CT Calc

WATER TREATMENT / A POCKET REFERENCE

The right CT.
Right where
you need it.

Disinfection calculations from the EPA’s published tables. Enter the conditions and get a reading, even when you’re offline.

Open CT Calc ↗

FOUR DISINFECTANTS · GIARDIA & VIRUSES

FIELD NOTE / WORKED EXAMPLE

Free chlorine → Giardia

Temperature
5 °C
Residual
1.0 mg/L
pH
7.0
Inactivation
2-log
CT REQUIRED / TABLE INTERPOLATION99.0mg·min/L

The manual’s regression gives 107 mg·min/L for the same conditions.

EPA TABLES→YOUR CONDITIONS→INTERPOLATED CT

01 / AT THE PLANT

No signal required.

The tables and calculations live on your device. Open the app once, then keep the reference close.

02 / BETWEEN ROWS

Read between the values.

Interpolation across temperature, and across residual and pH for free chlorine against Giardia.

03 / DEFINED LIMITS

The range stays explicit.

Conditions outside the published tables are refused. Cryptosporidium is not covered.

What it covers

Giardia from 0.5-log to 3-log inactivation in half-log steps, and viruses at 2-log, 3-log and 4-log — to 25 °C, for every disinfectant the manual tabulates. Cryptosporidium is not covered.

DisinfectantFromVaries over
Free chlorine0.5 °CTemperature, residual and pH
Chloramine1 °CTemperature
Chlorine dioxide1 °CTemperature
Ozone1 °CTemperature

READY WHEN YOU ARE

A reference you can
take into the plant room.

Open the calculator ↗