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November, 2016

Randy Holland Environmental Quality Consultant

Are Water Utilities Inheriting Professional Risk From Local Consultants?

Presented by

Utilities: Are you Inheriting Risk from Local Consultants?

IntroductionThe 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.


IntroductionCan we rid ourselves of the problem by dumping the system itself?

Sadly, we are learning through SCADA and AMI that there is actually more backflow occurring at the premise than we previously suspected.


IntroductionAnd 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.


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.

Introduction

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.

Introduction


Meanwhile, this past fall at the Bi-Annual ASPE National conference, one of the learning workshops had this title. The Board President of the Central Texas ASPE, Chris Phillips, a plumbing engineer at Jacobs in SAT contacted me and asked me to deliver the message.

Introduction


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.

1. Design differences DC vs. RPZ; Why it matters

2. Current placement practices and what the problems are with each

3. The explosive growth of the RPZ and why its happening

4. Recent changes in north Georgia

5. National survey of civil and plumbing engineers

6. Best Practice Examples Across the U S

Today We’ll Cover:


2 types of backflow Preventers:

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Double-Check Valve Assemble, DC or DCDA

Reduced Pressure Zone Valve Assembly, RP RPDA

A designer may specify one of two types of BFPs for premise isolation. Up until recently, the decision for which assembly to specify was based solely on the perceived hazard to the waste water system created by the processes of the end user. High hazard (better named, high waste-hazard) uses were required to utilize an RPZ. Uses that did not pose a risk to the waste water were allowed to use a DC.

Design Differences DC vs. RPZ


2 types of backflow Preventers:

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Double-Check Valve Assemble, DC or DCDA

Reduced Pressure Zone Valve Assembly, RP RPDA

Design Differences DC vs. RPZFor example, a medical facility or a chemical plant triggered the requirement for an RPZ while an office or simple retail user would be allowed to use a DC or, depending on the municipality, no premise isolation system at all.

Now, as we will discuss below, many purveyors are requiring RPZs on all premise isolation systems because of the inherent limits of protection provided by the double check valve for the public water supply.


DC: Low hazard?

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Design Differences DC vs. RPZThe Double-check assembly was developed in the 1950s for the fire industry. And for many years it was regarded as a satisfactory solution. The design is simple. Any time system-water pressure on the property (private) side exceeds the system pressure on the city (public) side, two redundant check valves close and water stops flowing backwards.

Premise Isolation: Best Practices & Standard Details

DC: Low hazard?

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Design Differences DC vs. RPZBut no remedy exists in the event of a malfunction of the valve closures or if debris in the water line causes the valves to not close completely. Additionally, The DC is a closed, or blind system making detection of any failure impossible without a field test performed by a licensed tester. Today, millions of DCs are in service that may have failed. When a Florida city began its annual testing program in 2010, it found 52% of the valves in service had failed with no way to determine how long they had been inoperable.

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Design Differences DC vs. RPZRPZ: Fail-safe against returning water

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The RPZ emerged in the 1970s as a remedy to the double-check limitations. Like the DC, it incorporates 2 redundant check valves. But unlike the DC, the RPZ incorporates a hydraulically operated differential relief valve directly beneath the # 1 check valve. It is this relief valve’s placement (along with the universal laws of hydraulics) that make this a fail-safe solution for water purveyors. As elegant as the design is, it comes at a cost. And that cost is the surrounding area.


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Flow

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Public (Supply)

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As the DC reveals, valves fail. But when they fail in an RPZ, the assembly is designed to create a deluge event directly under the assembly so that no contaminated water returns to the public water supply. Because of the danger of contamination, no water from the relief valve may be piped directly from the assembly. It must release into the atmosphere away from any piping. Watch this short video revealing an actual discharge.


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In a flow-stop situation the water between the check valves will often drain out the relief valve. Some think that that event defines the limit of what water can ever flow into a drain.

Not so.


Loss of pressure

#2 valve blocke

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Design Differences DC vs. RPZConsider a flow-stop situation, one that might naturally occur at the end of the day. If you look closely, you can see that a small pebble has lodged in the #2 check valve. Now let’s say there’s a fire around the corner that causes back siphon at this point in the system.

Because the # 2 check valve is not closing, all the water that has been delivered to the building will continue to flow out the relief valve until the private lines are cleared. If this is a four story building, that’s a lot of water!

RPZ: Fail-safe against returning water


#1 valve Failure

Normal delivery pressure

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Design Differences DC vs. RPZNow consider a failure of the #1 check valve. Under normal operating conditions, this failure would go unnoticed. After all, water is being called for by the user through the opening of taps. The water flows in undeterred.

But with this imbalance in the system, changes in demand tend to rock the remaining valves open and closed sporadically.


Demand


#1 valve Failure

Blockage

relief valve

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Demand


This creates the conditions for the “perfect storm” scenario. The imbalance created by the # 1 failure makes the relief valve more prone to opening momentarily, allowing debris to block the closure of that valve.

Under such conditions, a constant flow of delivered water will begin to flow directly out the relief valve. This reduces water pressure for the user, but delivery will continue.


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Design Differences DC vs. RPZ

No demand



The real damage begins when the user stops using water such as at the end of a work day.

With the relief valve blocked open and the # 1 valve inoperative, all the water that the purveyor can provide will flow unabated out the relief valve wherever it might be, and continue until the water source is interrupted.

This is the scenario that must be avoided: the perfect storm.


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This picture was tweeted last summer by a Nashville backflow tester. He was called to a multi-story office building on a Sunday to inspect a “malfunctioning backflow preventer”. By the time he completed his service of the assembly, a small pebble was all he recovered from the 8” RPZ in the background.


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This was the scene when he arrived.

By the way, the RPZ was working perfectly before and after the call, behaving precisely as it was designed to.


Above ground in an enclosure Inside a building Inside a vault

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Placement Practices3 options for backflow preventer placement


Inside a vault

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A subterranean vault would have to be considered the legacy method still widely practiced among designers today but as most of you know, an RPZ can never be installed below grade . Beyond the issue of being unsuitable for RPZs however, there are compelling reasons to discontinue the use of vaults altogether.


Placement Practices

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 vault3 options for backflow preventer placement

1. Safety


Placement Practices

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.


2. Liability


Placement Practices

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


2. Liability


Placement Practices

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

3 options for backflow preventer placement


Placement Practices

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.


3. Changing Demands


Placement Practices

Around the corner from our Nashville office, 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.


3. Changing Demands


Placement Practices

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. So after constructing this huge vault, they now leave it almost empty with an RPZ in an enclosure perched on top of it. They easily paid 3X the necessary cost because they began with a “DC-only” solution. Designers need to contemplate these latter-day retrofits as they make design decisions.


3. Changing Demands



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If the double check valve is commonly installed in a vault, then equally common is that the RPZ is installed in an indoor location.


Inside a building

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1. Space allocation/Accessibility

The space provided for an indoor BPA is routinely inadequate as provided by the architect. That’s because giving up space that would otherwise add value is being allocated as non-revenue space. Non-revenue space is the enemy of every development project.


Inside a building

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The BPA pictured cost tens of thousands in property value. Even a mere 3” indoor BPA will cost a developer $6,000 to $9,000 more than an outdoor installation in a heated enclosure. A separate presentation discusses the real costs of indoor BPA installation in detail.

1. Space allocation/Accessibility


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Inside a building

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2. Professional liability: indoor 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


Inside a building

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As we have illustrated, an RPZ, behaving as designed, creates a sudden flood.



Inside a building

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This flood occurred in a hospital mechanical room causing over $1M in damage.



Inside a building

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You are looking at 2 sides of one wall.



Inside a building

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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.



Inside a building

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The insurer sought recovery from all the risk holders including the engineer, architect, contractor, subcontractor, and even the most recent recorded tester;



Inside a building

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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.



Inside a building

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In times past, this event would have been seen as an unforeseeable casualty, a pipe burst. But insurers have been listening to the next part of the discussion. This commentary from experts changed everything.



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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.



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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.



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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.



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Inside a building


He concludes that regarding indoor RPZs…



Backflow Failure

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Placement Practices Inside a building

3 options for backflow preventer placement

Watch this video showing a check valve failure and the resulting flood water flow.



https://www.youtube.com/watch?v=d7MjJuZQoYo


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Above ground in an enclosure

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In 1996, the American Society of Sanitary Engineers (ASSE) developed a quality and safety standard for aboveground enclosures as a product class. It’s known as ASSE-1060 and it addresses 5 concerns. • Freeze protection to −30° • Vertical load strength of 100 PSF,• Full flow drainage capacity, etc.• Reliable Access• Keyed Security

1. Quality, 2. Safety, 3. Security



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Moreover, they took the guidance further by identifying all possible climate conditions and defining appropriate guidance for Freeze-prone areas (Class I); Frost-only areas (Class II); and warm areas where no climate control of any kind is required (Class III).




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This widely accepted standard simplifies the specification process for designers. By naming ASSE-1060 and the appropriate class, there will be no surprises upon delivery.




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Indianapolis attorney, Doug Cregor has been the leading attorney in the U.S. specializing in cross-connection control litigation and advocacy. He is quoted in Plumbing Standards Magazine as follows…

4. Legal endorsement

Douglas Cregor, Esq.



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“An outdoor, aboveground BFP installation may be the best way to 1) reduce the owner’s exposure to damage caused by flooding and the corresponding water contamination caused by a cross-connection; and 2) reduce the legal liability of the design engineers, the installers, and the certified testers whose professional actions, in part, may have otherwise caused the flooding harm. The water industry has a nationally accepted design criteria in ASSE’s Standard-1060 to protect these installations. It’s a win-win-win ‘insurance policy’.

Douglas Cregor, Esq.

4. Legal endorsement


Seattle

RaleighCharlotte

Austin

NashvilleAlbuquerque

Long IslandDenver

Las VegasLynchburgColumbus

Chicago

Roswell

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ArlingtonGwinnett Cty

Chesapeake

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PZUtilities: Are you Inheriting Risk from Local Consultants?

Another Reason For Growth

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PZUtilities: Are you Inheriting Risk from Local Consultants?

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MEPs Should-Not/Cannot Design For This Event

Perfect Storm


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Will CEs take on the task?


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U S Survey Results


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GenericCharlotte, NC

Denver, COColumbus, OH

Roswell, GAArlington, TXGwinnett Cty, GALas Vegas, NV

RPZ use is growing because: A DC failure is undetectable without a field test. Retrofits are disruptive, expensive, and create conflict with subscribers.

The design community is struggling with newly realized professional liability risks associated with containment BF systems.

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


Thank You!rholland@envirodesignmanagement.

com

envirodesignmanagement.com safe-t-cover.com

Are Water Utilities Inheriting Professional Risk From Local Consultants?