Talk to former employees who may be a good source of information. Next, determine if there is reason to believe that contamination exists by walking the site and looking for visual clues. Signs of contamination include stressed vegetation, discolored soil, pits or drums, oil sheen on standing water, and discoloration of surface water. Check with DEP to see if a file exists for that site. Once you know what raw materials were used at the site, find out how they were disposed of.
Former employees can often provide helpful information.
Hire a consultant, once you've identified the probable contamination. For a recommendation, check with peers who have conducted site assessment work. Together, you and the consultant will put together a work plan. When you've put together a work plan, it's a good idea to have DEP review the work plan. It's not required, except on specific industrial area cleanups.