CT Calc
Contact time needed to inactivate giardia and viruses, from the tables in EPA 815-R-99-013/Surface Water Treatment Rule Guidance Manual.
EPA tables
About
Disinfectant
Free chlorine
Chlorine dioxide
Chloramine
Ozone
Pathogen
Giardia
Viruses
Residual (mg/L)
≤ 3
pH
6 – 9
Temperature (°C)
0 – 25
Logs of inactivation
0.5
1
1.5
2
2.5
3
Enter a residual, pH and temperature to see the contact time.