How to Remedy Heavy Metal Contaminated Soil

Scoop up a soil sample and take it to a local extension agency for testing. If you have lead in the soil, find out how high the concentration is.

Multiply the amount of lead in the soil by 4. This figure is how much phosphate you need to get into the soil. Phosphate has been found to help immobilize heavy metals such as lead, zinc and copper.

Apply half of the required phosphate in the form of a phosphate amendment. Use a garden spreader to cast the phosphate. Water the surface to help the phosphate leach into the soil. Leave the soil alone for six weeks. During this time, the soil pH level becomes more acidic and breaks down the heavy metals, allowing them to be neutralized more easily.

Apply the other half of the phosphate in a phosphate rock form. Spread it over the soil and till it in. Other forms of phosphate could be used, such as more amendment, but the rock was proven to stabilize the pH level in the soil, bringing it back from the high acidic level.