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Ian van BeersDebra Long

Rasha Maal‐Bared

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Objectives

ApplicationApplication

Monitoring  Treatment

Chemical, physical and biological variablesChemical, physical and biological variables

Correlations Predictors

Cryptosporidium and Giardia distribution (2012‐2014)Cryptosporidium and Giardia distribution (2012‐2014)

Spatial  Seasonal

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■ U.S. EPA Method 1623 ■ Variables examined 

■ Chemical: Orthophosphates, nitrates, ammonia (ppm)■ Biological: Total coliforms and E. coli.  ■ Physical : Ambient temperature and rainfall.

■ Statistics (Matched pair t‐test, Spearman correlations, Partial Least Square)

Methods

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Results I. Spatial variation

Protozoa� E.L.�Smith�intake�(#/100L)�

Rossdale�intake�(#/100L)�

p‐values*�(n=21)�

Cryptosporidium� 9.88�±�2.24��(n=�26)�� 6.72�±�1.10�(n=�39)�� 0.056�

Giardia� 33.78�±�43.11�(n=�26)�� 40.00�±�7.42�(n=�39)�� 0.034�

*Paired matched t‐test

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‐20.0‐10.00.010.020.030.040.0

020406080

100120140160180 Air Tem

perature (˚C)#(oo

)cysts/100L

E.L. Smith Crypto/Giardia Levels in Comparison to Ambient Temperature

E.L. Smith Crypto (#/100L) E.L. Smith Giardia (#/100L) E.L. Smith Air Temperature (˚C)

‐20.0‐10.00.010.020.030.040.0

0

50

100

150

Air Temperature (˚C)

#(oo

)cysts/100L

Rossdale Crypto/Giardia Levels in Comparison to Ambient Temperature 

Rossdale Crypto (#/100L) Rossdale Giardia (#/100L) Rossdale Air Temperature (°C)

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Results III: Correlations

Protozoa� E.L.�Smith�WTP� Rossdale�WTP�

Cryptosporidium�

Giardia�(0.008)��Turbidity�(<�0.0001)�Temperature�(0.0005)�TC�(0.02)�Nitrates�(0.03)�(‐)�

Giardia�(<�0.0001)�Temperature�(0.007)�TCs�(0.001)�E.�coli�(0.01)�Nitrates�(0.02)�(‐)�

Giardia�Temperature�(0.0042)�TC�(0.04)�Nitrates�(<�0.001)�(‐)�

Temperature�(p�=0.002)�Nitrates�(0.0004)�(‐)�

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Results IV: Predictors

Protozoa  E. L. Smith WTP Rossdale WTP

Cryptosporidium TurbidityTotal coliformsAmbient tempRainfallE. coli94.02 %*

E. L. Smith CryptoE. L. Smith GiardiaNitratesTotal coliforms Turbidity86.46 %*

Giardia All variables< 55 % 

E. L. Smith GiardiaAmbient tempE. L. Smith CryptoNitratesTurbidity 94.70 %*

*Cumulative % variation explained by first 5 variables by Partial Least Square Analysis

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• Urban, non-point sources may contribute to Giardia prior to the Rossdale.

• Presence of Giardia was more difficult to predict and exihibited less correlations.

• Monitoring some water quality variables upstream of treatment plants could be used to indicate changes in (oo)cyst numbers.

Conclusions

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• Rian Dickson• Preety Busawon• Pearl Poon• Steve Craik• QA and Environment laboratory staff

Acknowledgments