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Glossary of terms
Many sources contribute to microbiological contamination, including combined or sanitary sewer overflows (CSOs and SSOs), unsewered residential and commercial areas, and failing private, household and commercial septic systems. However, it is important to note that simply because bacterial levels are present, it does not necessarily mean that sewage overflow is a problem. Other sources may be agricultural runoff (such as manure); fecal coliforms from animal/pet fecal waste washed from soil by heavy rains, either from the beach or washed into residential storm sewers; wildlife waste, as from large populations of gulls or geese fouling the beach; direct human contact, such as swimmers with illnesses, cuts or sores; or high numbers of swimmers/bathers in the water, which are related to increased bacterial levels; and direct discharges, for example from holding tanks of recreational vessels.
Other factors affecting contamination levels are low (shallow) water levels; hot weather and higher temperatures; high winds that can cause increased wave action that can transport bacteria from contaminated, non-recreational areas to recreational-use areas; high winds that can stir up bacteria that are in the sediments; and calmer waters that can slow dispersal and create excess concentrations of bacteria.
The shoreline of Lake Huron is the longest of the Great Lakes, its length extended by the shores of its numerous islands and bays. Rocky shores associated with the Precambrian shield cover the northern and eastern shores, limestone dominates the shores of Manitoulin Island and the northern shore of the Bruce Peninsula, and glacial deposits of sand, gravel, and till predominate in the western, southern, and south-eastern portions of the shore. Shoreline and inshore habitats are correspondingly diverse.
Many nearshore areas of Lake Huron have been altered due to human influences. The once natural shorelines offered fishand wildlife significant habitat for all of their life stages. Due to development in coastal areas, many areas now have shoreline protection structures. In many cases, the narrow band of transitional vegetation is now gone. The cumulative impact of these structures throughout the basin is significant and increasing.
In general terms, the state of health for specific nearshore terrestrial habitats in the Lake Huron ecoregions ranges from stable (northern portions of the basin), to moderately degrading (central portions of the basin) to severely degrading (southern portions of the basin). General threats to the nearshore areas include agriculture, shoreline development, and sedimentation.
It is important to note that most shoreline areas along Lake Michigan fully support all forms of water-based recreation, including swimming, boating, and wading. However, some areas do experience closures due to contamination. Beach closings resulting from high pathogen loads have a tremendous negative effect on the tourist industry. In 1996, for example, visitors to the Indiana counties bordering Lake Michigan spent over $523 million and beach closings can cost an area up to $5 million per day in lost revenue.
Federal and State recreational water quality guidelines recommend bacterial levels below which the risk of human illness is considered to be minimal. For public beaches along Lake Michigan, the regional Health Departments generally monitor beach water quality. In Chicago, for example, the Chicago Park District conducts beach water quality monitoring. When contaminant indicator levels in the bathing beach water reach levels that are considered to pose a risk to health, public beaches may be posted with a sign warning bathers of these potential health risks.
A number of initiatives have recently been developed to specifically address recreational water quality. The U.S. EPA established the Beaches, Environmental Assessment, Closure, and Health Program (BEACH) in 1997 to "significantly reduce the risk of waterborne illness at the nation's beaches and recreational waters through improvements in recreational water protection programs, risk communication, and scientific advances."
Under the BEACH Program, the first National Health Protection Survey of Beaches, conducted in 1997, focused on the collection of beach-specific information from coastal and Great Lakes states. Data from the other annual surveys, conducted in 1999 and 2000, are now accessible. EPA will also develop a national inventory of digitized beach maps which will be linked with locations of pollution sources through a Geographic Information System (GIS).
In Lake Ontario, a number of local beach closings occur due to microbial contaminants, primarily along the more populated shorelines. Exceedence of microbial standards and criteria typically occurs following a storm event when the treatment capacity of some sewage treatment plants can be exceeded. Given the localized nature of beach closings and their absence along much of the Lake Ontario shoreline, they are not considered a lakewide problem. The frequency of beach closings is expected to decrease as sewage treatment plants continue to improve and upgrade their systems. It should be noted that beaches may also be closed due to other factors such as storm events, excessive turbidity, or lack of funding.
Beach closings are restricted largely to shorelines near major metropolitan centers or the mouths of streams and rivers. These closings follow storm events when bacteria-rich surface water runoff is flushed into nearshore areas via streams, rivers, and combined sewer overflows (CSOs). In some instances beaches may be closed based on the potential for high bacteria levels to develop following storm and rain events. Beaches are also closed for aesthetic reasons, such as the presence of algal blooms, dead fish, or garbage. Given the localized nature of beach closings and their absence along much of the Lake Ontario shoreline, they are not a considered lakewide problem.
In Ontario, beaches are closed when bacterial (E. coli) levels exceed 100 organisms/100mL. During recent years (1995 to 1997), beach closings have continued in heavily urbanized areas in the western part of the basin due to storm events, but are less frequent in the central and eastern regions. Examples of areas with ongoing problems include the beaches of the Bay of Quinte, Toronto, Burlington, Hamilton, Niagara, Pt. Dalhouse, and St. Catherines. Upgrading stormwater controls through the installation of collection tanks so stormwater from CSOs can be treated in Toronto and Hamilton should reduce beach closings in these areas.
The only U.S. beach on Lake Ontario with recent closings is Ontario Beach within the Rochester Embayment Area of Concern (AOC). These closings have been posted due to rain events, storm runoff, excessive algae, waves greater than four feet, or visibility less than one-half meter. Ontario Beach is routinely closed as a precaution during storm and rain events because these conditions have the potential to cause high bacteria levels along the beach shore. Ontario Beach summer fecal coliform levels have been well below the state’s action level of 200 fecal coliforms/100mL. The implementation of a combined sewer overflow abatement program resulted in significant decreases in fecal coliform levels in the Genesee River and adjacent shoreline areas. Actions are also underway to address stormwater problems that impact other areas of the Rochester Embayment.
Ontario Public Health Units, who are responsible for the monitoring of Ontario public beaches, collect, document and house detailed data on the beaches they monitor, including: a beach pollution survey or similar report, either historical, or done at the beginning of the bathing season, to include information on potential sources of contamination impacting on the bathing beach area; E. coli data; beach postings data; and additional information on beach conditions on the day of monitoring (rain, winds, temperature, visibility, etc.). The Ontario Ministry of Environment has a historic database that identifies total annual beach postings for public beaches in Ontario from 1988 onward.
Last modified: May 20, 2005