CEDAR CREEK and AMCAST
Only a field exists where Mercury Marine Plant 2 washed PCBs over the picture perfect township of Cedarburg. Cedarburg is a model Wisconsin town with very cute downtown and parks running along Cedar Creek. Just beyond the downtown area are visible signs of industry and the vacant lot of Amcast. A relic of pollution that has devastated the creek and spread pollution into the Milwaukee River. Rather than listing 2 separate sites it might be best to list the whole town of Cedarburg as one Superfund Site.
The Cedar Creek site is in the historic city and township of Cedarburg in southeastern Wisconsin in a suburban residential area north of Milwaukee. The entire site consists of Mercury Marine’s Plant 2 and the segment of Cedar Creek from below the Ruck Pond dam to the point where it meets the Milwaukee River. This segment includes open stretches of creek as well as areas known as Columbia Pond, Wire and Nail Pond, and the former Hamilton Pond for a total of 5.1 creek miles.
PCBs from boat manufacturer Mercury Marine contaminated Cedar Creek and the Plant 2 property. It operated a plant on St. John Avenue from 1951 to 1982. Fluids, containing PCBs, leaked from equipment and were washed into floor drains. These drains emptied into storm sewers. Those sewers emptied into Ruck Pond on the creek and flowed into the Milwaukee River.
Mercury Marine’s Plant 2 building was demolished in May 2005. The building, which was in poor condition, also contained PCB contamination. An investigation and feasibility study outlining possible cleanup options was completed in October 2007. A decision on how to clean up Plant 2 was made in March 2008.
A separate likely source of contamination in the area was Amcast, a former local automotive industry supplier in Cedarburg. It also had a plant that may have emptied PCBs into the creek via storm sewers. One of them apparently emptied into Hamilton Pond, upstream of Green Bay Road. Due to heavy rains and high creek flow in 1996, the Hamilton Dam collapsed and was removed. The pond was drained leaving behind several acres of mud flats containing PCBs.
Sewers near the Amcast plant and soil under the building were sampled in November 2005. Since Amcast had filed for bankruptcy, its contractor was told to stop working and the results were never analyzed. Soil samples were also taken on private properties near the Amcast plant in summer 2005. Some of those samples showed PCB contamination slightly above what EPA considers to be safe levels.
Since the company is bankrupt, the Amcast portion of the project was separated from Cedar Creek in 2009. EPA is using Superfund money to address the contamination at and near Amcast Industrial Corp.
In September 2008, Mercury Marine signed an AOC with EPA to conduct the remedial design work required by the March 2008 ROD for OU1. EPA approved the remedial design in February 2012. In June 2012, EPA began negotiations with Mercury Marine for the remedial action work, and a consent decree between EPA and Mercury Marine was signed in September 2012 and entered by the court in November 2012. Mercury Marine started the remedial action cleanup work in the Fall of 2012 and completed the on-site work in late 2013.
As discussed above, Amcast filed for bankruptcy in November 2004. Subsequently, EPA decided to list the Amcast facility on the NPL so it would be eligible for federal cleanup funds. The Amcast facility is no longer being addressed as part of the Cedar Creek site.