Great Lakes Binational Toxics Strategy

Quarterly Update - April 1999

Canada and the United States have been reviewing their positions relative to continuing options for the Pesticide Workgroup.

Canada has concluded that Canada has met its Challenge, and little more can be accomplished for the Level I Pesticides. It is expected that the Canadian representatives will be recommending that Workgroup activities be suspended.

The United States published its draft report on the U.S. Challenge on December 31, 1998. The U.S. Challenge states:

Confirm by 1998 that there is no longer use or release from sources that enter the Great Lakes Basin of five bioaccumulative pesticides (chlordane, aldrin/dieldrin, DDT, mirex, and toxaphene).

In response to publication of the draft U.S. report, several comments were received, which have been distributed to Workgroup members, and will be discussed at the Workgroup session of the Stakeholders meeting in Toronto on April 27.

In contrast to the Canadian position, the U.S. has not concluded that the Challenge has been met. Highlights of the U.S. draft Report are the following:

Regulatory and Production Status

All Level I pesticide uses have been canceled, and all but chlordane have not been in production in the U.S. for many years. Velsicol Corporation, the sole domestic manufacturer, ceased production in 1997.

Trends in Environmental Loadings

Although the Level I pesticides continue to have an environmental presence, the environmental concentrations have shown a general decline in most media over the years. The few exceptions have physical explanations.

Based upon recent water concentration measurements, the quantities of the Level I pesticides remaining in the water column of all five Great Lakes total about 22,000 Kg; this is about one Kg per cubic kilometer of Great Lakes water.

Non-atmospheric sources of these pesticides entering the Great Lakes have been suggested, but have not been identified in follow-up testing. A study near South Haven, MI is underway to attempt to identify the reasons for seasonally high atmospheric concentrations of DDT in South West Michigan.

Time trend atmospheric data from the IADN network are available for dieldrin, DDT and DDE, and three principal components of commercial chlordane. Analysis of these trends projects a decline in atmospheric concentrations to the detection limit (0.1 pg/cu m) from about 2010 for DDT to about 2060 for DDE; dieldrin and chlordane fall in between those extremes.

While environmental concentrations in the Great Lakes Basin media have been generally declining for the past twenty years, current contamination levels remain a concern as reflected by water concentrations that exceed national water quality standards, sediment concentrations that exceed sediment guidelines, and fish consumption advisories based on unacceptable levels of these pesticides in sport and commercial fish.

Reservoirs and Stockpiles

The Level I pesticides are listed as contaminants 212 times at National Priority Superfund Sites within the eight Great Lakes States. A former Velsicol Chemical production site in St. Louis, Michigan, now under remediation, has considerable DDT contamination, and carp taken from the adjacent Pine River have high levels of DDT. These sites represent point sources that are being addressed through the U.S. EPA Superfund Program. In spite of these point sources, evidence of significant contaminant introduction to the Great Lakes beyond site boundaries has not been confirmed.

Reported removals of Level I pesticides at waste pesticide collections (so called Clean Sweeps) have totaled about 41,000 Kg for the period 1990 through 1997. This is quite significant considering that these collections represent about twice the total quantity estimated to be contained in water of all five Great Lakes.

Has The U.S. Met The Challenge?

All pesticide uses for all Level I pesticides have been canceled. The production facilities within the U.S. have been closed. No evidence of purposeful releases have been identified. In spite of these facts, in a strict sense, one can not conclude that the challenge has been met. This is because of the potential for *use or release from sources that enter the Great Lakes Basin* from the following:

Remaining stockpiles. As significant quantities of the Level I pesticides continue to be collected in Clean Sweeps in the Great Lakes Region, we believe that additional stored quantities exist. From that point of view, we can not guarantee that stored materials will not be used or released to the environment.

Atmospheric contributions from continued production and use internationally.

Release from reservoir sources. Sediments, soil, and localized contaminated industrial sites (NPL Superfund) remain a source of potential release to the Great Lakes Basin.

However, in a practical sense, two points are worth considering:

1. Much progress has been made, and no evidence of non-atmospheric sources entering the Great Lakes have been identified.
2. Additional options to the programs in place have not been developed, while continuation of the following is recommended:
   • Superfund site remediation and clean up
   • Waste Pesticide Collections (clean sweeps)
   • Continued monitoring of the various media to track progress.