When possible, TxDOT should perform mitigation for known hazardous materials contamination or waste materials by using a specialty contractor prior to beginning work on a project. Mitigation work such as removal of underground storage tanks (USTs), removal of waste materials, and removal of contaminated soil often can be addressed prior to the start of construction. The Environmental Affairs Division (ENV) retains specialty contractors to performs this work. Contact ENV for technical assistance and to acquire the appropriate environmental service contracts.