I spent more than a decade working for the Public Works department in a large metro area, including a longer stint in the sewer department than I care to admit.
There are three kinds of sewers: Sanitary, Storm, and Combined. Combined is what was the normal way of doing things until the middle of the last century. With combined sewers, everything goes to the sewer treatment plant before being discharged into waterways. The problem is, when it rains, the amount of flow is too great for the size of sewer treatment plant that taxpayers/rate payers can afford. The overflow either has to be held somewhere for later treatment, or it gets discharged directly into waterways.
Most big cities have had some kind of "deep tunnel" project over the last 30 years or so. Those deep tunnels are essentially storage tanks. As expensive as they are, they're less expensive than a bigger treatment plant, and way less expensive than seperating the sewers.
If you're in an area with seperate sewers (essentially any area developed in the last 50 years or so), what goes into the storm sewers doesn't go to a treatment plant. It goes directly into waterways. It is very important that nothing but storm water goes into these sewers. And it's also important that storm water not go into the sanitary sewers or else the treatment plant will be overwhelmed, and there usually isn't much in the line of storage.
So if there are combined sewers in the area of these pumps, the fuel is just friend-ing-up the treatment system. If there are seperate sewers, the fuel is friend-ing-up the waterway that the storm sewers empty into. Either way, if something isn't done, either the Feds or the state will have a fit once they discover the problem.
Worst money pit of a car I ever owned was a 2000 VW Passat that I bought new. Farfegneugen
