Northwest Indiana has been the home of oil refining since 1890. Historic practices of dumping waste oil into the ground, releases from aged and/or abandonned infrastructure, and reoiling from groundwater, and oil sediments have created a shoreline comprised of 15–35% oil. Conventional wisdom has been that oil can be neither bioremediated nor phytoremediated if the oil exceeds 8%.

This three year study was conducted in both the green house and the field. Trees, grasses and tuberous plants were investigated to determine if any of them would grow, if they would stay alive and if they actually were able to degrade oil.

The field study determined that plants could survive living in this environment, although certain cultivars as well as certain species performed much better than others. We chose the strongest cultivars and planted larger sections with them in the second year. We were able to show that biological activity in the soil was augmented by between 2–5 orders of magnitude. We were also able to show similar biological activity at the waters edge in the rhizosphere of native, naturally occuring tuberous plants.

The green house portion of the study allowed us to compare the oil degradation rates of the different plants and trees.

In the third year, we have a mixed planting to simulate a more natural habitat. This mixed planting scheme also seeks to use the most appropriate plants in order to treat the oil at multiple interfaces: the top foot of soil with grasses, the deeper soil and groundwater with trees, and the water's edge with tuberous plants.

This approach, although more time-consuming, is substantially less expensive than tradiational means of oil removal. It provides habitat to the birds and animals already using the area. It rapidly creates a barrier of plant litter, and creates soil thereby buffering wildlife from casual oil contamination.

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