@Matt M. & @Mike Wood
I reached out to several engineering companies and only this one responded. I sent him the geo-tech report that was done in 2010 and this was his response:
"Mark,
I have roughly reviewed the information you sent me.
I have the following comments:
1. Yes, I can assist you for this project.
2. For a site like this, I would use one of two methods for your new house foundations:
a. Don’t use excavation to avoid any environmental problem in soils.
b. Stabilize the soils by grouting and use mat foundation or similar.
c. Or install mini piles in additional to grouting or without grouting, depending upon the future detail investigation.
3. I may perform 2 additional deep borings to confirm the previous boring information.
4. I need to perform a site visit and need the previous boring location plan.
5. Do you have a site plan or survey drawing for your property?"
I'm trying to get my hands on the boring location plan from the previous testing, which is like pulling teeth. In the meantime, do either of this guy's solutions sound good? Cost prohibitive?