1) Measuring free residual chlorine is cheaper and faster than measuring faecal contamination but is only applicable when drinking water is disinfected either at the water source or by the household itself (with aquatabs or other similar reagent).
2) At the source level, this indicator will give a sense of the quality of the water committees’ work. At the household level, this indicator assesses the correct usage of the reagent.
3) BHA phrases the indicator slightly differently, as "percent of households whose drinking water supplies have a free residual chlorine (FRC) > 0.2 mg/L".