Are Water Utilities Inheriting Risk from Local Consultants?
•Download as PPTX, PDF•
1 like•421 views
The water engineering community has been struggling with new professional liability risk involving the location of premise isolation backflow preventer systems; Not because of new design practices, but because of new information about the old practices. And with this new risk realization comes a new interested party: The insurance company. Because of this very public commentary from experts and leading groups, casualty carriers, through subrogation, have new weapons for damage recovery. And anytime the accused designer is able to demonstrate that local government contributed, whether materially or passively, to the poor design, the water district and/or building authority may be at risk for the liability. How does the water utility avoid being named responsible? Use up to date standard details that address the risk and show you did not contribute. THIS SLIDESHARE WILL COVER: 1.What are the risks associated with backflow preventer installation? 2.Can that affect water jurisdictions? 3.National survey of civil and plumbing engineers 4.Standard details, best practices, and how to get your district up to date
Recommended
Recommended
More Related Content
Similar to Are Water Utilities Inheriting Risk from Local Consultants?
Similar to Are Water Utilities Inheriting Risk from Local Consultants? (20)
Recently uploaded
Recently uploaded (20)
Are Water Utilities Inheriting Risk from Local Consultants?
- 1. Randy Holland EnviroDesign Management Presented by Are Water Utilities Inheriting Professional Risk From Local Consultants?
- 2. Utilities: Are you Inheriting Risk from Local Consultants? Introduction The water engineering community has been struggling with new professional liability risk involving the location of premise isolation backflow preventer systems; Not because of new design practices, but because of new information about the old practices. There has been a slow trickle of warnings for years, but in the past 3 years important organizations and industry leaders have added new warnings with much stronger language that not only change recognized best practices, but actually challenge the fitness and safety of older placement methods altogether.
- 3. Utilities: Are you Inheriting Risk from Local Consultants? Introduction And with this new risk realization comes a new interested party: The insurance company. Because of this very public commentary from experts and leading groups, casualty carriers, through subrogation, have new weapons for damage recovery. And anytime the accused designer is able to demonstrate that local government contributed, whether materially or passively, to the poor design, the water district and/or building authority may be at risk for the liability.
- 4. 1. What are the risks associated with backflow preventer installation? 2. Can that affect water jurisdictions? 3. National survey of civil and plumbing engineers 4. Standard details, best practices, and how to get your district up to date Today We’ll Cover: Utilities: Are you Inheriting Risk from Local Consultants?
- 5. Backflow Installation Risks We’ve all seen the extraordinary measures OSHA imposes to legally access vaults for maintenance tasks. fresh air exchange hoses, tents, extra men. The costs are more and more prohibitive but frankly, the risk of serious injury is real as well. But beyond the cost of safety for onsite workers, liability issues persist. Inside a vault 1. Safety Utilities: Are you Inheriting Risk from Local Consultants?
- 6. Backflow Installation Risks Below grade vaults are classified by OSHA as a confined space. Each year confined spaces cause 92 deaths. Read more about this in our recent blog post on utility vaults. Inside a vault 1. Safety Utilities: Are you Inheriting Risk from Local Consultants?
- 7. Backflow Installation Risks When a vault floods like this one, the mandatory test cocks are submerged, and in that event, a violation of the International Plumbing has already occurred. Consider what would typically make up the constituents of that water. Runoff of lawn chemicals alone make this a clear and present danger to the water supply. Inside a vault 2. Liability Utilities: Are you Inheriting Risk from Local Consultants?
- 8. Backflow Installation Risks In fact, it led the USC Foundation of Cross Connection & Hydraulic Research in 2005 to change their recommendation of even double check BFP installation in vaults. “The foundation’s recommendation would be to install the double check valve above grade.” - USC-FCCHR “Crosstalk, Summer 2005 Inside a vault 2. Liability Utilities: Are you Inheriting Risk from Local Consultants?
- 9. Backflow Installation Risks The foundation added stronger language in 2014. “When a backflow preventer is installed below grade, the vault or pit in which an assembly is installed may fill up with water, The water in the pit could create a cross-connection between the water in the pit and the backflow preventer through the test cocks. This may occur whether the test cocks are opened or closed….” - USC-FCCHR “Crosstalk, Summer 2014 . 2. Liability Inside a vault Utilities: Are you Inheriting Risk from Local Consultants?
- 10. Backflow Installation Risks Most recently, the foundation had this to say on the subject in 2016. “"The Foundation recommends assemblies be installed 12” to 36” above grade. If an assembly needs to be hidden from view for aesthetic reasons, consideration should be given to installing it behind a wall or landscaping. For freeze protection or the threat of vandalism think about installing an assembly in an enclosure instead of a pit or vault. In some cases, an RP is replaced with a double check valve assembly (DC) since the DC has “no openings,” therefore reducing the risk of a cross-connection. Yet, the test cocks found on the DC could be the site of a cross-connection. If a test cock leaks or is broken off and becomes submerged backflow could occur through the test cock. So, instead of preventing backflow; a cross-connection has been created through the assembly.” - USC-FCCHR “Crosstalk, Winter 2016 . 2. Liability Inside a vault Utilities: Are you Inheriting Risk from Local Consultants?
- 11. Inside a building 2. Flooding Here’s what the American Society of Plumbing Engineers advise about indoor RPZs. “Before an RPZ is located, consideration should be given to both how much water will be discharged, and where it will drain. Consideration must be given to the drain system to assure the drainage system can handle the load. If a drain is not capable of accepting the flow, other choices as to the location of the valve, such as outside in a heated enclosure, should be made.” -2006 ASPE Plumbing Engineering Design Handbook, vol 2, p 70 Utilities: Are you Inheriting Risk from Local Consultants? Backflow Installation Risks
- 12. Inside a building So if an RPZ is designed to dump water, then drain capacity is the issue. The chart on the right is from the manufacturer of the BPA seen in the previous flood photos. It illustrates the anticipated flow rate from the relief valve at various pipe sizes and at various pressures. Note that the assembly shown will flow 375 GPM at 85 PSI. A 4” drain pipe with a 1% fall rate evacuates clean water at a maximum rate of 93 GPM. If that device is flowing at 375 GPM and your clearing 93, then you are flooding at a rate of 282 GPM. 2. Flooding Utilities: Are you Inheriting Risk from Local Consultants? Backflow Installation Risks
- 13. Inside a building An article published June 2013 in the Chicago chapter of the American Society of Plumbing Engineers written by David DeBord, a former president of that organization, and current Education chair of the national ASPE, states all these facts better than I can. 2. Flooding Utilities: Are you Inheriting Risk from Local Consultants? Backflow Installation Risks
- 14. Inside a building He uses the Manufacturer’s data supplied by a different manufacturer, and he uses a 65 PSI instead of my 85, but he actually does the math in the article and offers FLOOD rates or 219 GPM for 2 1/2 and 3”; and flood rate of 482 GPM for 4” and above. 2. Flooding Utilities: Are you Inheriting Risk from Local Consultants? Backflow Installation Risks
- 15. Inside a building He concludes that regarding indoor RPZs… 2. Flooding Utilities: Are you Inheriting Risk from Local Consultants? Backflow Installation Risks Read more about flooding caused by RPZ backflow preventers here.
- 16. Utilities: Are you Inheriting Risk from Local Consultants? Assuming the legal rights of a person for whom expenses or a debt has been paid. Typically, an insurance company which pays its insured client for injuries and losses then sues the party which the injured person contends caused the damages to him/her. How Does This Affect Water Districts? Because of subrogation, the water district needs to demonstrate that no unsafe methods are promoted by their plans review teams. The best way to demonstrate that is with published standard details and drawings that are consistent with recognized best practices.
- 17. How Does This Affect Water Districts? Let’s look at an example: This flood occurred in a hospital mechanical room causing over $1M in damage. You are looking at 2 sides of one wall. Utilities: Are you Inheriting Risk from Local Consultants?
- 18. How Does This Affect Water Districts? On the left, we see that the sudden water flow and volume moved the wall into the next room (right photo), which happened to be a telephone and low-voltage wiring room. Utilities: Are you Inheriting Risk from Local Consultants?
- 19. How Does This Affect Water Districts? The insurer sought recovery from all the risk holders including the engineer, architect, contractor, subcontractor, and even the most recent recorded tester; Utilities: Are you Inheriting Risk from Local Consultants?
- 20. How Does This Affect Water Districts? While the details of who paid what were not made public, we do know that the property insurer was made whole by one or more of the listed defendants. Utilities: Are you Inheriting Risk from Local Consultants?
- 21. How Does This Affect Water Districts? In times past, this event would have been seen as an unforeseeable casualty, a pipe burst. But insurers have been listening to the industry leaders about these risks. Utilities: Are you Inheriting Risk from Local Consultants?
- 22. Will CEs take on the task? Utilities: Are you Inheriting Risk from Local Consultants?
- 23. U S Survey Results Utilities: Are you Inheriting Risk from Local Consultants? According to a survey of 1220 civil and plumbing engineers across the nation, a survey in which over 140 Atlanta area consultants participated in over a 19‐month period, 3 out of 4 say they need local water authorities to provide standard details for outdoor aboveground backflow preventer systems.
- 24. U S Survey Results Utilities: Are you Inheriting Risk from Local Consultants?
- 25. U S Survey Results Utilities: Are you Inheriting Risk from Local Consultants?
- 26. Charlotte, NC Denver, CO Columbus, OH Roswell, GA Arlington, TX Gwinnett County, GA Las Vegas, NV Updated Standard Details Utilities: Are you Inheriting Risk from Local Consultants?
- 27. Updated Standard Details: Northern Georgia Best Practices: Containment Backflow Preventer Placement
- 28. Updated Standard Details Best Practices: Containment Backflow Preventer Placement Use these best practice examples to create or update standard details for your water municipality. Safe-T-Cover will help you create standard details. We have worked with Roswell, GA, Arlington, TX and others so far.
- 29. The design community is struggling with newly realized professional liability risks associated with containment BF systems. The risks include liability and safety of vaults and indoor floods caused by RPZ backflow preventers The positions of leading organizations and the opinions from experts have alerted casualty carriers to seek recovery from losses through subrogation. Consultants who can prove the building/water authority directed – or merely suggested – a design that led to a loss will have successfully avoided a liability loss and passed it to the civil authority. Even if the older methods remain, the presence of details consistent with best practices provide the legal cover needed to materially reduce the risk of liability through subrogation. Take-Aways Utilities: Are you Inheriting Risk from Local Consultants?
Editor's Notes
- The Eng commty: struggling w/ new professional liability risk involving the location of PremISO Backflow preventer systems. not because new design practice, but because of new information about the old practices. Slow trickle of warnings for years, * past two years: imp orgs and ind’ry leaders have added new warnings, much stronger lang: not only change recognized best practices, but actually challenge the fitness and safety of older placement methods altogether.
- And with this new risk realization comes a new Interested Party. The insurance company. Because of this very public commentary from experts, they now have new weapons for damage recovery. And anytime the designer is able to demonstrate that local government was causal to the poor design, they, through the magic of subrogation, have at least one more pocket to pick. * The Local Water Authority.
- Today we’ll cover design differences and why it matters Current placement practices and what’s wrong with them from a safety point of view The explosive growth of the RPZ and why it’s happening Arlington’s decision to move forward.
- So let’s look at the considerations. Safety, Liability, and changing demands * We’ve all seen the extraordinary measures OSHA imposes to legally access vaults for maintenance tasks. fresh air exchange hoses, tents, extra men. The costs are more and more prohibitive but frankly, the risk of serious injury is real as well. * But beyond the cost of safety for onsite workers, liability issues persist. * When a vault floods like this one, the mandatory test cocks are submerged, and in that event, a violation of the International Plumbing has likely already occurred. The water may look clean, but consider what would typically make up the constituents of that water. Runoff of lawn chemicals alone make this a clear and present danger to the water supply. In fact, it led the USC Foundation of Cross Connection & Hydraulic Research in 2005 to change their recommendation of even double check BFP installation in vaults. * (READ) Finally, Changing demands. Engineers are obviously preoccupied with new construction. But buildings, through their normal life of changing tenants over time, change uses with respect to hazard levels, and hazard levels, or more precisely, the named high-hazard threshold, has become a moving target. Around the corner from our office in Nashville, I snapped this picture. It sits in front of a warehouse owned by an automotive dealer. When they bought the property and erected the building, they put a double-check BFP down in that vault with the meter. A few years later, the city changed an ordinance that redefined their particular use to high-hazard. When they sought a permit to upgrade the HVAC system, the city forced them to change to an RPZ. After constructing this huge vault, they now leave it almost empty with an RPZ in an enclosure perched on top of it. They paid three times for a single solution. Now this enclosure – This is what happens all too often when tenants or hazard thresholds change in areas where no guidelines or Standard Details exist.
- So let’s look at the considerations. Safety, Liability, and changing demands * We’ve all seen the extraordinary measures OSHA imposes to legally access vaults for maintenance tasks. fresh air exchange hoses, tents, extra men. The costs are more and more prohibitive but frankly, the risk of serious injury is real as well. * But beyond the cost of safety for onsite workers, liability issues persist. * When a vault floods like this one, the mandatory test cocks are submerged, and in that event, a violation of the International Plumbing has likely already occurred. The water may look clean, but consider what would typically make up the constituents of that water. Runoff of lawn chemicals alone make this a clear and present danger to the water supply. In fact, it led the USC Foundation of Cross Connection & Hydraulic Research in 2005 to change their recommendation of even double check BFP installation in vaults. * (READ) Finally, Changing demands. Engineers are obviously preoccupied with new construction. But buildings, through their normal life of changing tenants over time, change uses with respect to hazard levels, and hazard levels, or more precisely, the named high-hazard threshold, has become a moving target. Around the corner from our office in Nashville, I snapped this picture. It sits in front of a warehouse owned by an automotive dealer. When they bought the property and erected the building, they put a double-check BFP down in that vault with the meter. A few years later, the city changed an ordinance that redefined their particular use to high-hazard. When they sought a permit to upgrade the HVAC system, the city forced them to change to an RPZ. After constructing this huge vault, they now leave it almost empty with an RPZ in an enclosure perched on top of it. They paid three times for a single solution. Now this enclosure – This is what happens all too often when tenants or hazard thresholds change in areas where no guidelines or Standard Details exist.
- So let’s look at the considerations. Safety, Liability, and changing demands * We’ve all seen the extraordinary measures OSHA imposes to legally access vaults for maintenance tasks. fresh air exchange hoses, tents, extra men. The costs are more and more prohibitive but frankly, the risk of serious injury is real as well. * But beyond the cost of safety for onsite workers, liability issues persist. * When a vault floods like this one, the mandatory test cocks are submerged, and in that event, a violation of the International Plumbing has likely already occurred. The water may look clean, but consider what would typically make up the constituents of that water. Runoff of lawn chemicals alone make this a clear and present danger to the water supply. In fact, it led the USC Foundation of Cross Connection & Hydraulic Research in 2005 to change their recommendation of even double check BFP installation in vaults. * (READ) Finally, Changing demands. Engineers are obviously preoccupied with new construction. But buildings, through their normal life of changing tenants over time, change uses with respect to hazard levels, and hazard levels, or more precisely, the named high-hazard threshold, has become a moving target. Around the corner from our office in Nashville, I snapped this picture. It sits in front of a warehouse owned by an automotive dealer. When they bought the property and erected the building, they put a double-check BFP down in that vault with the meter. A few years later, the city changed an ordinance that redefined their particular use to high-hazard. When they sought a permit to upgrade the HVAC system, the city forced them to change to an RPZ. After constructing this huge vault, they now leave it almost empty with an RPZ in an enclosure perched on top of it. They paid three times for a single solution. Now this enclosure – This is what happens all too often when tenants or hazard thresholds change in areas where no guidelines or Standard Details exist.
- So let’s look at the considerations. Safety, Liability, and changing demands * We’ve all seen the extraordinary measures OSHA imposes to legally access vaults for maintenance tasks. fresh air exchange hoses, tents, extra men. The costs are more and more prohibitive but frankly, the risk of serious injury is real as well. * But beyond the cost of safety for onsite workers, liability issues persist. * When a vault floods like this one, the mandatory test cocks are submerged, and in that event, a violation of the International Plumbing has likely already occurred. The water may look clean, but consider what would typically make up the constituents of that water. Runoff of lawn chemicals alone make this a clear and present danger to the water supply. In fact, it led the USC Foundation of Cross Connection & Hydraulic Research in 2005 to change their recommendation of even double check BFP installation in vaults. * (READ) Finally, Changing demands. Engineers are obviously preoccupied with new construction. But buildings, through their normal life of changing tenants over time, change uses with respect to hazard levels, and hazard levels, or more precisely, the named high-hazard threshold, has become a moving target. Around the corner from our office in Nashville, I snapped this picture. It sits in front of a warehouse owned by an automotive dealer. When they bought the property and erected the building, they put a double-check BFP down in that vault with the meter. A few years later, the city changed an ordinance that redefined their particular use to high-hazard. When they sought a permit to upgrade the HVAC system, the city forced them to change to an RPZ. After constructing this huge vault, they now leave it almost empty with an RPZ in an enclosure perched on top of it. They paid three times for a single solution. Now this enclosure – This is what happens all too often when tenants or hazard thresholds change in areas where no guidelines or Standard Details exist.
- So let’s look at the considerations. Safety, Liability, and changing demands * We’ve all seen the extraordinary measures OSHA imposes to legally access vaults for maintenance tasks. fresh air exchange hoses, tents, extra men. The costs are more and more prohibitive but frankly, the risk of serious injury is real as well. * But beyond the cost of safety for onsite workers, liability issues persist. * When a vault floods like this one, the mandatory test cocks are submerged, and in that event, a violation of the International Plumbing has likely already occurred. The water may look clean, but consider what would typically make up the constituents of that water. Runoff of lawn chemicals alone make this a clear and present danger to the water supply. In fact, it led the USC Foundation of Cross Connection & Hydraulic Research in 2005 to change their recommendation of even double check BFP installation in vaults. * (READ) Finally, Changing demands. Engineers are obviously preoccupied with new construction. But buildings, through their normal life of changing tenants over time, change uses with respect to hazard levels, and hazard levels, or more precisely, the named high-hazard threshold, has become a moving target. Around the corner from our office in Nashville, I snapped this picture. It sits in front of a warehouse owned by an automotive dealer. When they bought the property and erected the building, they put a double-check BFP down in that vault with the meter. A few years later, the city changed an ordinance that redefined their particular use to high-hazard. When they sought a permit to upgrade the HVAC system, the city forced them to change to an RPZ. After constructing this huge vault, they now leave it almost empty with an RPZ in an enclosure perched on top of it. They paid three times for a single solution. Now this enclosure – This is what happens all too often when tenants or hazard thresholds change in areas where no guidelines or Standard Details exist.
- So let’s look at the considerations. Safety, Liability, and changing demands * We’ve all seen the extraordinary measures OSHA imposes to legally access vaults for maintenance tasks. fresh air exchange hoses, tents, extra men. The costs are more and more prohibitive but frankly, the risk of serious injury is real as well. * But beyond the cost of safety for onsite workers, liability issues persist. * When a vault floods like this one, the mandatory test cocks are submerged, and in that event, a violation of the International Plumbing has likely already occurred. The water may look clean, but consider what would typically make up the constituents of that water. Runoff of lawn chemicals alone make this a clear and present danger to the water supply. In fact, it led the USC Foundation of Cross Connection & Hydraulic Research in 2005 to change their recommendation of even double check BFP installation in vaults. * (READ) Finally, Changing demands. Engineers are obviously preoccupied with new construction. But buildings, through their normal life of changing tenants over time, change uses with respect to hazard levels, and hazard levels, or more precisely, the named high-hazard threshold, has become a moving target. Around the corner from our office in Nashville, I snapped this picture. It sits in front of a warehouse owned by an automotive dealer. When they bought the property and erected the building, they put a double-check BFP down in that vault with the meter. A few years later, the city changed an ordinance that redefined their particular use to high-hazard. When they sought a permit to upgrade the HVAC system, the city forced them to change to an RPZ. After constructing this huge vault, they now leave it almost empty with an RPZ in an enclosure perched on top of it. They paid three times for a single solution. Now this enclosure – This is what happens all too often when tenants or hazard thresholds change in areas where no guidelines or Standard Details exist.
- There are three options for backflow preventer placement. 3 possibilities, all three are widely practiced.
- So if these things are designed to dump water, then drain capacity is the issue. The chart on the left is from Wilkins. It’s the Relief Valve Discharge Rate chart of its top of the line, 375 RPZ. It illustrates the flow rate of that device in various sizes and at various pressures. Note that a 2 1/2 inch device will flow 375 GPM at 85 PSI. If you remember your fluid volume tables, you’ll recall that a 4” drain pipe with a 6 inch fall per 100 horizontal feet evacuates clean water at a rate of 93 GPM. If that device is flowing at 375 GPM and your clearing 93, then you are flooding at a rate of 282 GPM. The chart on the right is a Drain Requirements chart created by the city of Columbus, OH. It’s importance cannot be overstated. It reveals that unless you intend to utilize 8” drain pipes at a 6” per 100 horizontal feet fall-rate all the way to the sewer, you cannot justify anything larger inside than a 2” RPZ inside. * An article published this summer in the Chicago chapter of the American Society of Plumbing Engineers written by David DeBord, a former president of that organization, states all these facts better than I can. He uses the Manufacturer’s data supplied by the Watts Corporation and he uses a 65 PSI instead of my 85, but he actually does the math in the article and offers FLOOD rates or 219 GPM for 2 1/2 and 3”; and flood rate of 482 GPM for 4” and above. * He concludes that regarding indoor RPZs, : (READ)
- So if these things are designed to dump water, then drain capacity is the issue. The chart on the left is from Wilkins. It’s the Relief Valve Discharge Rate chart of its top of the line, 375 RPZ. It illustrates the flow rate of that device in various sizes and at various pressures. Note that a 2 1/2 inch device will flow 375 GPM at 85 PSI. If you remember your fluid volume tables, you’ll recall that a 4” drain pipe with a 6 inch fall per 100 horizontal feet evacuates clean water at a rate of 93 GPM. If that device is flowing at 375 GPM and your clearing 93, then you are flooding at a rate of 282 GPM. The chart on the right is a Drain Requirements chart created by the city of Columbus, OH. It’s importance cannot be overstated. It reveals that unless you intend to utilize 8” drain pipes at a 6” per 100 horizontal feet fall-rate all the way to the sewer, you cannot justify anything larger inside than a 2” RPZ inside. * An article published this summer in the Chicago chapter of the American Society of Plumbing Engineers written by David DeBord, a former president of that organization, states all these facts better than I can. He uses the Manufacturer’s data supplied by the Watts Corporation and he uses a 65 PSI instead of my 85, but he actually does the math in the article and offers FLOOD rates or 219 GPM for 2 1/2 and 3”; and flood rate of 482 GPM for 4” and above. * He concludes that regarding indoor RPZs, : (READ)
- So if these things are designed to dump water, then drain capacity is the issue. The chart on the left is from Wilkins. It’s the Relief Valve Discharge Rate chart of its top of the line, 375 RPZ. It illustrates the flow rate of that device in various sizes and at various pressures. Note that a 2 1/2 inch device will flow 375 GPM at 85 PSI. If you remember your fluid volume tables, you’ll recall that a 4” drain pipe with a 6 inch fall per 100 horizontal feet evacuates clean water at a rate of 93 GPM. If that device is flowing at 375 GPM and your clearing 93, then you are flooding at a rate of 282 GPM. The chart on the right is a Drain Requirements chart created by the city of Columbus, OH. It’s importance cannot be overstated. It reveals that unless you intend to utilize 8” drain pipes at a 6” per 100 horizontal feet fall-rate all the way to the sewer, you cannot justify anything larger inside than a 2” RPZ inside. * An article published this summer in the Chicago chapter of the American Society of Plumbing Engineers written by David DeBord, a former president of that organization, states all these facts better than I can. He uses the Manufacturer’s data supplied by the Watts Corporation and he uses a 65 PSI instead of my 85, but he actually does the math in the article and offers FLOOD rates or 219 GPM for 2 1/2 and 3”; and flood rate of 482 GPM for 4” and above. * He concludes that regarding indoor RPZs, : (READ)
- So if these things are designed to dump water, then drain capacity is the issue. The chart on the left is from Wilkins. It’s the Relief Valve Discharge Rate chart of its top of the line, 375 RPZ. It illustrates the flow rate of that device in various sizes and at various pressures. Note that a 2 1/2 inch device will flow 375 GPM at 85 PSI. If you remember your fluid volume tables, you’ll recall that a 4” drain pipe with a 6 inch fall per 100 horizontal feet evacuates clean water at a rate of 93 GPM. If that device is flowing at 375 GPM and your clearing 93, then you are flooding at a rate of 282 GPM. The chart on the right is a Drain Requirements chart created by the city of Columbus, OH. It’s importance cannot be overstated. It reveals that unless you intend to utilize 8” drain pipes at a 6” per 100 horizontal feet fall-rate all the way to the sewer, you cannot justify anything larger inside than a 2” RPZ inside. * An article published this summer in the Chicago chapter of the American Society of Plumbing Engineers written by David DeBord, a former president of that organization, states all these facts better than I can. He uses the Manufacturer’s data supplied by the Watts Corporation and he uses a 65 PSI instead of my 85, but he actually does the math in the article and offers FLOOD rates or 219 GPM for 2 1/2 and 3”; and flood rate of 482 GPM for 4” and above. * He concludes that regarding indoor RPZs, : (READ)
- because of subrogation, the water district needs to demonstrate that no unsafe methods are promoted by their plans review teams. The best way to demonstrate that is with * published standard details and drawings that are consistent with recognized best practices.
- There are three options for backflow preventer placement. 3 possibilities, all three are widely practiced.
- There are three options for backflow preventer placement. 3 possibilities, all three are widely practiced.
- There are three options for backflow preventer placement. 3 possibilities, all three are widely practiced.
- There are three options for backflow preventer placement. 3 possibilities, all three are widely practiced.
- There are three options for backflow preventer placement. 3 possibilities, all three are widely practiced.
- According to a survey of 1220 civil and plumbing engineers across the nation, a survey in which over 140 Atlanta area consultants participated in over a 19‐month period, 3 out of 4 say they need local water authorities to provide standard details for outdoor aboveground backflow preventer systems.
- Roswell, GA has articulated a rational middle-ground position for getting Backflow preventers out of harm’s way. Recognizing that drain capacities for small sized RPZs CAN be accommodated with a typical 4” drain system, they detailed two methods of RPZ placement, one indoors for small RPZs, and one outdoors for larger sizes. The drawings for the indoor method explicitly address drain system requirements and force designers to reconcile the flood rate risks with specific drainage system capacities “DRAIN TO BE APPROPRIATELY SIZED TO ALLOW FOR MAXIMUM DISCHARGE OF WATER AS PER TABLE 1 ABOVE.” “…INSTALLED ABOVEGROUND IN A HEATED AND INSULATED ENCLOSURE MEETING ASSE-1060 GUIDELINES….” * And the outdoor method mandates an enclosure that is ASSE-1060 compliant.
- Roswell, GA has articulated a rational middle-ground position for getting Backflow preventers out of harm’s way. Recognizing that drain capacities for small sized RPZs CAN be accommodated with a typical 4” drain system, they detailed two methods of RPZ placement, one indoors for small RPZs, and one outdoors for larger sizes. The drawings for the indoor method explicitly address drain system requirements and force designers to reconcile the flood rate risks with specific drainage system capacities “DRAIN TO BE APPROPRIATELY SIZED TO ALLOW FOR MAXIMUM DISCHARGE OF WATER AS PER TABLE 1 ABOVE.” “…INSTALLED ABOVEGROUND IN A HEATED AND INSULATED ENCLOSURE MEETING ASSE-1060 GUIDELINES….” * And the outdoor method mandates an enclosure that is ASSE-1060 compliant.
- 1. 2. Strong nat’l migration toward RPZ, away from DC with many standard details that have ceased to iteratively improve. That’s a business school way of saying Best practices are now evident because as time continues, cities are defining the same methods. 3. Indoor RPZ 2 ½” and larger cause floods and feed insurers. It’s not enough to say that some large indoor systems are poorly designed. If your building has a flange-sized RPZ inside and does not have at least an 8” drain system all the way to the sewer, then it fails the flood liability test and should not be there. 4. MEP engineers cannot stamp anything that is to be installed beyond 6’ of the building envelope so how can they design flange-sized RPZ systems at all? 5. Civil Engineers are not plumbers and need standard details provided by water authorities in order to properly design these systems. 6. Water authorities are driving these devices inside because “that’s the way everyone knows how to do it.” Continuing to direct and favor methods that are unsafe, or even less safe, expose the jurisdiction to liability risk.