Common menu bar links

Environmental and Workplace Health

Print |

Canadian Guidelines for Household Reclaimed Water for Use in Toilet and Urinal Flushing

Table 4D: Indicative log removals of enteric pathogens and indicator organisms^a
Treatment	Indicative log reductions^b
Treatment	E. coli	Bacterial pathogens	Viruses	Phage	Giardia	Crypto-sporidium	Clostridium perfringens	Helminths
^aReproduced from EPHC/NRMMC (2005). ^bReductions are dependent on specific features of the process, including detention times, pore size, filter depths, disinfectant; N/A = not available. ^cSecondary treatment is described as a level of treatment that removes 85% of BOD and suspended solids, generally by biological or chemical treatment processes. Secondary effluent generally has BOD and suspended solids <30 mg/L, but concentrations may rise to >100 mg/L due to algal solids in lagoon or pond systems.
Primary treatment	0-0.5	0-0.5	0-0.1	N/A	0.5-1.0	0-0.5	0-0.5	0-2.0
Secondary treatment^c	1.0-3.0	1.0-3.0	0.5-2.0	0.5-2.5	0.5-1.5	0.5-1.0	0.5-1.0	0-2.0
Dual-media filtration	0-1.0	0-1.0	0.5-3.0	1.0-4.0	1.0-3.0	1.5-2.5	0-1.0	2.0-3.0
Membrane filtration	3.5->6.0	3.5->6.0	2.5->6.0	3->6.0	>6.0	>6.0	>6.0	>6.0
Lagoon storage	1.0-5.0	1.0-5.0	1.0-4.0	1.0-4.0	3.0-4.0	1.0-3.5	N/A	1.5->3.0
Chlorination	2.0-6.0	2.0-6.0	1.0-3.0	0-2.5	0.5-1.5	0-0.5	1.0-2.0	0-1.0
Ozonation	2.0-6.0	2.0-6.0	3.0-6.0	2.0-6.0	N/A	N/A	0-0.5	N/A
UV light	2.0->4.0	2.0->4.0	>1.0 adenovirus >3.0 enterovirus, hepatitis A	3.0-6.0	>3.0	>3.0	N/A	N/A
Wetlands - surface flow	1.5-2.5	1	N/A	1.5-2.0	0.5 -1.5	0.5-1.0	1.5	0-2.0
Wetlands - subsurface flow	0.5-3.0	1.0-3.0	N/A	1.5-2.0	1.5-2.0	0.5-1.0	1.0-3.0	N/A