two years later; the kitchen sink took over an hour to drain. Because the waste liquid didn't back up immediately, it was obvious that the cause was a main line blockage.
We compost most of the food waste that used to go down the garbage disposal; the line couldn't have accumulated that much gunk in 23 months, right? On successive nights I poured one gallon of lye solution (a brand that will remain unnamed) down the sink and let it sit overnight. No luck.
When the Roto-Rooter guy arrived, I saved him the trouble of working under the sink and directed him to the kitchen clean-out by the side of the house. After running the machine, he was done in under an hour. The cost was over $300, 50% higher than two years ago, and he spent less time. Well, why not? We who live on the Peninsula are all wealthy [said in a very sardonic tone for all you non-native English speakers].
I have no one to blame but myself. Forget about the drought---I'm running hot water down the sink on a regular basis and applying an enzymatic cleaner once a month. I won't be needing Roto-Rooter---at least for the kitchen---again.
On a positive note, I had spent a few bucks extra for the lye cleaner that was labelled "guaranteed to work." Home Depot gave me a full refund.