This is why it is important for you to know about Cryptosporidium , and what you can do about it. This fact sheet answers some questions you may have about Cryptosporidium in your water. Cryptosporidium parvum is a parasite commonly found in lakes and rivers. If swallowed, it can cause cryptosporidiosis, a disease with symptoms of diarrhea, stomach cramps, and fever. Cryptosporidium is found in the stool of infected animals, especially livestock.
Infected stool is carried by runoff into streams.
Infected human stool can contaminate streams by sewage treatment discharges, septic tank leaks, or sewer overflows. Crypto is found in almost all surface waters in the United States. However, it is usually found in small amounts and is usually removed by modern water treatment processes. Infrequently, it enters our drinking water if a lot of it finds its way into the water source and a breakdown occurs in the treatment process. Drinking water and swimming pools are the most common waterborne routes of infection.