Backflow and Cross Connection Prevention

Most water systems have good sources of water and sophisticated treatment plants to convert impure water to meet drinking water standards, and the City of Salisbury has exceeded those standards. However, there are instances within water systems where the drinking water supply can become contaminated due to backflow or cross-connection.

The City and State have backflows and cross connection regulations to further protect the public drinking water supply from the possibility of contamination. Also, in 1988 Salisbury-Rowan Utilities began installing meters with backflow prevention check valves for new customers connecting to the water system to help isolate contaminates and protect and pollutants.

When check valves are added, homeowners and businesses should have internal plumbing inspected and consider installing a pressure relief thermal expansion tank to absorb internal pressure caused by hot water heaters and other devices.

SRU also reviews new business and construction projects to insure compliance when additional backflow and cross connection is required.

Customers are responsible for preventing contamination of the public water supply as well as their own internal water systems; therefore, the following information is important to both residential and business customers.

Backflow is when water travels backwards through the distribution system under certain pressure conditions.

If a hose is submerged in a bucket of garden chemicals or connected to a lawn sprayer, and the water is left turned on then a drop in water pressure occurs (such as when there is a water main break or if a fire hydrant is opened, the chemicals in the bucket can actually flow backwards through the hose into the drinking water.

Always leave at least a 2-inch air space between a hose opening and any container of non-drinkable water. Installing a hose-bib vacuum breaker will reduce the possibility of backflow; however, it is recommended that hoses never be left submerged in any type of substance, even if a backflow device is present.

A cross connection is a point in a plumbing system where the drinkable (or potable) water supply is connected to a non-potable/contaminated source, The contaminaants can enter the safe drinking water system through uncontrolled cross connections when backflow occurs due to backsiphonage or backpressure.

Backsiphonage is caused by a negative pressue in the supply line to a facility or plumbing fixture, This may occur during waterline breaks and/or repairs, when the water supply is shut off, or when fire hydrants are opened/tested.

Backpressure occurs when the drinking water supply is connected to another system operated at a higher pressure or has the ability to create pressure, THese are caused typically by booster pumps, pressure vessels and elevated plumbing. Elevated plumbing can be caused by a pool near the home or even another home at an elevated level.

Some common cross connections can be found in existing plumbing and water systems including:

• Wash basins and service sinks
• Irrigation sprinkler systems
• Auxiliary water supplies
• Laboratory and aspirator equipment
• Photo developing equipment
• Processing tanks
• Boilers
• Water recirculating systems
• Swimming pools
• Solar heat systems
• Fire sprinkler systems

Residences with irrigation systems, high-risk businesses and industries must comply with specific state and local regulations, inspections and record keeping requirements.

Through the permitting process, SRU works closely with new businesses and new construction projects to help customers become compliant with regulations, testing and record keeping requirements.

Installation of plumbing can depend on several factors and the type of backflow device required. Location can also be a factor as well as the type of enclosure required.

Testing requirements are handled by SRU-approved, certified third-party providers. A list is provided below.

The following list of persons and businesses is based solely on information provided to Salisbury-Rowan Utilities (“SRU”) by others. SRU has not conducted any investigation into or obtained any confirmation from any source of the accuracy or completeness of the list or of the quality, cost, or any other characteristic of goods or services that might be provided by any person or business that appears in the list. The inclusion in the list of a person or business is not a recommendation by SRU or by any other person or entity. SRU makes no representation regarding any person or entity or the performance of any person or entity on the list and accepts no responsibility for the performance of any person or business whose name appears on the list. Use of the list is solely at the risk of the user. Before hiring any listed person or business to provide goods or services to you, you should investigate and obtain the information that is important to you in making such a decision.

1. Submit to the Backflow Program Coordinator the following:
   1. A copy of your certification and the location of the school attended with valid dates.
   2. The tester’s equipment information with calibration dates, date released to the field, model #, etc., and a copy of the original document.
   3. Your business name as well as a contact name as it should appear on the testers list, an email address, and fax # if applicable.
   4. The signed Certified Testers Agreement.
2. Please keep the Backflow Program Coordinator informed when your certifications are updated and testing equipment is checked for calibration. Our requirement is to have test equipment checked for accuracy one year from the date released to the field or (noted on the paper work received with the equipment when checked). We will attempt to contact you if we do not receive a copy of your training recertification or test kit calibration information. If we still do not receive the required information within a given date your name will be deleted from our certified tester’s list.
3. Important note: SRU does not allow and RPPA to be converted to a DCVA device serving a containment installation.
4. If you have any questions concerning backflow, please contact the Backflow Program Coordinator (info at the top of this page).