Rise and Fall of Pollution in our Lakes

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Rise and Fall of Pollution in our Lakes

Post by admin » Tue Oct 06, 2015 8:14 am

Originally posted by Kevin Browne - 07/05/2014

Adapted by Rem Westland* and Ralph Pentland** from an article written by Dr. Jim Bruce***

With the permission of Dr. James Bruce the following article is an adaptation of what Dr. Bruce presented to the House of Commons committee on March 27, 2014.¹ His presentation was focused upon the situation of Lake Erie in the context of broader Great Lakes issues. Upon our reading of his presentation, however, it struck us that the broad lines of concern he shared with members of the House of Commons should begin to worry us in the Frontenacs as well.

Property Owners’ Associations like ours typically get active about pollution when the need for a major clean-up is obvious. We then adopt pollution control programs of our own (lakefront rehabilitation) or press for the municipality to do its duty (septic system re-inspection).
Two main concerns were addressed to the Parliamentary Committee. The first is over-enrichment by the nutrient phosphorus, causing major algal blooms which subsequently result in dead areas at the bottom of our lakes, and near-shore problems visible from the surface. The second is the pervasive plague of toxic chemicals contaminating fish, water and sediments that is already seen in some of the Great Lakes and along the St. Laurence River.

Around larger lakes, like the Great Lakes, these problems can be tackled vigorously by building sewage treatment plants for all municipalities and industry along the shores. The federal government in the 1970s regulated phosphorus in detergents and some toxics such as PCBs and the pesticide DDT. Efforts like these have had wonderful effects. By the late 1980s the main body of many lakes – even the smaller ones like ours – were pronounced healthy again. When the MVCA issued a very positive report on our lake some five years ago we considered that the job was completed and well done. Some of you will recall that in the late 1970s our public beach had to be closed on account of E coli; and, as indicated in our association’s minutes of executive meetings in the early 1980s, we worried a great deal about algae growth.

WHY DOES THIS OCCUR? Inattention, such as a more lax attitude towards shoreline development and the use of cleaning fluids in our homes, is added to with more diffuse sources of pollution. There are large quantities of phosphorus in runoff from our villages and from farmland. Some of this increase is due to changes on the ground. This includes more construction – such as the new school – and more intensive agriculture using bio-available fertilizers. Such changes leave more phosphorus on the ground to be dissolved in the runoff (surface and sub-surface). Loss of wetlands, as evidenced by new construction along Highway 38, allows more rapid discharge to the lake as well.

But the contribution of the changing climate has also been critical. Studies of the Great Lakes watershed area have shown that the annual number of surface runoff events has increased 18% from the 1970s due to more frequent heavy rains and winter snowmelt periods. Intense precipitation events increase in a warming climate, in theory by 7% per degree C temperature increase. One of the consequences of this combination of changing land use and changing climate is that larger quantities of the nutrient phosphorus are carried in the runoff. This is a double whammy: increased large flow events on the one hand, and higher concentrations of dissolved reactive phosphorus in those flows on the other. When these polluted flows reach the warming waters of our lakes, larger algal blooms are produced. In the most recent report on our lake by the MVCA we learned that re-eutrophication is beginning to be observed in Sharbot Lake.

We must therefore renew our commitment to preventive actions. Steps must be taken to reduce phosphorus sources, on farmland and in village areas, from ending up in the lakes. Lakefront property owners are on the front line. They must become the champions of how to do things better.
In the Great Lakes, by the way, a new era of toxic chemical pollution has also been documented. For highly toxic mercury, after reductions from 1970 to 2005, scientists now see concentrations on the rise again in some fish and fish-eating birds such as loons, since 2005. Coal-fired electricity generation plants in USA continue to be a major airborne source of mercury to the Great Lakes, although Ontario has thankfully reduced its coal-burning power plants.

The good news is that serious health and ecosystem threats from DDT and from PCBs, have decreased, as a result of regulations, as shown by analysis of herring gull eggs at Burlington since 1972. Sharbot Lake and all lakes in southern and south eastern Ontario benefit from improvements such as these.

The new contaminants finding their way to the Great Lakes include drugs and pharmaceuticals dumped or excreted. For example there are small, but growing, concentrations of anti-inflammatory drugs in Lake Erie’s open water, far from shore. Anti-depressants are observed in Lake Ontario and antibiotics down the St. Lawrence River. Endocrine disrupting substances are found in Lake Huron. The gender composition of a community near Sarnia, Ontario is changing, with only half as many boys as girls being born. Toxic flame retardants are on the increase.

We would be naïve to think the same is not happening in our lake. Though it is surely happening on a smaller scale, the fact is that our septic systems have not been designed to deal with the new contaminants flowing into them. While our eye is now on phosphates and nitrates, and on Ecoli, we may soon have to turn our eye to those new contaminants as well. Ozone is known to deal with most of those new contaminants in large municipal systems. Perhaps we will be able to develop an effective treatment on the smaller scale of individual property owners.

Our generation, through individual property owners and throughout three levels of government, hold in trust our vital waters for all to use and for future generations. If we want our lakes to be healthy, fishable, drinkable and swimmable, we must renew our commitments. This means an increased commitment to monitoring and science, and a commitment to undertake control measures based on scientific findings. When the MVCA, health authorities, building authorities, and SLPOA representatives next knock on your doors to talk about preventative measures please welcome them in and be receptive to what they have to say. We will, in return, be open to your suggestions and advice.

We owe this to ourselves, to our grandchildren and to their children.

¹To see the article on which the above text is based go to the http://www.flowcanada.org/resource/375
* Environment Issues Coordinator, Sharbot Lake Property Owners Association
** Member at Large, Sharbot Lake Property Owners Association and Member, Forum for Leadership on Water
*** Member, Forum for Leadership on Water and former Assistant Deputy Minister, Environment Canada.

Sharbot Lake Property Owners' Association
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