Dave Butler wrote:

Speaking as someone who pumped gas to earn tuition money back in the
early 60s before there was gasahol, we'd 'stick' the tanks daily at
closing time to verify the amount in the tanks. There was always some
water that was evident at the bottom of the stick, but it was never
more than an inch or so.

The only way we knew it to be "evident" was to put the paste on the stick
and note a color change...

I used to pump gas in the 70's, later I serviced the pumps and fuel systems
themselves (80's)...