Good News from the 2006 Full Shore Water Sampling Program!
The analysis results for the 1,492 samples taken during the nine weeks of the summer of 2006 along the entire shore of Tiny Township and Farlain Lake suggest that water quality is better than it was in 2001, the year of our first full shore sampling program. But it’s still far from perfect.
SWIMMING WATER: The number of E. coli present in swimming water is still viewed as the best measure of its quality. A rough rule of thumb is that a sample of 100 ml of recreational water should contain less than 100 E. coli. (Drinking water, of course, should have a count of zero.) You can find the results for both years on www.tinycottager.org — under Water Report.
One way to see whether Tiny’s swimming water quality was better or worse in 2006 than in 2001 is to compare the average number of E. coli for each sampling location in each of those years. It turns out that 59% of them improved, 11% stayed the same, and 30% got worse.
A more revealing comparison concerns the distribution of E. coli numbers. In 2001, 67% of the samples were “excellent” (10-30 E. coli), 12% had readings of 40-60, 6% were in the 70-90 range, and 15% were unacceptable (containing 100 or more). In other words, in the first year of our water-testing program, the Township’s recreational swimming water quality was generally good. Fortunately, the numbers for 2006 are even better, with 84% of samples falling into the 10-30 range and only 13.5% into the 100+ category.
However, the geographical distribution of low and high E. coli levels is quite different in different parts of the shoreline.
North end (from Concession Road 17 W north to Cedar Point, the north shore, the eastern shore, and Farlain Lake): In 2001 83% of the samples were in the excellent 10-30 range, and only 6% were over 100.
In 2006, the north-end pattern was similar but slightly better, with 84% in the excellent range and 7.5% in the 100+ category.
Middle section (from Concession Road 6 W to Concession Road 17 W): The percentage of 2001 samples in the best range was 61.5%, with 18% in the 100+ category.
Here too the numbers improved moderately in 2006. The percentage of samples in the best range rose to 66% and the number of samples in the 100+ category fell a little to 16.5%.
South end (from the town line to Concession Road 6 W): In 2001, results here were not as good as those farther north. Only 35% of samples were in the 10-30 range, while 32% had readings of 100 or more, and many of these samples were substantially over 100. (Of the 57 samples in the 100+ range, 24 were higher than 300, and 10 were listed as above 600 E. coli per 100 ml.
Along this part of the shore there was real improvement in 2006. The percentage of samples in the best range rose from 35 to 56.5% and the number with readings of 100 or more fell from 32 to 24%. Not only that, but the highs were not as high. Of the 56 samples with counts above 100, 17 were above 300 and of those only six were above 600.
In spite of this general pattern of improvement, there are a few areas where water quality worsened in 2006 – notably the stretch of Woodland Beach from the town line to the north end of the Woodland Beach Park, and the 12th and the 13th Concession-ends. The sampling done at a beach north of the 16th Concession Road and at Sandy Bay in 2006, suggests that those areas need investigation too.
STREAMS: The E. coli loading of streams is a factor in swimming water quality, particularly after a heavy rainfall. In 2001, volunteers sampled 21 streams that flow into Georgian Bay, and discovered that, on either six or seven of the nine sampling days, the E. coli counts soared well beyond the usual limits of the test in seven streams. Unfortunately, the streams information for 2006 is not yet complete. The Severn Sound Environmental Association, which has taken over some stream sampling, has not yet presented its 2006 data to the Township. What we can say at this point is that streams sampled by our volunteers had lower E. coli numbers than in 2001.
WHAT HAS CHANGED? The septic re-inspection program undertaken by C.C. Tatham and Associates for the Township may well be a factor in the general improvement, especially if it caused repairs to failed or compromised septic systems located near a stream. (By the end of last summer, inspections had been done as far north as Concession Road 16.) Another factor may be the stream investigation undertaken for the Township each year since 2003 by the Severn Sound Environmental Association (SSEA). In one of his reports, Keith Sherman mentioned that he drew the attention of C.C. Tatham and Associates to the need for septic inspection follow up where spikes in E. coli numbers at a particular point along a stream were found. The SSEA’s counseling of farmers to fence cattle back from streams may also have had some impact. But so far the stream investigation itself appears to have produced no remedial actions.
It is also possible that the difference in E. coli numbers in the two years is weather-related – fewer rainy or windy sampling days, for example. The Health Unit has done some analysis of such factors in relation to E. coli levels, but has not, so far, presented its findings for 2006.
In sum, the figures show encouraging improvement relative to the situation in 2001, but more analysis is required if the results are to be interpreted properly. It’s certainly not appropriate to become complacent about water quality!
