Presentations

TRCA Monitoring Program in Western Durham, Lake Ontario

Authors
CHOMICKI, K.M., BROWN, C.J.M., and BOWEN, G.S.

Presented
Public Information Session hosted by TRCA, October 2013

Abstract
This presentation is geared to a general audience. It explains in plain language the complexities of the nearshore environment, including how lake water moves, how sampling is conducted. It describes analyses of the results of the water quality monitoring to date, their significance to understanding nearshore water quality, and the impacts of this project over the long-term.

Annual and Seasonal Differences in Nearshore Water Quality of Lake Ontario by Western Durham in Relation to Wet and Dry Years

Authors
CHOMICKI, K.M., BROWN, C.J.M., and BOWEN, G.S.

Presented
International Association for Great Lakes Research (IAGLR) Conference, 2014

Abstract
Water quality in the nearshore (NS) can be affected by tributary loading, which changes on a seasonal basis. Understanding NS water quality patterns and drivers is important as this is a region where the public interacts with the lake, and where drinking water is drawn from. Despite this, few longitudinal studies from the same site with spatial resolution exist which examine the relationships between water quality, seasons, and relationships with wet and dry years. In addition to calculating tributary loading, the Toronto and Region Conservation Authority has been monitoring NS water quality in the Western Durham region of Lake Ontario since 2007, analyzing nutrients such as SRP, TP, and nitrate+nitrite. The monitoring area is near the Pickering Nuclear Generating Station and the outfall to the Duffin Pollution Control Plant (DPCP)- the 3rd largest control plant on the Canadian shores of Lake Ontario. Higher nutrient concentrations were observed by the shoreline and near the DPCP outfall located within the NS monitoring area. In both wet and dry years, TP concentrations were below the IJC water quality objective for open waters at distances greater than 1 km from the shoreline. Significant differences in the median annual and median seasonal concentrations were observed for some nutrients which related to wet and dry years.

Spatial and Temporal Variability in Nearshore Water Quality by the Duffin Pollution Control Plant Outfall

Authors
CHOMICKI, K.M., and BOWEN, G.S.

Presented
49th CENTRAL Canadian Symposium on Water Quality Research, 2014

Abstract
The Duffin Pollution Control Plant has among one of the strictest effluent limits of all plants discharging effluent to the open waters of Lake Ontario, providing secondary treatment with no bypass capability. In 2010, the plant initiated its Stage 3 expansion which was completed in early 2012 increasing treatment capacity from 420 to 630 million litres per day. Additionally in 2012, updates to the Stage 1 and 2 phosphorus and ammonia removal were also completed and declines in the concentrations and loads in the total effluent exiting the plant were noted.

The outfall for the Duffin Pollution Control Plant is located on the north shore of Lake Ontario, east of Toronto, in the nearshore environment of Western Durham. The Toronto and Region Conservation Authority has been monitoring water quality in the nearshore environment of Western Durham approximately 5 – 8 times per year since 2007. From 2007 to the spring of 2010, water quality was examined along 8 transects extending to 3 km from the shoreline. Between 2011 and 2013, water quality was collected at 4 transects extending to 5 km from the shoreline. Although the purpose of the monitoring program was not to examine the impacts of the outfall on the nearshore, transect locations included regions surrounding the outfall. Earlier in the program, samples were taken at the surface and bottom of the lake by the diffuser.

Water quality in the nearshore of Western Durham in relation to the location to the outfall will be examined. Spatial patterns in nitrate, ammonia, and phosphorus extending from the outfall will be explored. Preliminary total phosphorus analyses suggests that concentrations approach nearshore background within 1 km of the outfall. Seasonal and annual water quality patterns are observed within the nearshore and can be statistically related to wet and dry years. The seasonal and annual water quality patterns surrounding the outfall will also be analyzed and compared to those observed over the entire nearshore environment, and to changes that have occurred at the plant.

Spatial and Temporal Variation in the Water Quality of Four Marshes Adjacent to the Nearshore of Western Durham, Lake Ontario

Authors
BOWEN, G.S. and CHOMICKI, K.M.

Presented
International Association for Great Lakes Research (IAGLR) Conference, 2014

Abstract
Western Durham coastal wetlands are examples of the general importance of the retention of sediments and cycling of nutrients originating from watersheds prior to waters entering Lake Ontario. In Western Durham, there are three drowned-river mouth marshes located by the outlets of the Rouge River, Duffins Creek, and Carruthers Creek, and one barrier beach lagoon marsh (Frenchman’s Bay marsh) adjacent to the nearshore of Lake Ontario. These marshes range in size from 23 to 141 ha, and are the recipients of water draining watersheds between 27 and 333 km2. Concurrent with a nearshore water monitoring program, the Toronto and Region Conservation Authority has measured water quality (e.g. total phosphorus, soluble reactive phosphorus, nitrate+nitrite) and E. coli at multiple locations within these marshes in the ice-off seasons from 2007-2009. This presentation will examine the spatial variation in water quality within and among the marshes, and explore seasonal differences in nutrient concentrations (e.g. nitrate+nitrite, ammonia, total phosphorus, and soluble reactive phosphorus). Additionally, linkages between marsh and lake nearshore water quality will be explored in relation to water levels in Lake Ontario.

The Western Durham Water Quality Monitoring Program 2006 to 2014

Authors
BOWEN, G.S.

Presented
Ontario Power Generation Community Advisory Council, November 2014

Description
This presentation is geared to a general audience. It explains in plain language activities for monitoring the nearshore environment,analyses of the results of the water quality monitoring to date, their significance to understanding nearshore water quality, and the impacts of this project over the long-term.

The Western Durham Water Quality Monitoring Program 2006 to 2014

Authors
BOWEN, G.S.

Presented
Durham Environmental Advisory Committee, November 2014

Description
This presentation is geared to a general audience. It explains in plain language activities for monitoring the nearshore environment,analyses of the results of the water quality monitoring to date, their significance to understanding nearshore water quality, and the impacts of this project over the long-term.7) Nutrient Distributions and the interaction between coastal wetlands and the nearshore of Lake Ontario (PDF 2.9 MB)

Nutrient Distributions And The Interaction Between Coastal Wetlands And The Nearshore of L. Ontario

Authors
CHOMICKI, K.M. and BOWEN, G.S.

Presented
International Association for Great Lakes Research (IAGLR) Conference, 2015

Abstract
Three drowned-river mouth marshes located by the outlets of the Rouge River, Duffins Creek, and Carruthers Creek, and one barrier beach lagoon marsh (Frenchman’s Bay marsh) intercept waters on route from Western Durham watersheds to Lake Ontario. These coastal wetlands aid in the retention of sediments and cycling of nutrients from the watersheds prior to their entry into the nearshore. Although studies have examined these wetlands and their associated nearshore areas individually, there has been little focus on the interactions of the two systems and how the dynamics and characteristics of each system influence the nutrient patterns observed. This talk will look at nutrient distributions (e.g. total phosphorus, soluble reactive phosphorus, nitrate+nitrite) and E. coli in the marshes and nearshore during the ice-off season and explore how nearshore dynamics affect the observed patterns. It will also examine whether there are differences between the coastal nutrient nearshore patterns observed near drowned river mouths and beach barrier marshes.

Variability In Phosphorus At Western Durham, Lake Ontario: Patterns And Potential Sources

Authors
BOWEN, G.S., CHOMICKI, K.M., and TAYLOR, W.D.

Presented
International Association for Great Lakes Research (IAGLR) Conference, 2015

Abstract
In the 1960s and 1970s, lakewide eutrophication and shoreline algal fouling were major issues threatening the health of the Lower Laurentian Great Lakes. After reductions in land-based nutrient loadings, water quality conditions improved; however, recently there has been a resurgence of algal fouling occurring in the nearshore regions of all of the Lower Great Lakes, including the region by Western Durham, Lake Ontario. The nearshore of Western Durham has a variety of potential nutrient sources including storm drain outlets, four rivers/creeks, and a sewage treatment plant. The Toronto and Region Conservation Authority has been monitoring water quality in the nearshore environment of Western Durham approximately 5 to 8 times per year during the ice off season since 2007. This talk will examine the variability in and distributions of total phosphorus and soluble reactive phosphorus in the nearshore, and highlight patterns near potential nutrient sources. In addition, we will explore time-trends in phosphorus concentration in the nearshore. Long term monitoring programs are wise investments and lead to informed decision making and management efforts.