Water tanks help to deliver drinking water to millions of New York City residents in apartment buildings, schools, and hospitals. In most buildings, pumps push water to rooftop tanks where it is stored until needed. The law requires that these tanks be inspected and cleaned at least once per year. The inspection results are reported to the New York Department of Health. The cleaning and disinfection must be performed by a licensed master plumber.
To clean a water tank, the first step is to flush and drain the tank. Ensure the tank inlet is isolated and any booster pumps associated with the system are also isolated. Then, add Sodium Hypochlorite to the tank to achieve 50PPM free chlorine and re-test to ensure levels are correct (note pH). After the tank has been drained and refilled with fresh mains water, test the temperature of the incoming mains water. It should be a minimum of 50degC and a maximum of 55degC in healthcare settings.
Next, scrub the interior of the tank to remove any dirt, silt, or slime that may have built up since its last cleaning. A power washer is often the best tool for this job, as it can reach into hard-to-reach corners. After scrubbing the tank, rinse it with water to remove any remaining bleach solution. Optionally, you can run the bleach solution through your water supply lines to sanitize them as well. After rinsing the tank and sanitizing the water lines, fill it part-way with potable drinking water and mark the tank with a service sticker showing that it has been sanitized and disinfected. water tank cleaning near me