Causes of a Waterborne Giardiasis Outbreak

Abstract

In November 1981, a waterborne giardiasis outbreak occurred within the Highlands Water and Sanitation District in Colorado. Although the immediate cause of the outbreak was reduced chlorine contact time because of a pump failure, numerous design and operational deficiencies existed at the plant. Lack of chemical pretreatment, improper backwashing procedures, poor application of raw water to the filter, and failure to monitor plant conditions all contributed to the outbreak. Turbidity and bacteriological records did not indicate any problems, confirming the crucial role of proper design, installation, and operation of the multibarrier technique in preventing waterborne giardiasis outbreaks. Giardiasis is an intestinal disease most

Evaluating particle counters

“…Since promulgation of the Surface Water Treatment Rule (SWTR) 1 and confirmed outbreaks of cryptosporidiosis 2 and giardiasis, 3 , 4 interest in particle counters as a process monitoring device for water treatment facilities has increased. Under the SWTR, credit is given for log removal and inactivation of Giardia cysts based on the unit process operations in a treatment facility.…”