ADDRESSING ALGAL BLOOMS IN THE GREAT LAKES
Western Lake Erie Basin
Algal Bloom Study
The Western Lake Erie Basin (WLEB) is experiencing Harmful Algal Blooms (HABs) with increasing frequency and intensity, causing regional ecological and human health concerns. Learning what does and does not contribute to HABs is critical to developing a strategy to protect the Great Lakes, a resource that makes up 21 percent of the earth’s surface fresh water. The WLEB HAB Study was designed to help the U.S. Army Corps of Engineers (USACE) Buffalo District determine if open-lake placement of dredged materials from Toledo Harbor contributed to HABs in WLEB.
Dredging is necessary for harbor maintenance, and the federal standard in Toledo Harbor is open-lake placement of dredged materials. In 2003, USACE significantly increased the quantity of dredged material moved from Toledo Harbor into Lake Erie. The same year WLEB experienced an exceptionally large HAB event. As HABs increased in frequency, heightened public awareness regarding the fragile WLEB ecosystem and its water quality caused concern and speculation that open-lake placement of dredged materials and HAB development were interrelated.
Apply and Share Science
E & E directed a team on a large-scale investigation to scientifically evaluate whether open-lake placement had an impact on the HAB. We looked into potential phosphorus release from the dredged sediment, changes in turbidity, and whether vulnerable WLEB areas may be impacted from materials released during transport.
E & E implemented a rigorous six-month water quality and sediment plume sampling and monitoring program and input the data into a calibrated modeling program to scientifically evaluate current and future scenarios of open-lake placement of Toledo Harbor dredged material and long-range transport of open-lake placed dredged material.
The comprehensive investigation demonstrated that Toledo Harbor maintenance dredging is not directly linked to HABs. This is important because the sheer quantity of annual material dredged makes alternative disposal options cost-prohibitive. E & E’s leadership in communicating the results to agency and public stakeholders allowed both parties to redirect focus to other potential causes of the HABs. The investigation sets the standard for future studies and questions pertaining to perceived connections among the placement of dredged material in open water and HABs.
E & E was awarded the American Council of Engineering Companies (ACEC) Platinum Award—the highest honor—in the area of Studies, Research, and Consulting Engineering Services.
“This investigation and the final report prepared by EEEPC exceeded all USACE expectations, and we believe their performance was outstanding. … Both the report and presentation have hit the mark. Great technical work and coordination.”
USACE Buffalo District