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Wholesome water and its requirements

Short answer

Wholesome water is safe, clear, odourless, pleasant taste, free from harmful organisms and chemicals. Physical: turbidity ≤5 NTU, colourless, odourless, cool. Biological: zero E. coli/100ml. Chemical: pH 6.5-8.5, TDS ≤1000 mg/l, hardness ≤500 mg/l, iron ≤0.3 mg/l, arsenic ≤0.05, fluoride ≤1.5, nitrate ≤50 mg/l, residual chlorine 0.1-0.2 mg/l.

What is meant by wholesome water? List the requirements for wholesome water according to its physical, biological and chemical characteristics.

Wholesome water is water that is safe to drink and suitable for domestic use. It is free from harmful organisms and chemicals, is clear, colourless, odourless, pleasant to taste, and does not harm health.

Requirements

Physical characteristics

  • Turbidity low (Nepal standard: 5 NTU, up to 10 NTU in small supplies).
  • Colourless (colour less than 5 TCU, maximum 15) and odourless.
  • Pleasant taste; temperature cool (about 10 to 25 degrees C).

Biological (bacteriological) characteristics

  • Free from pathogenic bacteria, viruses, protozoa and helminths.
  • Zero E. coli / thermotolerant coliform per 100 ml at the consumer's tap.
  • Free from algae and other organisms that cause taste, odour or toxins.

Chemical characteristics

  • pH in range 6.5 to 8.5.
  • Total dissolved solids not above 1000 mg/l; hardness not above 500 mg/l as CaCO3.
  • Iron up to 0.3 mg/l, manganese up to 0.2 mg/l, chloride up to 250 mg/l, sulphate up to 250 mg/l.
  • Toxic substances within limits: arsenic 0.05 mg/l, fluoride 0.5 to 1.5 mg/l, nitrate 50 mg/l, lead 0.01 mg/l.
  • Free residual chlorine about 0.1 to 0.2 mg/l at the tap.

(Values are as in the Nepal Drinking Water Quality Standards, 2062.)

✓ Answer checked by Claude Opus 5.5 (high effort)

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