A common concern for residents of residential buildings and office building users is the quality of their water supply, especially when it comes from rooftop water tanks. These tanks serve to store water and deliver it to the apartments below. Located on the roof, water pressure is created by force of gravity. The simple and relatively inexpensive water tank system is commonly installed for domestic use in many regions around the world. What the end users are often unaware of are the health hazards that can develop when the water in the tank is typically not being carefully monitored.

 

Protecting municipal water

Guaranteeing drinking water safety is basic in the prevention and control of waterborne diseases, yet reports abound of municipally sourced water that is found to be contaminated due to sanitation defects in water tanks. A tank can develop mold or contaminating bacteria from foreign organisms. Bird droppings and feathers, even dead fowl and other animals — and as in the recent case in a Los Angeles hotel, a dead human body — can find their way into a building’s water tank, which supplies its residents with water for drinking, cooking and hygiene.

In certain areas of the world, some homeowners have their water tanks on the roof too. Still, the concern is significantly greater for tower residents, where supervision and servicing of the tank is controlled by a property management company, maintenance team or water system operators, and where access to the tanks is not always properly supervised. Regional laws or recommendations might require that water tanks be emptied, inspected and cleaned once every two or three years or once a year in the best case, while it takes only one day for water to become contaminated or for its chlorine levels to become unbalanced and unfit for home use.

Added to this concern is the fact that municipal water is itself prone to contamination and other quality problems. This is frequently due to large amounts of industry-produced chemicals that find their way into the water system. Every resident would be happy to know about a water safety hazard as close to real-time as possible.

 

Different forms of protection

Real estate developers, water system operators and water consumers employ various alternative solutions to ensure safe drinking water for home and office use, but not all of them are the most efficient in terms of manpower, cost and convenience.

New buildings might be opting for pressurized systems to supply water from municipal pipes, eliminating the need for rooftop tanks and the contamination problems that they may pose. But these systems, which commonly use powerful pumps to move the water from municipal pipes into homes, are expensive to install and to maintain, and are therefore not an option in many cases for existing buildings and for new buildings being constructed in less affluent areas.

Individuals might choose to avoid the problem altogether, opting to use a building’s roof tank water supply for hygiene only. However, drinking and cooking with bottled mineral water, home water filters or boiled water is also a significant expense and inconvenience for families.

 

Solutions for detection of chlorine and pH levels

An efficient and cost effective way to cope with the problem is by employing chlorine detection systems that building operators can install on-site. This enables management to shift from manual water testing (if it is being done at all — the effort of regularly visiting the rooftop tank is a disincentive) to an automated system for monitoring and controlling the water’s chemical levels. A simple system, which ideally does not require calibration, can analyze the water at regular intervals — with a cost effective system this could be once or twice a day — and report the results online and in real-time to maintenance headquarters.

The latest in monitoring systems uses an automated test strip technology that for maintenance only requires switching the test strip cartridge and does not involve training or technical know-how. Electro-optics allow for accurate repetitive reading of the test results, and a remote status report via cell phone, SMS or ethernet will ensure peace of mind for all parties.

Maintenance is alerted if the chlorine level drops or when other measured parameters are imbalanced — whether they stem from changes in the water tank or in the municipal system. This allows for a prompt response to the problem. In some cases the system itself can adjust the chemical levels as necessary, ensuring that the water is continuously fit and safe for consumption and eliminating health risks.

Health and safety are obviously the primary benefits of installing a simple chlorine detection system, but no less advantageous are the need for fewer on-site visits and lower maintenance costs on the management level. It gives consumers and residents assurance and peace of mind knowing that their water supply is being constantly monitored. It goes without saying that a small investment in monitoring water tank water with the latest in automated systems is also well worth it to avoid the distress of finding out about a severely contaminated water supply after using it.

Stela Diamant is Chief Technology Officer of Blue I Water Technologies, a global provider of water quality analyzers and controllers. Prior to joining Blue I, Stela served as director of advanced process control solutions for MKS Instruments, Inc. Previous positions include technical staff member for Applied Materials, Inc., and head of R&D process and applications for Sagitta, Ltd. Stela holds patents in plasma sources, optical components process, and automated process control. She is a graduate of the Technion-Israel Institute of Technology with a D.Sc. degree in Physical Chemistry. She can be contacted at diamants@blueitechnologies.com