GAP Water Quality & Management 3 — Questions and Answers
Question 1: According to FDA's FSMA Produce Safety Rule, what is the geometric mean (GM) standard for generic E. coli in agricultural water used for direct contact with covered produce?
- 126 CFU/100 mL (Correct answer)
- 235 CFU/100 mL
- 10 CFU/100 mL
- 410 CFU/100 mL
Correct answer: 126 CFU/100 mL
The FSMA Produce Safety Rule sets a geometric mean of 126 CFU/100 mL for generic E. coli in untreated surface water used for direct produce contact.
Question 2: What is the purpose of maintaining a 'buffer zone' or setback between a water source and production fields under GAP?
- To reduce the risk of surface runoff carrying contaminants from neighboring areas into the water or field (Correct answer)
- To provide space for heavy machinery to turn around
- To meet zoning ordinances for agricultural land use
- To allow natural evaporation of excess irrigation water
Correct answer: To reduce the risk of surface runoff carrying contaminants from neighboring areas into the water or field
Buffer zones physically separate the water source or crop from potential contamination sources such as animal operations, roads, or flooded areas.
Question 3: A grower uses well water for irrigation and wants to assess contamination risk. Which site assessment factor is MOST important to evaluate?
- Proximity of the well to septic systems, animal operations, or latrines (Correct answer)
- Depth of the well casing below the surface
- Age of the pump installed in the well
- Color and odor of the well water
Correct answer: Proximity of the well to septic systems, animal operations, or latrines
Nearby septic systems or animal operations are the most significant contamination risk factors for a well because pathogens can travel through soil to the water table.
Question 4: How should water test samples be collected to ensure representative results for GAP compliance?
- At the point of use, such as the irrigation emitter or spray nozzle output (Correct answer)
- Only at the water source before entering the distribution system
- From standing puddles in the field after irrigation
- From the municipal meter at the farm entrance
Correct answer: At the point of use, such as the irrigation emitter or spray nozzle output
Sampling at the point of use captures any contamination introduced within the distribution system and reflects what actually contacts the crop.
Question 5: Which condition most commonly causes spikes in microbial contamination levels in surface water sources used for irrigation?
- Heavy rainfall events that increase runoff from surrounding land (Correct answer)
- Extended dry periods with low water flow
- Routine equipment maintenance near the pump station
- Increased sunlight during summer months
Correct answer: Heavy rainfall events that increase runoff from surrounding land
Rainfall events mobilize pathogens from animal waste, soil, and other sources through runoff into surface water bodies, causing sudden contamination spikes.
Question 6: Under GAP, which document must be completed to demonstrate compliance with agricultural water quality requirements?
- Water test records including sample date, location, method, and results (Correct answer)
- A verbal agreement with the testing laboratory
- An annual crop yield report submitted to the USDA
- A water use permit filed with the state environmental agency
Correct answer: Water test records including sample date, location, method, and results
Written records of water testing — including all sample metadata and results — are required to demonstrate GAP compliance during audits.
Question 7: What does 'sanitary survey' mean in the context of GAP agricultural water assessments?
- A physical inspection of the water source and its surroundings to identify potential contamination hazards (Correct answer)
- A laboratory analysis of water samples for chemical residues
- A government inspection of the farm's irrigation infrastructure
- An annual review of water usage volumes compared to crop needs
Correct answer: A physical inspection of the water source and its surroundings to identify potential contamination hazards
A sanitary survey is an on-site visual inspection that identifies hazards such as animal intrusion, failing infrastructure, or nearby pollution sources that could compromise water quality.
GAP Water Quality & Management 3
According to FDA's FSMA Produce Safety Rule, what is the geometric mean (GM) standard for generic E. coli in agricultural water used for direct contact with covered produce?