FEASIBILITY OF LAND TREATMENT OF COAL TAR

COAL TAR IS A BY-PRODUCT OF THE COAL GASIFICATION PROCESS USED BETWEEN 1820 AND 1950 TO PRODUCE A NATURAL GAS SUBSTITUTE. IT IS ESTIMATED THAT SEVERAL BILLION GALLONS OF THIS MATERIAL WERE LAND-DISPOSED AT OVER 1500 SITES IN THE U.S. THE TAR CONTAINS POLYNUCLEAR AROMATIC HYDROCARBONS (PAH) WHICH HAVE BEEN PLACED ON THE EPA PRIORITY POLLUTANT LIST AS A RESULT OF THEIR MUTAGENICITY AND TOXICITY. THE BURIED COAL TAR IS OF ENVIRONMENTAL CONCERN AS IT CAN MIGRATE AS A LIQUID PHASE, SLOWLY RELEASING THE TOXIC HYDROCARBONS TO SOIL AND GROUND WATER. RESEARCH BY CAA HAS SHOWN THAT THE 2- AND 3-RING PAH COMPONENTS OF COAL TAR ARE READILY DEGRADED IN TAR/SOIL MIXTURES, INDICATING THAT LAND TREATMENT MAY BE SUITABLE AS AN INNOVATIVE TREATMENT FOR COAL TAR. CAMBIDGE ANALYTICAL ASSOCIATES, INC. PROPOSES TO CARRY OUT LABORATORY SOIL MICROCOSM EXPERIMENTS TO DEMONSTRATE THE BIODEGRADATION OF THE 4- AND 5-RING PAH. TO ADDRESS THE QUESTIONS OF THE RE-USE OF TREATMENT SITES AND POTENTIAL CONTAMINATION OF GROUND WATER BY LEACHATE FROM TREATMENT SITES, THEY PROPOSE TO TEST BOTH THE TREATED RESIDUE AND TREATMENT LEACHATE FOR MUTAGENIC PROPERTIES USING THE AMES ASSAY.