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Cross Connection and Backflow

At Doylestown Township Municipal Authority (DTMA), we take great pride in providing you with the highest quality drinking water possible. In order to consistently maintain the high level of quality we strive for, DTMA has initiated a comprehensive backflow prevention/cross-connection control program. According to the PA State Plumbing Code International Plumbing Code (IPC) and the PA Safe Drinking Water Regulations, Chapter 109 and Doylestown Township Ordinance No. 350 we are authorized and required by state regulations to have you install, at your expense, an inline testable backflow prevention device. Under most circumstances, single family residential homes have a non-testable backflow preventer in place. This backflow preventer is called a residential dual check valve and most cases will help to safe guard the potable water supply. There are a few exceptions in which a testable backflow device is required for residential applications. Please call DTMA for information.

As a public water supplier, it is our responsibility to ensure that your drinking water is safe and free of contaminants at all times. Backflow induced contamination of drinking water systems can (and has) caused equipment damage, illness, and even death. In order to protect our distribution system (water mains) from contamination originating from backflow we are requiring all customers to install a containment backflow prevention device. This device should be installed just past the meter prior to any take-off lines. The meter should not be removed during this process!

The type of device that you install will be either a reduced pressure principal assembly or a double check valve assembly. The device that you are required to install will be determined according to the degree of hazard classification of your business. You will need to contact our Cross-Connection Control Program Coordinators, Scott Miele or Brent Eaton at 215-348-9915 to answer some questions on a short survey to determine which device is appropriate for your service connection. Once it is determined what type and size of device needs to be installed on your service, you will need to contact a licensed plumber to install the backflow device. All applicable plumbing codes must be followed by a licensed plumber who is registered to perform work in Doylestown Township.

Immediately after the device is installed it must tested by an ASSE certified tester who is required to report to the authority that the installation and testing of the backflow prevention device has been completed. After the installation and initial test you will receive annual testing notices. It is your responsibility to maintain this device in working order and to have the device tested annually.

Frequently Asked Questions

If I am a customer of Doylestown Township Municipal Authority (DTMA), what am I required to do?

All non-residential water customers are required to have an approved testable back-flow assembly installed and tested on an annual basis. Non-residential customers are required to maintain the assembly to be assured it is in proper working order. This includes a test performed by an American Society of Sanitary Engineering (ASSE) certified tester in accordance with Doylestown Township Ordinance No. 350. A Backflow Prevention Device Test Form should be completed by the tester. Be sure to get a copy of this completed test form from the tester. It is your responsibility to mail, fax or email a copy of the completed test form to DTMA. This applies even if the backflow assembly failed the test. Without the completed test form (pass or fail), DTMA has no documentation that any work was done and as a result, you will be subject to termination of water service.

Who gives the authority to implement the program?

1). Title 25 Chapter 109.709 of the Pennsylvania Code. 2).The Safe Drinking Water Act. 3). Doylestown Twp. Ordinance No. 350. 4). The Pennsylvania Uniform Construction Code as amended. 5).The International Plumbing Code (IPC).

What is a backflow prevention device?

Backflow prevention devices are mechanical plumbing devices installed in a plumbing system to prevent water from flowing backward in the system. A properly installed, tested and maintained backflow preventer at the service entrance to a building or property can reliably prevent the back-flow of water of an unknown quality from flowing back into the community water system. Backflow prevention is important to protect DTMA’s customers against accidental contamination of the public water supply due to a direct connection of a non-drinkable substance to the normal drinking water piping.

What kind of backflow device do I need?

The type of backflow device necessary depends on the degree of hazard present at your location. The degree of hazard depends on the use of water at your location and what could potentially enter the system.

Are residential customers required to have cross-control/backflow prevention measures in place?

Yes. All new construction/new residential service connections are required to have appropriate backflow protection in place before service is provided. All residential customers that have a water meter also have a backflow device in place. This backflow device is called a “Residential Dual Check Valve” (RDCV). It is part of the water meter assembly and is non-testable. Residential properties that have fire sprinklers and / or lawn sprinklers require a testable backflow assembly such as a Double Check Valve Assembly (DCVA), Reduced Pressure Principle Assembly (RPZ) or a Pressure Vacuum Breaker (PVB). If unsure of your application, please call DTMA at 215.348.9915.

Who should test a backflow device?

In accordance with Doylestown Twp. Ordinance No. 350, only ASSE Certified testers are allowed to test a backflow device. If the device is found to be faulty and repairs are required, only an ASSE Certified backflow repair specialist is allowed to make the repairs. If repairs are made, the backflow device is required to be tested again to be assured that it performs correctly. A list of qualified testers can be found by visiting the Please note: DTMA does not endorse any specific backflow testers, and we are not responsible for the accuracy of the information provided on this website. The link is provided as a resource only. There may be other qualified testers not listed on this site. Testing, repairs and installation of backflow assemblies/devices are performed in accordance with ASSE standards.

Where should the backflow device be installed?

The backflow device must be installed on the customer’s service line immediately after the meter and before any branching of the line to accommodate any additional taps, faucets or hose connections. Each type of backflow device must be installed in accordance with all applicable codes and regulations.

How much does a backflow device cost?

The cost of a backflow device varies based on the size, type and location. We recommend that you obtain several quotes.

Who is responsible for paying for the device and testing?

It is the customer’s responsibility to ensure that any contaminants or pollutants do not enter the water distribution system from their location. All costs related to the installation, maintenance and testing are the customers’ responsibility.

Are all non-residential customers required to comply?

Yes. All non-residential customers are required to comply. There are no exceptions.

What happens if I do not comply?

The regulations and codes previously mentioned allow for the termination of water service for failure to comply.

Once I have my device tested, where do I mail my completed test form each year?

Completed test forms should be:

Mailed to:

Fax:   or Email:

All applicable building and plumbing codes must be followed. In accordance with Doylestown Twp. Ordinance No. 350, any backflow tester that tests a backflow assembly must have a current and valid ASSE Certification card. If repairs to any backflow assembly are required, the repair specialist must have a current and valid ASSE Certification repair card. A Differential Pressure Gauge is a specialized tool that is used in the testing of backflow assemblies. The Differential Pressure Gauge is required to be calibrated annually. This gauge should have a current sticker affixed that indicates the most recent calibration. Be sure that the gauge information is documented on the test form. Contractors that work in Doylestown Twp. should have insurance. Some backflow assemblies can discharge water. It is extremely important to consider the location of the backflow assembly. Thermal expansion can happen after a backflow device is installed. Only qualified people should be allowed to install backflow devices and thermal expansion tanks. DTMA is committed to protecting the public water supply. Please call 215.348.9915 or email smiele@dovlestownpa.orq if you have any questions or concerns.


What is Backflow?

Backflow is the undesirable reversal of the flow of water or mixtures of water and other undesirable substances from any source (such as used water, industrial fluids, gasses, or any substance other than the intended potable water) into the distribution pipes of the potable water system. Backflow occurs as a result of a “cross-connection” within the water system, which exists when there is any actual or potential connection between a potable water system and any other source or system through which it is possible to introduce into the potable system any used water or other substance.

What is Cross Connections?

There are many instances of cross-connection hazard. To explain the risk involved, imagine that one end of a garden hose is attached to your home water system and the other end is placed down into a bucket of herbicide. At the same time an abrupt loss of water occurs in the main water line serving your home (such as a water main break or large volumes of water released from a fire hydrant). The pressure drop causes a reverse flow in the water line and in a system with no backflow prevention insecticide from the bucket is sucked into your home’s drinking water and potentially into the main water line serving your community. However, if the spigot your garden hose is connected to is equipped with a hose bib device, the reverse flow would cause the check in the hose bib to engage and stop the backflow at the spigot. If there is no hose bib or if it is not operating properly, the backflow prevention assembly installed between your home and the main water line would engage and prevent the herbicide from contaminating the main water line.

General Information – What is Thermal Expansion?

When water is heated it expands. For example, water heated from 90 0 F to a thermostat setting of 140 0 F in a 40 gallon hot water heater will expand by almost one-half gallon. This is because when water is heated, its density decreases and the volume will expand. Since water is not compressible, the extra volume created by expansion must go someplace. During no-flow periods in a system, pressure reducing valves, backflow preventers, and other one-way valves are closed, thus eliminating a path for expanded water to flow back to the system supply. Hence, household system pressure can increase. The installation of a thermal expansion tank is highly recommended. Please consult a licensed plumber for more information.