Some people may be more vulnerable to contaminants in the drinking water than the general population.

Immunocompromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune disorders, some elderly and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers. EPA/CDC (Center for Disease Control) guidelines on appropriate means to lessen the risk of infection by “Cryptosporidium” and other microbial contaminants are available from the Safe Drinking Water Hotline (800) 426-4791.