“Nearshore Water Quality- A Preliminary Report on Historic Nearshore Water Quality Information for Southeastern Lake Huron”

In 2003, a review of historic information (data, reports, interviews) on water quality in the nearshore area of Southeastern Lake Huron was commissioned from the Lake Huron Centre for Coastal Conservation by Environment Canada. The focus of the report was on bacteria used to indicate health risk (such as E. coli), nutrients (nitrogen and phosphorous), the potential sources of these two kinds of contaminants, and the impact they may be having on water quality and beaches.

The review considered information that related to the shoreline area from Sauble Beach to Sarnia, the shallower waters adjacent to it, and the streams and rivers that drain to it. Published and unpublished information from as far back as 1984 to as recent as 2003 was compiled.

Results of The Review

This review helps to set the stage for present and future work in the Southeast shore area by examining what is currently known about

i) how the land and the lake may influence water quality,

ii) how human activities may influence water quality,

iii) the most likely sources of pollution, and iv) the extent of the issue.

A summary of the results of the review is as follows:

The land plays a role in nearshore water quality.
 Some areas are more likely than others to transport pollutants to the shoreline because of soils and geology. Some areas of sandy soils may allow pollutants to flow through the soil to groundwater, and some areas of heavy clay soils are too dense to filter and hold surface runoff.

The lake plays a role in nearshore water quality.
Some beach areas are more sensitive than others because their physical features create better conditions for survival of bacteria. A large portion of the shallow lake bottom adjacent to the shoreline provides suitable conditions for the growth of attached algae. Currents, wind direction, and river flows are all important factors in the movement of bacteria and nutrients from streams and rivers to beaches and along the shoreline.

Land-use plays a role in nearshore water quality.
There have been significant losses of forest cover in the watersheds draining to the lake and this reduces the ability of the land to absorb and filter pollutants in surface runoff. In addition to forests, much of the natural filtering capacity of other natural features such as wetlands has been lost. Much of the strip of land adjacent to the lakeshore has been developed for seasonal cottaging, and there is an increasing trend towards permanent residency in these areas. Urban development is generally increasing in shoreline areas. The intensification of agriculture and the resulting manure production in main watersheds of the area has increased over the past two decades. These watersheds have been ranked high in provincial and nationalscale studies for their level of risk for water pollution (manure spills, cattle access concerns, nitrate, etc.).

It is a multiple-source problem.
Reviewed information pointed to three primary sources of nutrient and bacterial pollution to the shoreline from human activites; private septic systems, municipal wastewater and agriculture. A fourth source is wildlife, particularly gulls and geese living and feeding in the vicinity of beaches.

Beach postings and bacterial pollution are more frequent in some areas than others.
While most areas saw occasional postings on beaches warning swimmers of bacterial pollution between 1984 and 2003, the majority of cases occurred at public beaches in the area between Kincardine and Bayfield. There was no apparent trend in the frequency of postings over time.

There have been occasional and localized episodes of algae fouling the shoreline.
Public complaints and municipal records for the area show episodes of decaying algae at public beaches and along the shoreline. These appear to have been focused mostly in the Goderich and Point Clark areas, occurring on record as early as 1979, and as recently as 2002.

Many groups and agencies have been collecting, and are continuing to collect information.
Water quality and related information collected in this review came from the Ontario Ministry of the Environment, First Nations communities, Health Units, Conservation Authorities, the Township of Huron-Kinloss and other municipalities, and cottage associations. Many of their water quality monitoring programs are ongoing.

A copy of the complete report is available for downloading in adobe acrobat format by Clicking Here.