The more protective risk levels stem from the draft 2001 TCE health risk assessment:
http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=23249

Those levels are reflected in the new EPA draft vapor intrusion guidance:
http://www.epa.gov/epaoswer/hazwaste/ca/eis/vapor.htm

As a result of this new assessment nearly all EPA regions and many states have adopted the more protective risk levels; below are web links to those regions that have published this in formation on line:
http://www.epa.gov/region4/waste/ots/healtbul.htm#hhexp
http://www.epa.gov/region6/6pd/rcra_c/pd-n/screen.htm
http://www.epa.gov/reg3hwmd/risk/human/rbc/rbcl003.pdf
http:/www.epa.gov/region09/waste/sfund/prg/index.htm

Below are some web sites that help explain the TCE and vapor intrusion issues:

http://www.geosyntec.com/vi_links.asp
http://www.envirogroup.com/vaporintrusionnewsletter.htm
http://www.svtc.org/sustwater/moffett/ tce_03.htm
http://www.cpeo.org/

For information about The Campaign for Responsible Development, visit:
http://www.fresc.org

If you have any questions not answered in this flyer, please call:
Steven Beda, 303-477-6111 x17
VaishaLee Mishra, 303-477-6111 x l5
at The Front Range Economic Strategy Center