Requiring the seller of residential real property located within 1 mile of a National Priorities List (NPL) Superfund site to include a certain addendum, written in conspicuous type, to the contract for the sale of the property; requiring the addendum to provide notice that within 5 days after signing and dating the contract of sale and on written notice to the seller, the buyer may void the contract and is eligible to receive a full refund of any money paid to the seller; etc.