Water Quality & Management Flashcards
7 cards from real GAP practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Water Quality & Management flashcards as text
A farm uses reclaimed municipal wastewater for irrigation. Under GAP, what additional precaution is MOST critical compared to using potable water?
Answer: Verify the reclaimed water meets agricultural use standards and obtain documentation from the supplier
Reclaimed water must meet specific regulatory standards for agricultural reuse, and written documentation from the supplier is required to demonstrate compliance.
Which physical barrier is most effective at preventing wildlife from entering and contaminating an irrigation reservoir?
Answer: Fencing that completely surrounds the reservoir with a secure gate
A complete perimeter fence with a secure gate physically prevents wildlife from accessing the water and depositing fecal matter.
When testing agricultural water for microbial quality, what is 'statistical threshold value' (STV) used to measure?
Answer: The 90th percentile concentration of generic E. coli across multiple samples
STV represents the 90th percentile E. coli level across the dataset, indicating how bad contamination levels can get at their worst, complementing the geometric mean.
Which chemical treatment method is most commonly used by farms to disinfect agricultural water on-site before irrigation?
Answer: Chlorination
Chlorination is the most widely used and cost-effective on-farm disinfection method to reduce pathogen loads in irrigation water.
How does water temperature affect microbial survival in irrigation water stored in open ponds?
Answer: Warmer temperatures promote faster microbial growth and survival, increasing risk
Pathogens like E. coli and Salmonella multiply more rapidly in warmer water, making summer months a higher-risk period for open water sources.
Under GAP standards, how should a farm respond if water testing is not possible due to a laboratory closure or supply chain issue?
Answer: Use the most conservative water management practices and document the reason testing was not completed
When testing is genuinely impossible, applying conservative practices and documenting the circumstance demonstrates good faith GAP compliance.
What is the main food safety risk associated with using water from a flooded field or flooded water source for produce irrigation?
Answer: Floodwater may contain sewage, animal waste, and other pathogens at elevated concentrations
Flooding events mix surface water with sewage overflow and animal waste, dramatically elevating pathogen levels and making flooded water unsafe for produce irrigation.