Bizarre petroleum smell in water

This is so weird it’s hard to wrap my head around. We put 10–12 gallons of house water in the fresh water fill up and didn’t notice anything at the time. First time using water at the sink we were overwhelmed by a strong diesel odor. To mitigate we put about 4-6 ounces of dish soap in the tank and ran down the road to shake contents, then dumped the tank and drained the lines. We think someone sabotaged our tank. Can’t think of anything else. Suggestions?

Sabotage, IMO.  No other way there would be a diesel smell in your water unless your house water comes from a contaminated well.  

Was there any sort of greenish tint to the water? If so, then the issue was not petroleum, but algae. We had a problem with that last year. I finally got it cleared up with a stronger sanitizing bleach solution than I would normally have used, followed by some baking soda to cut the bleach odor.

I use 1/2 cup of bleach and then fill my FWT and let it sit then give it a good flush to clean it out.