On-Site Biological Treatment of Creosote-Contaminated Soils
On-site biological treatment was selected as the preferred remedial alternative for creosote sludges and contaminated soils resulting from the closure of RCRA and CERCLA impoundments at a former wood-treating plant in Minnesota. This option was selected after completing a one-year pilot-scale study. The three-acre treatment facility was constructed in the fall of 1985 and has been in operation since the spring of 1986. The pilotscale studies consisted of six box plots, each 50 feet−2, loaded with waste/soil mixtures. The studies evaluated the degradation of the creosote constituents [primarily polynuclear aromatic hydrocarbons (PAHs) and phenolic compounds] under three waste-loading rates. The use of nutrients and commercially available bacteria were evaluated. The optimum treatment method consisted of a batch-loading rate at 5% benzene extractables in the soil and the use of nutrients and irrigation. Seeding the treatment area with commercially available bacteria did not have any measurable advantage.