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Residential Prevention

Most Frequently Asked Questions

watts.com Residential Backflow Prevention The combined efforts of cross-connection control (first line of defense) and containment (second line of defense).

Most Frequently Asked Questions

Q I know that cross-connection control is Q If plumbing codes require backflow protec- important on industrial and commercial tion at the cross-connection, why is a facilities, but is it necessary on residential second line of defense needed? connections? Is there really a risk? ☛ Residential A There are several reasons: The first is that A Cross-connection control is important no plumbing codes, like other rules and regula- Series 8 Hose matter what type of service is involved. should have been installed here. tions, are not always adequately enforced. Industrial cross-connection control programs Pesticides: Chlordane The second, and by far the most compelling have been used for years. Historically, water and Heptachlor reason, is that the day after the certificate of purveyors have recognized the potential risk occupancy is issued, plumbing becomes sub- of health hazard industrial connections in their ject to unauthorized changes. Economic fac- systems and have taken an active roll in pro- tors motivate homeowners to do-it-yourself

tecting the public water supply (primary sys- Series 7 Dual Check plumbing. The bottom line is the cost of a tem) from them. The potential risk from resi- backflow preventer should 6" Feed 6" Main competent plumber versus the savings when have been installed here. Water Supply was dential connections has been, for the most (Second Line of Defense) contaminated with pesticide the homeowner does it himself. Generally, the part, overlooked, even though some of the homeowner is not only ignorant of the plumb- most serious cases of backflow originated at ing code requirements, he is totally unaware of a residence. Chlordane was siphoned through the dangers of cross-connection and backflow. a hose at a residence in Roanoke, Virginia, Closed Finally, the installation of a Dual contaminating the water supply of an entire backflow preventer at the service connection neighborhood. The cost to the water purveyor divorces the public water supply from the to replace water mains, , meters, service domestic water supply and establishes juris- lines, water heaters, ice makers, and other dictional authority and responsibility between plumbing was about $200,000. In addition, the public water supply and domestic water lawsuits totalling several million dollars were system. filed. Since these suits were settled out of Residential - (Second line of defense) Q What types of water system protection are court by the water purveyor and the extermi- Containment at the water meter required in a residence? nator, no records are available on the actual amount paid, but it was probably considerable. Dual Check Valve here A Plumbing codes are very specific here. They (Second line of defense) require backflow protection by cross-connec- Q What do you mean by “second line of

To Sill Cock To tion control and many important safety devices defense?” ☛ as follows: A We call this program of containment at the Service 1. Air gaps built into sink, tub, and basin service connection with a Dual Check Valve faucets backflow preventer the “second line of defense” 2. Anti- type ballcocks in water because it is intended as a backup to the closets (toilets) plumbing cross-connection control program Industrial - (Second line of defense) 3. Vacuum breakers on hose bibbs and which controls backflow at the cross-connec- sill cocks tion itself. It might be compared to the safety 4. Backflow preventers or vacuum breakers latch on an automobile door where both would on lawn sprinklers have to fail simultaneously before the door 5. Backflow preventers on supply lines to could open unintentionally. or other equipment containing Q Is the second line of defense concept non-potable fluids and cross-connected limited to residential systems? ☛ to the potable water system A No, the principle must be applied to all sys- Because some local authorities modify existing tems, although the backup for health hazard national codes, certain areas require backflow facilities would require the use of an assembly protection on the following as well: that was designed for such installations, such 1. Residential swimming pools, hot tubs, as the Reduced Pressure Zone Assembly back- and spas flow preventer. The Dual Check Valve backflow 2. Residential solar heating systems preventer simply was not developed for use in Reduced Pressure Zone 3. Private wells and other auxiliary water Assembly health hazard industrial applications. You supplies wouldn’t put a residential deadbolt on the door Most homeowners do not know they alone to the bank vault, would you? Reduced Pressure Zone are responsible for the safety of domestic Assembly Installed Here. (Second Line of Defense) water system. It is up to the water purveyor Water meter to inform him.

Cold water supply from street main Q Is the water purveyor responsible for Q I understand the Dual Check Valve is lim- enforcing the plumbing code? ited by national standards to one-inch size. A No, but the water purveyor is responsible for Suppose a residence had a service con- ☛ Assembly protecting the public water supply. That nection larger than one inch—what type of responsibility may include taking secondary device would be practical? Series 007 1 measures beyond the plumbing code require- A This would be an unusual situation, but a larg- Sizes ⁄2" – 3" ments, such as installing a backflow preven- er size Double Check Valve Assembly could be tion assembly at residential connections to installed in lieu of the Dual Check Valve. ensure that contaminated water does not enter Q Speaking of national standards, what the distribution system at one point, only to be standards does the dual check meet? served to another consumer down the line. The Dual Check Valve meets the ANSI/ASSE ☛ Series 709 A 1 Generally, the water purveyor’s responsibility Sizes 2 ⁄2" – 10" ends at the service-connection to the consum- Standard 1024. Generally speaking, most er’s water system. However, since the need for standards address the performance and con- this added protection is relatively new (past 15 struction requirements including the quality of years) many premises exist that must be retro- materials and workmanship and the quality of fit or brought up to today’s standard. the bronze, stainless steel, plastic and rubber Therefore, the water purveyor must require the parts, and the spring tension, tolerance and owner to provide proof of compliance with the tightness. current plumbing code and install a contain- Q Do standards ensure reliability? Dual Check Valve ment control device at each service or meter. A No, all water works equipment requires a Backflow Preventer The minimum standard of performance must maintenance program. The more sophisticated No. 7 3 be met before being tied into the system. assemblies, such as the Reduced Pressure Sizes ⁄4" – 1" Q If you are going to install a Dual Check Zone Assembly, the Double Check Valve Valve at the service connection, why not Assembly, and the Pressure Vacuum Breakers go ahead and install a more stringent all have something in common with the Dual device, such as the intermediate atmo- Check Valve. We know that after we test a spheric vent backflow preventer or the sophisticated assembly, a year will generally Reduced Pressure Zone Assembly? go by before we test it again. A If that idea had merit, the water industry During that time, we trust we are protected. would already have adopted it. The fact is, This trust is being hedged, however, with the the industry made repeated requests to back- knowledge that the assembly is manufactured Q Is spot-testing adequate? flow preventer manufacturers to produce a to national standards and will, in all probability, A Selective spot-testing is the mainstay method compact, economical product that could be prevent anyone from getting hurt. The story is of quality control used in every industry in the installed in the meter box as a second line of the same with the Dual Check Valve. The most world today, including the potable water supply defense for the community water system. The significant difference here is that we know the industry. Clearly, spot-testing is nothing new to Dual Check Valve is a direct result of those Dual Check Valve is not installed as a primary the water industry. It is used regularly to test requests. It is the only practical device for device, but as a backup, a sort of insurance meter accuracy, flow rates, and system pres- large-scale residential programs and it is policy against a residence not being or not sure. In fact, spot-testing is used to en-sure designed to be installed with the meter, includ- becoming in full compliance with the plumbing that the water is within the bacterio-logical ing in the meter box, for new or retrofit instal- code. and chemical limits established by EPA. The lations. One could equate the use of a Dual Q You mentioned testing. What are the major Safe Drinking Water Act re-quires that random Check Valve to the installation of a deadbolt on utilities doing about testing the Dual Check samples of water be sent to certified labs. the front door: it provides better protection Valve? Using this method to test Dual Checks Valves than a single lock in the handle, but it certainly A For the most part, they are using selective not only makes good economic sense, it can doesn’t provide the protection of a full-scale spot-testing; but a few are using 100 percent often provide additional valuable information electronic security system—nor does it cost annual testing. All are testing at the time the to the water purveyor regarding the overall as much to install and maintain. meter is serviced or upon change of owner- condition of his distribution system. Q Even so, suppose I decided to use the ship. Q If spot-testing is adequate, why are all intermediate atmospheric vent backflow Q How can a water purveyor gain confidence Reduced Pressure Zone Assemblies test- preventer or a Reduced Pressure Zone in a Dual Check valve that is designed for ed annually? Assembly at the meter as the second line selective spot-testing? Unlike the Dual Check Valve, RPZs are intended of defense, could it be installed in the box A for use in health hazard installations and are with the meter? A By experience. All backflow preventers, like other mechanical devices, are depended upon considered the first line of defense. Positively not, because meter boxes are sub- A to work for a reasonable period of time after Interestingly, the , purported to be the ject to flooding. Each of these items have an installation. Assuming the water purveyor ultimate in cross-connection control, is air-intake valve that would create a cross-con- removes a certain percentage of the assem- assumed to remain in place and function indef- nection the instant it became submerged. You blies on a selected grid of his distribution sys- initely, since no periodic reports on inspections could be creating a more dangerous situation tem, he will be able to determine if the assem- are maintained on these installations, even than having no protection at all. The air-intake blies are performing as intended and are suit- though defeating an air gap by adding an valves must be installed above ground, and able for extended service, or if his water condi- extension is a very simple and commonplace they must be protected from freezing and tions dictate the need for extensive mainte- procedure. The selection, maintenance, and vandalism. While these products meet specific nance or replacement. He can then make testing of every backflow prevention assembly needs in the industry, they simply aren’t prac- adjustments to his spot-testing procedures to demands the use of sound judgement, based tical for meter box installation. ensure even higher reliability. on a reasonable assessment of the risk involved versus the cost of protection. Q Regarding risks, is there a potential for lia- Q Could the water purveyor make his own Q Can the Dual Check Valve be adapted to bility from backflow into the mains when provision for thermal expansion? existing meter installations? the source is beyond the jurisdictional A No. The control of thermal expansion is plumb- A Yes, Watts offers models with meter threads, authority of the water purveyor? ing by nature. All domestic water systems that pipe threads, male or female threads, or com- A Most definitely. All purveyors connect the pub- are in compliance with the plumbing code binations on one or both ends. Unions are also lic water supply of the utility to the domestic would have provisions built in. It makes more available on one or both ends. water systems of the consumer. Purveyors sense for water purveyors to get on with pro- ☛ must require domestic water systems to com- tection of the public water supply and advise ply with state and local plumbing codes (the the owner or his designated agent to comply first line of defense), but experience teaches with the plumbing code. that this is not always the case. Accordingly, Q Is the residential containment method of Outlet: 3 we have a bonafide risk of contamination. The water system protection being favorably ⁄4" Female NPT connection concern over potential liability is intensified by accepted, and can you elaborate on the the Insurance Crisis in America and the fact actual operations in some of the major cit- 3 that most utilities can no longer purchase lia- ies’ programs? Inlet: ⁄4" Female Union NPT connection bility insurance. Because we cannot assume that 100 percent of the consumers will comply A Yes. “Containment” or the “second line of with the plumbing code, there is no alternative defense” has been very favorably accepted in the U.S.A. and Canada. Recently, major cities Outlet: but to take additional measures to protect the 1" Female Union NPT public water supply. That’s where the Dual have reported very successful operations of connection Check Valve comes in, as a second line of their backflow programs. Since these commu- nities are extending backflow prevention to 1 defense and establishes jurisdictional Inlet: 1 ⁄4" Female Meter Thread connection authority. It is economical, dependable, suit- include residential homes, the water supply is able for installation in the meter box, and a lot now safe. The actual operations or mechanics of backflow prevention is based on the follow- Outlet: 3 better than the millions of unprotected servic- ⁄4" Male NPT es in the country today! ing: connection Q Is there a possibility the utility would be 1. A valve is required on all new residential held liable for an incident that occurred in homes located at the meter Inlet: 1" Female Meter Thread spite of an active second line of defense 2. Existing homes are retrofit during meter Union connection program? change out programs or at the time of A That’s highly unlikely. Certainly not if the con- change of ownership tamination was contained in the domestic 3. All customers are required to provide a cer- water system and highly unlikely if some of it tificate of compliance with the plumbing got into the public water supply. There would code. Residential homeowners utilize a How much does it cost to establish a “sec- be a legal defense for an on-going backup pro- short, simple, self certification form. Q ond line of defense” program utilizing Dual gram, even if it failed. There would be no Rather than specifically calling for compliance Check Valve backflow preventers? defense for a nonexistent program. with cross-connection control, the form is The cost, of course, will vary depending on the What about thermal expansion? Doesn’t the designed to cover water system safety in A Q type of installation. However, compared to the Dual Check Valve create a closed system? homes. cost of serious backflow incident, a second A A backflow preventer, like any other checking Included is a check off for the T&P valves on line of defense program is relatively inexpen- device installed at the service connection, cre- water heaters, anti-siphon ball cocks, thermal sive. In addition to the cost of replacement or ates a closed domestic water system. The expansion relief devices, etc. repair when a public water supply is contami- water purveyor has the right and duty to con- The plumbing code is clear that the owner or nated, courts may impose judgements in favor tain all domestic water systems that, in his his agent is responsible for safety of his of injured parties and the cost can skyrocket judgement, represent a threat—or a potential plumbing system. It would not be prudent for —along with bad publicity. How can a utility threat—to his public water supply. Prior to the public water supplier to require anything afford NOT to take extra precautions to pro- closing the domestic water system by install- less than the minimum legal requirements. No tect the public water system, its customers, ing a Dual Check Valve backflow preventer, reasonable person would conclude otherwise. and its good reputation? however, the purveyor has a responsibility to Send for our folder F-BDL that explains the notify the consumer and the plumbing official, “Governor” 80-M1 importance of jurisdictional authority, total in writing, of his intent to do so. The consumer Ball Cock and Relief Valve containment, and several other important sub- must then make provisions for any resulting jects that every individual in the water industry thermal expansion through the installation of a should be informed about. Watts Gov. 80 antisiphon ball cock and relief ☛ valve, auxiliary pressure relief valve, or a ther- Relief Valve mal expansion tank.

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