Your local water provider is responsible for ensuring the water delivered to your home is safe for everyone to drink. However, certain hydraulic conditions left unprotected within your plumbing system may allow hazardous substances to contaminate your own drinking water or even the public water supply.

A cross-connection is an actual or potential connection between the safe drinking water (potable) supply and a source of contamination or pollution. State plumbing codes require approved backflow prevention methods to be installed at every point of potable water connection and use. Cross-connections must be properly protected or eliminated.


Examples of Residential Cross-Connection Hazards


State regulatory agencies require all public water suppliers to maintain an on-going Cross-Connection Control program involving public education, onsite inspections/surveys, and possible corrective actions by building and home owners if required.


Water normally flows in one direction. However, under certain conditions, water can actually flow backwards; this is known as backflow. There are two situations that can cause water to flow backward: backsiphonage and backpressure.


Backsiphongage - this may occur due to a loss of pressure in the public water system from a fire fighting emergency, water main break or system repair. This loss of pressure creates a siphon effect in the plumbing system which can draw water out of a sink, bucket, or pool and back into your water or public water system.

Backpressure - may be created when a source of pressure in your home plumbing system (such as a boiler or pump) creates a pressure greater than the water pressure supplied through the public water system. This may cause contaminated water to be pushed into your plumbing system through an unprotected cross-connection.



Why is HydroCorp inspecting my Home?

HydroCorp has been contracted by the City/Village/Township to assist with their Cross-connection Control (CCC) Program. The CCC program includes two parts: On-site inspections and testing of backflow prevention assemblies. The HydroCorp inspector will be conducting a visual inspection of the water uses outside of your home (outside spigots, lawn irrigation system, secondary sources of water, pools, etc.) to identify cross-connections that could possibly contaminate your drinking water or the public water supply. If your water provider requires an inspector to enter your home to evaluate other cross-connection and plumbing hazards inside your residence, you will be notified and instructed to schedule an appointment for your inspection.

I’ve never had an inspection before. Why do I need one now?

The City/Village/Township has had a CCC program for a number of years, which began with inspections of all of the commercial and industrial accounts. As a natural progression of our program we are now inspecting residential customers as required by the State.

My home has to be inspected, but the house across the street doesn’t have to. Why?

All water customers (residential and nonresidential) connected to the public water supply are required to be inspected for cross-connections. Most programs strive to ensure that all water customers receive an initial inspection during their first 3-5 years of program implementation.

How long does the inspection take?

An average inspection normally takes from 10 to 20 minutes, depending on the size of your home/property.

Do I have to be present for the inspection?

Interior Inspections: YES - if you received a letter informing you to call and arrange for an appointment, someone over 18 must be home to allow our inspector to enter the home and complete the inspection.

Exterior Inspections: NO - if the inspection is for the exterior of your home only, HydroCorp will not be entering your home and they will only require access to your front and backyard. Some states and local jurisdictions allow for a mail/electronic water use survey to be completed by the homeowner.

Can I request a specific inspection time?

Yes. We just need a name and number so that the inspector can contact you to set up a time that is convenient for you.

Who is responsible for completing the repairs if necessary?

If you are the owner of the home being inspected, you are responsible for any needed repairs. Renters may have to refer to their lease agreements in order to determine whether they are responsible for repairs.

I’ve completed the necessary repairs, installation or other requirements. Now what?

If your specific community program has the option that you can upload a photo of the work that was performed or the plumbing installation, click here. Otherwise, call our office and let them know that you have completed the necessary requirements and are ready for a compliance inspection.

Does your inspector carry identification?

All HydroCorp inspectors wear photo ID badges during inspections and are prepared to provide appropriate documentation verifying their identities.

Is this inspection mandatory?

Yes. These inspections are conducted in order to ensure compliance with state regulations to maintain the safety of your drinking water.

What happens if I refuse to have the inspection done or to correct any problems it identifies?

Penalties for refusing to cooperate with inspections and/or refusing to make needed repairs are determined by your local water utility. These typically can include termination of water service, a fine, or both.

I just had my assemblies tested – why are you doing another inspection?

There are two components of a cross-connection control program: Testing of backflow prevention assemblies and onsite inspections. It is the responsibility of the assembly’s owner to have backflow prevention assemblies tested periodically by a certified tester. Your local water supplier is responsible for the inspection portion of the program. The inspection is to verify that the proper backflow prevention methods are in place to maintain drinking water safety.


Why do I need to test my backflow prevention assembly?

Just like any other mechanical device, backflow prevention assemblies are prone to wear and tear, and do break down from time to time. Regular testing is required in order to ensure that your device remains in proper working order.

How often should I test my backflow prevention assembly?

(Varies by state and local authority)
It is recommended that all testable backflow preventers are tested annually, however The City/Village/Township may require less frequent testing on residential lawn irrigation systems. (Consult your local Cross-Connection Control ordinance.) If you are injecting chemicals into your lawn irrigation system, most state regulations and plumbing codes require the backflow preventer to be tested on an annual basis.

Why doesn’t the City pay for the testing of my backflow preventer?

In most jurisdictions, a lawn irrigation system is not a required component of the water system. Homeowners who choose to install a lawn irrigation system as a convenience are responsible to assure the backflow preventer is properly installed and maintained in accordance with State laws and regulations. It would be unfair for the City/Village/Township to require home owners who choose not to have a lawn irrigation system to absorb the financial burden of maintaining your privately owned system.

I received a test notice, but your inspector was just here and said everything was fine.

There are two parts to the Cross-connection Control Program. The first is an on-site inspection by a cross-connection control inspector to ensure that the proper backflow prevention devices and assemblies are in place to protect your drinking water. Some of the assemblies the inspector finds or asks you to install are testable assemblies, which are mechanical and can malfunction. The testing notice refers to testing the operation of these backflow prevention assemblies. These tests must be performed by a certified tester.

Is any older, legacy equipment “grandfathered” in?

“Grandfathering” is not typically permitted due to the high importance of maintaining drinking water safety. Just like any other mechanical device, backflow prevention assemblies are prone to wear and tear, and do break down from time to time. Regular testing is required in order to ensure that your device remains in proper working order.


What is an anti-siphon fill valve device and why does mine need adjustment?

The anti-siphon fill valve device is located in the tank of your toilet. This device has a dual purpose: To fill the toilet and prevent backflow. This device must be placed at the proper height in order to insure that water from your toilet does not backflow into your drinking water. Proper placement is typically done during the installation process but can be easily overlooked. This device must be raised or the overflow pipe must be cut down in order to achieve a 1” air gap separation between the “critical level” of the assembly.

Click here to see an installation diagram.

Click here for 3 minute video overview.


Hose connection vacuum breakers:

Example: Hose connection
vacuum breakers


Example: Integrated vacuum breaker
on outside hose spigot.

Avoid these cross-connection hazards:

Example: Hose end in bucket


Example: Hose end in pool

Incorrect continuous pressure installations:


Vacuum breaker should not be subject to continuous pressure like the example here illustrates. (This type of irrigation set up/system would need to be corrected.)


These require periodic performance testing by a Certified Tester.

Pressure Vacuum Breaker Assembly


Reduced Pressure Principle
Backflow Prevention Assembly