Module 5 – Agricultural Water

Part 1: Production Water

Slide 4 - Two Sections on Water

• Sprout Safety Alliance.

Slide 8 - Production Water Concerns

• Beuchat, L.R. (2006). Vectors and conditions for pre-harvest contamination of fruits and vegetables with pathogens capable of causing enteric diseases. Brit Food J, 108(1), 38–53.

Slide 9 - Production Water Uses Include:

• Guan, T.Y., Blank, G., Ismond, A., & Van Acker, R. (2001). Fate of foodborne bacterial pathogens in pesticide products. J Sci Food Agric, 81(5), 503–512.
• Steele, M., & Odumeru, J. (2004). Irrigation water as source of foodborne pathogens on fruit and vegetables. J Food Prot, 67(12), 2839–2849.
• Stine, S.W., Song, I., Choi, C., & Gerba, C.P. (2005). Application of microbial risk assessment to the development of standards for enteric pathogens in water used to irrigate fresh produce. J Food Prot, 68(5), 913–918.

Slide 16 - Methods of Irrigation

• Steele, M., & Odumeru, J. (2004). Irrigation water as source of foodborne pathogens on fruit and vegetables. J Food Prot, 67(12), 2839–2849.

Slide 18 - Pathogens on Produce May Die Off Over Time

• Lopez-Velasco, G., Tomas-Callejas, A., Sbodio, A. O., Pham, X., Wei, P., Diribsa, D., & Suslow, T. V. (2015). Factors affecting cell population density during enrichment and subsequent molecular detection of Salmonella enterica and Escherichia coli O157: H7 on lettuce contaminated during field production. Food Control, 54, 165–175.
• Gutiérrez‐Rodríguez, E., Gundersen, A., Sbodio, A. O., & Suslow, T. V. (2012). Variable agronomic practices, cultivar, strain source and initial contamination dose differentially affect survival of Escherichia coli on spinach. J Appl Micro, 112(1), 109–118.
• Yuk, H. G., Warren, B. R., & Schneider, K. R. (2007). Infiltration and survival of Salmonella spp. on tomato surfaces labeled using a low-energy carbon dioxide laser device. Hort Technology, 17(1), 67–71.

Slide 21 - Generic E. coli is an Established Indicator

• Suslow, T. (2002). Eliminate Fecal Coliforms From Your Vegetable and Fruit Safety Vocabulary.
• United States Environmental Protection Agency (EPA) 2012 Recreational Water Quality Criteria
• Wade, T. J., Pai, N., Eisenberg, J. N., & Colford Jr, J. M. (2003). Do US Environmental Protection Agency water quality guidelines for recreational waters prevent gastrointestinal illness? A systematic review and meta-analysis. Environmental Health Perspectives, 111(8), 1102.

Slide 22 - Water Quality Criteria for Water Used During Growing Activities

• FD&C Act Chapter IV: Food, Section 342 Adulterated Food
• United States Environmental Protection Agency (EPA) 2012 Recreational Water Quality Criteria
• Food and Drug Administration (FDA) (2015) How did FDA Establish Requirements for Water Quality and Testing of Irrigation Water?  Questions and Answers with Samir Assar
• Suslow, T. (2009). Standards for Irrigation and Foliar Water Contact. Pew Charitable Trusts at Georgetown University. Produce Safety Project.
• Dufour, A., & Schaub, S. (2007). The evolution of water quality criteria in the United States. Statistical Framework for Recreational Water Quality Criteria and Monitoring, 65, 1.

Slide 23 - Geometric Means and Statistical Threshold Values

• Western Center for Food Safety. University of California Davis. Excel Tools to Calculate Geometric Means and Statistical Threshold Values

Slide 28 - Assessing Water Quality Now

• FSMA, Produce Safety Rule; Extension of Compliance Dates for Subpart E, 21 CFR 112 (2019), Comment/Response 9, page 9712.

Slide 29 - Where Do I Collect Samples?

• FSMA, Produce Safety Rule, 21 CFR 112 (2015), Comment/Response 237, pages 74451 to 74452.

Slide 31 - Where Do I Go For Testing?

• Pope, M. L., Bussen, M., Feige, M. A., Shadix, L., Gonder, S., Rodgers, C., Chambers, Y., Pulz, J., Miller, K., Connell, K., & Standridge, J. (2003). Assessment of the effects of holding time and temperature on Escherichia coli densities in surface water samples. Appl Environ Micro, 69(10), 6201–6207.
• EPA (2014). Method 1603: Escherichia coli (E. coli) in Water by Membrane Filtration Using Modified membrane-Thermotolerant Escherichia coli Agar (Modified mTEC). EPA-821-R-14-010. U.S. Environmental Protection Agency, Washington, DC.

Slide 32 - Equivalent Water Testing Methodologies

• FDA Fact Sheet. (2018). Equivalent Testing Methodologies for Agricultural Water.
• Francy, DS and Darner, RA. (2000). Comparison of methods for determining Escherichia coli concentrations in recreational waters. Water Research, 34(10): 2770–2778.
• Stoeckel, D., Clements, D., Fisk, C., Wall, G., Woods, K., and Bihn, E. (2019). The Water Analysis Method Requirement in the FSMA Produce Safety Rule. Factsheet.
• Pope, M. L., Bussen, M., Feige, M. A., Shadix, L., Gonder, S., Rodgers, C., Chambers, Y., Pulz, J., Miller, K., Connell, K., & Standridge, J. (2003). Assessment of the effects of holding time and temperature on Escherichia coli densities in surface water samples. Appl Environ Micro, 69(10), 6201–6207.
• EPA (2014). Method 1603: Escherichia coli (E. coli) in Water by Membrane Filtration Using Modified membrane-Thermotolerant Escherichia coli Agar (Modified mTEC). EPA-821-R-14-010. U.S. Environmental Protection Agency, Washington, DC.
• EPA (2010). Escherichia coli (E. coli) in Water by Membrane Filtration Using membrane-Thermotolerant Escherichia coli Agar (mTEC). EPA-821-R-10-002. U.S. Environmental Protection Agency, Washington, DC.
• APHA (2012). Natural Bathing Beaches (2007). In: Standard Methods for the Examination of Water and Wastewater, 22nd Edition (Rice E.W., et al., Ed.), 9-46 – 9-48. American Public Health Association, Washington, DC.
• ASTM (2000). Standard Test Method for Isolation and Enumeration of Escherichia coli in Water by the Two-Step Membrane Filter Procedure. In: Annual Book of ASTM Standards, Volume 11.02. ASTM International. (1996, 1999, 2000).
• Hach Company. Method 10029: Coliforms, Total and E. coli: m-ColiBlue24 Broth PourRite Ampules. Doc316.53.01213. Hach Company.
• APHA (1997). Standard Total Coliform Membrane Filter Procedure (1997), followed by 9222 G – MF Partition Procedures (1997) using NA-MUG media. In: Standard Methods for the Examination of Water and Wastewater, 21st Edition (Eaton A.D., et al., Ed.), 9-60 – 9-65, and 9-70 – 9-71, respectively. American Public Health Association, Washington, DC. (2005).
• EPA (2002). Method 1604: Total Coliforms and Escherichia coli in Water by Membrane Filtration Using a Simultaneous Detection Technique (MI Medium). EPA-821-R-02-024. U.S. Environmental Protection Agency, Washington, DC.
• IDEXX, Inc. Colilert .
• IDEXX, Inc. Colilert-18.

Slide 33 - Equivalent Water Testing Methodologies

• FDA Fact Sheet. (2018). Equivalent Testing Methodologies for Agricultural Water.
• Stoeckel, D., Clements, D., Fisk, C., Wall, G., Woods, K., and Bihn, E. (2019). The Water Analysis Method Requirement in the FSMA Produce Safety Rule. Fact Sheet.
• EPA (2014). Method 1603: Escherichia coli (E. coli) in Water by Membrane Filtration Using Modified membrane-Thermotolerant Escherichia coli Agar (Modified mTEC). EPA-821-R-14-010. U.S. Environmental Protection Agency, Washington, DC.
• EPA (2019). Analytical Methods Approved for Compliance Monitoring under the Ground Water Rule.  EPA-815-B-19-006. U.S. Environmental Protection Agency, Washington, DC.  
• Code of Federal Regulations 2018 Alternative Testing Methods for Contaminants Listed at 40 CFR 141.21(f)(6) (E. coli).
  • Modified Colitag Reference 13:  Modified Colitag^TM Method, “Modified Colitag^TM Test Method for the Simultaneous Detection of E. coli and other Total Coliforms in Water (ATP D05-0035),” August 28, 2009. Available at http://www.nemi.gov or from CPI, International, 580 Skylane Boulevard, Santa Rosa, CA 95403
• Code of Federal Regulations 2018 Alternative Testing Methods for Contaminants Listed at 40 CFR 141.402(c)(2) (E. coli)
  • Readycult reference 20: Readycult^® Method, “Readycult^® Coliforms 100 Presence/Absence Test for Detection and Identification of Coliform Bacteria and Escherichia coli in Finished Waters,” January, 2007. Version 1.1. Available from EMD Millipore (division of Merck KGaA, Darmstadt, Germany), 290 Concord Road, Billerica, MA 01821
  • Colilert, Colisure, Colilert-18 referenced as Standard Methods 9223 B
  • Tecta EC/TC Reference 33: Tecta EC/TC. “Techta^TMEC/TC Medium and Techta^TMInstrument: A Presence/Absence Method for the Simultaneous Detection of Total Coliforms and Escherichia coli (E. coli) in Drinking Water,” version 1.0, May 2014. Available from Pathogen Detection Systems, Inc., 382 King Street East, Kingston, Ontario, Canada, K7K 2Y2
  • Tecta EC/TC Reference 43: Tecta EC/TC. “Tecta^TM EC/TC Medium and the Tecta^TM Instrument: A Presence/Absence Method for the Simultaneous Detection of Total Coliforms and Escherichia coli (E. coli) in Drinking Water,” version 2.0, February 2017. Available from Pathogen Detection Systems, Inc., 382 King Street East, Kingston, Ontario, Canada, K7K 2Y2
• Charm Sciences documentation
  • E*Colite Vial Test for Total Coliforms and E. coli in Potable Water: resources.charm.com/file/120
  • E*Colite: Test for Total Coliforms and E. coli in Potable Water: resources.charm.com/file/89

1. TECTA^TM EC/TC medium and the TECTA^TM Instrument: A Presence/Absence Method for the Simultaneous Detection of Total Coliforms and Escherichia coli (E. coli) in Drinking Water. (2017). Veolia Water Technologies 
2. Modified Colitag^TM Test Method for the Simultaneous Detection of E. coli and other Total Coliforms in Water. ATP D05-0035. (2009).
3. IDEXX Colilert Test Kit 
4. IDEXX Colilert-18 Test Kit 
5. IDEXX Colisure Test Kit
6. E*Colite Bag or Vial Test for Total Coliforms and E. coli in Potable Water. Charm Sciences, Inc.
7. 101298 Readycult Coliforms 100. EMD Millipore (division of Merck KGaA, Darmstadt, Germany).

Slide 38 - Corrective Actions Needed? Unintentional Water Contact

• FDA Guidance for Industry: Evaluating the Safety of Flood-affected Food Crops for Human Consumption

Part 2: Postharvest Water

Slide 61 - Turbidity

• Suslow, T. (2012). Top FAQs about Produce Wash Water Management for Small-Scale and Direct Market Farms (Including the Secchi Disk method)

Slide 64 - Choosing an Antimicrobial Product, Including Sanitizers

• Suslow, T. (1997). Postharvest Chlorination. University of California, Division of Agriculture and Natural Resources. 
• Suslow, T. (2004). Ozone applications for postharvest disinfection of edible horticultural crops. University of California, Division of Agriculture and Natural Resources. 
• Suslow, T. (2006). Making sense of rules governing chlorine contact in postharvest handling of organic produce. University of California, Division of Agriculture and Natural Resources. 
• University of California Davis: Postharvest Technology Yellow Pages

Slide 65 - Follow the Label!

• Suslow, T. (2001). Water Disinfection: A Practical Approach to Calculating Dose Values for Preharvest and Postharvest Applications. University of California, Division of Agriculture and Natural Resources. 
• U.S. EPA Antimicrobial Products Registered with the EPA as Sterilizers
• Clements, D., Wall, G., Stoeckel, D., Fisk, C., Woods, K., & Bihn, E. Introduction to Selecting an EPA-Labeled Sanitizer. Produce Safety Alliance
• U.S. FDA Decision Tree for Determining Whether any Particular Antimicrobial Intervention for Food is Regulated by the Environmental Protection Agency or the Food and Drug Administration

Slide 67 - Oxidation Reduction Potential (ORP)

• Suslow, T. (2004). Oxidation-Reduction Potential for Water Disinfection Monitoring, Control, and Documentation. University of California, Division of Agriculture and Natural Resources.