What backflow testing involves
Backflow testing confirms that the check valves and relief valves inside a backflow prevention assembly still close and hold as designed. The U.S. EPA Cross-Connection Control Manual (EPA 816-R-03-002) defines a cross-connection as a link between a source of pollution and a potable water supply. The manual describes backflow as flow produced by a pressure difference between two systems, and backsiphonage as flow in the reverse direction from the one intended.
The EPA manual describes the main types of protection and where each fits:
- Air gap. A physical separation, at least twice the supply pipe diameter and never less than one inch. It protects against both backpressure and backsiphonage.
- Atmospheric vacuum breaker. Protects against backsiphonage only and is not used where backpressure can occur.
- Pressure vacuum breaker (PVB). Can stay under constant pressure but does not protect against backpressure. Widely used on irrigation.
- Double check valve assembly (DC). Protects against backpressure and backsiphonage and is commonly used for low to medium hazards. A double check detector assembly is used mainly on fire lines.
- Reduced pressure principle assembly (RP or RPZ). Two check valves with a relief valve between them that vents to atmosphere. It is used at high hazard connections.
A testable assembly has two shut-off valves and numbered test cocks. The certified tester connects a test kit to the test cocks, closes the downstream shut-off valve and checks each check valve and, on an RP, the relief valve. The EPA manual states that test data should be recorded on the appropriate forms. Because the downstream valve is closed during the test, water to the building or system is interrupted briefly while each assembly is tested.
The EPA manual also notes that a leaking second check on an RP shows as water discharging from the relief port, and that the relief port must never be plugged. A discharging relief valve is a reason to call for repair and retest, not to cap the port.
Requirements and standards for backflow testing
Backflow rules are set by state drinking water regulations, the local plumbing code and the water utility’s cross-connection control program, so requirements differ by location. The EPA manual says assemblies should be tested at the intervals the local cross-connection control ordinance sets, by certified test personnel, both at installation and periodically. It also notes that property owners may be required to install, test and maintain the protection at their own expense.
Examples of state and local rules:
- Florida. Rule 62-555.360, F.A.C., requires backflow preventers at non-residential service connections to be tested after installation or repair and at least annually, and air gaps to be inspected at least annually. Its minimum protection table calls for an RP at car washes and at hospitals and clinics where surgery is performed, and a DC or double check detector assembly on non-residential fire sprinkler connections without chemical additives.
- Miami-Dade County. The Water and Sewer Department states that certain assemblies must be tested on installation and every year by a certified tester who has completed a 40-hour course and passed a proficiency test. Test reports can be submitted online.
- Texas. 30 TAC 290.44(h)(4) requires assemblies to be tested on installation by a licensed backflow prevention assembly tester, and those protecting against health hazards to be tested at least annually. The tester completes a report for each assembly and submits the signed original to the public water supplier. Only testers employed by an approved fireline contractor may test fire lines, and test gauges must be checked for accuracy every year.
- Washington. The Department of Health states that backflow assemblies should be tested at least annually by a certified backflow assembly tester (BAT) and that test records be kept.
Tester certification, report forms and filing deadlines are set by each water utility. Facility First confirms the local rule for each location before the first test.
Preventive maintenance schedule for backflow testing
Annual backflow testing is a compliance task. The AWWA policy statement reproduced in the EPA manual says water service can ultimately be discontinued where required protection measures are not taken. A planned schedule keeps every assembly tested on time, catches failing check valves before a backflow event and keeps test reports ready for the utility, the fire inspector and the insurer.
| Task | Recommended frequency | Basis |
|---|---|---|
| Test each backflow prevention assembly | At installation, after repair, and at least once a year | Florida Rule 62-555.360 (non-residential); 30 TAC 290.44(h)(4); Miami-Dade Water and Sewer Department |
| Test at the interval the local ordinance sets, where it differs | As set locally | U.S. EPA Cross-Connection Control Manual |
| Inspect air gaps | At least once a year | Florida Rule 62-555.360 |
| Submit the signed test report to the water utility | After each test | 30 TAC 290.44(h)(4)(C); local utility rules |
| Confirm the tester’s gauge accuracy check | Annually | 30 TAC 290.44(h)(4)(B) |
| Inspect assemblies for relief valve discharge, leaks, damage and access | Quarterly | Facility First program default, adjusted per site |
| Confirm freeze protection on outdoor assemblies before winter | Annually, in the fall | Facility First program default, adjusted per site |
| Update the inventory of assemblies, locations, sizes and serial numbers | At each annual test | Facility First program default, adjusted per site |
The authority having jurisdiction, the manufacturer and the property’s insurer can require more frequent service, and each location’s schedule is set in its program and recorded on every visit.
Signs an assembly needs attention
- Water discharging from the relief port of an RP assembly
- A failed test, or a notice from the water utility that a test is due or overdue
- Leaks at shut-off valves, test cocks or the body of the assembly
- Freeze damage, impact damage or an enclosure that blocks access for testing
- New equipment, irrigation or a change of use that adds a cross-connection
Records to keep
- Inventory of every assembly: type, size, make, model, serial number and location
- Each test report with date, tester name, certification number and gauge information
- Pass or fail result, readings and any repair parts replaced
- Proof of submission to the water utility
- Retest results after repair
- Correspondence and notices from the utility
How Facility First runs backflow testing across a portfolio
- Inventory. Facility First builds a list of assemblies at each location from prior reports, utility notices and a site check.
- Schedule. Test dates are set ahead of each utility’s due date, grouped by market where practical.
- Dispatch. A vetted local provider with the tester certification the water utility recognizes receives the work order. Fire line assemblies go to providers qualified for fire line work where the rules require it.
- Test and repair. The provider records readings and photos. A failed assembly is repaired or replaced within the client’s approval limit and retested; larger work is quoted first. See what NTE means.
- Filing and verification. Facility First confirms the report was submitted to the utility, files it on the location’s history in PostControl and invoices in one format.
What affects the cost of backflow testing
- Number, size and type of assemblies at each location
- Fire line assemblies that need a qualified fire line tester and coordination with the fire protection provider
- Access, such as assemblies in vaults, ceilings or locked rooms
- Repair parts or full replacement after a failed test
- Utility filing fees, where they apply
- After-hours testing to avoid interrupting water during trading hours
Backflow testing for retail stores, restaurants and offices
Retail stores. A store can have assemblies on the domestic water service, the fire line and irrigation. Testing is scheduled before opening so restrooms and sinks are not out of service during trading hours.
Restaurants. Kitchens rely on water for food preparation, handwashing and dish machines, so the brief shutoff is timed before service. Equipment added to the kitchen is reviewed against the local plumbing code for cross-connection protection. Related work includes grease trap cleaning, commercial drain cleaning and commercial water heater repair.
Offices. Multi-tenant buildings often have assemblies on domestic, fire and irrigation lines. Testing is coordinated with building management and tenants are notified of the shutoff in advance.
Frequently asked questions
How often is backflow testing required?
Florida’s rule for non-residential connections and Texas rules for health hazard protection require testing at installation, after repair (Florida) and at least once a year. The local water utility’s ordinance sets the exact interval.
Who can test a backflow preventer?
A tester certified or licensed under the rules of the state and the local water utility. Miami-Dade, for example, requires a 40-hour course and a proficiency test.
What happens if a backflow test fails?
The assembly is repaired or replaced and retested, and the passing report is submitted to the water utility.
Will the water be shut off during the test?
Briefly. The tester closes the downstream shut-off valve while testing, so testing is scheduled outside trading hours where possible.
Who sends the test report to the water utility?
In many programs the tester submits it. Texas requires the tester to send the signed original to the public water supplier, and Miami-Dade accepts reports online. Facility First confirms each filing.
Sources
- U.S. EPA: Cross-Connection Control Manual (EPA 816-R-03-002)
- Cornell Law School LII: Florida Administrative Code 62-555.360, Cross-Connection Control for Public Water Systems
- Cornell Law School LII: 30 Texas Administrative Code 290.44, Water Distribution
- Miami-Dade Water and Sewer Department: Cross-Connection and Backflow Prevention
- Washington State Department of Health: Group B public water systems, cross connection