Backflow is the reversal of water flow from its intended direction of flow. This commonly occurs because the public water system loses pressure – a backpressure or back-siphonage. Water coming into your home should be in a singular direction. When it’s not, backflow can happen. Fresh supply water may be tainted by contaminated water when normal water pressure in the system abruptly drops and the flow of supply water reverses, sucking unhealthy water from any source cross-connected to the fresh water system back into your drinking water supply.
Consider the following steps in order to protect your plumbing and sprinkler systems from backflow this winter.
Types of Backflow
Backpressure backflow occurs when the downstream pressure from a non-potable water source is greater than the pressure of the public water source. This can happen from either an increase in downstream pressure or a reduction in potable water pressure. Downstream increases can be caused by pumps or heat expansions from boilers, while decreases could be due to firefighting, line flushing, or a water main break.
Back siphonage is caused by a vacuum or partial vacuum created by negative pressure in the water line. This draws the water from a source that may be polluted or contaminated, into the public water system. Imagine sticking a drinking straw into a flowing stream of water. When you suck water into the straw, you create a vacuum, which reduces pressure in the stream. When you stop sucking, water (that may now be contaminated) flows back into the stream. Just like back pressure, back siphonage can also be caused by large-scale firefighting efforts, water main breaks or other construction accidents.
No matter what industry you’re in, preventing backflow isn’t as complicated as you might think. Here are steps to help you determine the best way to prevent and protect from backflow contamination.
- Identify and examine all cross-connections. If you don’t have experience in this area, a qualified plumber or a representative from your water supplier should be able to offer you an inspection.
- Determine and address areas of risk. If your cross-connections are opening your facility up to the possibility of backflow, you need to determine how to best reinforce these areas. Small changes to the facility’s plumbing may be all you need, or you might need to look into backflow preventers.
- Learn the types of backflow preventers, and how they can meet your needs. For valves and plumbing, you can find some other options for reduced pressure and vacuum breaker assemblies. If you need additional prevention in bathrooms or kitchen, you can check out plumbing fixtures such as faucets with air gaps or backflow prevention valves.
- Cover your bases. You might not think an average garden hose could cause problems, but if you have chemicals hooked up to, it can be a major issue. Chemical dispensers with built-in backflow preventers work well for any facility that utilizes spray-cleaning chemicals.
- Get your facility inspected. Regular checkups and maintenance will help ensure minimal risk of backflow from your facility. Ask your plumber how often they recommend inspection of cross-connections and backflow preventers, or check with your water supplier for best practices. Before you do this, make sure to consult a professional advisor.
This is ideal during the months of winter. Shut off the water supply to the lawn irrigation systems before the thermometer hits freezing temperatures. The main shut-off valve for your sprinkler system should be protected because of this. If you have not done already, make sure to wrap the pipes with insulation or at least protected from these low temperatures.
If your home has a main shut-off valve, you are in good hands. This device can measure the flow rate of water through your pipes. If you have not installed one, it would be wise to invest in one.
If you have an above ground sprinkler system, your piping must be insulated. Self-sticking foam-insulation tape or foam insulating tubes commonly found at home supply stores.