ENVIRONMENTAL IMPACT AND RECOVERY OF A HIGH MARSH PIPELINE OIL SPILL AND BURN SITE, UPPER COPANO BAY, TEXAS

Abstract

ABSTRACT On January 7, 1992, a rupture in an underground oil transfer pipeline resulted in a spill of about 2,950 bbl (469 m3) of crude oil into a high marsh community near Chiltipin Creek, San Patricio County, Texas. Authorization for burning the oil, as a cleanup method, was given by the Texas General Land Office (the designated state on-scene coordinator). The environmental impact of the spill and ensuing burn on this high marsh has been assessed by monitoring changes in the total petroleum hydrocarbon (TPH) content of the associated floral community and soil over time. Ultimately 6.5 ha of oil and vegetation of the 15.5 ha surrounded by sorbent booms were burned, causing them to become barren. These bare patches produced by the burn were rapidly colonized by grasses, mainly Distichlis spicata. Secondary succession by perennial climax species is slow, resulting in significantly lower species diversity and biomass in the oiled and burned area even after 30 months. Significant changes within, and interactions between, impacted and control areas were determined using repeated measures MANOVA. TPH measurements made in December 1992 and repeated in July 1993 show consistent decreases. The obvious disadvantages of burning as a cleanup method in this high marsh area are the substantial initial damage to plants and the high residual hydrocarbon levels in the sediment.