Anyone who has worked on the construction of inverted siphons will tell you that sewage does not necessarily flow down hill.
Historic boundaries and conservation efforts.
But anything you drop will roll right into said sewage stream
About 35 years ago we were building a wastewater treatment plant that had an 84" inverted siphon included. After a pretty serious thunder storm the dirt contractor placed a pump to empty the pipe. The "none too bright" union operator placed a gasoline powered pump. After a couple of hours there was no water coming out so he figured it was dry. He went in to retrieve the pump. He didn't come out. Note to self and others. Carbon monoxide will shut down a gasoline engine AND kill you.
Andy
That is a sad story Andy. OSHA training for entry into confined spaces should be mandatory. Unfortunately construction workers are not hired for their brain power. I treat everyone with respect no matter what their educational level or rank in the organization. It should be the responsibility of all team members to look out for each other. It is also a crime if management considers the expense of proper precautions for entry into confined spaces a burden.
Historic boundaries and conservation efforts.