Water Three

Water Testing 103 – E-coli & Total Coliform This is the third and final article about water testing on Loon Lake. Volunteer members of the Loon Lake Property Owner's Association “Water Committee” have been involved in this water testing process for decades. Originally, one individual would gather random water samples and have the water tested. To-day, a coordinated group of volunteers works together to gather samples at fixed and predetermined locations on the lake before they are submitted to a laboratory for testing . Decades ago, the results of the tests were saved by the individuals who did the sampling. To-day, the sample results are kept in centralized known locations, readily accessible to anyone. The results are now published in newsletters and on the Internet so all property owners have access to the information. The results, which also indicate Provincial Water Quality Limits, can now be compared and analyzed to detect trends or any significant changes. Additional testing can be done if required. And health authorities can be contacted if needed. This water testing involves sampling for E-coli and total coliform bacteria. E-coli bacteria are commonly found in animal and human feces. Total coliform bacteria are commonly found in the environment. The presence of E-coli is a good indicator that sewage contamination has occurred. Like many other bacteria, they are transferred via the fecaloral route and may cause illness in humans – which is why we test for them. And their presence may indicate that other pathogens are also present in the water. For additional information on E. Coli and total coliform bacteria, contact your local health unit or healthcare provider. Information is also available on the Internet. The process involves sample collection and laboratory work. The actual collection of water samples is quite straightforward. There are predetermined locations on Loon Lake where water samples are taken at a depth of about 25 cm. Each location, while known to volunteers, also has it's own GPS coordinates. This is done to maintain consistency over time. The days on which sampling occurs are carefully chosen so as not to coincide with recent rainfalls, which may affect surface water conditions. The sealed and sterilized plastic sampling bottles are received from the testing laboratory prior to the sampling date. And while taking the water samples, utmost care is taken not to contaminate the sample bottles. The volunteers hands are carefully cleansed beforehand and care is taken in the handling of the bottles and the placement of the caps while sampling. As each bottle is resealed, the sampling location is marked on the bottle. The bottles must be kept refrigerated and delivered to the laboratory within a specified time frame by a volunteer. While the actual lake sample collection is quite straightforward, what follows next is not! For decades I have wondered what happens to the water samples after they are delivered to the laboratory. We use SGS Environmental Services, located in Lakefield Ontario, for our water sample testing.

A recent tour, in October 2009, of the SGS facility , explained what happens to those samples. It also more than answered my questions and left me with a respect of the capabilities and the professionalism of SGS Environmental Services. And the belief that our water is in the best of hands! Their quality control; the cleanliness of the facility; their monitoring of the chain of custody, and the extensive use of the latest technologies at SGS are very impressive. But to get back to the samples... Once each sample enters the laboratory, and after the initial documentation is done, the sample is then vacuum filtered. The residue is then placed onto a culture in a petri dish. The petri dish is then placed into a controlled temperature cabinet where any bacteria grow within 24 hours to form colonies .[The growth, I am told, is extremely fast and of an exponential nature]. In order to get that high rate of growth, SGS uses a special culture that they manufacture on their premises that provides not only superior nourishment to the bacteria but guarantees consistent quality control. Their process also eliminates the masking [or hiding] of any E-coli bacteria. After 24 hours, the petri dishes are removed from the controlled temperature cabinet. Any colonies that have grown are carefully examined under a microscope for identification. To confirm identification, a duplicate examination is done by another laboratory specialist. On the day of the tour of the SGS facility, tests were being performed for total coliform and E-coli bacteria – the same tests that are done for Loon Lake ! The picture below shows colonies that have grown on the culture. In the following picture, the BLUE dots are E-coli colonies and the RED dots indicate the total coliform colonies. And each dot represents a colony forming unit, hence the use of the term “CFU” that is used in the reports that we receive. An aside - at our tour, we had very uneasy feelings as we stood only a few inches from a potentially deadly bacteria.

[Courtesy SGS Environmental Services] When you consider the two phases of E-coli and total coliform testing – the sample collection and the testing , it appears that the entire process is not quite as simple or as straightforward as one may think. And that is indeed true! The sample collection requires careful handling as well as coordination of volunteers, timing, and travel within certain time constraints. The testing process produces results. And before fully understanding those results you must appreciate that Loon Lake is not static and that changes in test results do happen. A high CFU reading may be very transient and can even disappear ! And a continually high CFU reading can be an indication of a problem. You must question anomalies or variances and know to retest if required. And it's important to ask those who have historically been involved as well as contact a professional when needed. I've written about the overall testing for the presence of E-coli and total coliform in Loon Lake and explained it's importance. It's one of several tests that are done on the lake to ensure that the lake water quality remains high and that the pristine waters of our lake will be here for future generations.

Mike Grinnell (with assistance from SGS Environmental Services and input from the Chair – LLPOA Water Committee)