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tap. Rather, corrective actions are that which is done to immediately correct
any deviation from critical control limits.
Hazard Control in Potable Water Systems
Supplemental hazard control is often, but not always, necessary for the
control of microbial hazards in the potable water system of US buildings.
Water Management Teams should always begin with the simplest, safest
and most cost-effective option for building water system hazard control.
There is ample evidence from laboratory tests, pilot scale simulations
and practical real-work experience that sodium hypochlorite treatment of
building water systems is often the simplest, safest and most cost-effective
option. In chlorinated building water systems where microbial fouling
persists, usually the problem is due to lack of adequate distribution of
disinfectant throughout the facility.
Pilot-scale Potable Building Water System
A study to compare the efficiency of different disinfectants applicable
to
Legionella
control in domestic potable water systems was undertaken.
A domestic water supply simulation unit that allowed simulation of real-
world conditions was developed for this purpose. The system, consisting
of seven identical rigs, was used to compare treatment efficiency under
equivalent conditions of system design, materials, hydraulics, water
quality, temperature and initial contamination. The water temperature
during all experiments was 35 °C and the pH was 8.5. Other details of
water chemistry and operating conditions were set to simulate building
water system conditions and have been previously described (Loret 2005).
