Requiring, in Frederick County, the seller of residential property that is located within 0.5 miles of a National Priorities List (NPL) Superfund site to provide the buyer with an addendum to the contract for the sale of the property that contains, in conspicuous type, identification of the Superfund site and its proximity to the property, the definition of a NPL Superfund site, and the Uniform Resource Locator (URL) for the U.S. Environmental Protection Agency Search for Superfund Sites Where You Live website; etc.