USDA Ellen Phillips Good Agricultural Practices Water in ......Application Method Before Harvest E. coli: mean less than 126 MPN/100 ml. None > 235 no standard no standard During

Good Agricultural Practices Water in Field and Packing Shed

Purdue University Cooperative Extension Service is an equal access/equal opportunity institution.

“This activity was funded, by Purdue, as part of AgSEED Crossroads funding to support Indiana's Agriculture and Rural Development”.

Ellen Phillips USDA

Water: Major Source of Contamination for

Fresh Fruits and Vegetables • Pathogens Found in Water:

– Escherichia coli – Salmonella spp. – Cryptosporidium parvum – Cyclospora cayetanensis

E. coli Salmonella

Salmonella on muskmelon

Describe the water system •  Perform a sanitary survey

–  Water sources •  Water movement onto farm •  Portable, surface, well

–  Facilities •  Plumbing: back flow prevention? cross connections? dead

end lines? –  Equipment

•  Irrigation pumps, pipes, lines •  Water storage tanks

•  Testing Water – Sample water close to point of use

•  Water use –  Irrigation, application –  Post-harvest

•  Use water of appropriate microbial quality •  Treatment

•  Keep records of testing and results Purdue Extension Safewater Site https://engineering.purdue.edu/SafeWater/

Sanitary Survey

•  Run-off from surrounding areas •  Flooding •  Liquid manure applications •  Water Sources

– Potential upstream sources of contamination – Point-source contamination – Non-point-source contamination

•  run-off •  tile drains

Resource: http://indianamap.org

Contamination Human or animal feces is the most common source of contamination in water Prevent contamination by proper

–  Personal hygiene –  Livestock management –  Manure management

Water Sources

•  Public water systems

•  Surface water –  Ponds, ditches, streams, rivers

•  Wells –  Open –  Capped

Public Water Systems

•  Least likely to be contaminated •  Legally must be potable •  Request copies of water quality

tests at least annually

Surface Water • Most likely to be contaminated

– Run-off or wind-dispersal from animal facilities or compost operations

– Improperly treated sewage – Wildlife  

•  Protecting Surface Water –  Manage livestock and manure

appropriately –  Upgrade sewage systems (public

and private) –  Reduce run-off –  Maintain wetlands

Wells •  Less likely to be contaminated

–  Contamination can enter at the well-head •  Uncapped or improperly capped wells •  Damaged wellhead or casing risky

•  Protecting Wells –  Don’t mix pesticides or other chemicals near the well –  Don’t apply solid manure near well –  Use backflow prevention fittings when applying ag

chemicals through irrigation system –  Retire and properly cap abandoned or unused wells –  Keep livestock away from active recharge area –  Inspect wells annually

Image and reference: Indiana Farmstead Assessment: Drinking Water Well www.extension.purdue.edu/waterquality/resources/surveys/factsheets/farmassess1.htm

Sealed Well Managing the Wellhead Protection Area https://engineering.purdue.edu/SafeWater/wellhead/manage.htm

Pay Attention to Water Distribution Systems

•  Irrigation system parts –  How are they stored when not in use? –  If contaminated, how can they be cleaned? –  Potential for contamination while in use?

•  Plumbing connections –  No cross-connections in plumbing system –  Backflow prevention devices in place –  No dead-end or unused lines

Photo source: yelp.com Purely Water, Lake Hopatcong, NJ

Pay Attention to Water Storage

•  Water reservoirs or storage tanks –  Tanks for hand washing water –  Cisterns for rainwater collection –  Nurse tanks for pesticide applicators

Testing Water Sources •  Public water

–  Yearly (obtain tests from water company)

•  Surface water –  Yearly before use –  Regularly during use

•  Well water –  at beginning of season and then

every three months

Measuring Water Quality: Microbiological Tests

•  Sample close to point of use. •  Tests are used to track water quality, not

for daily monitoring •  Records of test dates and results are

important to establish patterns •  Change in pattern may indicate a problem

Microbial Tests Presence of indicator organisms means there may be a problem with fecal contamination Indicator organisms:

–  Total coliform –  Fecal coliform –  Generic E. coli Reported as MPN/100 ml

“Most Probable Number per 100 milliliters of sample”

Generic E. coli is the preferred indicator organism for GAPs

Microbial Standards for Water Before Harvest

“Agricultural water must be safe and of adequate sanitary quality for its intended use”

Proposed Produce Safety Rule, 2013 Industry standards are based on:

EPA drinking water standards or EPA recreational water standards

Industry standards vary with commodity

Proposed FSMA Rule •  compliance dates for water quality standards, and related

testing and recordkeeping provisions –  additional two years beyond the compliance dates of the final rule.

•  proposing a tiered and more targeted approach to testing each source of untreated water

•  reduce how often the water is tested, with the frequency depending on the water source (i.e. surface or ground water) and on the results of prior tests.

•  updating the microbial quality standard to reflect data that supports the 2012 Environmental Protection Agency recreational water quality criteria.

•  establishing a sufficient interval of days between last irrigation and harvest to allow time for potentially dangerous microbes to die off. (9/14)

Water Quality Before Harvest For water that DOES NOT contact edible portion of the crop:

Criteria from Leafy Greens Marketing Agreement (8/4/2010), derived from EPA recreational water standards.www.caleafygreens.ca.gov

Generic E. coli MPN/100 ml

Geometric mean of 5 samples

less than or equal to 126

Any single sample less than or equal to 576

Water Quality Before Harvest For water that DOES or is LIKELY TO contact edible portion of the crop:

Generic E. coli MPN/100 ml

Geometric mean of 5 samples

less than or equal to 126

Any single sample less than or equal to 235

Proposed  FSMA  Water  Quality  Microbial  Standards  Summary  

Produce Not Usually

Cooked

Produce Usually Cooked

Water Contacts Produce

Water Does Not Contact Produce or Food Contact

Surface

Any

Application Method

Before Harvest

E. coli: mean less than 126 MPN/100 ml. None > 235

no standard no standard

During/After Harvest

E. coli: zero or not detectable

no standard

no standard

courtesy W. Kline

Sampling Water Sources •  Contact lab before sampling

– Confirm desired tests available: •  Generic E. coli MPN for surface water OR test for potable water

– Request sampling instructions – Follow them! – Obtain containers – Request shipping information

•  Deliver as soon as possible, certainly within 24 hours of sampling •  Keep samples on ice

•  Create chain of custody forms – documents who took the sample –  time of sample collection –  time of delivery to the lab

Surface Water Test Record

Water Testing Methods •  Official Methods of Analysis of the Association

of Official Analytical Chemists (AOAC) International, 18th ed., rev 4., 2011)

•  Standard Methods for the Examination of Water and Wastewater (21st ed., 2005), American Public Health Association

•  FDA Bacteriological Analytical Manual (BAM) (8th ed., rev. A, updated 2011)

•  Or equivalent method

Indiana Certified Microbiology Drinking Water Laboratories

www.in.gov/isdh/22450.htm

When Water Source Doesn‘t Meet the Grade

•  Stop using the water •  Identify the problem

– One-time issue or ongoing? •  Well treatment

– Chlorine treatment of well. – See IDEM recommendations

https://engineering.purdue.edu/SafeWater/drinkinfo/welldisinfection.pdf •  Surface water treatment

– Chlorine treatment before irrigation

Irrigation water treatment: Dosatron injector

Water Uses

•  Irrigation •  Pesticide application •  Nutrient application •  Frost protection •  Postharvest

Irrigation •  Greatest Risk?

– Water contacting edible portion of crop near harvest • Drip Irrigation

–  Lower risk of crop contamination –  May not wet edible portion of crop –  High water use efficiency

• Overhead Irrigation –  Higher risk of crop contamination –  Likely to wet edible portion of crop

Water used for Pesticide, Nutrient Application and Frost Protection Water used to apply materials to crop should meet the same standards as irrigation water. • Nutrients • Pesticides • Frost protection

Preventive Controls Field Water

•  Select the source of water with lowest contamination –  Use only approved water treatments and follow label instructions

•  Test water quality of water sources •  Minimize water applied directly to edible part of plant •  Inspect and clean equipment

Postharvest Water Uses •  Washing •  Hydrocooling •  Ice •  Flumes •  Dump tanks •  Hydration

Photo credit: Lanes End Farm

Purpose of treating the water •  prevent cross-contamination by killing microbes in the water

Water Temperature •  Water can infiltrate into Produce

–  tomatoes, apples, cantaloupe

•  If water is colder than the product, it is sucked in •  Any pathogens enter with the water, could spread

through the product •  Most likely when product is submerged in water •  Keep dump tank water within 10°F of produce core

temperature for products where infiltration is likely –  water 10°F above produce is often recommended

Postharvest Water Quality At the start of the process . . .

•  All water that contacts the crop during and after harvest should meet EPA standards for microbial quality of drinking water(standards for potable water) • Test water source

Generic E. coli Test

negative

or below detection limit

Postharvest Water Quality

Water should be treated before use or reuse if: - doesn’t meet microbial standards for drinking water -  becomes contaminated during postharvest use

Sanitizers for Postharvest Water

Chlorine Peroxyacetic acid

Ozone UV-C Illumination

Source: Suslow, T. 1997. Postharvest chlorination. Pub. 8003, UCDANR. anrcatalog.ucdavis.edu/pdf/8003.pdf

Preventive Controls Postharvest Water

If you must use water after harvest: •  Start with water that meets microbial standards for

drinking water (potable water) •  Consider treatment for single-pass water •  If water is re-used, remove debris and treat •  Change water regularly (at least daily is recommended) •  Monitor sanitizer in water and keep records •  Keep dump tank water within 10°F of produce core

temperature for products where infiltration is likely (water 10°F above produce is often recommended)

•  Use only approved water treatments and follow label instructions

Potential Water Contamination: Flooding! We don’t always control the water…

•  Flood waters may contain –  Sewage –  Chemicals –  heavy metals –  pathogens

•  FDA considers food contacted by flood water to be “adulterated” and not fit for human consumption

“Flooding is the flowing or overflowing of a field with water outside a grower's control” FDA Guidance Evaluating the Safety of Flood-affected Food Crops for Human Consumption.

“Pooled water that is not reasonably likely to cause contamination of the edible portions of fresh produce is not considered flooding.” FDA Guidance Evaluating the Safety of Flood-affected Food Crops for Human Consumption.

Flood Waters Contact Edible Portion of Crop

•  Do not harvest for food •  Manage so that the contaminated crop

does not contaminate unaffected crops

FDA Guidance Evaluating the Safety of Flood-affected Food Crops for Human Consumption.

Flooding In or Near Crop Flood Waters do NOT Contact

Edible Portion “Evaluate on a case-by-case basis for

likelihood of contamination”"Consider testing for:"

Mycotoxins "Heavy metals"Pathogens "Pesticides"PCBs " "Other contaminants"

Get technical advice"

FDA Guidance Evaluating the Safety of Flood-affected Food Crops for Human Consumption.

Prevent cross contamination between flooded and non-flooded areas "

•  Document extent of flooding with photos and markers in field"

•  Clean equipment after use in flooded area"•  Avoid travelling through flooded area on

way to crop"•  Wear boots, gloves when working in

flooded areas"•  Don’t harvest near flooded area (30-ft.)"

•  Consider field history and crop selection •  Consider time between the flooding, planting and

harvest –  LGMA recommends 60 days before planting

•  Consider source of flood (drainage ditch, river, etc.) and potential for human pathogens

•  Allow soils to dry; rework before planting

•  Maybe: sample soil for microorganisms

Flooded Before Crop is Planted E

TM: IM

G_6211.JPG

FDA Guidance Evaluating the Safety of Flood-affected Food Crops for Human Consumption.

Notes on Sampling Soil for Microbes in Flooded Fields

•  Sampling does not guarantee that crops are pathogen-free.

•  EPA Soil Screening Guidance: Technical Background Document provides guidelines for sampling (see ch. 4). http://www.epa.gov/superfund/health/conmedia/soil/introtbd.htm

•  EPA Standards for the Use and Disposal of Sewage Sludge 40 CFR Part 503 provides criteria for microbial content (see ch.4).

http://water.epa.gov/scitech/wastetech/biosolids/

Pooled Water •  Contact with pooled water from irrigation or

rainfall should be avoided (ECFS) •  Reduce potential for contamination from pooled

water –  Protective barriers –  Staking –  Change irrigation method

FSMA: requires addressing risks of pooled water.

Water Recordkeeping •  Documentation and summary of survey •  Potable water for workers •  Source and method of irrigation •  Sampling location, date, and test results for

all water sources •  Procedures for water treatment •  Water treatment monitoring records •  Packing line water temperature records •  Procedure and records for cleaning of water

contact surfaces •  Documentation of potable water for ice

Purdue  University  is  an  Equal  Opportunity/Equal  Access  InsBtuBon  

Funded  in  part  by  a  USDA  Specialty  Crops  Block  Grant  from  the  Indiana  State  Department  of  Agriculture  

Questions?

Acknowledgments Por$ons  of  this  presenta$on  adapted  from  the  work  of:    

Elizabeth  Bihn,  NaBonal  GAPs  Program  at  Cornell  Wes  Kline,  Extension  Agent,  Rutgers  Liz  Maynard,  Extension  Specialist,  Purdue  ScoQ  Monroe,  Extension  Educator,  Purdue  North  Carolina  State  University  MarketReady  Team    NaBonal  GAPs  Program    Par$ally  Funded  by:    • Purdue, as part of AgSEED Crossroads funding to support Indiana's Agriculture and Rural Development • USDA Specialty Crops Block Grant from the Indiana State Dept. of Agriculture