Texas Customer Service Inspections & Cross-Connection Requirements

Learn Texas TCEQ customer service inspection and cross-connection control requirements, including CSI triggers, authorized inspectors, backflow prevention, high-hazard connections, testing, records, and operator responsibilities.

Texas public water systems must protect the drinking-water distribution system from cross connections, backflow, and other potential contamination hazards. The Texas Commission on Environmental Quality, or TCEQ, requires public water systems to implement cross-connection control measures that include customer service inspections, appropriate backflow protection, testing of backflow prevention assemblies, and recordkeeping.

For water operators, cross-connection control is an important part of distribution-system protection. A system can produce safe drinking water at the treatment plant and still experience contamination if nonpotable water or another contaminant is allowed to flow backward into the public water supply.

What Is a Cross Connection?

A cross connection is a physical connection between a public water system and:

another water supply of unknown or questionable quality;
a source containing contaminating or polluting substances;
a source of water treated to a lesser degree than the public drinking-water supply.

Why Cross Connections Are Dangerous

A cross connection creates a pathway through which contaminants can enter potable water.

Potential hazards can involve:

chemicals;
industrial process water;
medical fluids;
irrigation water;
private wells;
boilers;
fire-protection systems;
other nonpotable water sources.

What Is Backflow?

Backflow is the unwanted reversal of flow from a customer's plumbing or another source into the potable water distribution system.

Backflow can occur through:

backsiphonage;
backpressure.

Backsiphonage

Backsiphonage can occur when pressure in the public water system falls below the pressure at a connected source.

Possible causes include:

water-main breaks;
high fire flow;
pump failure;
rapid system drainage;
other low-pressure conditions.

Backpressure

Backpressure occurs when pressure in a customer's system exceeds pressure in the public water system.

Possible sources include:

boilers;
pumps;
pressurized industrial processes;
elevated nonpotable systems.

The Public Water System Is Responsible for Cross-Connection Control

TCEQ rules place responsibility on the public water system to recognize and evaluate hazards connected to its distribution system.

When a hazard is identified, the PWS must ensure that customers are protected from contamination.

Elements of a Cross-Connection Control Program

An effective Texas cross-connection control program can include:

plumbing ordinances, regulations, or service agreements;
customer service inspections;
hazard identification;
backflow prevention;
testing of backflow prevention assemblies;
records;
enforcement.

Customer Service Inspection

A Customer Service Inspection, or CSI, is an examination of a private water distribution facility for the purpose of determining whether water service can safely be provided.

The inspection is limited to identifying and preventing:

cross connections;
potential contaminant hazards;
illegal lead materials.

A CSI Is Not a General Plumbing Inspection

A Texas customer service inspection is not the same as a complete plumbing-code inspection.

The CSI is focused specifically on conditions that could contaminate the public drinking-water supply.

When a CSI Is Required

A Texas public water system must require a customer service inspection under circumstances that include:

new construction before continuous water service is provided;
existing service where substantial or material plumbing changes have been made;
existing service where the PWS has reason to believe a cross connection or other contaminant hazard exists.

New Construction

Before continuous water service is provided to new construction, the required CSI must be completed.

This helps verify that the new private plumbing system does not introduce an unacceptable connection to the public water supply.

Existing Customers

A CSI can also be required at an existing service connection when:

plumbing is materially modified;
distribution facilities are altered;
the PWS suspects a contaminant hazard;
a potential cross connection is identified.

Who Can Perform a CSI?

Texas authorizes specified licensed individuals to perform customer service inspections.

These include:

a TCEQ-licensed Customer Service Inspector;
a Texas licensed Plumbing Inspector;
a licensed plumber with a Water Supply Protection Specialist endorsement.

Water Operators Are Not Automatically Customer Service Inspectors

Holding a water operator license does not automatically authorize an individual to certify a CSI.

The person performing and certifying the inspection must have the appropriate authorization under current Texas requirements.

Customer Service Inspection Certificate

TCEQ Form 20699 is the official Customer Service Inspection Certificate.

The certificate documents the findings of the CSI.

CSI Records

The public water system should maintain the required CSI documentation for affected service connections.

These records can be reviewed during TCEQ compliance investigations.

Service Agreements

Public water systems can use service agreements or applicable plumbing ordinances or regulations to prohibit unacceptable plumbing practices and cross connections.

A service agreement can address:

cross connections;
return of water to the public supply;
potential contamination hazards;
access for inspections;
lead restrictions.

Private Water Systems

A direct cross connection between the public drinking-water supply and a private water system is prohibited unless appropriate protection is provided as required.

Examples can include:

private wells;
rainwater systems;
reclaimed water;
other alternative water sources.

Backflow Prevention

When a cross-connection hazard exists, the potable water supply must be protected using an appropriate method.

Protection can include:

air gap;
backflow prevention assembly;
other approved isolation appropriate to the hazard.

Select Protection Based on Hazard

The type of backflow protection should be appropriate for:

degree of hazard;
type of cross connection;
potential direction of backflow;
pressure conditions;
applicable TCEQ requirements.

Health Hazard

A health hazard is a cross connection capable of introducing substances that could create a public-health risk.

Higher-risk connections require a higher degree of protection.

High-Hazard Facilities

TCEQ identifies examples of facilities where significant cross-connection hazards may exist, including:

hospitals;
medical facilities;
mortuaries;
chemical plants;
certain industrial facilities.

Reduced Pressure Principle Assembly

A reduced pressure principle backflow prevention assembly, often called an RP or RPZ assembly, is commonly used for high-hazard applications where appropriate.

Operators should understand that installation alone is not enough. The assembly must remain functional.

Air Gap

An air gap provides physical separation between the potable supply outlet and the receiving vessel or nonpotable system.

Because there is no physical connection, an approved air gap can provide a high level of protection when properly designed and maintained.

Backflow Prevention Assembly Testing

Backflow prevention assemblies that require testing must be tested by appropriately qualified personnel according to applicable Texas requirements.

Testing verifies that the assembly actually functions as designed.

Annual Testing for Certain High-Hazard Assemblies

TCEQ identifies high-hazard facilities where backflow prevention assemblies are required to be tested annually.

Examples include:

hospitals;
mortuaries;
minor surgery centers;
chemical plants.

Backflow Prevention Assembly Test Report

TCEQ Form 20700 is the Backflow Prevention Assembly Test and Maintenance Report.

The form documents:

assembly identification;
test results;
repairs if required;
final operating condition.

Backflow Test Records

The responsible public water system should maintain required testing records.

During a TCEQ investigation, the system may need to provide evidence that installed assemblies:

were tested;
passed testing;
were repaired when necessary.

Failed Backflow Assembly

A failed assembly should not simply be left in service as if it were providing protection.

The responsible parties should follow applicable procedures to:

repair or replace the assembly;
retest it;
document acceptable operation.

Cross-Connection Hazard Must Be Corrected

If a health hazard is identified and remains unprotected, the PWS must ensure that the hazard is isolated from the potable system.

Current TCEQ guidance states that the PWS can terminate water service to a connection with an unprotected health hazard and restore service when:

the hazard no longer exists; or
appropriate backflow protection has been installed.

Operators Help Identify Hazards

Water operators may observe conditions suggesting a cross-connection problem during:

service calls;
main repairs;
pressure investigations;
customer complaints;
meter work;
distribution inspections.

Warning Signs of Possible Backflow

Possible warning signs can include unexpected:

color;
odor;
taste;
chemical characteristics;
pressure behavior;
customer complaints limited to a particular area.

Backflow Incident

A suspected backflow event should be treated as a potential drinking-water contamination event.

Operator response can include:

protecting public health;
isolating the suspected source;
notifying responsible system personnel;
collecting operational information;
following applicable TCEQ notification requirements;
flushing and sampling as required;
documenting corrective action.

Pressure and Backflow Risk

Maintaining adequate distribution pressure is an important cross-connection control measure.

When public-system pressure falls, the possibility of backsiphonage can increase.

Operators Reduce Risk by Maintaining the System

TCEQ identifies good system maintenance and sound operation as important parts of backflow prevention.

Examples include:

repairing failing pipes;
maintaining pumps;
maintaining adequate pressure;
managing high-demand conditions;
responding to leaks promptly.

Irrigation Systems

Landscape irrigation systems can create cross-connection hazards.

Risks can involve:

fertilizers;
pesticides;
standing water;
submerged sprinkler heads;
auxiliary water supplies.

Fire Protection Systems

Water-based fire-protection systems may require appropriate backflow protection depending on their design and hazard characteristics.

Operators should not assume every fire connection has identical protection requirements.

Boilers

Boilers can create backpressure and can contain treatment chemicals.

An unprotected boiler connection can therefore present a serious cross-connection hazard.

Medical Facilities

Medical facilities can contain high-hazard cross connections because potable water can be connected near:

medical equipment;
chemical systems;
laboratory equipment;
other potentially contaminated processes.

Industrial Facilities

Industrial customers can contain complex process piping and chemicals.

The PWS should ensure that hazards are identified and appropriately isolated from the public drinking-water system.

Lead Materials

Customer service inspections also identify prohibited lead materials in applicable private water distribution facilities.

The CSI therefore addresses both:

cross-connection hazards;
illegal lead plumbing materials.

CSI Does Not Replace Backflow Testing

A completed customer service inspection does not eliminate separate requirements to test installed backflow prevention assemblies.

These are related but distinct compliance activities.

Backflow Testing Does Not Replace CSI

Likewise, a passing backflow assembly test does not necessarily satisfy a required customer service inspection.

Operators should keep the two requirements separate.

Recordkeeping

Cross-connection control records can include:

Customer Service Inspection Certificates;
Backflow Prevention Assembly Test and Maintenance Reports;
service agreements;
hazard surveys;
corrective-action records;
correspondence with customers.

TCEQ Investigations

TCEQ can review a public water system's cross-connection control program during routine compliance investigations.

The system should be able to demonstrate that it:

requires CSI when required;
identifies hazards;
requires proper backflow protection;
requires testing where applicable;
maintains required records.

Official Forms

TCEQ maintains official forms for cross-connection control.

Important examples are:

TCEQ Form 20699, Customer Service Inspection Certificate;
TCEQ Form 20700, Backflow Prevention Assembly Test and Maintenance Report.

Alternate Forms

TCEQ guidance states that alternate forms differing from the official forms require TCEQ approval before use.

A PWS should therefore avoid creating its own substantially different CSI or backflow-test form without confirming compliance.

Example: New House Requests Water Service

Before continuous service is provided, the system should verify that the required customer service inspection has been completed by an authorized individual.

Example: Existing Commercial Customer Remodels Plumbing

A material plumbing change can trigger a new CSI requirement.

The PWS should not assume that an old inspection remains sufficient after substantial plumbing modification.

Example: Operator Finds a Private Well Connected to the Building Plumbing

This can create a prohibited cross connection between the public drinking-water supply and another water source.

The condition must be appropriately corrected or isolated.

Example: RP Assembly Fails Annual Test

The assembly should be repaired or replaced as required and successfully retested before relying on it for protection.

Example: Main Break Causes Low Pressure Near High-Hazard Customer

The operator should recognize that reduced public-system pressure can increase backsiphonage risk.

Review:

affected pressure;
cross-connection hazards;
backflow protection;
water-quality conditions;
applicable notification and sampling requirements.

Example: Customer Presents CSI Signed by an Unqualified Person

The PWS should verify that the person performing the certification was authorized under Texas requirements.

Example: Backflow Assembly Is Installed but No Test Record Exists

Installation alone does not demonstrate that a testable assembly is functioning correctly.

The PWS should obtain the required test documentation.

Common CSI and Cross-Connection Mistakes

Assuming a CSI is a complete plumbing-code inspection.
Providing continuous service to new construction before required CSI completion.
Failing to require a new CSI after material plumbing changes.
Allowing an unauthorized person to certify a CSI.
Assuming every water operator can perform customer service inspections.
Failing to identify private wells or other auxiliary water supplies.
Installing backflow protection without required testing.
Failing to retest an assembly after repair.
Ignoring cross-connection risk during low-pressure events.
Failing to maintain CSI and backflow-testing records.

A Practical CSI Review

Determine whether a CSI is required.
Confirm that the inspector is authorized.
Complete the inspection before continuous service when required.
Identify cross connections and contaminant hazards.
Identify prohibited lead materials.
Correct unacceptable conditions.
Complete the official inspection certificate.
Maintain the record.

A Practical Backflow Protection Review

Identify the cross-connection hazard.
Determine the degree of hazard.
Select appropriate backflow protection.
Install protection correctly.
Test the assembly when required.
Repair failed assemblies.
Retest after repair.
Maintain test records.

A Practical Operator Review

Maintain adequate distribution pressure.
Watch for possible cross-connection hazards.
Report suspected backflow incidents.
Verify that required protection is in place.
Review CSI and backflow records when relevant.
Follow system cross-connection control procedures.
Escalate unprotected health hazards promptly.

What to Remember for the Exam

A cross connection is a physical connection between the public water system and another source that can contaminate the potable supply.
Backflow is the unwanted reversal of flow into the public drinking-water system.
Backflow can occur through backsiphonage or backpressure.
Texas public water systems are responsible for identifying and controlling cross-connection hazards.
A Customer Service Inspection focuses on cross connections, potential contaminant hazards, and illegal lead materials.
A CSI is not a general plumbing inspection.
A CSI is required before continuous service to new construction.
A CSI is also required after applicable material plumbing changes or when a contaminant hazard is suspected.
Authorized CSI personnel include a TCEQ-licensed Customer Service Inspector, a licensed Plumbing Inspector, and a licensed plumber with the Water Supply Protection Specialist endorsement.
A water operator license alone does not automatically authorize an operator to certify a CSI.
TCEQ Form 20699 is the Customer Service Inspection Certificate.
Backflow protection must be appropriate for the degree and type of hazard.
High-hazard connections may require an air gap or an appropriate high-level backflow prevention assembly.
Certain high-hazard facilities require annual testing of backflow prevention assemblies.
TCEQ Form 20700 documents backflow prevention assembly testing and maintenance.
A failed backflow prevention assembly must be repaired or replaced and retested as required.
An unprotected health hazard can require termination of service until the hazard is removed or properly isolated.
Maintaining adequate distribution pressure helps reduce backsiphonage risk.
CSI records and backflow-testing records can be reviewed during TCEQ investigations.
Customer service inspections, backflow protection, assembly testing, and recordkeeping are separate but connected parts of a Texas cross-connection control program.