The idea that harmful substances could be slowly invading our nation's water supply sounds like something straight out of a low-budget horror movie. However, it is a possibility that all water systems, regardless of size, need to address.
When "yellow gushy stuff" began pouring out of water faucets in a sleepy Pennsylvania community a few years ago there wasn't a movie director around to yell "cut" when people started getting ill.
Without Superman or Wonder Woman to step onto the scene and "save the day," the water system of a 75-unit apartment complex was quickly infiltrated by the mysterious "yellow" substance.
Was this a case of alien invaders or mutant creatures from the "black lagoon" seeking to destroy the planet?
No, in fact it turned out to be a much spookier scenario.
According to investigators, the yellow substance residents discovered "oozing" out of their faucets turned out not to be a mind-controlling ectoplasm, but rather a combination of pesticides that had been siphoned into the public water system through a hose that had been left in a local exterminator's tank truck.
When a nearby waterline was cut, a siphon (or backflow) was created, which pulled the poisonous chemical cocktail into the water hose that was connected to the community's water distribution system.
Had the community clearly understood the dangers associated with cross connections, this tale might have had a happier ending.
In this issue of the Safe Drinking Water Trust eBulletin we'll take a look at the need for Cross Connection Control policies and programs to protect your customers and keep your community from ending up featured in a bad movie script.
Additional Resources
www.epa.gov/safewater/pdfs/crossconnection/crossconnection.pdf [1]
It Came From Beyond the Aquifer!
Far from being an isolated incident, according to the good folks over at the Environmental Protection Agency (EPA) there have been 459 reported incidents involving backflow since 1970. These occurrences resulted in 12,093 illnesses. However, since many cases of backflow ultimately go unreported, the American Backflow Prevention Association estimates that more than 100,000 incidents may actually occur each and every year.
"When it happens it is a major problem," said Jay Tarara of the Pennsylvania Department of Environmental Protection's water supply office in a recent interview. "Is it a problem all the time? No," he said, adding that one of the most troubling aspects of cross connections is that most occurrences are only realized after customers begin to get sick.
Whether your system has a Cross Connection Control (CCC) policy already in place, or needs to implement one, the fact remains that all water systems should have and enforce a clearly defined plan to keep hazardous substances from accidentally ending up in their customers' drinking water. While not yet required by every state's primacy agency, it is a good idea to make a CCC policy a vital part of your system's security Vulnerabilty Assessment.
Additional Resources
www.usc.edu/dept/fccchr/epa/hhcc.report.pdf [2]
Godzilla vs. the Giardia!
Before a water or municipal board can develop a CCC policy, it is important that they understand what a cross connection is, why it is dangerous, and what can be done to correct the problem.
A cross connection is any physical connection between the public water supply and any piping or arrangement that contains any foreign liquid or substance. A cross connection creates the potential of contamination of the public water supply as a result of backflow.
Backflow is literally the reversal in the normal direction of flow within a water system which can turn a cross connection into a health hazard. This can occur when water systems are working on lines or at times when water pressure is lost.
According to the EPA , this reversal of pressure in a water system may be "freakish and unpredictable."
Potential cross connection situations are usually created as a simple matter of convenience when plumbing is not properly designed or installed.
Generally, the best way to prevent cross connections from being a problem is to identify potential sources of backflow and require that backflow-prevention devices be installed. The legalities of requiring these devices to be installed and that all systems being connected to your water distribution system meet certain requirements can be addressed by implementing a CCC policy for your system.
Most viable Cross Connection Control programs recognize five methods for properly controlling backflow:
• Air Gap: Nonmechanical backflow preventer that creates a gap (or open area) in the pipe that is twice the supply-pipe diameter.
• Atmospheric Vacuum Breaker (AVB): Among the simplest and least expensive mechanical types of backflow preventers, AVB's generally consist of a valve with a float that drops down to effectively vent the system and prevent backsiphonage when the water supply is terminated.
• Pressure Vacuum Breaker (PVB): Mechanical backflow preventer that is a variation of the AVB, which can be utilized under constant pressure consisting of a float assembly, two added gate valves, test cocks, and an additional first-check valve.
• Double-Check Valve Assembly (DC): Essentially two single-check valves coupled within one body and furnished with test cocks and two tightly closing gate valves.
• Reduced-Pressure Principle Backflow Prevention Assembly (RP): Mechanical backflow preventer is essentially modified double-check valves with an atmospheric vent placed between the two check valves.
Additional Resources
http://www.nesc.wvu.edu/ndwc/articles/OT/WI04/TB_WI04.html [3]
Attack of the Water Board Zombies!
The first line of defense against cross connections is a good offense.
To combat the evil presence of cross connections, it is important that all governing bodies adopt and enforce a CCC policy.
According to the Rural Community Assistance Corporation (RCAC), the Rural Community Assistance Partnership's (RCAP) western region, this feat can be completed in just five simple steps.
Step 1: Adoption of the program.
Prepare a cross connection control (CCC) ordinance, by-laws and policy statements for approval by the governing board and get them approved. Remember, it is important that the proposed regulations comply with all state regulations, health and plumbing codes. The proposed ordinance should be reviewed by the system attorney.
Step 2: Preparation, approval and implementation of the plan.
Prepare a CCC policy manual. This manual will be tailored for each individual water system and will contain clearly defined regulations and enforcement tools. This will also be the time to notify the system's customers of the CCC program explaining its purpose and function.
Step 3: Survey the system.
To successfully protect your system from cross connections you must be aware of the design and purpose of every connection to your distribution system, the purpose of the connection and how the connection was made. Categorize service connections by class to identify a priority list of potential hazards from which to conduct inspections. Remember, it is important to begin a survey right at home by first inspecting your own water-treatment system.
Step 4: Complete the necessary system improvement.
Compliance. Compliance. Compliance. Notify all customers who were identified in the survey as being high-risk that they will be required to install an approved backflow-prevention device.
Step 5: Testing and tracking of backflow devices.
Once compliance with the survey requirements is achieved, all existing and newly installed backflow-prevention devices must be tested and records of those tests maintained. Customers who fail to have their backflow-prevention device tested by an approved tester will face disconnection.
Tip: Check out the Safe Drinking Water Trust eBulletin's Management-At-A-Glance and Success sections this month for sample policies and manuals!
While a CCC program may seem rather strict, it is important to remember that the most important role of any water system is to protect its customers.
Return of the Living Bacteria!
Creating an effective CCC program is an important and challenging responsibility that every water system should undertake. An organized approach from the very beginning will help avoid many problems and conflicts once the program begins to function.
While in reality, implementing a lengthy CCC ordinance may not be possible in your community or water service district, water boards clearly have the ability to implement a CCC policy that offers much of the same protections as an ordinance.
Taking action now, before a problem arises, will not only protect your customers, it could help prevent your water supply system from becoming the subject of its very own scary tale.
Additional Resources
www.water.ky.gov/NR/rdonlyres/851A81AB-9752-4B76-930A-C134062598D9/0/CCCforsmallsyst.pdf [4]