How to Remove Hydrocarbons From Soil

Use a rototiller or similar equipment to expose the top 4 to 6 inches of the soil saturated with oil. Depending on how much oil has spilled, along with how old the spill is, the oil may have penetrated farther down. For smaller, fresher spills, 4 to 6 inches will suffice.

Apply gypsum particles to the soil. The amount will depend on the severity of the oil spill, but ranges from 180 to 450 pounds per 1,000 square feet.

Apply leonardite, which is a naturally occurring mineral, to the soil. As with gypsum, the amount will vary, depending on the severity of the spill. It ranges from 100 to 364 pounds per 1,000 square feet.

Add fertilizer to the soil. Besides aiding the biodegradation of hydrocarbons, fertilizer will also help stimulate microbial growth in the soil, actively helping it to return to a healthy state. Five pounds per 1,000 square feet is the ideal amount of fertilizer, and you should use a 10/20/10/10 fertilizer mix.

Supplement the fertilizer with additional sulfur. Sulfur is an ingredient in most fertilizers, but adding more is an option, particularly if you are using gypsum, as sulfur will increase the solubility of gypsum. Using 2,200 pounds per acre is a good starting point.

Do a second pass with the rototiller to make sure that the treatment method or methods used penetrate at least 2 inches in to the soil.

Monitor the affected area to make sure that plants begin to return. A full recovery can take three to four years, even if you did everything right.