Much has been made recently about toxic sediment in Lake Erie that is slowly creeping toward a water intake, and for good reason. With recent water crisis in Toledo, Ohio – and even more recently in Flint, Michigan and Sebring, Ohio – we seem to be becoming more and more conscious as a society about the health and quality of our freshwater resources. The general public is increasingly aware of the infrastructure that supplies our water and the land uses that threaten our shared water resources. This is why when Cleveland Plain Dealer reporter James McCarty wrote about the impending crisis in a recent issue of the newspaper, it gained a lot of attention. But this problem is not new – in fact, it is rooted in a practice that took place a generation ago.
A Harmful Algal Bloom shut down Toledo’s water supply in 2014 (source: Ohio Sea Grant)
So, what is this toxic blob and where did it come from?
The Cuyahoga River Watershed drains over 800 square miles in Cuyahoga, Summit, Portage, Geauga, Stark and Medina Counties. In rivers with such large watersheds, sediment often accumulates near the mouth, which in the case of the Cuyahoga River happens to be in Downtown Cleveland in the federal navigational shipping channel.
The Cuyahoga River drains much of Geauga, Portage, Summit and Cuyahoga Counties
(source: Cuyahoga River Restoration)
In order to maintain the navigational shipping channel in the Cuyahoga River, the United States Army Corps of Engineers dredges sediment from the river twice a year – once in the late spring and once in the fall. The shipping channel must be maintained at 23 feet deep to allow for freighter passage. If the river was not dredged, freighters would have to “light load” their boats so that they could pass through, resulting in fewer materials being delivered up the channel, thus lessening the economic benefit of Cleveland’s port.
Up until 1970, this dredged sediment was openly dumped into Lake Erie. Unfortunately, the sediment was laden with harmful toxins which still exist in the sediment today. These toxins are called polychlorinated biphenyls (PCBs) and polycyclic aromatic hydrocarbons (PAHs). PCBs are a man-made chemical that were once used in electrical equipment, paints and surface coatings before they were banned by the EPA in 1979 for environmental concerns. Although they have been banned for over 30 years, PCBs are durable and these legacy chemicals are still present in sediment today. PAHs can be found naturally in fossil fuels such as crude oil and coal – as well as in man-made materials such as asphalt and coal-tar pitch. Both PCBs and PAHs have been found to have moderate to severe health effects in humans.
PCBs can work their way up the food chain (source: Wisconsin Dept of Natural Resources)
The accumulation of PCBs in the body can cause diarrhea or difficulty breathing, stomach and pancreas damage, and even liver cancer. They can affect fertility and hormonal activity as well as impair the immune system. Long term exposure to PAHs can cause liver and kidney damage and increase risk of cancer. Needless to say, these toxins are something that we would like to keep far away from our water resource.
The location of this PCB and PAH contaminated sediment is referred to as Area 1. This two-square mile area is a dead zone in Lake Erie – with no freshwater mussels or sediment dwelling invertebrates living there.
The City of Cleveland Water Department is confident that the contaminated sediment does not pose an immediate threat and that any toxins could be removed by their treatment processes. The further treatment, however, would introduce more chemicals to the water.
Location of Area 1 (photo source: cleveland.com; information source: Ohio EPA)
The Army Corps of Engineers has a differing opinion from the Ohio EPA and Port of Cleveland on the threat that the sediment poses. The Army Corps maintains that the sediment is not moving and can simply be capped by dredge material that is collected this year to prevent threats in the future. The Ohio EPA has recently collected data that suggests that the sediment is indeed moving and can potentially breach a water intake in the future.
This is just the latest in the dispute between the two government organizations over contaminated dredge material. After the passage of the River & Harbor Act in 1970, the Army Corps was required to dump contaminated sediment into combined disposal facility (CDF) if contaminants were found to be above a certain threshold. These CDFs are located along the lake shore and were built to receive this material. One former CDF – which was filled to capacity in 1999 – is now Cleveland Lakefront Nature Preserve. There are two open CDFs that are both adjacent to Burke Lakefront Airport.
Cleveland Lakefront Nature Preserve is located on top of a closed CDF and is a hotspot for migratory birds crossing Lake Erie (source: Port of Cleveland)
Despite the open CDFs, the Army Corps has reverted to open lake dumping since 2014, citing improved sediment quality that meets the federal standards for open lake dumping. The Ohio EPA disagrees with this rationale, claiming that further introduction of PCBs and PAHs to Lake Erie can cause public health issues, threaten the water supply and increase concentrations of these toxins in fish tissue.
There have been several public hearings to discuss concerns over this issue with the United States Army Corps of Engineers, Ohio EPA and the Port of Cleveland and there are sure to be more in the future, until this issue is resolved. To voice your opinion on the matter and offer creative solutions to the problem, keep an eye on the news for upcoming public hearings or write your congressional representatives or Ohio EPA or the Army Corps of Engineers directly.
To learn more about this issue and other issues facing our water resources, visit the Watershed Stewardship Center at West Creek Reservation.