Hi Don,
The first ant invasion in my house this summer might be supporting your San Leandro prediction. Instead of entering from the roof and through the built-in microwave, this evening their sudden entry was from the under-counter cupboard where the gas pipe for my cooktop enters (I think that pipe runs under this home's concrete slab). Only pots and pans were in that cupboard, and no food was on the counter; they climbed to the counter and headed for the sink. Sudden ant invasions here sometimes precede or accompany nearby earthquakes, and it looks like this area is within your prediction's range.

http://www.indo.com/cgi-bin/dist
shows the distance between San Leandro, California, and Livermore, California, as the crow flies, is 22 miles (35 km) (19 nautical miles).

Mary C.