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EF/ ICR Logo Source Water (Untreated) Levels of Giardia for
McAllen Public Utilities


Water System Giardia Report
REMINDER: Data Purpose: The ICR data were collected as part of a national research project to support development of national drinking water standards. They should NOT be used to determine local water systems compliance with drinking water standards, nor should they be used to make personal judgements about health risks.

Detection Method Limitations: The ICR method for detecting Cryptosporidium and Giardia has technical limitations.

Results of Zero: A measurement of zero means that no Giardia was found in the sample volume that was analyzed. Zero results do not indicate the absence of Giardia in the source water because the method recovery is low and the amount of sample analyzed is small. In other words, Giardia may be present in source water even if no cysts are counted for the sample volume analyzed. The presence of Giardia may also be mistakenly identified as other organic material such as algae.

Efforts Beyond Regulations: Many large public water systems are voluntarily improving the control of pathogens by participating in the Pa rtnership for Safe Water, an initiative between EPA, the States, and water suppliers to improve the performance of treatment.


Source Water (Untreated) Levels of Giardia for McAllen Southwest Water Plant

Water Type Month Giardia Level (#cysts/100L) Volume Analyzed
Surface Water JUL 1997 NO DATA NO DATA
Surface Water AUG 1997 0 .3
Surface Water SEP 1997 0 .1
Not Reported OCT 1997 0 .2
Surface Water NOV 1997 0 2
Surface Water DEC 1997 NO DATA NO DATA
Surface Water JAN 1998 0 .4
Surface Water FEB 1998 0 .7
Surface Water MAR 1998 0 .7
Surface Water APR 1998 0 .3
Surface Water MAY 1998 0 .1
Surface Water JUN 1998 NO DATA NO DATA
Surface Water JUL 1998 0 .7
Surface Water AUG 1998 0 .1
Surface Water SEP 1998 0 .2
Surface Water OCT 1998 0 .2
Surface Water NOV 1998 0 .6
Surface Water DEC 1998 0 1


How does this utility's source water compare to source waters nationally for giardia? Click on "view report" to see the state and national levels of giardia.

Month State Report National Report
July 1997 view report view report
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Dec 1997 view report view report
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