Yes, but that was his own tank. He didn't put her in someone else's.There was a case in England recently where the wife was missing for 40 years. She was in the septic tank. Husband is old and got life so he will die in prison.
Also, killing one's wife involves different motives than killing a random woman out jogging.
To be frank, there is meaning in why a husband might put his wife there: it reflects his opinion of her, and he's lazy.
Whereas a young man who kills a female jogger is, IMO, usually quite interested in her body, and is (horrible but true) excited by the whole process.
JMO