Backflow is when contaminated water flows backward into clean drinking water lines, usually due to a change in water pressure. The reversal of water flow causes a public health hazard.

The Louisiana Department of Health and the U.S. Environmental Protection Agency mandate backflow prevention because backflow is a public health hazard.

LAC Title 51:XIV says that:

• It shall be the duty of the owner of the backflow assembly to ensure that their assembly gets tested at least annually by a certified Backflow Prevention Assembly Tester.
• Failure to have your backflow preventer tested may result in fines of up to $3,000 per day out of compliance, and it may result in water being disconnected from your property.

Whatever water line your backflow preventer is on will be shut off during testing. This means that if your backflow preventer is on your domestic line, your building will not receive water during the test. Please keep this in mind when you schedule testing.

Commercial customers with backflow preventers on their fire line must notify their fire alarm company before a test can be performed.

Generally, backflow preventers are located next to your water meter outside your building. Sometimes they are indoors.

Here are some examples of the most common backflow preventers: