Ohio EPA seeks comments on US Army Corps of Engineers’ Report
Ohio EPA is seeking public comments on a U.S. Army Corps of Engineers’ report entitled “Influence of Open-Lake Placement of Dredged Material on Western Lake Erie Basin Harmful Algal Blooms” and the Corps’ position on open lake disposal of dredge material in Lake Erie.
The federal standard for the management of most material dredged from Toledo Harbor federal navigation channels is open lake placement, as it is the least costly, environmentally acceptable alternative that is consistent with sound engineering practices. However, in recent years, the problem of harmful and nuisance algal blooms in the Western Lake Erie Basin has become widespread and has been linked to the increased loading of soluble reactive phosphorus (SRP). Harmful Algal Blooms (HABs) occur in nutrient enriched environments when other factors, such as elevated temperature and calm water, are also present.
Some HABs produce toxins, called cyanotoxins, which can be harmful to human and animal health. In 2003, a large HAB event occurred after a significant increase in the quantity of Toledo Harbor dredged material placed in the Western Lake Erie Basin. Since then, there have been recurring concerns about the amount and intensity of annual HABs, and the potential exacerbating influence over external nutrient loads posed by dredged material placement in the Lake. The major factors of concern with regard to dredged material placement are: phosphorus release from the dredged sediment (exacerbating HAB development); changes in turbidity; and the horizontal transport of the material potentially leading to the transport of suspended solids and nutrients to other vulnerable parts of the basin, such as the potable water intakes for the City of Toledo and City of Oregon.