CH2M HOLDS ON FOR NO. 1 SPOT; LIST SEES 3 NEWCOMERS Environmental Consultants Up 2.2% on OC Billings By By Samar Khoury Saturday, February 2, 2013 Tweet EMAIL Tetra Tech: Irvine office at 17885 Von Karman new entry at No. 2 on list The largest environmental consultants in Orange County were up about 2% in OC office billings last year... Take 1 minute to subscribe and you'll get this story, plus: Already a subscriber? Sign in 52 weekly issues Subscriber-only digital content every business day, plus full access to OCBJ.com archives Book of Lists — the most comprehensive business resource in Orange County NEW: Orange County 500 — influential business leaders you need to know Yours for only $99. Click Here for more information and subscription form.