Recommended Treatment Levels of Ozone For Particular Microbial Species

Note: The CT factor is the product of the ozone concentration and the contact time in minutes. Essentially, the higher the CT factor, the more difficult the organism is to kill. Note also that a microbial species with a CT factor of 0.01 for example will be killed by an ozone concentration of 0.01 mg/L end a contact time of 1.0 minutes, or an ozone concentration of 1.0 mg/L for 0.01 minutes, (0.6 seconds), e.g., the case with Staphylococcus aureus. – Similarly, 2.0 mg/L ozone, in the case of Staphylococcus will produce a CT factor of 0.01 in 0.005 minutes, or 0.30 seconds

 

Organism mg/O3/L Minutes CT
Algae (blue green) 0.30 5.0 1.5
Bacteria (all species), recommended 0.10 1.0 0.1
Aeromonas & Actinomycetes yes
Bacillus, all yes
Campylobacters yes
Clostridium Botulinum & others yes
Escherichia coli (E. coli) 0.04 1.0 0.04
coliphage MS2 0.20 0.5 0.1
Flavobacterium yes
Helicobacter (pylori) yes
Heterotrophic Bacteria,- HPC 0.20 0.5 0.1
Leqionella pneumophlia yes
Micrococcus, all yes
Mycobacterium tuberculosis, leprae 0.01 6.0 0.06
Pseudomonas aeruginosa, fluorescens 0.01 1.0 0.01
Salmonella, all 0.01 1.0 0.01
Shigella shigellosis dysentery yes
Staphylococcus sp, albus, aureus 0.01 1.0 0.01
Streptococcus all 0.01 2.0 0.02
Vibrio: aiginolyticus, anguillarium yes
cholerae, comma, parahemolyticus yes
Yersinia enterocolitica yes
Fungus, Molds, Yeasts 0.3 5.0 1.5
Mold Spores 0.03-0.30
Nematodes, all, recommended 1.0 5.0 5.0
Hook worm & etc. 0.3
Protozoa. all, recommended 7.5 5.0 0.1
Acanthamoeba & Naegleria 0.2 0.5 1.6
Amoeboe Trophozoites cysts 0.4 4.0 7.5
Cryptosporidium, recommended 5.0
Cyclospora yes 4.0
Entamoebea (histolytica) yes 2.5
Giardia lamblia 0.8 5.0
Giardia muris 0.50 5.0 2.5
Microsporidium yes 5.0
N. gruberi 0.50 5.0
Trematodes, all, recommended 1.0 5.0 1.6
Flat worms, flukes & etc. 0.3 0.9
VIRUS, all, recommended 0.40 4.0
Adenovirus, 7A 0.30 3.0
Astrovirus yes 1.2
Calicivirus yes
Echovirus 5,12 & 29 0.40 4.0 1.2
Encephalomyocarditis yes 0.6
Enterovirus, over 35 types 0.30 4.0 1.2
coxsachie, B3 & B5 0.60 1.0
poliovirus, 1, 2 & 3 0.30 4.0
Hepatitis, A E & HAV yes
nonA and nonB yes
Myxovirus Influenza yes
Norwalk yes
Picobimavirus yes
Reovirus 3 types, yes
Rotavirus, 3 types yes

Information written for the Drinking Water Unit of EPA’s Region 10 by Jim Eagleton.