Backflow Prevention

Indeed, Colorado mandates the use of backflow preventers to safeguard public water systems. These devices ensure that water flows only in the intended direction. They keep contaminants that might be present in the water on private property from reversing course and flowing back into the public water supply.

In Denver, backflow testing generally costs between $30 and $100, with the actual amount often hinging on how complicated the backflow prevention assembly is and who exactly is doing the testing.

Check the entrances for water into your home where it could resemble a valve or mechanical device for backflow preventers. These water-safety devices are often found, near as we can tell, where we also find the sorts of plumbing arrangements that deliver water to the inside of a house—near water meters, hose bib connections, and irrigation systems, for instance. And do check for any labeling that might indicate the presence of a backflow preventer. If all else fails, consult your plumbing plans or a licensed plumber to either locate your plan or determine if there is a backflow preventer in your house.

A backflow preventer can cost anywhere from a few hundred dollars to several thousand, depending on what you need. For a simple system in a small, straightforward residential application, you could get by with something in the range of a few hundred dollars. For larger, more complicated systems, especially those that need to be installed in a high hazard situation, costs can skyrocket. These systems are designed to be complex for a reason—to protect the water supply from the kinds of high hazard cross-connections that could contaminate it.

Indeed, to safeguard your water supply from contamination that might result from reverse flow, a backflow preventer is a vital piece of equipment.

The plumbing law in Colorado as of 2023 requires all residential and commercial properties to install backflow prevention devices. The intention of this new law is to enhance public health and ensure that the public water system is not contaminated by any kind of backflow, especially since the law expects compliance in new constructions and during any plumbing work that amounts to a significant renovation.

It is unwise to use a check valve instead of a backflow preventer. Although both devices are intended to do the same job—stop water from flowing backward in plumbing systems—backflow preventers are designed to give you a much better chance of not having contaminated water in your pipes. If water from some external system tries to come into your plumbing system, a backflow preventer uses several layers of security to stop it. Because check valves are less reliable, they are not commonly found in systems where water quality is at risk. Plumbing codes often require a backflow preventer in places where it is possible for water quality to be threatened.

The installation of backflow preventers is not universal in all homes. Their installation and the very type of device used largely depend on local plumbing regulations and the risk—if any—plumbed systems pose to the drinking water supply. Some homes have them because particular plumbing configurations quasi mandate them; other homes don't have them and aren't required to. If homeowners are unclear on the issue, local plumbing inspectors should be able to clarify the need for backflow preventers and offer recommendations on what to install (if anything) and how to install it (if it can be installed).

There's a risk of contaminated water flowing into the clean water supply if a sprinkler system doesn't have a backflow preventer. That can cause big water quality and even health problems. A backflow preventer is a key safeguard in keeping the water safe and ensuring contamination doesn't happen.

The backflow prevention device with the highest reliability is the Reduced Pressure Zone (RPZ) valve.