What is the meaning of environmental baseline survey?

(DoD) A multi-disciplinary site survey conducted prior to or in the initial stage of a joint operational deployment. The survey documents existing deployment area environmental conditions, determines the potential for present and past site contamination (e.g., hazardous substances, petroleum products, and derivatives), and identified potential vulnerabilities (to include occupational and environmental health risks). Surveys accomplished in conjunction with joint operational deployments that do not involve training or exercises (e.g., contingency operations) should be completed to the extent practicable consistent with operational requirements. This survey is performed in conjunction with the environmental health site assessment whenever possible. Also called EBS. See also general engineering.