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Jeff Green | Nov 22, 2007

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Sydenham Water: What to do We have to Show for it?byWilma Kenny

Very early in the process of planning the Sydenham water system, the residents expressed concern about the formation of trihalomethanes (THMs) which occurs when chlorine interacts with organic matter in water. They were assured that the lake water would be thoroughly filtered to remove organic matter, and there should be no problem. However, a small amount of research confirms that most surface-water systems do experience problems with THM levels, because these water sources are by definition high in organic matter. Although this would suggest that problems could have been predicted, the plant was none the less designed using one of the most commonly available filtration systems.

Because THM levels fluctuate, a reading is not considered definitive until a year has passed, and an average can be taken of 12 months. In spite of this, one cannot help wondering why, if the readings were consistently high from the onset, was there no attempt to improve the filtration until a month ago, almost a year and a half after the plant went into operation? And why was the plant not initially designed with a more effective filtration system?

Last week, residents of Sydenham received a letter and information sheet from Dr Ian Gemmill, Medical Officer of Health, in which he notes that in the summer of 2007, KFL&A Public Health was notified by the Sydenham water treatment plant operating authority that the annual average concentration of THMs in the village water exceeded the Ontario standards, which are .100mg/L. The letter goes on to say that "because the levels have not been significantly elevated over the standard, corrective action was needed as soon as feasible. Since no imminent health risk was posed by consuming water at this level over the short-term, extraordinary emergency measures were not necessary." Dr Gemmill says that Utilities Kingston water treatment specialists are currently working on various methods to decrease the levels of THMs, and he is "confident that the work will be completed very soon.".

Nowhere does Dr Gemmil mention BDCMs, one of the four chemical compounds that are included in THMs. However, an information sheet attached to his letter tells us that Health Canada’s guideline for this particular compound is much lower: .016 mg/L. In 1997, Dodds & King published a study of single births in Nova Scotia between 1988 & 1995 which measured exposure to BCDM through municipal water supplies. It states: "Exposure to BCDM at concentrations of .020mg/L or over was associated with an increased risk of neural tube defects." Neural tube defects occur in the first 3 or 4 weeks of pregnancy, and often lead to spinal bifida or stillbirth. This is certainly not a long-term effect. This may account for Health Canada’s much more stringent guideline in respect to this chemical.

Nowhere does Dr Gemmill suggest there are any short-term adverse effects of THM ingestion. Nor is there any mention of the BDCM level in Sydenham water. It may be adequately low, it could be too high. It just isn’t mentioned.

All three levels of government and the residents of Sydenham have paid millions of dollars for this water system. Are we getting good value for our money?