Credit: Philadelphia Water Department Historical Collection 

In the late 1800s and early 1900s Philadelphia was infamous for having some of the most polluted rivers in the country, and thus some of the worst public water supplies. This 1928 photo shows wastes in Bridgeport Canal below the outlet of March Packing Company.  The Canal fed into the Schuylkill River, from which Philadelphia received much if its drinking water.  The investigator in the picture holds a pig gut on the end of the pole.