Although oil spills are most common at sea, land-based oil releases are equally devastating, with potential impacts on soil, water, flora, fauna, and human health. Environmental recovery requires diverse remedial actions, with long-term monitoring to document this recovery. For eight years, Battelle has been involved in such an effort in Northern Italy.

When an Italian National Oil Company (AGIP) oil well erupted, crude oil was released into the surrounding agricultural area, threatening one of Italy’s largest nature preserves. In response to concerns over the safety of local residents and ecosystem health, the farm fields were taken out of production. AGIP contracted Battelle to assist with recovery and to serve as mediator between the company and the government. Battelle began monitoring of hydrocarbons in soil, groundwater, vegetation, and wildlife; performed geophysical and hydrogeological characterizations; formulated the remediation plan; set up the implementation of individual cleanup technologies; and conducted risk assessments.

Long-term risks from the spill to the local biological communities and human population were posed by polycyclic aromatic hydrocarbons (PAHs), oil residues that are relatively persistent long after a spill. Some PAHs possess carcinogenic and toxic properties. Transport of hydrocarbons by groundwater also posed a potential threat to the nature preserve; Battelle assessed this risk using models describing the fate of pollutants underground.

Recovery of the site and its return to agriculture have been top priorities for all parties. Battelle has evaluated recovery with annual ecological risk assessments and animal censuses, soil toxicity tests, and greenhouse experiments designed to determine phytotoxicity of the soil. Thousands of groundwater, soil, fauna, and flora samples have been collected for PAH analysis.

The results have been used to create a large database documenting the recovery process and to update the risk assessments, which indicate that over the years, risks posed to local biological communities and to man became negligible as soil PAH concentrations declined. Battelle provided these data to regional authorities who concluded that a large portion of the formerly contaminated area could be returned to agricultural production three to four years after the spill.

The monitoring effort has documented that the preserve was spared any impact from the oil spill and that even in the area of direct impact, the bird and mammal populations have gradually returned to their pre-spill levels. A human health risk assessment conducted specifically for a hypothetical farm population living and working near the former oil well eased concerns of residents when it revealed that risks were negligible five years after the spill.

Battelle continues to monitor residual underground pollution to make sure it generates no ecosystem impacts and to survey a small area close to the former oil well in the final stages of cleanup. It is hoped that phytoremediation will achieve soil hydrocarbon levels acceptable for fields in agricultural production.

For more information, contact Marco Pellei 41-22-827-2727, pelleim@battelle.org.