The J6 crude oil spill site is located in The Nature Conservancy's Tallgrass Prairie Preserve, Osage County, Oklahoma. Contamination resulted from a pipeline break on January 6, 1999 releasing about 70 barrels of dewatered crude oil. Immediately downslope of the pipeline it contaminated an area of about 10,000 ft² (J6N). The crude oil then flowed down a gully in a lease road and contaminated another area of the prairie (about 4,800 ft², J6S). The initial total petroleum hydrocarbon (TPH) concentration in J6N was about 33,500 mg/kg and in J6S, 4,800 mg/kg. For the purpose of treatment comparison, each of these sites was divided into fertilized and non-fertilized sections. Further, for comparison, two types of controls have been used--one is unimpacted prairie disturbed by tilling and the other is unimpacted and undisturbed prairie.

This paper discusses the effect of managed bioremediation by fertilizer addition on the restoration of the soil ecosystems of the different test plots following remediation in terms of ecological indicators such as phospholipid fatty acids (PLFA), nematode populations, nutrient cycling and revegetation. Both the J6N and J6S sites experienced similar decreases in TPH concentrations with and without fertilizer addition. However at the higher TPH concentration (J6N) ecological indicators show that the rate of restoration of the soil ecosystem is increased by using fertilizer addition during remediation.