structural:reformatting, quality:correction
Pathogens

Most of the bacteria, viruses, parasites, and fungi that contaminate well water comes from fecal material from humans and other animals. Common bacterial contaminants include E. coli, Salmonella, Shigella, and Campylobacter jejuni. Common viral contaminants include norovirus, sapovirus, rotavirus, enteroviruses, and hepatitis A and E. Parasites include Giardia lamblia, Cryptosporidium, Cyclospora cayetanensis, and microsporidia.