The Lake Huron Centre For Coastal Conservation
Advocating Wise Stewardship of Lake Huron's Coastal Ecosystems
Pathogens
Health Units
Ontario Ministry of Health switched bacterial indicators from Faecal Coliform to E. Coli effective April 1, 1993. Consequently, the Lambton County Health Unit’s testing indicator changed from measuring for Faecal Coliform (1984-92), to measuring E. coli from 1993 on. For Huron County, and for Bruce County, E. coli data was available from 1990 and 1994 to present respectively. Graphs in the Appendix show the frequency in percent that E. coli was found to be above the Provincial Water Quality Objectives (PWQO) of 100/100 mL at each sampling location in each year.
There are caveats to observe when trying to compare one county’s results with another. As discussed previously, there are differences in the frequency that some sites are monitored. The data shortfall in some sampling locations makes it difficult to make direct comparisons between health unit data and makes it more difficult to take a regional outlook to nearshore water quality.
The data show that all three counties have stations with frequent and consistent exceedences above the PWQO for E. coli. Huron County shows the greatest impairment, with Amberley Beach, Ashfield Twp. Park, Goderich beaches, Black’s Point and Port Albert having consistently poor readings. Huron County also had 32 postings in 2001 for a total of 354 beach-days posted with a “red” warning sign. That was up from 2000 with 6 postings and 260 beach-days with “red” warning signs. A red sign is posted if the geometric mean of two consecutive sets of sample readings exceed 100 E. coli per 100 mL of water.
Bonte-Gelok and Joy(1999), evaluated the Health Unit data for Huron County. The beach data were considered to be high in both reliability and quality. All of the beaches analyzed over the 1990 to 1997 period exceeded the PWQO for significant parts of the summer season. In Huron County, the three beaches with the highest average time exceeding the PWQO were: Amberley, Goderich Main beach and Port Albert (at the mouth of the Nine Mile River). All three had results that showed that the beaches exceed the PWQO over 40% of the time. While the highest Faecal Coliform concentrations occurred at the south end of the county, in the lakeshore gullies and Ausable River, Total Coliform loadings were highest in the Maitland and Bayfield Rivers.
Lambton County’s poorest historical beach water quality was at Centennial Park in Sarnia (43% exceedences between 1984 and 1994), and at Grand Bend (47 % exceedences between 1984 and 1994), although all beaches had some exceedences over the period of record. Lambton had 8 postings in both 2000 and 2001. It has had a total of 80 postings over the last 10 years. Data indicating how many days the beaches were posted in Lambton County are presented in Table 3.
Bruce County’s poorest water quality over the past nine years appeared to occur at Point Clark and Kincardine’s Station Beach with periodic exceedences at Sauble Beach. The only data for beach postings included an account of 13 days at Station Beach in Kincardine in 2002.
Rapid Detection Study
The Rapid Detection Study was a five year study undertaken in the late 1990s to test a faster method of determining E.coli at public bathing beaches. The study was undertaken between St. Joseph, north of Grand Bend, and Highland Glen. This was a local partnership initiative between, the Lambton County Health Unit, local municipalities, Ausable Bayfield CA, Pinery Provincial Park, Ministry of Environment and a water quality consultant. The motivation was a dissatisfaction by the local community with the conventional protocol of sampling that took too long (sometimes upwards of four days) to make a determination of whether or not to ‘close’ a beach. This was considered to be too much time from the initial sample period where conditions could be substantially improved at the time of posting or closing a beach.
Rapid detection would theoretically allow sampling results to be analyzed and a public health decision made within a 24 hour period. Comparing the rapid detection test with the conventional test, it was found that the rapid test had an 85% accuracy relative to the conventional testing. This was an acceptable outcome to the Ministry of Health as it met their targets, however, until the study was replicated in another part of the Province, it would not be permitted to become a standard form of testing (Prout, 2003).
CURB Program
From the late 1980’s to the mid-1990’s, the Ministry of the Environment administered the “Clean Up Rural Beaches” (CURB) Program. This program was implemented by many conservation authorities in Ontario. Along Lake Huron, all five conservation authorities were involved in the CURB Program. CURB essentially had two components: (1) identify the relative impact of pollution sources of rural beaches by undertaking a monitoring program of targeted watersheds, and (2) administering grants to rural landowners for septic system upgrades, milkhouse washwater control, manure storage and livestock barriers to watercourses.
Similar to the county Health Unit beach monitoring, CURB monitoring switched from analyzing faecal coliform to E. coli in 1993. The CURB program’s water monitoring included E. coli, Faecal streptococci and Pseudomonas aeruginosa. With this information, conservation authorities determined the potential pollution sources and estimated the relative contribution of each of these sources to the water quality problem at area beaches.
In its 1994-95 Annual Report, the Saugeen Valley C.A.’s CURB Program identified that at many of their Lake Huron shoreline sampling locations, PWQO’s were exceeded for E. coli, and concentrations were considered excessively high for Pseudomonas aeruginosa, Total Phosphorous and Nitrate. Similar results were obtained from the other conservation authorities. All identified faulty septic systems as a major source of bacterial pollution, although there is some controversy over whether the assumptions made had sufficient data to support this conclusion.
In its CURB report on the Penetangore watershed, the SVCA concluded that for the sources of faulty septic systems, livestock access, milkhouse washwater discharge and sewage treatment plant discharges, dry weather bacterial inputs were far greater than wet weather inputs. About 1.6% of the source contaminant bacteria was estimated to reach Lake Huron under high flow conditions. Three times as much, or 5.5% of the bacteria was estimated to be delivered to Lake Huron under low flow conditions (SVCA, 1992).
Huron-Kinloss Township
The Township of Huron-Kinloss has two surface water quality monitoring programs in place. The Pine River water quality monitoring program was initiated in June 2001 at twenty-six locations throughout the Pine River watershed. Six lake sites were included in this program. The second program, the Point Clark water quality monitoring program, was initiated in 1998. The purpose of this program was to build a database of information that could be used to detect long-term trends in water quality, in relation to development using septic systems in the Point Clark area.
E. coli data from the Township of Huron-Kinloss’ (see Figure 2) Pine River Water Quality Monitoring Program showed that the PWQO were exceeded 76% of the time in 2002. Results from the Township’s 2002 Point Clark Water Quality Monitoring Program showed a 30% exceedence over Provincial objectives. Four of the seven sample stations at Point Clark are beach locations. For the purpose of this study, only data from the four beach stations were used. Huron-Kinloss also monitored Pseudomonas aeruginosa in the Point Clark area in 1998 and 1999. Using <10 cfu/100mL as the acceptable limit of P. aeruginosa (B.M. Ross, 2000), 66% of samples in 1998 and 89% of samples in 1999, exceeded this limit. Due to questions concerning the sampling protocol, and the difficulty controlling the pathogen from multiplying between the time of sampling and laboratory analysis, this indicator was discontinued in 2000.
As was noted by the study, “Water sampling for PSA can be misleading, as the amount of bacteria evident at the source (e.g. human, animal waste) may be far less than is recorded by lab results. This could explain the elevated counts of PSA found in the past years of monitoring.”
Ashfield-Colborne Lakefront Association
Local groups, like the Ashfield-Colborne Lakefront Association, have been getting similar results for E. coli. At their 12 monitoring sites between Point Clark and Goderich, 80% of samples exceeded PWQOs in 2001. Results in 2002 dropped slightly to 75% of samples exceeding PWQOs. ACLA takes samples once every two weeks from each of their sampling locations, from mid-May to early September. In September 2003, ACLA attempted to identify the source of E. coli in the area by having samples analyzed for DNA fingerprinting. Initial testing suggests the probable source of E. coli could be animal. Further tests using this technology are planned, depending on funding, to further isolate the source.
St. Joseph’s Shores
At St. Joseph Shores Beach, north of Grand Bend, results over the past seven years of monitoring showing exceedences above PWQOs is presented in Table 1.
The St. Joseph Shores Association generally sample between mid-May and the end of August. In 2000, the Association sampled from late March to the end of October. The poorest water quality due to E. coli contamination was during the summer (see Appendix A).
Bonte-Gelok and Joy, (1999), concluded that based on the beach bacterial data analyzed for Huron County, there does not appear to be a clear trend as to whether or not water quality at beaches was getting better or worse over time for the duration over which data was available.
This conclusion appears to hold true for beaches in Bruce and Lambton Counties, as well.
MOE studies on Bacterial Pollution
Two studies were found where the Ministry of the Environment carried out monitoring and analysis of nearshore water quality along Lake Huron, as it related to bacterial pollution (see map 2). Both studies appeared to be in response to elevated bacterial concentrations and beach postings.
In 1984, an extensive monitoring program was undertaken at Grand Bend, Ipperwash Provincial Park and Goderich, with some supplemental work at Sauble Beach. A number of samples were taken at the mouths of gullies between Grand Bend and Goderich. Over 10,000 microbiological tests were carried out over a thirteen week study period, between June 13 and August 24. Samples were taken each day at specific time intervals (morning, afternoon and evening) over the course of the study period. The study found a high correlation between beach bacterial levels and lake roughness. On rough days when the beach waters were turbid, bacterial levels tended to be elevated. Under calm-water conditions, bacterial levels were normally low.
Besides water turbidity, runoff was another important factor in elevated bacterial levels as the bacterial load to Lake Huron increased significantly during major rainfall events (MOE, 1984). Other factors included: winds, which can result in the re-suspension of bacteria-rich bottom sediments; wind direction can direct contaminated river water onto beaches; sunny days can be significant as ultraviolet light can reduce bacterial levels — at times when bacterial levels were decreasing, daily hours of direct sunlight tended to be greater; and water temperature can affect the survival rates of various types of bacteria, as well as affect beach usage.
The conclusion that significant increases in the levels of pathogens in the water result from sediment re-suspension was linked to the slope geometry of the nearshore ramp. Ipperwash and Sauble Beach each have a very shallow nearshore slope (3%), while Grand Bend and Goderich had much steeper nearshore slopes (30% and 40% respectively). Gradual foreshore slopes at Ipperwash and Sauble Beach result in waves breaking further offshore, resulting in less re-suspension. However, the fine beach sands found at Ipperwash and Sauble Beach support higher concentrations of bacteria than the coarse sands found at Grand Bend and Goderich. This was suggested to be related to the difference in surface area available for adsorption by bacteria (MOE, 1984).
In 1990, the MOE conducted another nearshore water quality survey along Lake Huron between Canatara Beach (Sarnia) and Brights Grove. The study of this fourteen kilometre reach of shoreline was undertaken at the request of the Abatement Section of the Sarnia District office of MOE, who were receiving queries from the Lambton County Health Unit, municipal officials and the local media regarding the sources of the bacterial contamination that was responsible for numerous beach postings in 1989.
In this study, bacterial results were generally poorer at the mouths of creeks and consequently the adjacent Lake Huron beach areas within the study area. Sampling runs were carried out between March 28 and August 28, 1990. Unlike previous summer months, Canatara Beach and Brights Grove Beach were not posted due to elevated bacterial counts in 1990. This complicated the results of this study to identify sources of pathogenic pollution (MOE, 1991).
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The Lake Huron Centre for Coastal Conservation P.O. Box 178, Blyth, Ontario, Canada N0M 1H0 Phone: (519) 523-4478 Email: coastalcentre@lakehuron.on.ca |
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