Abstract: A method and system for allocating cost of treatment, storage, and disposal of waste material generated to sites of generation thereof. At least one database containing information including sites of waste material generation and routes of possible flow of waste material after it is generated to disposal thereof is provided in a computer memory. Information containing the date, type, source, cost, and destination for each transaction of the waste material generated is input to the computer. The computer is operated to recursively search the inputted transactions to locate all transactions of the waste material having a type and destination which match the type and source of the previously located transactions respectively of the waste material for which cost is to be allocated and having transaction dates which are on or before the respective dates of subsequent transactions of the waste material in the flow routes respectively thereof to thereby locate sites of generation of the waste material.