Question

By people and animals pooping in or near the water, then decaying to form coliform bacteria as it flows in the stream. Animal and agricultural waste being carried from rain runoff into the waters of the land. Third world countries are more susceptible to coliform due to the bad environmental laws and infrastructure in place to handle such waste and disease carrying pathogens. People in poverty stricken countries gather diseased water to their homes for cooking and drinking which causes all the health problems and death rates of those areas.