Jump to main content.


Lake Michigan Mass Balance Study - PCBs

LMMB Study
Overview Contaminants

Summary

The purpose of PCBs modeling was to simulate their transport, fate, and bioaccumulation in Lake Michigan.  PCBs are a group of persistent, bioaccumulative hydrophobic organic chemicals (HOCs) that are ubiquitous in the Great Lakes.  Although anthropogenic inputs from production and disposal largely ceased following their ban in the 1970s, atmospheric and watershed tributary transport pathways to the lake continue the import of PCBs.  In addition, a large in-lake sediment inventory represents an internal source of PCBs, which are recycled annually.  PCBs have been consistently identified as the contaminant of greatest concern to human and ecosystem health in the Great Lakes.

map of PCB inventory on Lake Michigan

A mass budget analysis was done for the LMMBP period (1994-1995) to identify the critical contaminant sources, sinks, and key environmental processes in Lake Michigan using the model LM2-Toxic.  The average masses of total PCBs  presented in the water column and the surficial sediments (0-1 cm) of the lake during 1994-1995 were 1,216 kg and 13,085 kg, respectively.  The inventories divided by the volumes of the water and the surficial sediment layer of the lake lead to an average concentration of total PCBs equal to 0.259 ng/L in the water column and 12,037 ng/L in the surficial sediment layer.  The single largest flux (kg/y) leaving the Lake Michigan system was gross volatilization.  This flux was countered by the flux from gas absorption as the largest source to the lake.  The air-water exchange was the most important process for Lake Michigan.  It produced the largest PCB net loss out from the lake.  Resuspension was a major influx of PCBs to the water column offset by the flux from settling.  Resuspension and settling were very important processes in the lake system.  The results of these processes made the net flux between resuspension and settling the second largest net source.  The total external load (tributary loads + atmospheric loads) to the water column of the lake was the largest net PCB source to the lake water column.  The flux by burial was the largest net loss from the surficial sediment layer.  There was a net loss of 1,863 kg/year of total PCBs for the entire Lake Michigan system (the water column + the surficial sediment layer of both Green Bay and Lake Michigan).  This indicated both the water column and the surficial sediment layer of the lake were not at steady-state during the LMMBP period.

Functions developed for the purpose of forecasting PCBs in various media were developed from the 1994-1995 Lake Michigan Mass Balance Project (LMMBP) data and data from various published and unpublished sources.  The data were used to develop functions that describe the apparent loading trends for PCB loads from the atmosphere and tributaries.  Three trends were considered based on observations.  These were loadings continuing at those of 1994-1995 and a slow and fast recovery that bracketed observed loading trends.

chart of PCB concentration

The model was then applied to forecast the long-term responses (62-year simulation, starting on January 1, 1994) of the PCBs in Lake Michigan for the three load functions  All of the control actions started on January 1, 1996.  The long-term responses of total PCBs in the water column of Lake Michigan clearly demonstrate that, during the LMMBP period, the Lake Michigan system was not at steady-state with respect to the 1994-1995 loads, vapor phase concentrations, and the level of sediment total PCB inventory.  If loads remained at those of 1994-1995, the water column PCB concentration in the future would never meet the USEPA water quality criteria for the protection of wildlife (0.12 ng/L) (U.S. Environmental Protection Agency, 2005) and human health (0.026 ng/L) (U.S. Environmental Protection Agency, 1997) in the Lake Michigan system.  For the fast recovery, it would take about five years for the water column concentration to reach the USEPA water quality criterion for the protection of wildlife and more than two decades to reach the USEPA water quality criterion for the protection of human health.  For the slow recovery, it takes about 12 years for the water column PCB concentrations in the lake to reach the USEPA water quality criterion for the protection of wildlife and that the water column PCB concentration will reach the USEPA water quality criterion for the protection of human health around 2046 (five decades after 1996).

chart of total PCB

LM Food Chain, linked to LM2-Toxic, was used to forecast future concentrations of PCBs in lake trout at two sites for various loading scenarios.  Scenarios included constant 1994-1995 conditions, fast continued recovery with an atmospheric load half-life of 6.0 years, slow continued recovery with an atmospheric load half-life of 20.0 years, and various combinations of reduced atmospheric and tributary loadings.  Forecasts indicate that PCBs concentrations in lake trout will continue to decrease.  For the fast continued recovery scenario, the target level for the unrestricted consumption of fish (0.075 ppm) was forecasted to be achieved for five to six year-old lake trout between the years 2030 and 2036.  The narrow forecast range for scenarios, past actions, the long-term decrease in loads, and decreasing PCB concentrations in the system indicate that PCBs are presently controlled by dynamic interactions among media, as well as air and sediment cycling.

Publications

Zhang, X., K.R. Rygwelski, and R. Rossmann. 2009.  The Lake Michigan contaminant transport and fate model, LM2-toxic:  development, overview, and application.   Jour. Great Lakes Res.  35:128-136.

Zhang, Xiaomi, K. R. Rygwelski, R. Rossmann, J.J. Pauer, and R.G. Kreis, Jr. 2008. Model construct and calibration of an integrated water quality model (LM2-Toxic) for the Lake Michigan Mass Balance Project. Ecol. Modell. 219:92-106.

Zhang, Xin and R. G. Kreis. 2008. Importance of temperature in modeling food web bioaccumulation in large aquatic systems. Ecol. Modell. 218:315-322.

Reports

Rossmann, R. (Ed.).  2006.  Results of the Lake Michigan Mass Balance Project:  Polychlorinated Biphenyls Modeling Report.  U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division-Duluth, Large Lakes and Rivers Forecasting Research Branch, Large Lakes Research Station, Grosse Ile, Michigan.  EPA-600/R-04/167, 579 pp. 

Rossmann, R. (Ed.)  December 2005.  MICHTOX:  A Mass Balance and Bioaccumulation Model for Toxic Chemicals in Lake Michigan.  U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division-Duluth, Large Lakes and Rivers Forecasting Research Branch, Large Lakes Research Station, Grosse Ile, Michigan.  EPA-600/R-05/158, 140 pp.

Richardson, W.L., D.D. Endicott, R.G. Kreis, Jr., and K.R. Rygwelski.  2004.  The Lake Michigan Mass Balance Project: Quality Assurance Plan for Mathematical Modeling.  U.S. Environmental Protection Agency, Office of Research and Development, National Health and Environmental Effects Research Laboratory, Mid-Continent Ecology Division-Duluth, Large Lakes and Rivers Forecasting Research Branch, Large Lakes Research Station, Grosse Ile, Michigan.  EPA-600/R-04/018, 233 pp. 

Presentations

Kreis, R. G., Jr., X. Zhang, E. Murphy, R. Rossmann, K. R. Rygwelski, G. Warren, P. J. Horvatin, and W. Melendez.   2009.  Lake Michigan Mass Balance Study post audit:  integrated, multi-media PCB modeling and forecasting for lake trout.  2009 International Association for Great Lakes Research Annual Conference, 18-22 May 2009, Toledo, Ohio, p. 122 of abstracts.

Kreis, R.G., Jr.,  K.R. Rygwelski,  X. Zhang,  J.J. Pauer,  R.Rossmann, T. Fiest, P.J. Horvatin, D.A. Griesmer, W. Melendez, and X. Xia.  2008.  Linking Watershed Atrazine and PCB Loads to Lake Michigan.  Land-Lake Nearshore Loading Workshop, Center for Lake Erie, Oregon, OH, March 17-19, 2008.

Kreis, R. G., Jr. and J.V. DePinto.  2007. Contaminant Mass Balance Model Applications in the Great Lakes:  Lower Fox River/Green Bay and Lake Michigan. Invited presentation, Special Symposium on the Great Lakes, 233rd American Chemical Society Conference, Chicago, Illinois, March 25-29, 2007.

Warren, G.J., R.G. Kreis, Jr., and P.J. Horvatin.  May 2006.  Combining Prediction and Monitoring for Reductions of Toxics:  The Lake Michigan Mass Balance Study.  Presented at the National Monitoring Conference, San Jose, California.  May 7-11, 2006.

Kreis, R.G., Jr., X. Zhang, X. Zhang, D.D. Endicott, K.R. Rygwelski, R. Rossmann, G. Warren, P.J. Horvatin, and W. Melendez.  November 2005.  The Lake Michigan Mass Balance Study:  PCB Mass Balance and Forecasting Models.  Presented at the Lake Michigan State of the Lake and Great Lakes Beach Association  Conference, Green Bay, Wisconsin.  November 2-3, 2005.

Zhang, Xiaomi, K.R. Rygwelski, R. Rossmann, and R.G. Kreis.  May 2005.  Application and Results of Using LM2-Toxic Model for Forecasting PCBs in Lake Michigan Under Long-Term Source Reduction Scenarios.  Presented at the 48th Conference on Great Lakes Research, International Association for Great Lakes Research, The University of Michigan, Ann Arbor, Michigan.  May 23-27, 2005.

Zhang, Xin, R.G. Kreis, Jr., and R. Rossmann.  May 2005.  Definition of Food Web Exposure History in the Calibration of Bioaccumulation Models.  Presented at the 48th Conference on Great Lakes Research, International Association for Great Lakes Research, The University of Michigan, Ann Arbor, Michigan.  May 23-27, 2005.

Endicott, D.D. and R.G. Kreis, Jr.  June 2003.  Modeling Sediment Transport for the Lake Michigan Mass Balance Project.  Presented at the 46th Conference on Great Lakes Research, International Association for Great Lakes Research, DePaul University, Chicago, Illinois.  June 22-26, 2003.

Gerstner, G., W. Melendez, D.D. Endicott, and K.R. Rygwelski.  June 2003.  High Resolution Modeling of PCB Congeners in Lake Michigan Using the Lake Michigan Level 3 (LM3) Contaminant Model.  Presented at the 46th Conference on Great Lakes Research, International Association for Great Lakes Research, DePaul University, Chicago, Illinois.  June 22-26, 2003.

Kreis, R.G., Jr., G.J. Gertsner, D.D. Endicott, G. Warren, K.R. Rygwelski, X. Zhang, P.J. Horvatin, K. Wissing-Taunt, and W. Melendez.  October 2003.  Lake Michigan Mass Balance Study:  Prognosis for PCBs.  Presented at the Lake Michigan State of the Lake Conference, Muskegon, Michigan.  October 21-22, 2003.

Rygwelski, K.R. and R.G. Kreis, Jr.  June 2003.  An Overview of the Lake Michigan Mass Balance Project:  Background, Accomplishments, and Future Work.  Presented at the 46th Conference on Great Lakes Research, International Association for Great Lakes Research, DePaul University, Chicago, Illinois.  June 22-26, 2003.

Zhang, Xiaomi, K.R. Rygwelski, and D.D. Endicott.  June 2003.  Development, Calibration and Application of a Contaminant Transport and Fate Mass Balance Model for Lake Michigan, LM2.  Presented at the 46th Conference on Great Lakes Research, International Association for Great Lakes Research, DePaul University, Chicago, Illinois.  June 22-26, 2003.

Endicott, D.D., X. Zhang, and X. Zhang.  June 2002.  Lake Michigan Mass Balance Project: Modeling Total PCBs Using the MICHTOX Model.  Presented at the 45th Conference on Great Lakes Research, International Association for Great Lakes Research, University of Manitoba, Winnipeg, Manitoba, Canada.  June 2-6, 2002.

Rygwelski, K.R., R. Rossmann, R.G. Kreis, Jr., and W.L. Richardson.  May 2002.  Linking Great Watersheds and Rivers to Forecast the Impact of Stressors on Large Receiving Waters.  Presented at the U.S. Environmental Protection Agency Science Forum 2002:  Meeting the Challenges, Washington, D.C.  May 1-2, 2002.

Warren, G. and R.G. Kreis, Jr.  November 2001.  Lake Michigan Mass Balance Update.  Presented at the Lake Michigan State of the Lake Conference, Muskegon, Michigan.  November 6-7, 2001.

Zhang, Xiaomi  January 2001.  Approach for Defining PDC Resuspension for LMMBP Level 2a Models.  Presented at the Lake Michigan Mass Balance Project Sediment Workshop, U.S. Department of Commerce, National Oceanic and Atmospheric Administration, Great Lakes Environmental Research Laboratory, Ann Arbor, Michigan.  January 27-28, 2001.

Zhang, Xiaomi, W.L. Richardson, M. Velleux, and D.D. Endicott.  June 2001.  Development and Calibration of an Organic Basis Sorbent Dynamic Model for Lake Michigan.  Presented at the 44th Conference on Great Lakes Research, International Association for Great Lakes Research, University of Wisconsin, Green Bay, Wisconsin.  June 10-14, 2001.

Zhang, Xin and R.G. Kreis, Jr.  June 2001.  Importance of Temperature in Modeling PCB Bioaccumulation in the Lake Michigan Food Web.  Presented at the 44th Conference on Great Lakes Research, International Association for Great Lakes Research, University of Wisconsin, Green Bay, Wisconsin.  June 10-14, 2001.

 

Top of page


LLRS Navigation


Jump to main content.