Is this grey water or actual sewage? You can actually water plants with grey water.
Sounds like rain run-off. She should check to see what New Orleans does with their extra rain water. LOL!
Untreated sewage mixed with surface runoff. Seems that they run both through the same sewers.
Nothing wrong with grey water. Lotsa minerals. Bad bugs have been eliminated.
If you have ever, or never, you would get an eyeful in the Scottish town of Dunoon at low tide.
Look up and down the shore at all those sewage lines running into the bay. Right straight from the toilet into the water.
One does not walk along those shores there because there is things laying on that shore one does not want to step on.
And its the same with most of the towns along the shores there.