Fecal Indicators and Microbial Fecal Indicators and Microbial Pathogens in Effluent Irrigated Pathogens in Effluent Irrigated Crops and Soil Crops and Soil 1 , Osnat Gillor 1 , Nirit Bernstein 2 , Woutrina Miller 3 , Ezra Orlofsky 1 , Osnat Gillor 1 , Nirit Bernstein 2 , Woutrina Miller 3 , Ezra Orlofsky 3 and Stefan Wuertz 3 Karen Shapiro 3 and Stefan Wuertz 3 Karen Shapiro 1 Ben 1 Ben- -Gurion University, Israel Gurion University, Israel 2 Agricultural Research Organization, Volcani Center, Israel 2 Agricultural Research Organization, Volcani Center, Israel 3 UC Davis, California. 3 UC Davis, California.
Wastewater- - Its not all waste Its not all waste Wastewater � Many countries, especially poor and developing Many countries, especially poor and developing � ones, reuse wastewater in some way. ones, reuse wastewater in some way. � Wastewater is cheap, high in nutrients and Wastewater is cheap, high in nutrients and � available even in countries with water scarcity available even in countries with water scarcity problems. problems. � There is a need to assess the risks associated There is a need to assess the risks associated � with wastewater usage, especially vis- -à à- -vis vis with wastewater usage, especially vis agricultural application. agricultural application. � Adhesion to produce Adhesion to produce � � Survival/accumulation in soil Survival/accumulation in soil �
Israeli Policy Israeli Policy � Zero tolerance Zero tolerance � � Barrier method Barrier method � � Irrigating trees/horticulture only Irrigating trees/horticulture only � � Reallocation of potable water to the sector Reallocation of potable water to the sector � that needs it most that needs it most
Safety Guidelines Safety Guidelines � “ “Pathogens are rarely measured directly in Pathogens are rarely measured directly in � wastewater, because their concentrations vary wastewater, because their concentrations vary and analytical procedures are often difficult or and analytical procedures are often difficult or expensive to perform.” ” expensive to perform. – Guidelines for the safe use of wastewater, excreta and greywater Guidelines for the safe use of wastewater, excreta and greywater, vol 2 (WHO, , vol 2 (WHO, – 2006). 2006). � It is standard practice to assess microbial It is standard practice to assess microbial � contamination with indicator organisms contamination with indicator organisms � Total Coliform/E. coli Total Coliform/E. coli � � Enterococcus Enterococcus � � Viral indicators Viral indicators �
Objectives Objectives � Comparing the effectiveness of the Comparing the effectiveness of the “ “Indicator Indicator” ” � method to predict a health risk in soil and crops method to predict a health risk in soil and crops irrigated with treated effluents. irrigated with treated effluents. � Direct, quantitative testing of pathogens using Direct, quantitative testing of pathogens using � both culture dependent and culture independent both culture dependent and culture independent methods. methods. � Water: Ultrafiltration with cut Water: Ultrafiltration with cut- -off >35 KD off >35 KD � � Quantitative testing of indicators according to Quantitative testing of indicators according to � standard means standard means � Water/Produce : EPA Water/Produce : EPA � � Soil: Microbiology literature Soil: Microbiology literature �
Experimental Design Experimental Design Effluent/ Potable water Water Sample 5 Plots (N=5) Soil Sample Tomato Sample
Method validation – – Recoveries Recoveries Method validation from spiking studies from spiking studies � Protozoa are ~50% recoverable from all Protozoa are ~50% recoverable from all � matrices matrices � Culture dependent methods for bacteria Culture dependent methods for bacteria � show high replicability for water (70- -80%), 80%), show high replicability for water (70 but not for soil but not for soil � qPCR tends to show >100% recovery, but qPCR tends to show >100% recovery, but � within reason. within reason. � Standard methods for indicators are Standard methods for indicators are � replicable replicable
Results- - Effluent Water Effluent Water Results � Coliforms were always Coliforms were always � Effluent Water Characteristics detected in high detected in high abundance abundance 500 � Enterococcus and E. Enterococcus and E. � coli coli- - sometimes sometimes 400 CFU/100 mL Coliforms � Salmonella was Salmonella was � 300 Enteroccocus detected (putatively) in detected (putatively) in 200 E. Coli the time 2, as well as the time 2, as well as Salmonella E. coli E. coli 100 � Protozoa was detected Protozoa was detected � 0 at time 1 at levels that at time 1 at levels that time 0 time 1 time 2 approach the limit of approach the limit of detection detection
Soil Results Soil Results � In Soil, coliforms In Soil, coliforms � appear to be the appear to be the major indicator group major indicator group 100000 Coliforms present- - perhaps perhaps present Enterococcus 10000 E. Coli environmental environmental Salmonella 1000 � Salmonella (putative) Salmonella (putative) � 100 was identified in both was identified in both 10 treatment plots. treatment plots. 1 Tap 0 Eff 0 Tap 1 Eff 1 Tap 2 Eff 2
Interim Conclusions Interim Conclusions � Currently, the indicators exceed the Currently, the indicators exceed the � pathogens (represented by Salmonella) pathogens (represented by Salmonella) � Waiting for qPCR results Waiting for qPCR results �
Conclusion Conclusion �יבר��ימעל�חיכוהו��יוגה��יב�טפשו � ���היתותינחו��יתאל��תוברח�ותתכו �תורמזמל �דוע�ודמלי־אלו�ברח�יוג־לא�יוג�אשי־אל �׃המחלמ And they will hammer their swords into plowshares and their spears into pruning hooks. Nation will not lift up sword against nation, And never again will they learn war
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