Piping Disinfection Certificate for Form 4 - A Contractor's Guide

Before a new building is occupied, you have to confirm that the water system is clean and safe to drink. Disinfecting the piping and the water test that follows are a precondition for obtaining Form 4. For contractors and project managers, we've gathered everything you need to know to clear this stage without delays.

Why Piping Disinfection Is Required Before Occupancy

During construction the piping is exposed to dust, welding residue, building materials and standing water. All of these create fertile ground for bacteria and biofilm. Before residents start drinking the water, the entire system must be disinfected and laboratory-verified to meet drinking-water values.

Stages of the Disinfection Process

• Initial flushing: running water through the system to clear residue and debris from the piping.
• Disinfection: injecting disinfectant at a controlled concentration and holding it in the system for the required contact time.
• Final flushing: flushing the system until the disinfectant concentration drops to a safe level.
• Sampling and testing: taking samples from end points and testing them at an accredited laboratory.

Which Documents You Receive

On successful completion of the process you receive a piping disinfection certificate alongside the test results report from the accredited laboratory. Together, the two documents make up the proof the approving authority requires for Form 4, confirming that the water system is clean and safe to use.

How to Avoid a Delay in Occupancy

The most common delay stems from scheduling the disinfection and sampling too late relative to the project timeline. We recommend booking the date in advance, making sure all end points are accessible and that the system has proper water pressure. The Kesar Digum team carries out the disinfection, coordinates the sampling and delivers the samples to an accredited laboratory - all nationwide and aligned with your schedule.