https://www.siliconvalley.com/2022/09/02/residents-forced-to-sell-homes-as-part-of-earthquake-upgrade-at-largest-reservoir-in-santa-clara-county/

Last year, while they were sitting in their home in a picturesque wooded area along the shores of Anderson Reservoir between Morgan Hill and San Jose, Trevor Holler and his father, Martin Holler, noticed a bad smell.

It lasted for days. Then they realized it was coming from under the house.