Environmental Science & Engineering Magazine (ESEMAG) March 1993

Page 73

By J.N. Bishop^ report states:"This result was thought to be anomalous by the laboratory analyti

duct off the shelves. Some of them were

cal staff. If it was an anomaly, why was

into local sewers, and yet the levels they

the test not repeated? Why wasn't this result verified? If it is an anomaly, why was it reported? I don't know the an swers to these questions, but I do know that in the private laboratory sector, this would not be an acceptable comment on such a serious analytical outcome. And it should not be acceptable to the people in Kingston, who drink this water. Lindsay's treated water had benzene levels of 1.2 ppb,toluene at 2.4 ppb. and o-xylene at 1.3 ppb.The fact that each of these chemicals are found at the same

time of year consistently in treated and distributed water, but not in raw water, would indicate that the source of con tamination lies within the treatment

plant itself. Municipal staff are "still in vestigating". but the public has no way of knowing whether these chemicals will show up in their water again, or the level they might have to consume, or from what source. Also, since the pro blem results showed up in mid-1990.the

public has every right to know what the investigation showed, and whether they have been consuming benzene and other hazardous chemicals since 1990.

I would also point out that the level of benzene reported for some municipali ties. like the level of toluene, is in the same order that has caused bottled

water manufacturers to pull their pro-

prevented from putting their product were dumping were often lower than the level of benzene or toluene currently

being found in the tap water of cities like Lindsay.

Lindsay also had hexachlorocyclopentadiene reported in treated water and in its distribution system at levels

up to 170 ng/L. While this number is well below the U.S. EPA guideline, it is not much below the New York State

guideline. This underlines one of the basic problems with the DWSP pro gram. namely — these data should form the basis for instant response from both MOE and the municipalities when such chemicals are reported in the drinking water. These are not small blips mar ginally above a detection limit — these are major peaks indicating serious con tamination and warranting serious ac tion. They deserve more than just a comparison to the highest available guideline or a scientific shrug of the shoulders, accompanied by the refrain that the result was probably just bad MOE lab data.

Other DWSP problems

The DWSP program consistently re ports significant levels of trihalomethanes (THMs) in treated water in all municipal water supplies. Levels vary, but they are always present and are

sometimes close to 350 ppb in some wa ter supplies. Of course, the Ontario Drinking Water Objective is currently 350 ppb. leaving Ontario and the rest of Canada as the only jurisdictions in the world with guidelines this high for this chemical. Recently, the Ministry of the Environment and Health and Welfare

Canada are said to be moving toward a lower guideline of 50 ppb for THMs. However, it is worth noting that there are many, many drinking water plants in Ontario that do not currently meet this guideline and the question must be asked: is the guideline going to be changed,and if so. will there be changes in the water treatment plants to help these municipalities meet the guide lines? Or will Canada and Ontario's

THM guidelines remain artificially high in order to avoid such expen ditures?

In closing. I believe that DWSP is a very worthwhile, environmentally use ful program. However, the data report

ing needs re-examination.The MOE lab needs to find a more consistent way to

report trace levels, and the Ministry needs to use the data it generates to act upon potential drinking water pro blems. instead of reporting problem data and then questioning the validity of their own data. ES&E

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