interesting article was on the front page of yesterday's Waterloo Region Record titled "Road salt, fertilizers contaminate local streams. Overall I would agree with the concerns expressed that chlorides and phosphorous are much too high in our local waterways. As salt consists of sodium chloride (NACl) it's pretty clear where a lot of the chloride, albeit not all, is coming from. Also of interest is the fact that actually the sodium (Na) appears to be more of a concern when one looks at either the Ontario Drinking Water Standards or the Region of Waterloo Annual (Drinking Water) Reports.

Sodium is often above the guideline of 20 mg/l (parts per million) however that guideline is merely the point where the local Public Health Dep't and M.O.E. are advised. Chlorides seem to have a Canadian aesthetic guideline as high as 250 mg/l. That said perhaps the 120 mg/l quoted in the newspaper article is in regards to aquatic life.

Chlorides I believe are considered inorganic parameters. They are actually often used as an indicater compound when tracking organic contaminants leaching from landfills. This would include hydrocarbons, hence organic (ie.carbon based) compounds such as solvents, gasolines, oils etc..

Whether the chlorides are primarily due to road salt nevertheless they are a bad sign in our waterways. Similarily phosphorous is a huge problem both in smaller waterbodies as well as in parts of the Great lakes. Lake Erie is probably the best well known with large areas of toxic algae rendering the water inhospitable to natural life. More locally we have had postings right here at the Woolwich Dam due to blue-green algae which can be toxic to pets and wildlife as well as humans. Discharging septic tank systems as well as agricultural practices allowing excessive runoff of manures and fertilizers also add to the phosphorous and eventual algae load.

Thank you K-W Record for the prominence of this article and the public service you have done. There is no free lunch. Whether road safety, pedestrian safety (sidewalks) or increased farm productivity (fertilizers) there is a price which can however be mitigated with greater care.