FSMA Agricultural Water Microbial Quality Standards

Introduction to FSMA Water Standards

The Food Safety Modernization Act (FSMA) represents the most sweeping reform of our food safety laws in more than 70 years. Enacted in 2011, FSMA aims to ensure the U.S. food supply is safe by shifting the focus from responding to contamination to preventing it. One critical component of FSMA is the Produce Safety Rule, which establishes science-based minimum standards for growing, harvesting, packing, and holding produce on farms.

Agricultural water quality is a key focus within the Produce Safety Rule, as water is a common pathway for pathogens that can contaminate produce. The agricultural water standards specifically address microbial quality to reduce the risk of contamination by harmful microorganisms in water used for growing produce or for certain post-harvest activities.

Types of Agricultural Water Covered

FSMA's agricultural water standards cover two distinct categories of water use on produce farms:

• Production Water: Water used to directly contact produce during growing activities. This includes irrigation water that contacts the edible portion of the crop, water used for preparing crop sprays, and water used for cooling or other field operations.
• Post-harvest Water: Water used during or after harvest to directly contact produce. This includes water used for washing, cooling, waxing, or other similar operations that occur after produce is harvested.

Notably, water used exclusively for hand washing during harvest is subject to other standards outside the agricultural water requirements.

Microbial Quality Criteria

The FSMA agricultural water standards establish specific microbial quality criteria based on two key indicators:

• Generic E. coli: A fecal indicator organism that suggests potential contamination by animal or human waste and possible presence of pathogens.
• Pre-harvest interval: The time between water application and harvest, which allows for natural microbial die-off between application and when produce is consumed.

Sampling and Testing Requirements

The frequency of water testing depends on the type of water source and how the water is used:

For each testing event, samples must be collected using appropriate methods and analyzed for generic E. coli using either direct Enumeration Method or Alternative Testing Methods validated by the FDA.

Microbial Quality Criteria Based on Use

The microbial quality criteria vary based on how the water contacts produce:

Production Water

• Direct Contact with Edible Portion: No detectable generic E. coli in 100 mL water sample
• Indirect Contact (e.g., drip irrigation below soil surface): Geometric mean of 126 CFU/100 mL or less and statistical threshold value of 410 CFU/100 mL or less

Post-Harvest Water

• Water quality criteria similar to production water for direct contact
• For treatment water systems, specific criteria based on antimicrobial treatment efficacy

Corrective Actions

When testing results indicate that agricultural water does not meet the microbial quality criteria, farms must implement corrective actions. These may include:

• Repeating the water test within a reasonable timeframe
• Implementing measures to treat the water to achieve appropriate microbial quality
• Changing the source of water
• Applying intervals between water applications and harvest to allow for microbial die-off
• Discontinuing use of the water until appropriate corrective actions are taken

For post-harvest water, farms must discontinue use of the water immediately if it does not meet the microbial quality criteria and implement corrective actions before resuming operations.

Compliance Timeline

The compliance timeline for FSMA's agricultural water standards varies based on farm size:

• Small Businesses ($25,000 and <$500,000 in annual produce sales): January 26, 2024
• Very Small Businesses ($25,000 and <$250,000 in annual produce sales): January 26, 2025
• Other Businesses ($500,000 in annual produce sales): January 26, 2023

Note that these dates may be subject to extension or modification by the FDA.

Exemptions and Qualified Exemptions

Certain farms and produce may be exempt from or subject to modified requirements of the Produce Safety Rule, including the agricultural water standards:

• Farms with average annual produce sales of less than $25,000: Exempt from the Produce Safety Rule
• Qualified Exemptions: Farms with an average annual monetary value of produce sold during the previous three-year period of less than $500,000 and whose sales to qualified end-users exceed sales to others
• Produce rarely consumed raw: Some produce that is rarely consumed raw is exempt from certain requirements
• Personal/Congregate food consumption: Produce consumed on-farm or at certain other locations

Farms with qualified exemptions must still comply with certain requirements, including prominently displaying the farm's name and business address on packaging or at point of purchase.

Implementation Strategies

Implementing FSMA agricultural water standards requires a systematic approach:

1. Conduct a water system survey: Assess all water sources, distribution systems, and potential contamination sources
2. Develop a written water assessment: Document findings from the survey and identify potential risks
3. Create a sampling and testing schedule: Based on water type and frequency requirements
4. Establish corrective action protocols: Plan for what to do when water doesn't meet standards
5. Implement appropriate agricultural water treatment: If needed, consider physical, chemical, or biological treatments
6. Train employees: Ensure all workers understand their roles in water safety
7. Develop and maintain records: Document all testing, assessments, and actions taken

Agricultural Water Treatment Options

When water quality issues are identified, several treatment options may be employed:

• Physical treatments: Filtration, ultraviolet (UV) light, heat treatment
• Chemical treatments: Chlorine, peroxyacetic acid, ozone, hydrogen peroxide
• Biological treatments: Probiotic competitive exclusion approaches
• Process modifications: Changing application methods (e.g., moving from overhead to drip irrigation)

Farms must ensure that any treatment used is effective and does not create new food safety hazards or regulatory compliance issues.

Resources for Farmers

Several resources are available to help farms comply with FSMA agricultural water standards:

• FDA Produce Safety Rule Webpage: Official guidance and documents
• Produce Safety Alliance: Training curriculum and technical assistance
• State Departments of Agriculture: Many provide on-farm technical assistance
• University Extension Services: Technical support and research-based guidance
• Agricultural Water Quality Testing Labs: Accredited laboratories for water testing

Conclusion

FSMA's agricultural water microbial quality standards represent a significant advancement in produce safety. By implementing systematic water testing, monitoring, and appropriate corrective actions, farmers can reduce the risk of microbial contamination in their water supply and ultimately in the produce they grow.

While compliance requires effort and resources, these standards provide a framework for maintaining safe agricultural water practices. The focus on prevention rather than reaction helps ensure the safety of fresh produce from farm to fork, protecting both public health and the economic viability of produce operations.

Farms should begin by conducting comprehensive water system assessments, developing testing schedules, and establishing corrective action protocols. With proper planning, implementation of FSMA agricultural water standards can be effectively integrated into farm operations, contributing to the overall safety and marketability of fresh produce.