Private wells tested for TCE, PCBs by town

By Douglas Glynn Midland Free Press May 13 2010
The town has collected water samples from private wells within an 800 meter radius of the Sundowner well to test for Trichloroethylene (TCE) and Polychlorinated Biphenyls (PCBs).
The tests were ordered after TCE was discovered following a second test of water at the Sundowner well, where both chemicals had been found in water samples taken days earlier. No PCBs were found in the second tests.
Test results from the private wells are expected to be known by May 19.
Meantime, the medical officer of health has advised residents in the sampling area there is no need to “discontinue using their water at this time.”
And town officials have emphasized that since the Sundowner well is not connected to the town’s water supply “there is no impact on the quality of the town’s drinking water.”
Letters -hand-delivered to residents of the sampling area -explained the town is in the process of developing a new groundwater supply well (‘Sundowner Well’) at the north-west intersection of Sundowner Road and County Road 25 (Balm Beach Road). The new well is part of the Mountainview Water Tank and Sundowner Pumphouse project.
The letter said, in part, that “as part of standard procedure for the development of new municipal well for the Town of Midland’s water supply system, a 72-hour constant rate pumping test was conducted.
“The analysis of a water sample collected at the end of the pumping test indicated the presence of TCE at a concentration of 8.7 micrograms per litre, which slightly exceeded Ministry of the Environment Ontario Drinking Water Standard (ODWS) for TCE of 5.
“In addition, a low concentration (2.4 micrograms per litre) of Polychlorinated Biphenyls (PCB’s) was also detected, which is below the ODWS for PCB’s of 3.”
The letter emphasized that “the provincial ODWS limits have a substantial safety factor built in. The Health Unit has indicated that the health risk at the levels detected would not be expected to be significant.”
Town officials say a second round of water tests carried out at Sundowner on April 30, 2010 confirmed the presence of TCE, but at lower concentrations – ranging from 3.1 to 3.9. No PCB concentrations were detected during the re-sampling.
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“Although there is no indication that TCE or PCBs are present in other water sources outside of the affected well,” says the letter, “the town, in consultation with the Ministry of the Environment and with the Medical Officer of Health for the Simcoe Muskoka District Health Unit, decided to sample the private wells.
The town says it will advise well owners of the analysis results once they are received from the Town’s laboratory (Caduceon Laboratories).
If there are any levels over the ODWS, Caduceon Laboratories is required to notify the property owner directly. Otherwise, the test results will be mailed to the property owner or arrangements can be made to pick them up from the Town of Midland Municipal Office by calling the Engineering Department at 526- 4275.
For information about the health effects of TCE and PCBs, contact the health unit at 721- 7520 (1-877-721-7520) or check its website at www.simcoemuskokahealth.org.
The Ministry of the Environment regulates the operation of public water supplies and its Barrie office can be reached at 705-739-6441.