EPA listed Giardia lambia as a Primary Pathogen in sludge Biosolids in 1989
23.    Giardia lambia ------------------------------------  Giardiasis

During the past 2 decades, Giardia infection has become recognized as one of the most common causes of waterborne
disease (found in both drinking and recreational water) in humans in the United States . Giardia are found worldwide
and within every region of the United States.
http://www.cdc.gov/Ncidod/dpd/parasites/giardiasis/factsht_giardia.htm#what

Symptoms include diarrhea, abdominal pain, bloating, nausea, and vomiting.  In chronic giardiasis the
symptoms are recurrent and malabsorption and debilitation may occur.
http://www.dpd.cdc.gov/dpdx/HTML/Giardiasis.htm

A potentially serious consequence is nutritional insufficiency which may result in impaired growth and development of
infants and children.
Other reported associations with giardiasis in children include malabsorption of iron,
allergic reactions, inflamation of the synovial membranes of major joints, and nonprogressive retinal
changes; these all require
additional study.
http://www.epa.gov/waterscience/criteria/humanhealth/microbial/giardiafs.pdf

The giardia parasite is the most common intestinal parasite worldwide, infecting an estimated 200 million people each
year.

No drug can prevent giardia infection. And exposure to giardia parasites in food or municipal drinking water is
unavoidable.

Each year in the United States, about 250 people in every 10,000 contract giardiasis from public drinking
water
.

the giardia parasite isn't just a problem in developing nations. Giardia infection (giardiasis) is one of the most common
waterborne diseases in the United States. Though the parasites are often associated with backcountry streams and
lakes, they also turn up in municipal water supplies, swimming pools, whirlpool spas and wells. Giardia infection, which is
highly contagious, also can be transmitted through food and person-to-person contact.

Most cases of giardia infection clear up in two to six weeks without lasting effects. But some people have recurrent
episodes for years or have intestinal problems long after the parasites are gone. Children who have a severe giardia
infection may fail to grow normally or have learning difficulties later in life.

Lactose intolerance. Many people with giardia infection develop lactose intolerance — the inability to
digest milk sugar. The problem may persist long after the infection has cleared, leading to malabsorption
and weight loss in some.

Skin rash. In rare cases, giardia infection may cause a skin rash or hives.

Signs and symptoms of giardia infection usually improve in two to six weeks, but in some people they become chronic,
lasting for months or years.

Drug resistance is also a growing problem, especially in people who need longer therapy or who are treated more than
once.
http://www.mayoclinic.com/health/giardia-infection/DS00739