HOW TO PREVENT DRINKING WATER CONTAMINATION

-

 Protecting Water Systems from Cross-Connections

What is a Cross-Connection?

A cross-connection is any connection between potable (drinking) water and non-potable water. 

The Florida Department of Environmental Protection (FDEP) defines a cross connection as "any temporary or permanent connection between a public water system or consumer’s potable (i.e., drinking) water system and any source or system containing nonpotable water or other substances."

FDEP requires all water utilities to have a Cross Connection Control Program to prevent contamination of the drinking water distribution system with any type of non-potable substances. 

The program must include requirements for backflow protection where possible cross-connections could happen.

How to Prevent Cross-Connections

Preventing Cross-Connections in the Water Distribution Pipelines

FDEP rules require all water distribution piping to be physically separated by at least 3 feet from all other pipelines, including reclaimed water, sewer collection, and storm drainage pipes.  FDEP reviews engineering plans before issuing a construction permit  for any new or replaced pipelines to ensure this separation.

In addition, pipelines must use color-coded pipe as follows:  

Blue = Potable Water
Green = Sewer Collection, Wastewater
Purple = Reclaimed Water/Reuse

This makes it easy to identify specific pipelines during repairs or upgrades.

Connections to fire hydrants are only allowed by the Fire Department and approved utility personnel. All connections must include backflow protection.

Preventing Cross-Connections in Homes and Businesses

This is where the Cross-Connection Control Program comes in. 

Plumbing in homes, businesses and industries is connected to the public water system. If there's a cross-connection, non-potable water, chemicals, or other substances could end up in the distribution system.

Water distribution systems are pressurized to push water into the customers' buildings. 

But contamination can occur when there is backflow from non-potable water or substances into the public water supply.

What is Backflow?

Backflow is the unintentional reversal of flow from a non-potable source, through a cross-connection, and into the potable water system. This can occur due to backpressure or backsiphonage. 

Backpressure is when pressure on the customer's side of the meter is greater than the pressure in the water distribution system. This can happen with tall buildings or pressurized systems, such as in commercial businesses or industries.

Backsiphonage occurs when the water pressure in the distribution system drops, creating a vacuum. This pulls nonpotable water through a cross connection and into the public water system. Water system pressure can drop due to a large water break or a fire requiring large water usage or a major mechanical failure.

Here is a video from the American Water Works Association with some examples of cross connections and potential for backflow at businesses and industries:

What Kind of Cross-Connections Can Happen at Home?

Some common cross-connections happen with hoses! 

The water in pools and hot tubs is considered non-potable.

A hose without a shutoff nozzle becomes a cross-connection if it is submerged in a swimming pool, spa, or a tub of water used to wash the dog. Also, hoses connected to insecticide or pesticide sprayers create potential for contamination.

Some homes have private wells for irrigation. Any potential connection between the private well and the home plumbing creates a cross-connection.

Irrigation systems may create a potential problem as well, especially if connected to reclaimed water.

Your showers, faucets, toilets and appliances are protected from cross-connection by design. They all have an an air gap. This is a physical distance between the full sink/tub and the bottom of the faucet. 

However, if you attach a hose to the faucet that reaches into the bowl, tub or bucket - it becomes a cross-connection. 

Backflow Prevention Protects Drinking Water from Contamination

If there are potential cross-connections, a backflow prevention device must be installed on the water service. These devices prevent non-potable substances from reaching the public water system.

Most all businesses and industries are required to have backflow preventers on their water service as well as on separate fire lines into the buildings.

Homeowners may be required to install a backflow preventer per the utility's cross-connection control program or a city or county ordinance.

There are different types of backflow preventers, and the type required depends on the level of risk. For instance a chemical factory will need a different type of backflow preventer than a home with a reclaimed water irrigation system.

Backflow preventers must be inspected, tested and maintained on a regular basis by trained and certified people. In the video below, the City of Tallahassee explains cross-connections and shows how residential and commercial backflow preventers work--and how they are inspected and tested.


The Cross-Connection Control Program


Water utilities must have a written cross-connection control program. This program describes
  • Which properties need what type of backflow preventer.
  • Backflow preventer standards.
  • Backflow preventer testing and maintenance requirements. (Some utilities perform testing/maintenance and charge the customer, others may require the customer to hire certified testers/repairers).
  • Required notifications and information about cross-connections and backflow preventers.
Image Generated by ChatGPT


Your utility is responsible for making sure backflow preventers are installed where needed. They also need to inspect the backflow devices, and either test them or ensure they were tested by certified testers.

This short video from Manatee County does a good job of showing how their cross-connection control program works:


How Can You Prevent Cross-Connections?

By being vigilant and preventing cross-connections, you can protect the drinking water system:
  • Be careful with hoses. Avoid submerging hoses in a pool, hot tub, bucket, pond, or even a pool of rainwater or mud. Also when using an attached sprayer for fertilizer, etc. Attach a hose bibb vacuum breaker at the hose connection to protect against backflow. They're cheap and easily available.
  • Do not add any extensions (such as flexible tubing) to a faucet that would connect the faucet to liquid in a tub, sink, or other container.
  • If you have a private well for irrigation, never connect the well to your household plumbing.
  • Check with your utility to determine if you need a backflow preventer at your meter. Many utilities require them for irrigation systems (especially with reclaimed water), private well, pool or hot tub. 
  • If you are required to have a backflow preventer, make sure it is inspected/tested as required by certified personnel. (Many utilities will do this for you for a small fee).
  • If you see someone connected to a fire hydrant that is not identified as a utility or fire department, call your utility immediately. 

Geek Out



Check out the Cross-Connection Control Program Manual from the Florida Keys Aqueduct Authority.

FDEP requires utilities to submit an Annual Cross-Connection Control Program Report.













Comments

Post a Comment

Popular posts from this blog

WHERE DOES YOUR DRINKING WATER COME FROM?

-
Image
Have you ever wondered . . .  Where your drinking water comes from? How it gets treated?  How it's delivered to your faucet?   Your Water Utility Water Tower at Fantasy of Flight, Polk City Photo by Donna Kaluzniak In Florida, about 88% of people get their drinking water (also called potable water) from a utility.  The rest of the population have their own private wells. Some utilities provide more than just water. They may also include electric, gas, or sanitation.  Public water systems (PWS) --are water utilities that are owned by a local government or agency. They serve about 93% of Florida's population. Sometimes the water utility is part of a city or county public works department.  Florida has nearly 5,000 public water systems, but only about one-third (1,585) are community water systems that provide drinking water to homes year-round. The remaining two-thirds serve businesses, schools, campgrounds, factories, and other nonresidential facilities. Priv...
Read more

WHAT HAPPENS TO THE WATER USED IN YOUR HOME?

-
Image
  The Wastewater Collection System Have you ever wondered what happens to the water you use for drinking, cooking, flushing, showering, washing dishes, and doing laundry? Until I was in the "water business' I really didn't give it much thought. But it's a very important process!! Sewer Service Lines: The plumbing in your house or business connects to a sewer service line that goes through your property and connects to the utility's wastewater collection system (also called the sanitary sewer collection system ).  The sanitary sewer system  is designed to transport wastewater to a treatment plant to remove contaminants. The treated water is then discharged to a receiving water and/or reused. NOTE: Some utilities combine the sanitary sewer system with the storm sewer system. These are called combined sewer systems. Florida law does NOT allow combined sewers. Stormwater and wastewater must be transported in separate piping systems. This illustration from the EPA s...
Read more

WHAT ARE FLORIDA'S DRINKING WATER SOURCES?

-
Image
Your Drinking Water Sources C.W. Bill Young Regional Reservoir - Tampa Bay Water The answer is. . . it depends on your location.  To find the source of your community's drinking water, check your annual Water Quality Report (also called a Consumer Confidence Report ). This report should either be mailed to you or a website link provided for you. It should also be available on your water utility's website. Most Florida communities rely on  groundwater , typically from underground  aquifers .  Some utilities use  surface water  (rivers, lakes and reservoirs) a source.  Utilities in certain areas of the state, such as Tampa Bay Water , blend water sources, including seawater .  And more recently, source water may be augmented with reclaimed water. An  aquifer  is an underground layer of rock, sand, or gravel that stores water—like a huge natural sponge beneath our feet. Rainwater seeps through the soil and eventually collects in the spaces...
Read more