Backflow Prevention and Customer Service Inspection (CSI)

The program safeguards the public drinking water and protects the health of its customers by ensuring that contaminants that may cause backflow into the public water supply system are isolated within the customer’s internal distribution system.

A Customer Service Inspection is necessary to identify illegal lead materials, cross-connections, backflow prevention assemblies, or potential contamination hazards. The CSI shall be completed before NBU provides continuous water service to new construction or on any existing service. The inspection should be done when NBU suspects that cross-connections or other potential contaminant hazards exist, or after any material improvement, correction, or addition to the customer’s private water system.

Customer Service Inspections ensure there are no direct connections between the public water supply and a potential source of contamination or private water system not protected by an air gap or an appropriate backflow prevention assembly. New Braunfels Utilities contracts with a third-party company to perform CSIs for NBU customers. Notifications are sent to NBU customers, informing them to schedule the required inspection.

New Braunfels Utilities uses a contracted vendor to complete CSI certificates on all new residential and commercial properties. If you would like to schedule your CSI Inspection, please contact Hardin & Associates at 830-433-7715, email admin@hactexas.com, or schedule online at www.hactexas.com.

Backflow is the reversal of the flow of water or other substances through a cross-connection into the public water system or consumer’s potable water system. There are two types of backflow: backpressure backflow and back-siphonage.

Cross-connections are the physical links that allow backflow to occur. A cross-connection is any temporary or permanent connection between a public water system or consumer’s potable (i.e., drinking) water system and a source or system containing non-potable water or other substances. An example is the piping between a public water system or consumer’s potable water system and an auxiliary water system (well or rainwater collection), cooling system, swimming pool, water softener, or irrigation system. Possible cross-connections are so common that they may go unnoticed and unrecognized. Recognition of common cross-connections is essential to eliminate the potential for contamination to the public water supply.

Backpressure backflow is backflow caused by a downstream pressure that is greater than the upstream or supply pressure in a public water system or consumer’s potable water system. Backpressure can result from an increase in downstream pressure, a reduction in the potable water supply pressure, or a combination of both. Causes of increases in downstream pressure include pumps (such as wells and booster pumps), temperature increases in boilers, etc. Causes of decreases in downstream pressure include water line flushing, firefighting, or breaks in water mains.

Back-siphonage is backflow caused by a negative pressure (i.e., a vacuum or partial vacuum) in a public water system or consumer’s potable water system. The effect is similar to drinking water through a straw. Back-siphonage can occur when there is a stoppage of water supply due to nearby firefighting, a break in a water main, etc.

The program safeguards the public drinking water and protects the health of its customers by ensuring that any contaminants that may cause backflow into the public water supply system are isolated within the customer’s internal distribution system. Backflow into a public water system can pollute or contaminate the water in that system, making it unsafe to drink. Each water supplier has a responsibility to provide water that is usable and safe to drink under all foreseeable circumstances. Furthermore, consumers have faith that water delivered to them through a public water system is safe to drink. Therefore, NBU must take precautions to protect its public water system against backflow and cross-connection.

New Braunfels Utilities follows the Texas Commission on Environmental Quality (TCEQ) mandates and regulations established to protect the public water system, which includes:

1. The requirement of backflow prevention at each service connection that may create a threat to the public water supply.
2. The requirement of backflow devices and assemblies within a premise as outlined by federal requirements and state-required plumbing codes as described in the NBU Cross-Connection Control & Backflow Prevention Policy. Water service connection to each dedicated fire protection system or irrigation piping system, and the water service connection applies to each of the following types of premises:

• An auxiliary or reclaimed water system;
• Industrial, medical, laboratory, marine or other facilities where objectionable
  substances are handled in a way that could cause pollution or contamination of the
  public water system;
• Facilities exempt from the State Plumbing Code inspection and where an internal
  backflow preventer required under the State Plumbing Code is not correctly installed or
  maintained;
• Classified or restricted facilities; and
• Multi–story buildings.

The two main ways to prevent backflow is to install a backflow prevention assembly or create an air gap.

A backflow preventer is a means or device which prevents pollutants and contaminants from flowing into the public water system by providing a physical barrier to backflow.

An air gap is a vertical, physical separation between the end of a water supply outlet and the flood-level rim of a receiving vessel. This separation must be at least twice the diameter of the water supply outlet and never less than one inch. An air gap is considered the maximum protection available against backpressure backflow or back-siphonage, but it is not always practical and can easily be bypassed.

An RPBA protects water from substances that may contaminate water, causing illness or death. A sprinkler/irrigation system that has a chemical feed requires this assembly. It is also commonly used in commercial establishments to protect against numerous contaminants. These assemblies must be installed above12” above final grade.

A DCVA protects water from substances that may pollute but not contaminate the water. For instance, non-health hazard applications require these assemblies, which are normally installed near the meter according to manufacturer recommendation and state plumbing codes.

A hose bib vacuum breaker (HBVB) is one of the least expensive and most commonly used backflow prevention devices. When attached to an outside water tap, these backflow devices keep water that may be contaminated with fertilizer or insecticide from entering your drinking water. State and local codes require HBVB on all faucets/hose bibs

Mechanical backflow prevention assemblies have internal seals, springs, and moving parts that are subject to fouling, wear, or fatigue. Also, mechanical backflow preventers and air gaps can be bypassed. Therefore, all backflow prevention assemblies have to be tested periodically to ensure that they are functioning correctly.

The backflow preventer must be tested and certified upon installation and periodically as required by manufacturer requirements, federal, state, and local codes to ensure proper operation. If the hazard (the substance you are protecting against) is considered high risk (i.e., hazards that can cause health problems), TCEQ requires that the device be tested annually. The TCEQ oversees the state requirements.

Some backflow prevention assemblies are below ground while others are above ground; in either instance, it is essential to properly insulate your device to protect them from freezing, while ensuring the integrity and functionality is not obstructed.

• TCEQ: https://www.tceq.texas.gov/drinkingwater/cross-connection
• Texas Administrative Code on Landscape Irrigation: 30 TAC §344.50-.52
• Texas Administrative Code on Cross-Connection Control: 30 TAC § 290.44
• The federal Safe Drinking Water Act 42 USC Chapter 6A, Subchapter XII)
• Recommended Practice for Backflow Prevention and Cross-Connection Control,
  Manual M14, 4th edition http://www.awwa.org.
• University of Southern California’s Manual of Cross-Connection Control, tenth
  edition (2009) is available at the Foundation for Cross-Connection Control and
  Hydraulic Research;