Tiny's Toxic Plume - What is it and Where is it?
By Jack Ellis

Some people in Tiny are well aware that there is a ‘toxic plume’ oozing its way underground from a former landfill site on the 9th Concession towards the waters of Georgian Bay. Others may never have heard of such a thing.

Since this issue of the Tiny Cottager contains lots of information about water in the Bay, it may be well to bring everyone up to date on what this underground water plume is and what it is doing.

Up to the late 1970s, a landfill intended for municipal waste was operated on the 9th Concession about 1 km east of County Road 6 on lands owned by Eric Pauze. Unfortunately, the site became the target for illegal dumping of industrial wastes, some of which were toxic and cancer causing in nature, and which leached all too readily into the light sandy soil.

Some wells in Perkinsfield became contaminated with toxic and carcinogenic substances, and a major environmental investigation in 1981 showed that these came from the Pauze site. A special mediation process to compensate those affected was implemented, and the Perkinsfield piped water system was upgraded and extended as a result.

The initial studies showed that toxic leakage from the dump had indeed entered the groundwater aquifer that heads west and south from the dumpsite. This aquifer is a sandy layer of soil, between 10 to 20 metres thick, about 8-10 metres below the surface, and is contained between layers of heavier clay till soil above and below. Various projections were made as to how fast it would travel and where it might go. The worst case assumptions were that it could head for the waters of the Bay, and some were even fearful that our beautiful beaches could become toxic playgrounds.

Fortunately, time has shown that these scary assumptions were wrong, and that, while there is no room for complacency, there is also no need to fear the worst.

The Ministry of the Environment has monitored the situation regularly for almost 20 years now. They have installed test wells in the path of the plume, and also monitor selected private wells, mainly along Concession Roads 8 and 9.

The last full cycle of tests was done by consultants in 1998. Tests originally planned for 2000 were postponed to 2001 because of the Walkerton situation.
The 1998 tests confirmed that there are several plumes, not just one:
• A chloride plume from municipal waste, which is unpleasant stuff at best
• A tricloroethene (TCE) plume, a cancer causing substance, which is gradually decomposing chemically
• Three plumes of tricloroehene decomposition products, each of which is still a hazard, even if less so than the original TCE

The TCE and other plumes are migrating southwest at the rate of 80-100 metres per year. The map below shows the approximate location of the plume in early 1998. It is now advancing along a somewhat more southerly heading, and is expected to affect wells on the 8th Concession in the near future. The Ministry of the Environment plans to send staff out to sample the test wells later this autumn, and the test results will subsequently be made public. One other potential problem is that the plume may eventually ooze out in springs that flow from the face of the Nipissing Bluff, likely to occur south of Concession Road 8. This year's tests may indicate when, or if, this may occur.

The Figure above shows the location of the TCE plume in 1998. Since then it has likely migrated about 240-300 m to the south and west.

It is the leading edge of the plume that contains the highest concentration of pollutants, and after it passes, well water has been seen to return to the drinkable range. Fortunately, the peak concentration of the toxic substances also seems to have decreased over the years, and at some point, the quality of all the aquifer water may meet drinking water guidelines. It would appear that Mother Nature may be saving us from a really terrible situation, caused by man’s past stupidity!