The HSTL program was created in 1990 jointly by ORD, the Office of Solid Waste and Emergency Response (OSWER) and the regional offices to expand the technical support available to Regional staff. It is managed within ORD's Office of Science Policy.

The Hazardous Substances Technical Liaison Program (HSTLP) was created to:

	Station a Hazardous Substances Technical Liaison (HSTL) in the Regions to facilitate access to ORD laboratories, national centers and ORD headquarters.
	Provide and facilitate ORD's technical support programs in Regional OSWER programs.
	Promote the use of sound science and engineering in Regional decision making in the OSWER programs.

The name of the program was changed in 2001 from "Superfund Technical Liaison Program" or STLP to reflect that the program assists other programs which focus on hazardous substances and/or hazardous wastes as well as Superfund.

Technical Liaisons are ORD senior scientists and engineers located in the Regional Superfund offices. They interact on a daily basis with Superfund Remedial Project Managers (RPMs), On-Scene Coordinators (OSCs), RCRA Project Managers, Federal Facility Project Managers, Regional management, and other regional scientists and engineers. The Liaisons foster communications, especially the transfer of scientific and engineering products, between ORD Laboratories and the Regions. They also provide direct assistance by applying their expertise in a variety of areas.