Table 2.

Possible measures to reduce OPPP numbers in premise plumbing.

Measures to be taken	Outcome measure
Water provider action
Reduction of turbidity	Turbidity measurement
Reduction of biologically available carbon	AOC or BDOC measurement
Biofilm-discouraging pipes	Biofilm mass and microbial number reduction
Building manager or homeowner action
Raise hot water heater temperature	Temperature in hot water heater or tap
Employ point-of-use filters at taps and showers	Frequency of POU filters
Increase oxygen levels	Frequency of installed aerators
	Plumbing water oxygen levels
Abbreviations: AOC, assimilable organic carbon; BDOC, biodegradable dissolved organic carbon.