Frequently Asked Questions: Backflow Prevention Program and Using Wells for Irrigation

Because there is a possibility of a cross connection between the well and treated water systems that could result in the contamination of the treated water supply, an approved Denver Water RPZ (Reduced Pressure Zone) backflow prevention device must be installed on the treated water service line. The device must be certified as working and a dual water supply agreement for the property must be signed by the property owner. Once all this has been done, Denver Water will issue a well permit sign for posting at the property, and the well can then be used for irrigation as so desired by the property owner.

Two reasons, the Colorado State Health Department requires that all purveyors of treated water have a cross connection policy, and Denver Water allows no commingling of its water. Should commingling occur, the water is isolated from the water system. Denver Water’s cross connection rule and policy is detailed in Chapter 11 of the Denver Board of Water Commissioners Operating Rules.

Yes, Denver Water’s Operating Rule on Cross Connections does apply to your property regardless of the date that the rule was adopted. Whenever it is determined by Denver Water that there is a well on a property, the treated water supply must be protected with a device approved by Denver Water and installed on the treated water service line. The installation of the device is to be completed within 90 days of the notice being issued to the customer.

Denver Water will give the property owner written notice of non compliance and if the notice is ignored, Denver Water, in accordance with its Operating Rules and the Water Supply License that was issued for the property, can interrupt water service at the property until it has complied with the notice.

The device must be installed by a licensed plumber and tested annually by a state certified backflow technician. The cost of the device, its installation, and the annual testing of the device varies, and will depend on what must be done to install the device and who tests the device. Information on who installs and tests the device can be obtained from a phone book or online phone directory by looking under “Backflow Prevention Products and Services.” The device is installed at the owner’s expense. The property owner is encouraged to shop around and compare prices.

No, at this time Denver Water does not have the personnel to do this work.

The device is installed downstream (house side) of the meter pit either inside the house in the basement with a drain as the service line comes through the wall/foundation, or outside the house in a hotbox to prevent freezing of the device. The hotbox would be located downstream (house side) of the meter pit. A hotbox requires electricity to generate the heat needed to prevent the device from freezing. An outside setting of the device is generally more expensive than an inside setting.

No, the device spills water when it is operating that would flood the meter pit and could cause the device to freeze. The water from the device must be delivered to a drain or to daylight.

No, a device does not have to be installed, but the well site must be inspected by Denver Water’s quality control lab, and the lab will determine if the well is dry, abandoned or inactive. In order for Denver Water to consider a well inactive, the pump motor for the well must be removed from the well site, and the electrical wires for the pump motor cut off. This is a minimum.