Your household plumbing system can be defined as fresh water in, dirty water out. Sounds pretty simple, but big problems arise when the lines blend and waste water ends up mixing with fresh water.

At the 1933 Chicago World’s Fair 98 persons died of dysentery and hundreds more took ill due to a cross-connection between water supply and waste lines at a downtown hotel. That’s how serious the problem can get.

Pressure fluctuations are the main cause of backflow incidents, along with cross-connected plumbing lines. Normally your household water supply is under 35-40 pounds of pressure. If this pressure gets interrupted – perhaps by a water main break in the street, a power failure, fire fighters battling a nearby blaze or other causes – then water can flow backward in the system. Then it may come in contact with waste water from drain lines.

A fairly common type of backflow occurrence is when a garden hose gets submerged in polluted or contaminated water. If the pressure in the water main drops, the water in the garden hose could be sucked back into the pipes connected to your drinking water. This could be very dangerous if you are using your garden hose to spray lawn fertilizer or weed killers. Household cleaning products and the soapy water from your laundry tub also could be hazardous if swallowed, as could water filled with bacteria from a pool or waterbed.

The simplest way to eliminate backflow hazards is simply to leave a physical air gap between faucets or garden hoses and standing water. Never submerge a hose in a tub of water or swimming pool.

Sometimes it is impossible to use an air gap to prevent water mixing. So for additional protection, our plumbers are adept at recommending and installing various types of mechanical backflow prevention devices.

One of the simplest forms of protection for your home is an anti-siphon toilet float valve. Many of the cheap float valves sold at local hardware stores and home centers do not have sufficient anti-siphon capability. Our plumbers install only professional-caliber products that protect your health and safety.

Another simple type of backflow preventer is an atmospheric vacuum breaker. Ask our plumber to make sure you have a hose bib vacuum breaker where you attach your garden hose. Never use spray attachments with your garden hose without such a device. Lawn chemicals are extremely toxic and can even be fatal.

Other forms of backflow prevention are more complicated. These include pressure-type vacuum breakers, double check valve assemblies and reduced pressure principle backflow preventers.

If you have an underground lawn sprinkling system, the pipe feeding this system should have one of these. Otherwise contaminants can enter the water supply through the sprinkler heads in your lawn.

Plumbing may look simple at times but it involves a reckoning with the laws of physics. That’s why you always want to call on our fully trained plumbers to deal with issues that impact the health and safety of your family.