007 Whole Building Backflow Preventer

Bob Gagnon plumbing and heating

Our city is requiring all business to have back flow preventers on the water main, do I have to install an expansion tank to absorb capacity as the water is heated in the water heaters?



Thanks, Bob Gagnon

Mark Eatherton

Yes, absolutely...

Hi Bob,



See this thread for more information.



http://www.heatinghelp.com/forum-thread/141147/expansion-tanks-on-DHW-systems



ME

STEVEusaPA

Govt strikes again.

Around here they havent mandated it, but the water company has taken the lead.  And they have plenty of leverage.

icesailor

Blame:

Go ahead, blame the government. Be careful though, don't show your ignorance. This has been around for a while. It is an EPA Reg.  BECAUSE!!!!

When you have natural disasters, like tornados, earthquakes, hurricanes, and the power goes out, and the water pressure drops, and houses are directly connected to the municipal water system WITHOUT BACKFLOW DRVICES the contaminated water can and will "back flow" into the water system and can make people very sick. There is a serious outbreak of water bourne diseases after the Fukajima earthquake and Tsunami

Mark Eatherton

You are correct sir...

One year after I graduated from High School, it became law.



http://www.epa.gov/lawsregs/laws/cwa.html



Many municipalities are just now getting around to enforcing it, and in a lot of cases, its because they are going to need EPA funding soon, and in order to get it, they must be in compliance with the CWA of 1972.



ME

TonyS

Smaller cities

That use the same water main for potable and fire have negative pressure every time they open a couple of hydrants for a fire.

Big box stores still sell non anti-syphon fill valves to home owners, who cant understand why the blue tidy bowl water is coming out the kitchen faucet.

icesailor

Blue Water Tidy Bowl:

Actually, that can't happen. What is more likely to happen is that after some event in the water supply like a disruption or loss of pressure, the services in the higher elevations of the system wouldn't have flow pressure. Water tanks ccollapse and suck fluids into the potable water system.

If you don't believe it can happen, read this. I carried a copy of this around for years in my wallet to show to any who doubted the need for back flow prevention

Read and enjoy.

http://www.holycross.edu/departments/publicaffairs/hcm/fall04/features/feature1.html

STEVEusaPA

Ice....

I probably could've phased my reply differently. Instead of 'mandated' I should've said they don't enforce it. And local municipalities don't require it unless its new construction or a plumbing permit is pulled on a remodel.

Mark Eatherton

I've seen blue water before...

As noted, there are ball cocks out there that DON'T meet the anti siphon requirements of the code. The problem is that it depends upon the refill tube for its air gap, and if it is not properly placed, it WILL siphon whatever is in the tank into the potable water lines.



And when I query the code officials about these products, they say that it is not their job to police every hardware store... Not enough hours in the day, days in the week, weeks in a year... Seems that someone has to die before action will be taken.



ME

Bob Gagnon plumbing and heating

Rare Occurrence

I'm all for water safety, but it seems like a rare occurrence, I remember reading about the cross connection at Holy Cross when I was in high school in the late 70's, if it was a big problem you would think we would have had another incident since then. I'd like to see the backflow preventer on the service leading up to the building, so it couldn't be tampered with by someone trying to poison the water supply. I would like to see the National Plumbing Code require that amalgam, mercury, traps be installed on all dentist sinks that will intercept the mercury used in fillings before it enters our waterways. The mercury is poisoning people every day.



Thanks, Bob Gagnon

Jean-David Beyer

I would like to see the National Plumbing Code require that amalgam, mercury, traps be installed on all dentist sinks that will intercept the mercury used in fillings before it enters our waterways. The mercury is poisoning people every day.

My dentist does not put in mercury fillings anymore. He said the instructions that come with the ingredients are full of precautions to protect the dentist who is exposed to the vapors for a few hours each day, but nothing to protect the patients who are exposed 24 hours a day. He does not want to pay for the liability insurance to protect himself from lawsuits from those  injured by the mercury. It was simpler for him to stop using amalgam fillings altogether.



He does need a full time clerk now in his office to argue with insurance companies who will pay for amalgam fillings, but not for gold or ceramic (or whatever it is) fillings. But his conscience is clear and he can look at himself in the mirror and sleep nights.

Bob Gagnon plumbing and heating

A step in the right direction

BUT, what about the old mercury fillings he removes, most of that goes down the drain, virtually all our waterways are polluted by mercury.



Thanks, Bob Gagnon

Plumdog_2

Back Room at the Dentist OfficeI

I was fixing a big electric water heater in the Utility Closet of my Dentist's Office awhile back and saw a big filter canister (maybe 60-70 gallons) that looked to be used for straining crud from the suction tools. Pretty darn gross, too.

But rest assured that the Municipal water supply will be protected from contamination by the end users, whether residential or industrial. It will take awhile. The Clean Water Act passed into law during the Nixon Administration (yes, he did some good things). The implementation is still going forth. Backflow Prevention is interesting stuff, and a real eye opener. I think all Plumbers (and related tradespersons) should be required to bone up on it. It's not too difficult to create conditions where boiler treatment, insecticides, hepatitus, or plain raw sewage COULD come out of the drinking fountain at the Elementary School around the corner!

Jean-David Beyer

what about the old mercury fillings he removes

Trap in the drain line after the sinks before it goes into sewer system. Eliminates the solids. Such as dissolves, too bad. Most of the water-soluble mercury has already dissolved in the mouth of the patient and been swallowed. The component that has evaporated has mostly been inhaled and absorbed in the nasal cavity or the lungs. (Are you sure you want to keep your mercury fillings?)

Bob Gagnon plumbing and heating

This Is What I'm Talking About

While we go to great lengths to prevent the crud, including mercury, from backing into the water piping with backflow preventers, in many places this crud goes down the sewer and into our waterways, polluting our rivers, then oceans, and while a backflow preventer may prevent a cross connection affecting maybe dozens of people; we allow a cross connection when we put the hazardous materials into our drinking water, via sewage disposal,  that effects millions of people.



Thanks, Bob Gagnon

icesailor

Backflow and interceptors:

There are a lot more backflow incidents in the USA than you hear about. But no where near as many as they have worldwide.

Massachusetts requires "interceptor" traps in dental offices. They require and enforce a whole lot of interceptors in a whole lot of situations.

And EPA requirements ABSOLUTELY require interceptors wherever toxic minerals and substances can be introduced in to the waste stream.

That includes flushing prescription drugs down the toilets. But many do. That should include prescription drug/chemicals excreted by humans entering the waste stream. Found in potable water samples in minute traces.

Jean-David Beyer

That should include prescription drug/chemicals excreted by humans

"And EPA requirements ABSOLUTELY require interceptors wherever toxic

minerals and substances can be introduced in to the waste stream.



That includes flushing prescription drugs down the toilets. But many do.

That should include prescription drug/chemicals excreted by humans

entering the waste stream. Found in potable water samples in minute

traces."



I agree with you, but I see no way of enforcing this, and not because there are not enough police to enforce the regulations. People do take prescription drugs; they also take non-prescription things. They flush toilet bowl cleaner down the toilet. They spray insecticides around, and then wash their clothes and some of that spray goes down the drain. Etc.



Perhaps we need all household waste to be treated before discharge. I mix my photo developer (basic) with stop bath (acidic) and fixer (acidic) before discharge to sort-of neutralize them. But I do not mix potassium permanganate (that I almost never use) with developer and fixer to add oxygen (both of those contain oxygen scavenger, sodium sulfite). And I do not extract the silver from the used fixer because in the small quantities I use it, it is uneconomical to recover the silver even at $31.35/troy-ounce. Kodak do not even make the silver recovery cartridges anymore. But to have an analyzer to examine my toilet output to remove the Enalapril, metaprolol, Plavix, Crestor, etc., would not be practical. Luckily for the environment, I am taking no psychoactive medications. I hope unused vitamin C is not hurting anyone. At some point, it will have to be the local sewerage authorities that must deal with it because they are the only ones who can handle these things on the scale that makes doing it practical.

icesailor

Impractacalities:

I kniow that it is impractical, I was just pointing out that there are other sources of pollution.

Bob Gagnon plumbing and heating

That's What I'm Talking About

As Plumbers, we have a difficult time enforcing EPA rules, and some states don't seem to enforce mercury dumping rules at all, if regulations were stated in the National Plumbing Code we could easily enforce it. Many other substances may be harmful, but I think mercury is the worst for the environment, but perhaps the easiest to intercept, because its used at very few places..



Thanks, Bob Gagnon