I live in San Lorenzo. It is a great place to be. There are different areas to consider, depending on your needs and price range. We have a listing that is not on the market yet at 16134 Via Chiquita. It is in the heart of San Lorenzo in a good neighborhood. It should be listed around $300,000. If you want to take a look at it, give me a call at 510-501-5865 or email me at firstname.lastname@example.org.
As for earthquake fault line, I believe the nearest major fault line is along the Hayward hills by CSU East Bay. The homes in our neighborhood withstood all the major earthquakes the last 50 years+, so we are not too concerned.
There are some minor flood zones along the channel way and in a few spots. I'd have to look at a flood map.
In general, the closer you get to 880 the lower the the home values.
Keller Williams Realty
Go to this site to see the fault lines in Northern Califonria (Bay area) http://geology.about.com/library/bl/blwg02map.htm
As for asbestos, visit this site for do's and don'ts about asbestos in a home http://www.epa.gov/asbestos/pubs/ashome.html#dosdonts
Depending on what you're looking for and what your budget is, this is a good time to be a buyer because of the many choices.
Let me know if you need additional information. Call or email me.
510 205 2992 cell