The Centers for Disease Control and Prevention, in 2016, published that the US witnesses an estimated 4-32 million cases of acute gastrointestinal illness (AGI) per year from public drinking water systems, even after having one of the safest drinking water systems in the world. So, where do you think lies the problem? The answer is the dangerous backflow incidences that have the potential to contaminate large water bodies.
In the usual household, cross-connections exist within the plumbing system, where the drinking water piping is connected to various plumbing fixtures or water utilizing equipment, including dishwashers, garbage disposals in the kitchen, toilets and steam bath generators in bathrooms, faucets, swimming pools, all of which could become a source of backflow and cause potentially lethal contamination of water supplies. Skokie Plumbers such as Mike’s Chicago Plumbing, offering 24 hour emergency plumbing services in Chicago and its surrounding areas, encounter backflow issues on a regular basis, which puts the household on a halt, till it is taken care of.
In any water distribution system, water flows from the distribution system to the end user. Backflow events are often the result of unfavorable, hydraulic incidents, such as a broken water main or distribution pipe, water drainage during plumbing repair, usage of large quantities of water by firefighters to extinguish a fire or the use of high pressure creating equipment in a water system, reversing the water flow. These hydraulic events, creating negative pressure, can back-siphon or back-pressure, contaminating the drinking water.
Causes of Backflow
Backflow is possible in the following two situations:
- Back Siphon: As mentioned above, certain hydraulic events like a water main break, create a sudden reduction in water pressure in the distribution system. A suction effect is created, which reverses the water flow, mixing the non-potable substance into the potable (drinking safe) water body.
- Backpressure: When the water system at the consumer’s end contains soap, acid or antifreeze, it can increase the pressure, making the contaminated water reverse its direction of flow through cross-connections in the piping to enter the main water body.
How to Prevent Backflow
There are two methods that can be used to prevent backflow:
- Air Gap: This is a vertical, physical separation, installed between the end of a water supply outlet and the flood-level rim of a receiving vessel, and is a popularly used preventive method for backsiphonage, although it doesn’t always work.
- Backflow Prevention Assembly: A Hydraulic Research and Cross Connection Control at the University of Southern California approved backflow preventer, installed at the closest possible distance to the water service, yet remaining within the property, uses valves in different configurations to prevent backflow. There are three types of backflow assembly available:
- Double Check Valve Assembly
- Reduced Pressure Principal Assembly
- Pressure Vacuum Breaker Assembly
Based on the degree of hazard the potable water supply in a household is susceptible to, The Environmental Division determines the suitable type of protection needed to prevent backflow. When installing the backflow prevention assembly, trust only the emergency plumbing services that use licensed professionals.