ABPA San Antonio 1 12-17

January, 2017

Best Practices:

Containment Backflow Preventer

Design & Placement

Presented by

Randy HollandEnvironmental Quality Consultant

Backflow Prevention: 2 doctrines

Isolation: Plumbing code enforcementAdvocates asserts that we can take care of any cross connection contamination risks by enforcing the plumbing code.

Containment: Protection against unknown changes Advocates say no, not good enough because of risk of unknown changes to individual plumbing systems after the C of O is issued.

Best Practices: Containment Backflow Preventer Placement

Backflow Prevention: 2 doctrines

Isolation vs ContainmentNo matter where you stand on the issue, you will occasionally find yourself in a district that requires a containment system. When that happens, the worst thing you can do is install it indoors.


New professional liability risk for engineers


The entire water system design community is struggling with new professional liability risk involving the location of containment backflow preventer systems. Not because of a new design practice, but because of new information about the old practices.

There has been a slow trickle of warnings for many years.

New professional liability risk for engineers


But in the past 2 years important organizations and noted 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.


It seems very clear that we will not get rid of the problem of placement by ignoring the containment advocates. Advanced Metering Infrastructure (AMI) systems are revealing that more backflow is occurring at the meter than was previously believed. Its far more likely that aggressive containment rules will increase rather than decrease.

The risks are finally being revealed.


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.

Consider:


1. Water utilities are seeking more containment backflow protection than ever before.

1. Water utilities are seeking more containment backflow protection than ever before.

Consider:

“…. The return of any water to the public

water system after the water has been used for any purpose on the customer’s premises

or within the customer’s piping system is unacceptable and opposed by AWWA.…”

- preamble to EPA’s Cross Connection Control Manual


2. More containment systems are being specified as RPZ, regardless of hazard threshold, than ever before.

Consider:


Why?• Older low hazard-use buildings with lead in every plumbing

joint cannot be considered low-hazard forever. • As buildings turn over tenants, they are often transitioned from

low to high hazard uses. Management and enforcement of retrofits is an extraordinary burden

• Bad/ignorant actors changing plumbing systems without permits or oversight..


Consider:

2. For containment, AWWA, ASPE, & the legal community recognize “outside aboveground”as best practice.

1. Why outside?

2. Why not a vault?

3. Momentum: What is driving the change to better solutions?

4. Survey of Engineers

Today We’ll Cover:


1. RPZs are an indoor flood hazard

“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


Why Outside? Indoor Flood Risk.



Flow Stop

The most important thing a designer must understand is the worst case scenario. What canhappen. What describes the ‘perfect storm?

We all know that with an RPZ, when water demand stops the water between the valves often evacuates into the relief valve. Some (many) think that that event defines the limit of what water can ever flow into a drain.

Not so.

Loss of pressure

#2 valve blocked

Consider 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!



#1 valve Failure

Normal delivery pressure

Now 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

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.



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.



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.



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.





This flood

occurred in a

hospital

mechanical room

causing over $1M

in damage.



You are looking at

2 sides of one

wall.



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.



The insurer

sought recovery

from all the risk

holders including

the engineer,

architect,

contractor,

subcontractor,

and even the

most recent

recorded tester;



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.



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.

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.



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.





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.



He concludes that regarding

indoor RPZs…

Backflow Failure

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.

2. Professional liability: indoor flooding

Premise Isolation: Best Practices & Standard Details

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

2. Indoor RPZs Reduce the rentable square footage of a building reducing revenue & property value


Why Outside? Increase revenue and property value.

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.

Charlotte: 32.000 SF

Columbus: 36.000 SF

Suffolk Cty: 33.333 SF

Arlington: 32.000 SF

Average: 33.325 SF

Why Outside? Increase revenue and property value.

Consider the average square footage required for just a 3-inch indoor in-line backflow preventer. To the right, four representative cities are represented. The average required space is 33.325 SF.

Assuming a discount rate of 9%, rent value of $30 per foot annually, and a 25 year life, the net present value of that space to the property owner is $12, 156.48.

Arlington, TX: 32 SF


Average: 33.325 SF

Annual Rent Value (based on Class A Office

@ $30/sf)

$999.75

25-year Cash Flows(based on 2.5% inflation)

$34,149.22

Net Present Value (based on 9% discount

rate)

$12,156.48

Why Outside? Increase revenue.

Assuming a discount rate of 9%, rent value of $30 per foot annually, and a 25 year life, the net present value of that space to the property owner is $12, 156.48.

NPV: Landlord has lost this amount of value

by placing CBPA inside.

$12,156.48

CONSIDER:

1. If space is recaptured for rental value, what will my alternative cost be?

2. Will placing the system outside cost more or less than $12,156.48?

3. If it’s less, then how much less? (I don’t like the look of a box outside.)


Aboveground heated enclosure for 3” BPA with heat.

Option A: Use conventional model e.i., Watts 957 NRS

Safe-T-Cover 300-AL-H$3,266.00

72 X 38 X 22 = 60K CI


Option B:

Use new ”n-type” model

e.i., Watts 957N NRSSafe-T-Cover 200SN-AL-H

$1,120.0046 X 38 X 19 = 33K CI

$1,000

$1,120

$1,800

$3,920

$3,266

$1,200

$1,800

$6,266

Irrational Costs, Irrational Risks!


Indoor

CBPA


$3,920.00

plus assembly

$6,266.00

plus assembly

$12,156.48

plus assembly

Owner’s Cost: 3” Domestic line


“How much more value does my building have with the additional rent?”

ANSWER:


Year AnnualRent*

1 $999.75

PropertyValue*

$10,289.09

5 $1,103.54 $11,357.2310 $1,248.55 $12,849.67

15 $1,412.62 $14,538.2220 $1,598.25 $16,448.66

25 $1,808.27 $18,610.15

* - Today’s dollars: Assumptions: Annual rent growth of 2.5%; 5% vacancy; 35% operating expenses; capitalization rate of 6%.

Owner’s Property Value


2. Increase cash flow & prop value

Why Outside?

1. Eliminate indoor flood hazard


1. No RPZs in Vaults

Why not a vault?


41 states have written code that prohibits the installation of RPZs below grade. And as far as I know, where it remains unwritten, it is invariably enforced as an unacceptable practice.

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.

Why not a vault?


2. Confined Space Hazards

Why not a vault?


3. Liability

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.

Why not a vault?


3. Liability

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

Why not a vault?


3. Liability

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 .

Why not a vault?


4. Changing Demands

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.

Why not a vault?


4. Changing Demands

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.

Why not a vault?


4. Changing Demands

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.

Why not a vault?


5. Legal Community Support

Before his recent death, Indianapolis attorney Doug Cregor was the nation’s leading litigator of Cross-Connection Control cases.

He was quoted in Plumbing Standards Magazine initially in 2009. I most recently saw it republished as part of a blog post on the LinkedIn Group, “MEP Engineers & Managers”:

Douglas Cregor, Esq.

Why not a vault?


5. Legal Community Support

“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.

3. Submerged valves and test cocks violate IPC

2. Confined space hazards

1. No RPZs below grade

4. Changing hazards and changing hazard thresholds means expensive retrofits

Why not a vault?

5. Legal interests recommend enclosures



Where is the momentum?

What is driving change to get these installations into a safer environment?


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.

Trade Org. LeadershipWhere is the momentum?

Seattle, WA

Raleigh, NC

Charlotte, VAAustin, TX

Nashville, TN

Albuquerque, NM

Long Island, NY

Denver, CO

Las Vegas, NV

Lynchburg, VA

Columbus, OHChicago. IL

Forth Worth, TX Roswell, GA


Longview, WA

Arlington, TX

Gwinnett Cty, GA

Chesapeake, VA

Olympia, WA

Kent, WA

Franklin, TN

Where is the momentum? More RPZs, more outdoors.

All these cities have made changes whereby RPZ use has been expanded either by lowering or eliminating the hazard threshold for use on domestic water lines in the past 5 years. (These are the cities we know of….)

Charlotte, NC

Denver, CO

Columbus, OH

Roswell, GA

Arlington, TX

Gwinnett Cty, GA

Las Vegas, NV


Where is the momentum? More outdoor, aboveground SDs.

Where is the momentum? Smaller solutions.

12’

6’8” 5’2”

5’4”


Consider the required enclosure for the industry standard Watts 709 DCDA on the left. It is housed by our Model 1000-AL. It’s 12 feet long and stands 6’8” tall. Compare it to the enclosure required for the Wilkins 450DA on the left. It is housed in our Model 1000TLU880M. It’s 5’4” square and stands just 5’2” tall. These two options offer the same plumbing solution and make a much smaller visual footprint.


Where is the momentum? Adjustments for aesthetics.

AWWA has long resisted the practice of placing the BPA near the building because it increased the risk that illegal taps might occur between the meter and the BPA. But Arlington noted that all their indoor RPZs were already “living with that risk”. Enabling the enclosure to reside close to the building dramatically increases the opportunity to screen it with landscaping and thereby improve the aesthetics of the grounds.



Arlington’s decision to add details based on:1. Too much backflow detected through AMI

2. Isolation from the inspection process.

3. Non-conforming/Illegal changes after C of O

4. Subrogation risks

5. Local engineers’ survey


Newly committed TX Cities:1. Fort Worth

2. Bedford

3. Grand Prairie

4. More to come…


Where is the momentum? Feedback is helping move gov.






3. Civil engineers are ready to take on the task if SDs exist

Take-Aways1. 3” and larger CBPAs should not be installed indoors and MEPs are

seeking to be excluded from the taska. Indoor flood risksb. Designing for sudden flood water flows exceeds expertise

4. Water/building authorities are feeling pressure to add aboveground standard details so that civil engineers can do this work and improve the safety by advocating safer placement


2. CBPAs should not be installed in subterranean vaultsa. Contamination risksb. Probability of subsequent aboveground retrofit

Thank [email protected]

