If this article is right and there is a risk of a large earthquake that will release a century of pressure buildup, it might be good to keep a week or two worth

If this article is right and there is a risk of a large earthquake that will release a century of pressure buildup, it might be good to keep a week or two worth of supplies, including a bucket with attachable toilet seat lid, bag of saw dust, and a shovel to bury the waste. If you're in a home, you might want to make sure that your supplies are more easily accessible from the perimeter of your structure in case enough damage is done that your home is not able to be entered. Ideally, a backyard shed or storage box would be the best place to store your supplies. If that's not available, in a garage near the rolling door or by a back door of the house. If as much damage occurs to water and waste water infrastructure as they fear, and if your home becomes inaccessible, it might be prudent to make sure that you also have several changes of clothes and a pair of boots in your kit. Basically, pretend that you're preparing for a week-long camping trip in the middle of nowhere and pack accordingly. Tent, sleeping bag, clothing, supplies, small solar panel to charge a phone, etc. It'll take a lot more space but it will make the (potential) experience a lot more tolerable.