Backflow testing and repair in Laredo, TX

What backflow is

Water normally flows one way: from the city main, through your meter, into the house and the yard. Backflow is water moving the opposite direction. It happens in two ways. Back-siphonage occurs when pressure in the city line drops, for example during a main break or heavy firefighting, and water in your plumbing is pulled backward. Backpressure occurs when pressure on your side rises above the city’s, for example from a pump or a boiler.

Either way, whatever is in your lines can go with it. Sprinkler pipes hold stagnant water that sits in soil with fertilizer, pesticides and animal waste. A hose left in a pool, a bucket of cleaning solution or a hose-end sprayer full of weed killer can be drawn in too. The Texas Commission on Environmental Quality lists these exact examples in its consumer guide to backflow prevention.

Why Laredo takes it seriously

On May 22, 2026, the City of Laredo issued a precautionary boil water notice for customers served by the Jefferson Water Treatment Plant after a positive bacteriological sample. City officials traced it to a failed backflow prevention device at one home, which allowed contaminated water back into the system. The notice affected roughly half the city for four days, until testing cleared the system and the Texas Commission on Environmental Quality approved lifting it.

Afterward, the utilities director said homeowners should have their devices inspected by a professional every year, and the city said it plans to divide the water system into zones so a future problem can be isolated to one neighborhood. One household’s maintenance, in other words, affects everyone on the system.

What the city ordinance requires

Laredo rewrote its cross-connection rules in Ordinance 2025-O-103, which amended Section 31-115 of the city code and took effect July 18, 2025. The parts that matter most for homeowners:

• Every lawn irrigation system needs a backflow prevention assembly. Standard systems are classified as non-health hazards. A system with a chemical injector is a health hazard and needs a reduced pressure principle assembly at the service connection.
• Testing schedule. The owner must have health-hazard assemblies tested every year and non-health-hazard assemblies every three years. The city can require more frequent testing.
• Other required tests. Assemblies must also be tested right after installation, whenever moved, right after repairs, and before a property that sat vacant for a year is occupied again.
• Who tests. Only a state-certified backflow prevention assembly tester who is registered with the City of Laredo. The tester submits results through the Utilities Department’s online portal within two calendar days.
• New sprinkler systems need a permit, and installation must follow the plumbing code and the ordinance.
• Hose bibs. All outdoor faucets must have a hose bibb vacuum breaker. No permit or inspection is needed to add one.
• Hose-end chemical sprayers connected to home plumbing are not allowed without proper backflow protection.
• Costs and records. The owner pays for the assembly, installation, testing and repairs, keeps it working, protects it from freezing and vandalism, and keeps test and repair records on the property for at least three years.
• Enforcement. If an assembly is not tested and repaired as required, the Utilities Department can terminate water service within two weeks of notifying the owner, unless an alternate plan is approved.

Types of backflow protection

Signs your assembly needs attention

• Water dripping or spraying from the device, or a wet spot around it
• An RPZ relief port that discharges water while the system is not running
• Low sprinkler pressure or heads that barely pop up
• A cracked bonnet or body, especially after a freeze
• Missing test cocks or caps, or a device that has been bypassed
• No test record for the last three years

Leaks count under the drought rules too. Laredo’s drought contingency plan prohibits failing to repair a controllable leak from a sprinkler, backflow preventer or meter within 5 days, and the Utilities Department issues written warnings when it finds a private-side leak.

Testing, repair and replacement

1. Test. The tester attaches a differential gauge to the test cocks, checks each valve and relief, and records the results on the city’s system.
2. Repair. A failed test often means a worn rubber part, a spring or debris in a check valve. Many assemblies can be rebuilt with a repair kit.
3. Retest. Every repair must be followed by a new passing test, submitted the same way.
4. Replace if needed. Cracked bodies, discontinued models or devices installed lower than the code allows usually need replacing.

Who does what

Several licenses can be involved, and it helps to know which one you need. Backflow prevention assembly testers are licensed by the TCEQ, and Laredo also requires them to register with the city each year. Installing or repairing lawn irrigation systems for others in Texas is generally the work of TCEQ-licensed irrigators. Plumbing connected to the house supply is the work of plumbers licensed by the Texas State Board of Plumbing Examiners, some of whom hold an endorsement for water supply protection.

Some companies hold several of these licenses. Ask the plumbing company you call which of them it holds, and whether it can test, repair and file the report in one visit.

Sprinkler habits that help

• Water on your designated days and hours, which the city sets by the last digit of your address during drought stages
• Fix broken or misting heads promptly; running a system with broken heads is prohibited during drought stages
• In-ground systems installed in Laredo on or after January 1, 2006, must be zoned; keep zones adjusted so they do not spray streets and driveways
• Do not leave a hose running into a pool, pond or bucket
• Protect above-ground assemblies from the rare hard freeze with an insulated cover

Sources

Official and primary sources used on this page. Rules change, so check the source before acting on a detail.

• City of Laredo Ordinance 2025-O-103: cross-connection control and backflow (Sec. 31-115)
• TCEQ GI-411: A Consumer’s Guide to Backflow Prevention in Texas
• KGNS: Laredo leaders push for stricter water safety rules after partial boil water notice (June 2026)
• City of Laredo: partial boil water notice lifted for the Jefferson plant service area
• City of Laredo Ordinance 2024-O-095: water conservation and drought contingency plan