What should I do about a property that is hiding illegal waste?

I am only licensed to practice in Ohio so my comments are subject to that limitation. Your question raises several other questions that need to be answered before a complete analysis can be provided.  First, when you say the lot"was cited" do you really mean that the lot was "suspected of being used" as a dumping ground for railroad ties about 20 years ago?  How long has your church owned the lot?  Did the individuals mentioned actually participate in the waste burial or simply know about it?  Railroad ties would be considered solid waste unless they were treated with chemical preservatives to a level that qualifies them as a hazardous waste.  Do you know anything about the condition of the buried railroad ties?  Your obligation to disclose your knowledge will depend on the answers to those questions. So, I recommend that you engage a qualified environmental attorney licensed to practice law in Illinois to advise you on your affirmative reporting obligations, if any.  Such an attorney would have the capability of engaging an environmental consultant to perform some site investigation and/or sampling to confirm your suspicions, and at the same time preserve your ability using the attorney client privilege to keep the consulting firm's findings confidential....if possible. I hope this response is helpful.  Good luck.