BNSF Railway says less oil spilled from derailed tanker cars in northwest Iowa last month than originally believed.
BNSF spokesman Andy Williams says officials now believe 160,000 gallons (605,648 liters) of tar sand oil spilled from 10 of 32 tanker cars that derailed on June 22 into floodwaters of the Little Rock River near Doon. Officials had previously said 14 tanker cars were compromised, spilling an estimated 230,000 gallons (870,619 liters).
Williams also says testing of nearby private water wells and municipal wells in Rock Valley, which is downstream from the spill, show no contamination of drinking water.
The oil mostly contaminated nearby corn crops and topsoil, which Williams says will be replaced with clean topsoil.
Williams says cleanup is expected to take several months.