A community health officer inspects a village well. The 'sanitary survey score' approach to water quality assurance evaluates risk based on:

• A Chemical parameters such as nitrates, fluoride, and arsenic measured by laboratory titration
• B Presence of coliform organisms detected by membrane filtration at the time of inspection
• C Observable environmental deficiencies around the well that predict faecal contamination risk — each 'yes' response to a risk factor increases the risk score ✓
• D Turbidity and pH measured by portable meters during field visits

Explanation

The WHO Sanitary Survey (also called sanitary risk inspection) is a structured observational checklist applied at the water source that identifies environmental risk factors predisposing to faecal contamination — such as defecation within 10 m, damaged apron, drainage channel absent, latrine within 10 m, animal access to well, etc. Each identified deficiency adds to a numerical risk score (low, medium, high, very high risk). The sanitary survey does not require laboratory equipment and provides immediate, actionable field-level risk assessment. Bacteriological testing complements but does not replace sanitary survey.

Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.