On July 23, 1998, Lakehead Pipeline Company (Lakehead) was in the process of drilling a route for a new pipeline when they released bentonite, a mud-like drilling substance, into Millhurst Fen. Milllhurst Fen is a natural wetland area located near the Fox River in Kendall County. A number of endangered and threatened plant species are present in this area. Millhurt Fed is considered one of the highest quality fens in the State of Illinois. Lakehead was also responsible for additional releases of bentonite into Millhurst Fen on August 5, 1988 and November 4, 1998.
Natural Resource Damage Assessment (NRDA) action was taken by the Illinois Natural Resource Trustees. Lakehead agreed to compensate the public for interim losses and a settlement was agreed to by all parties. The matter was settled in January of 2000.
A restoration plan was put together by the Illinois Natural Resource Trustees. Activities in the restoration plan included prescribed burning, brush cutting, and herbicide application to prevent-control exotic species encroachment.