As you have asked about the steps to download the Central Public Health and Environmental Engineering Organisation (CPHEEO) Manual on Water Supply and Treatment, I am giving you information about it, check below for the details

You can download it from the CPHEEO website
To download it, you can follow steps given below

Go to CPHEEO website, the page open look like




Here place cursor on the CPHEEO Manuals in the left side of the screen.
Then click on Manual on Water Supply and Treatment, the page open look like



Here you will find the various parts of the manuals.
Click on it
Then you can download the manual.