The EPA is certifying contractors for lead paint removal. They expect to certify 125,000 contractors. Any home or building built before 1978 is a potential job lead.
It's not the sort of thing that all pressure wash contractors want to get involved in but it could be very lucrative. If this kind of work is of any interest to you, check out the requirements here: http://www.epa.gov/lead/pubs/toolkits.htm