In my 'real' life, I work as a civil/environmental engineer doing the clean-up of sites like the Tustin base. Disclaimer: I've not had any involvement with the Tustin base and its redevelopment, although I have done work on other military facilities, as well as a small project for the Irvine Ranch Water District. I did a quick review of EPA's Record of Decision for the Tustin site, and, for myself, I would not have a concern for living on the redeveloped site. If I had small kids that would play in the dirt in the back yard (if I had a back yard!), I might want to take a look at the contaminant maps to see what concerns were present in the immediate area where I plan to live, and then get a more complete description of the remediation that was undertaken for those concerns. If contaminated soil was present, was it left in place, treated in place, or removed? What level of contamination was permitted to remain? At what depth? As far as the tap water is concerned, it comes from the same sources as all the other drinking water in Irvine, so there's no added concern because of possible groundwater contamination beneath your home. You don't use the groundwater for anything, not even irrigation. There are two concerns with groundwater and soil that I consider legitimate. First, are volatile organic chemicals (VOCs) diffusing from the water, upward through the unsaturated soil above it, and entering the breathing space of your home? I believe this to be extremely unlikely in this instance, because it is one of the risks considered (and addressed) before the developer was allowed to build on the property. Also, Southern California homes in general are NOT tightly built. Any gaseous contaminant that manages to diffuse through your floor will pass quickly out to the outdoor air. It won't accumulate in the home. The second possible concern is fruits and garden crops grown, either in contaminated soil, or in areas where contaminated groundwater would be drawn into the roots. I would rank this concern as very minor for three reasons. If shallow soils were contaminated, they would have been excavated and replaced as part of the remediation process. Second, the groundwater depth is listed as being between four and 34 feet beneath the surface at various locations on the site, according to the document I scanned. Few food crops have roots that go that deep. I am not an agricultural expert, but I'll bet your typical backyard orange tree doesn't have roots deeper than five feet. Finally, what percentage of your food intake is from your backyard? Think of it like eating one slice of pizza. It may not be the most healthy food you will eat, but it's probably not going to kill you in moderation.