This report presents cost and performance data for the application of on-site incineration at the Bayou Bonfouca Superfund site in Slidell, Louisiana. A rotary kiln incinerator was operated from November 1993 through July 1995 as part of a remedial action. Contaminants of concern at the site included specific polynuclear aromatic hydrocarbons (PAHs).
The Bayou Bonfouca site was a former creosote works facility that operated from 1892 until its closure in 1970. During this period, numerous creosote releases occurred. In 1970, a fire at the plant released large amounts of creosote into the environment. Sediment at the Bayou Bonfouca site was contaminated with PAHs.
In August 1985, a Phase I Record of Decision (ROD) was signed, specifying excavation and off-site landfilling of creosote waste piles. In March 1987, a Phase II ROD was signed. The remedial actions for the Phase II ROD included the excavation and on-site incineration of sediment and the contents of surface waste piles with placement of an engineered cap over residual ash and surface soils
The material specified for excavation and incineration included approximately 165,000 cubic yards of bayou sediments contaminated with PAHs in excess of 1,300 mg/kg and 10,000 cubic yards of contaminated material from waste piles. The ROD also specified incinerator requirements that included a destruction and removal efficiency (DRE) of 99.99% for each contaminant of concern.
During 1988, a detailed design investigation showed that the volume of contaminated sediment was underestimated by a factor of three. The volume increase resulted in a cost increase and prompted EPA to issue an Explanation of Significant Difference (ESD) in February 1990.
The ESD divided the Phase II ROD remedial action into two operable units: a groundwater and a source control operable unit. On-site incineration was a component of the response for the source control operable unit.
The selected incineration system consisted of a feed system, a rotary kiln, a secondary combustion chamber (SCC) and a gas cleaning system. Sediment was dewatered and then mixed before being fed to the incinerator.
A countercurrent kiln lined with castable refractory brick was used at the Bayou Bonfouca site. The resulting ash was discharged from the kiln and quenched outside of the kiln, while exhaust gases were channeled to the SCC. The SCC provided additional combustion of organics in the exhaust gas which was subsequently quenched with water.
The gas cleaning system consisted of a quench system, a combustion gas conditioner, a Hydro Sonic® scrubber, and a vane separator. Particulate matter and acid gasses were removed throughout the gas cleaning system.
During its operation, the incinerator processed approximately 250,000 tons (over 170,000 cubic yards) of contaminated sediments. Treatment performance and emissions data collected during this application indicated that all performance standards and emissions requirements were met.
The actual cost for remediation
using the incineration system was approximately $110,000,000.
Click here for
an Adobe Acrobat PDF version of the full report.
Adobe Acrobat Reader is
required to view PDF documents.
Click
here to download a free copy of the Reader.