Defining ‘‘good’’ potable water quality: Which combination best represents acceptability for human consumption?
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AFree from suspended matter
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BColourless
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CFree from pathogenic organisms
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DTasteless (no offensive taste or odour)
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EAll the above
Answer
Correct Answer: All the above
Explanation
Introduction / Context:Potable water must meet microbiological and physicochemical standards to protect public health and ensure consumer acceptability. The listed attributes are routine indicators of aesthetic and sanitary quality at the treatment-plant outlet and at consumer taps.
Given Data / Assumptions:
- Treated municipal water supply.
- Compliance with typical standards for turbidity, colour, taste/odour, and microbiology.
Concept / Approach:
Safe drinking water should be aesthetically pleasing and pathogen-free. Absence of suspended matter and colour implies adequate clarification; lack of pathogens indicates effective disinfection and barrier integrity; neutral taste/odour suggests no residual contamination, algae, or excessive disinfectant by-products.
Step-by-Step Solution:
Ensure turbidity control (coagulation, sedimentation, filtration).Confirm disinfection performance (e.g., CT values for chlorine/ozone/UV).Monitor aesthetic parameters (taste, odour, colour) within guideline ranges.Verification / Alternative check:
Routine compliance monitoring (coliform absence, turbidity < threshold, colour units low, taste/odour complaints minimal) verifies “good” water quality.
Why Other Options Are Wrong:
- Any single attribute alone is insufficient; comprehensive quality demands all listed features together.
Common Pitfalls:
- Assuming colourless water is necessarily safe; microbiological safety is paramount.
- Ignoring distribution-system regrowth or intrusion after treatment.
Final Answer:
All the above.