Assuming a 40-hour week (which may not be the case), $40/hour works out to about $83,000/year. That may seem like a lot, but it depends on one's family structure and if there are other wage earners in the household. Marin is extremely expensive to live, and Sonoma isn't far behind. The Government's most recent definition of "low income" for a family of four (and I'm rounding here) for San Francisco/Peninsula/Silicon Valley is about $105,000 or less, and $85,000 or less for the East Bay. I would think the North Bay falls into that range. The job requires experience and already being a licensed engineer. If money is the object, one could easily make more working for a Class I (which, of course, ain't no 40-hour job).