It is believed that Pemaco began on-site operations in the late 1940s. Pemaco was purchased by the LUX Chemical Company in July 1988, and operations ended at the site in June 1991. Due to safety concerns after the fire, the
Environmental Protection Agency was asked to conduct an emergency assessment and stabilize the site. The Agency responded by doing the following:
Toxic contaminants During the initial assessment study at Pemaco, the EPA found high levels of
volatile organic compounds (VOCs) in the soil beneath the site. The groundwater beneath the site was also contaminated with VOCs. VOCs at the site included:
Perchloroethylene (PCE),
Trichloroethylene (TCE),
Trichloroethane (TCA),
Dichloroethane (DCA) and
vinyl chloride (VC). VOCs are known or suspected carcinogens and, therefore, could have posed a serious risk to neighbors if they were exposed to the chemicals. It included automatic safeguards to shut down in the event of malfunction, and it was tested to guarantee that emissions were within limits required by County, State and Federal Agencies. During incineration, most of the contaminants were reduced to non-toxic compounds, such as carbon dioxide and water. The soil vapor extraction filter and thermal heating system worked as follows: • the soil gas passed through a filter system where a majority of contaminants were captured on filter material. • the unfiltered contaminants in the soil gas were then treated in a heated chamber that broke down the contaminants at temperatures exceeding 1,400 degrees F. In 1998, the EPA collected weekly data on VOCs going into and coming out of the incinerator. The air at the fence line was sampled weekly to verify that no VOCs were leaving the site. EPA turned off the system later in 1998, because the sampling program did not measure potential dioxin emissions. However, based on tests of similar systems used on other projects, it is believed that emissions of VOCs, dioxins, and other chemicals were low and did not pose an elevated threat to public health. The Record of Decision (ROD) for the permanent Pemaco site soil and groundwater pollution remediation was signed on January 13, 2005. Construction of the final remedy began during 2005. EPA completed construction of the remedy that was included in the Maywood Riverfront Park by June 2006. Construction of the treatment plant and placement of the equipment into the treatment plant continued until early 2007. EPA turned on the groundwater treatment system in April 2007. The soil vapor recovery and treatment system was turned on during May 2007, and
Electrical resistance heating remediation for the source area of the site began full operations in September 2007. EPA turned off the Electrical Resistive Heating remedy in April 2008, and permanently transferred vapor treatment over to carbon filtration in June 2008. The concentrations in the ERH area, vapor treatment system, and groundwater continue to decrease over time. ==Maywood Riverfront Park==