Posted by Andrew Morrow on March 24, 2015, 10:44 am, in reply to "Safer beaches to swim nearby?"
189.164.201.10
Since the discussion of issues wanders from thread to thread I am reposting some of the information posted elsewhere and adding some new information.
The device used in water testing is a product of Bluewater Biosciences. From their web site this is how they deccribe the product: "The Coliplate™ kit is a convenient test for quantitative measure of total coliforms and E. Coli bacteria. The test is designed to meet regulatory guidelines for surface water, recreational water, processing water and wastewater. The Coliplate™ test quantifies density of target bacteria, coliforms and E. Coli, ranging from 5 to 5,000 colony forming-units (cfu) per 100 mL sample, without dilutions. Coliform positive test results in a distinctive blue colour, which enables analysis of brownish, turbid or rust-filled water.". Like other water tests the unit is then allowed to sit for 24 to 30 hours in an incubator which allows the coliform and e-coli in the cells to grow. Blue colour in a cell indicates coliform.The number of wells that turned blue and were fluorescent under the UV light is the positive reaction for E. Coli.
We are looking to also acquire a test from IIDEX who provide testing material for salt water enterococci (evidently there are 3 strains we need to be concerned with).
You will note that the bubbling water on either end the street had the highest readings in our tests posted elsewhere. The crocodile lagoon only a few feet away had lower readings for e-coli than the water coming from the manhole cover adjacent to the crocodillo viewing statation.
I saw the great flood of water headed to the area that we did those two tests by the crocodile viewing point on the day after the rain stopped. It would not be hard to speculate that all the contaminants in that water eventually ended in the crocodile lagoon or the ocean. Now that we have the test equipment in the community it will no longer be necessary to speculate on the origins of these two bacterial contaminants.
I read the material on the EPA site and see that the agency considers enterococci a better single screening indicator for health issues in water, particularly salt water. That said the basic issue is still how long after a release of any of the three bacteria would the test be a reliable predictor of a problem? The enterococci is favoured because of its ability to survive longer in salt water. This is why we are interested in acquiring an appropriate test for enterococci.
Regarding the local sources of contamination, it is clear that there are engineering problems with the sewer pipes as they run through town. Since the bubbling occurs only after heavy rain one could speculate that groundwater might be entering the system at a higher point, or perhaps the rudimentary sealing of the covers allows large input of surface water in these rains. Maybe it is a combination of both.To get a better handle on this problem a local committee of the Terrealegre Group is having engineers look at the system this summer.
The health of the crocodile laguna is also a concern of this group and the local residents. Some people speculate that the breach of the road barrier in rainy season is problematic for salt water recreational use. Already we have started to collect sample readings to determine the health of the laguna and what would be released when the barrier is breached.
I hope this summary will help you understand what we are trying to accomplish with testing and what we have learned so far.
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