In a majority of jurisdictions, a seller of real property has an affirmative obligation to make certain disclosures to the buyer concerning the on-site condition of the property being sold.  However, somewhat more ambiguous, is the issue regarding the scope of the seller’s obligation to disclose off-site conditions affecting the property.  Examples of such conditions include: noisy neighbors, a nearby highway, an adjacent wastewater treatment plant, construction of an apartment complex in the area, a neighbor’s plans to build a tennis court, and a toxic waste contamination problem on a neighboring property (somewhat similar to your situation).States have taken different approaches to this issue.  Some jurisdictions use the same test as they would if the defect were on the property itself.  Other jurisdictions have formulated specific rules applicable to off-site conditions.  While others appear to limit the disclosure duty to on-site defects only (i.e. there is no duty to disclose off-site conditions).  And some states’ disclosure statutes contain broad catch-all provisions that could be interpreted as including off-site conditions.  LA's real property form requires disclosure of “other adverse materials or conditions".However even when there is an affirmative duty to disclose imposed, sellers are not automatically liable for non-disclosure.  Typically, a seller may be liable only if they make a material misrepresentation of fact which they know/believe to be false, they intend the buyer to rely on this misrepresentation, the buyer does rely on it, and the buyer suffers damages result.  If such a case exists, then a buyer may in fact sue the seller.  Additionally, misrepresentation further includes the failure to disclose certain conditions (for example conditions that are not readily observable). Real estate brokers have similar responsibilities concerning disclosure issues. Also, realtors may also be subject to violations under consumer laws for knowingly concealment a material fact about the property.At this point you need to speak directly to a real estate attorney in your area who can further advise you as to the specifics of LA state disclosure law and liabilities.