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EF/ ICR Logo Source Water (Untreated) Levels of Cryptosporidium for
San Francisco Water Department


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 Cryptosporidium was found in the sample volume that was analyzed. Zero results do not indicate the absence of Cryptosporidium in the source water because the method recovery is low and the amount of sample analyzed is small. In other words, Cryptosporidium may be present in source water even if no oocysts are counted for the sample volume analyzed. The presence of Cryptosporidium 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 Partnership for Safe Water , an initiative between EPA, the States, and water suppliers to improve the performance of treatment.


Source Water (Untreated) Levels of Cryptosporidium for Blended Water from Two Water Treatment Plants

This water represents water from more than one treatment plant.
NO DATA - Click here to find out why.


Source Water (Untreated) Levels of Cryptosporidium for Hetch Hetchy Water Treatment Plant

Water Type Month Cryptosporidium Level (#oocysts/100L) Volume Analyzed
Surface Water JUL 1997 0 15
Surface Water AUG 1997 0 10
Surface Water SEP 1997 0 40
Surface Water OCT 1997 0 10
Surface Water NOV 1997 0 67
Surface Water DEC 1997 0 14
Surface Water JAN 1998 0 14
Surface Water FEB 1998 0 14
Surface Water MAR 1998 0 38
Surface Water APR 1998 0 18
Surface Water MAY 1998 NO DATA NO DATA
Surface Water JUN 1998 0 26
Surface Water JUL 1998 0 21
Surface Water AUG 1998 0 43
Surface Water SEP 1998 0 9
Surface Water OCT 1998 0 4
Surface Water NOV 1998 0 15
Surface Water DEC 1998 0 6


Source Water (Untreated) Levels of Cryptosporidium for Harry Tracy Water Treatment Plant

Water Type Month Cryptosporidium Level (#oocysts/100L) Volume Analyzed
Surface Water JUL 1997 0 20
Surface Water AUG 1997 0 769
Surface Water SEP 1997 0 20
Surface Water OCT 1997 0 10
Surface Water NOV 1997 0 40
Surface Water DEC 1997 0 11
Surface Water JAN 1998 0 2
Surface Water FEB 1998 0 20
Surface Water MAR 1998 0 24
Surface Water APR 1998 0 20
Not Reported MAY 1998 NO DATA NO DATA
Not Reported JUN 1998 NO DATA NO DATA
Not Reported JUL 1998 NO DATA NO DATA
Surface Water AUG 1998 0 15
Not Reported SEP 1998 0 14
Surface Water OCT 1998 0 9
Surface Water NOV 1998 0 14
Surface Water DEC 1998 0 11


Source Water (Untreated) Levels of Cryptosporidium for Sunol Valley Water Treatment Plant

Water Type Month Cryptosporidium Level (#oocysts/100L) Volume Analyzed
Not Reported JUL 1997 NO DATA NO DATA
Surface Water AUG 1997 0 9
Surface Water SEP 1997 0 20
Surface Water OCT 1997 0 20
Surface Water NOV 1997 0 17
Surface Water DEC 1997 0 12
Surface Water JAN 1998 0 5
Surface Water FEB 1998 0 2
Surface Water MAR 1998 0 5
Surface Water APR 1998 0 15
Surface Water MAY 1998 NO DATA NO DATA
Surface Water JUN 1998 0 16
Surface Water JUL 1998 0 11
Surface Water AUG 1998 0 23
Surface Water SEP 1998 0 24
Surface Water OCT 1998 0 7
Surface Water NOV 1998 0 7
Surface Water DEC 1998 0 15


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

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