Frequently Asked Questions

No. The governing regulation for cross connection control, The Safe Drinking Water Act, doesn’t distinguish between versions of the plumbing code and only requires that the water system comply with existing laws, regulations, and rules. As such, the City of Novi has no enforcement discretion to allow non-conforming backflow prevention devices under a “grandfather” clause. It should be noted that the Safe Drinking Water Act (P.A. 399 Part 14 Rules) is not a construction code which would allow whatever is lawfully installed in a building under a set of codes to remain for the history of the building unless changed. The safe drinking water act is a mechanism to protect the public drinking water supply which requires that whenever it is found that there is the potential for a cross connection that that link between a potable (drinking water) and non-potable water supply that it be properly protected.

Potable water is free from impurities present in amounts sufficient to cause disease or harmful physiological effects and conforming in bacteriological and chemical quality to the requirements of the public health authority having jurisdiction.

“Cross Connection” means a connection or arrangement of piping or appurtenances through which a backflow could occur.

Cross connections that may be found in your residence include but are not limited to:

  • Lawn irrigation system which may or may not have a chemical feed.
  • Unprotected hose bibs on the side of your house or in your garage.
  • Water assisted back-up sump pump
  • A boiler used for heating purposes which may or may not have a chemical feed.
  • The fill valve on your toilet which does not meet the minimum safe air gap.
  • Solar system which may or may not have a chemical feed depending on type (see attachment “C” solar systems below).
  • Heated driveway with a water supply.
  • Hard piped pool or pond fills by other than a garden hose.
  • Any connection with a waste line to a water supply.
  • A hose connected to the faucet of your laundry tub.
  • Fire Sprinkler system which may or may not have a chemical feed.

PDF Attachment C - Solar Water-heating Systems Protection of Drinking Water Supply Options

“Backflow” means water of questionable quality, wastes, or other contaminants or pollutants entering a public drinking water supply due to a reversal of flow.


  • Contamination is an impairment of the quality of the potable drinking water that creates an actual hazard to the public health through poisoning or through the spread of disease by sewage, industrial fluids or waste.
  • Pollution is an impairment of the quality of the potable drinking water to a degree that does not create a hazard to the public health but that does adversely and unreasonably affect the aesthetic qualities of such potable drinking water for domestic use.

An approved backflow prevention device/assembly is required when your drinking water supply is connected to a non-drinking water source. Examples of non-drinking water sources include lawn irrigation systems, connections to water assisted backup sump systems, garden hoses placed in and used to fill a swimming pool, water supply connections to boilers, fire sprinkler systems and carbonated beverage machines. Drinking water supplies and non-drinking water supplies must be isolated from one another by the installation of an approved backflow prevention device or assembly based upon the degree of hazard.

Protective requirements are determined based upon the potential hazard to the water system tap; contaminant verses pollutant. The protective measure is determined through codes and rules pursuant to the type of hazard. Examples of hazard types include; a water supply to a boiler which may or may not have a chemical additive for baseboard heating, water supply lines to fill a swimming pool, the hose connected to the side of your home or laundry tub faucet and a water supply line to a water assisted backup sump system or to a lawn irrigation system which may or may not have a chemical fertilization or pesticide feed.

A backflow prevention device is a mechanical non-testable valve (no shutoff valves) used to protect potable water supplies from contamination or pollution due to backflow.

In water supply systems, water is normally maintained at a significant pressure to enable water to flow from the tap, shower etc. When pressure fails or is reduced, as may happen if a water main bursts, pipes freeze or there is unexpectedly high demand on the water system, then such reduced pressure in the pipe may allow contaminated water from the ground, from storage or from other sources to be drawn up into the system.

The most important component of a plumbing system is the protection of the public drinking water. A backflow preventer is a valve that separates the water you drink from potential contaminated sources.

Drinking WaterThe City of Novi, State of Michigan approved Cross Connection Control Program requires backflow testers to be a licensed plumbing contractor in addition to the State required ASSE 5110 Testing Certification.

PDF Backflow Preventer Tester Plumbing License Code Path

The Michigan Department of Environmental Quality (MDEQ) soon to be renamed the Michigan Department of Environment, Great Lakes, and Energy (EGLE) adopted a National Standard known as ASSE 5110 for testing backflow preventers that became effective January 1, 2018 via the Public Act 399 Safe Drinking Water Act, Part 14 Cross Connection Rules. This standard however does not take into account the Michigan Plumbing Law (because it's a national standard) now known as the Skilled Trades Act, Public Act 407. This act requires a licensed plumber to make repairs on backflow preventers. The concern with this is that if a non-licensed plumber tests the backflow preventer and it fails, the tester can't repair it. It should be noted that failures are not uncommon as these assemblies are mechanical in nature. The water user would now be required to hire a licensed plumber as required by State Law to make the repair. The Water and Sewer Division looked at this as an added unnecessary expense and inconvenience to the water user. For these reasons this issue was then corrected in the City's Cross Connection Control Program submitted and approved by the MDEO/EGLE to require testers in our community to be a licensed plumber (Novi requirement) and ASSE 5110 Certified (State requirement) in order to prevent a water user from being double charged and the inconvenience of having to hire a second contractor.

No. A plumbing permit is not required for repairs to a backflow preventer that does not involve or require the replacement or rearrangement of the assembly or piping. A plumbing permit is required for new installations, rearrangement or relocation of valves and piping.

All test reports should be forwarded to the Department of Public Works / Water & Sewer Division located at 26300 Lee BeGole Drive, Novi, MI 48375. Fax # 248-735-5659.

The following codes and state laws require the City of Novi Department of Public Works to provide for cross connection inspection, corrective measures and backflow assembly testing:

  • City of Novi Code of Ordinances’ Division 2, Sections 34-36 through 34-43
  • Safe Drinking Water Act; Act 399 of 1976 as amended, Part 14 Cross Connection Rules
  • Skilled Trades Act of 2016, P.A. 407, Article 11 Plumbers and Plumbing Contractors
  • Stille-Derossett-Hale Single State Construction Code Act; Act 230 of 1972 as amended
  • The Michigan Plumbing Code, Section 608; Protection of Potable Water Supply
  • The Michigan Residential Code, Section P2902; Protection of Potable Water Supply

Backflow events can occur during water main breaks when the section of distribution pipe affected is no longer at 60psi. When a main break occurs, valves are shut down to isolate the area for repairs to be made and your water main may now be at Spsi or lower depending on the break. Backflow events can also occur during a large fire with fire hydrants lowering the water pressure during a fire event or even City hydrant flushing programs. In all of these examples the POTENTIAL for water to reverse flow due to hydraulics exists and therefore appropriate backflow preventers are necessary to be in place. Whenever you here "boiled water alert", backflow conditions could exist.

No, Indoor and outdoor hose bib vacuum breakers are a myth. The Michigan Plumbing Code and Michigan Residential Code require hose bib vacuum breakers to meet one of two standards that include ASSE 1011 or ASSE 1052. There are multiple manufacturers manufacturing these products that come in various different models and price points. All meet one of these two standards and some are more user friendly than others such as only needing to remove the hose to drain it. These devices are not manufactured as an indoor/outdoor use but rather to only meet the required standard. ALL require some form of winterization maintenance if installed outdoors and subject to freezing temperatures. Please refer to this short video showing the different types and how to winterize them. It's the resident's responsibility to maintain their plumbing system and hose connections. The video is intended to assist you with this. It's also the resident's responsibility to decide which type of protective device to install based upon cost and convenience for them. Also refer to the PDF Hose Bib Protection Identifier that identifies where adding a hose bib vacuum breaker is not required or recommended.

Yes, technically the plumbing codes require hose bib vacuum breakers to be installed permanently. The reason for this is because they are frequently removed. Read the manufacturers installation instructions. This is achieved by tightening the set screw until it snaps as it has been designed to do so. This however has not been a major focus for our inspections. Our focus has been ensuring the protective devices are on. In cases where we find they are frequently removed for re-inspections, we have required permanent attachment by breaking off the set screw.

Cross connection control is based upon the potential of cross contamination to happen. If there are threads on the valve that allows a hose to be connected to it, the potential is there, and it must be protected. A hose can easily be installed even on a temporary basis. A hose can be used to fill a swimming pool or decorative pond, connection to a power washer, many various different reasons. It should be noted however that if you have an approved anti-siphon or also known as a frost-free type no backflow preventer is required to be added as the valve already has backflow protection built into the valve. See the PDF Hose Bib Protection Identifier for clarification on this.

Yes, plumbing codes reference ASME A112.18.1/CSA B125.1 for compliance. Specifications should list these standards for compliance. PDF Here is an example of a faucet specification.