Sharon, I first need to ask a few questions. What leads you to suggest you have problems with mercury in your soils? Have you had a soil test that confirms there is a mercury problem? What levels did it show? Typically mercury in soils is not a problem. Generally in soils, especially urban soils, we worry more about lead content. Generally people are exposed to mercury through ingesting contaminated fish as opposed to eating vegetables. Also what vegetables do you intend to grow? If you send me more info, I would be glad to try to help you further.