STUDY DESIGN

A water quality monitoring program was conducted on Lake St. Clair and the Clinton
River Watershed during the spring, summer and fall of 2005. The overall purpose of this
project was to collect data and characterize water and sediment quality in the lake and
watershed.

The project included five complementary monitoring activities; near shore, off shore,
watershed, bathing beach and wet weather. The near shore testing was conducted at
23 major inputs to the lake, including the mouths of the Clinton River and Spillway, urban
storm drains, smaller rivers and creeks and retention basin discharge points. Near
shore sampling was conducted adjacent to the outfalls, however, many samples were
collected further from the outfalls than during previous years due to lower lake levels.

Off shore sampling was conducted at 13 sites. Seven of the off shore locations
corresponded to major near shore sample locations, two were adjacent to public
beaches, two were municipal drinking water intake sites and the mouths of the North and
South Channel. Water chemistry samples were collected during the spring, summer and
fall seasons at 20 near shore and all off shore sites. Aqueous bacteriological samples
and water quality meter readings (temperature, dissolved oxygen, conductivity, pH and
turbidity) were collected weekly from April 29 to September 15 at all 23 near shore sites.

Off shore water bacteriology testing and water quality meter readings were collected
during the spring, summer and fall seasons. Sediment E. coli samples were collected
during the summer and fall from 9 near shore and 7 off shore sites. Sediment chemistry
samples were collected at 13 near shore locations. Aqueous samples for trace mercury
analyses were collected at 10 sites on the lake and 6 sites in the watershed.

Concurrent sediment and water samples were collected at 14 locations in the watershed
for bacteriological examination during the spring, summer and fall. Sediment chemistry
samples were collected at 5 locations. Water chemistry samples were collected at 5
locations during wet and dry weather conditions.

Bathing beach water and sediment sampling was conducted at 15 sites on the public
beaches along Lake St. Clair (Blossom Heath, Memorial Park, HCMA Metropark, and
New Baltimore). The sampling was performed at locations established for the Bathing
Beach Water Quality Monitoring Program. Samples were collected monthly from July
through September, and analyzed for water and sediment bacteriology.

Event sampling was conducted in the watershed in response to rain events exceeding
one half inch in a 24-hour period. Water samples were collected for bacteriological
analysis at 20 strategic locations between April and September. Sample locations were
selected based on three criteria: proximity to known sewer overflows, locations of
frequently high bacteria counts and at the most downstream sample site of each major
sub-watershed drainage area of the Clinton River.

EXECUTIVE SUMMARY

Key Findings in the 2005 Lake St. Clair Assessment
(See cover for sample site locations)

The annual geometric mean did not exceed the 30 day Total Body Contact Standard of
130 E. coli CFU/100 mL at any Lake St. Clair sample site during 2004, nor did the
geometric mean for all Lake St. Clair sample sites exceed this standard during any
individual sampling event.

The statistically significant decrease in the Lake St. Clair all-site E. coli geometric means
continued for the period 1998-2005. This year, the statistics were extended to cover the
off shore sites as well as the near shore sites.

Statistically significant decreasing E. coli counts were noted at the Clinton River (n23) for
the period 1998-2005. Statistically significant decreasing E. coli counts were also noted
at the Clinton River Spillway (n19), Stephens Relief Drain (n4), and Crapeau Creek
(n29) over this time period.

The average PNA concentration of 220 mg/kg in the sediments of the Clinton River at
Moravian (w68) is the highest PNA concentration ever found at any site tested in the
history of the Lake St. Clair Assessment.

The average lead concentration of 250 mg/kg in the sediments of the Clinton River at
Moravian (w68) is at the Ontario Ministry of the Environment’s Severe Effect Level.

The average zinc concentrations of 280 mg/kg in the sediments of Red Run at Utica
Road (w55) and 210 mg/kg in the sediments of the Clinton River (n23) exceed the
USEPA heavily polluted level.

Every site sampled in Lake St. Clair had a higher average annual water temperature in
2005 than in 2004.

Lake St. Clair average chloride concentrations have shown a statistically significant
increase from 1998 to 2005.

Dissolved oxygen levels at the Clinton River (n23) have shown a statistically significant
increase from 1998 to 2005.

A statistically significant inverse relationship between turbidity and water temperature
was noted at Metropolitan Beach (o6) between 1998 and 2005.

              TO VIEW THE 2005 SITE SUMMARIES click here

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