A Port-o-Potty in our Yard

When we came home from work today there was a port o potty in our yard!! I think they are working on the streets/water, but still, did they really have to put that in our yard? And one of their pipes is in our garden. Nelson tried calling the public works but no answer, so then he tried the non-emergency number of the police department but they said call public works. So he will try again in the a.m. to get this resolved. We don't have an easement in our front yard so that property is all ours (except maybe a foot in from the street but the port o potty is clearly in our yard). One of our neighbors even came and knocked on our door to make sure we were aware of it being there. Kinda a silly question seeing how big and obvious it is. But we will see what happens with it tomorrow!