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ozark1
Topic Author
Posts: 889
Joined: Fri Mar 03, 2006 4:38 am

potable water systems on 737

Tue Nov 01, 2016 4:59 pm

Hi everyone. Yesterday I work a 737 that had no potable water. The toilets worked, but we had towlettes in the lav sinks and no ability to serve coffee or tea. When we asked what the problem was to the mechanic he responded "The EPA". So apparently the water on the plane was being tested or had been tested and found to be undrinkable. My question is how is a problem like this fixed. We worked the same plane back from MEM this morning. It looks like it has been flying around awhile in this condition. What will have to be done? Will the water lines have to be flushed or replaced? Is this a major and time consuming fix? I would appreciate anyone's expertise on this. Would a plane be out of service a while to fix this?
Thanks .
 
Woodreau
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Re: potable water systems on 737

Tue Nov 01, 2016 6:23 pm

I'm not familiar with the mechanics part of this.

Your aircraft potable water tanks tested positive for chloroform bacteria. So the whole system was MEL'd to prevent getting people sick until the tanks can get sanitized.

How long it can go depends on the category of deferral. It might be a Cat C deferral which means it can fly around for 10 days before it must be fixed. But I'm not sure on the category.

I have no idea what the required testing periods for the potable water tanks are But I'm pretty sure they don't test them every day so the bacteria could have been in the tanks for a while since the last time they tested the tanks for chloroform.

So that's why I personally never drink anything that comes from an aircraft potable water tank.

Also there's many points of contamination when it comes to aircraft potable water. I cringe when I see some potable water hoses on the ramp used to fill water tanks. Some are in very bad shape. Not stowed properly etc
Bonus animus sit, ab experientia. Quod salvatum fuerit de malis usu venit judicium.
 
KPWMSpotter
Posts: 461
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Re: potable water systems on 737

Tue Nov 01, 2016 6:45 pm

Sounds like the aircraft failed its regular Coliform bacteria sampling, as required under the EPA's Aircraft Drinking Water Rule (ADWR). The ADWR was instituted in 2011 as 40 CFR Subpart X (40 CFR 141.800 to 141.810).

The ADWR requires air carriers to establish a regular plan for both disinfecting aircraft drinking water facilities, and testing those potable water systems for bacteria on a regular basis. The minimum interval is approximately 4 disinfecting washes per year, and at least one sampling of the water for bacteria per year (per aircraft). Most carriers implement much more frequent test plans.

In the event that an aircraft tests positive during its water sampling, the ADWR requires that the potable water system be either immediately cleaned/disinfected, or it may be rendered inoperative and deferred to MEL. Cleaning/disinfecting is a relatively straight forward process, essentially you just need to flush the entire system with a disinfecting agent, however it's rather time consuming. Typically the system is deferred to MEL (typically a Cat 'C' ten day maximum deferral) until the aircraft hits an overnight maintenance station. The aircraft must also pass a follow-up water sampling after the disinfecting is complete; your aircraft may have already been fixed, just pending lab results.
I reject your reality and substitute my own...
 
Veetwo
Posts: 218
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Re: potable water systems on 737

Tue Nov 01, 2016 6:46 pm

I was under the impression that you shouldn't drink the potable water on any aircraft except for the coffee as it has been boiled.
Airline employee and Crohn's sufferer.
 
Dalmd88
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Re: potable water systems on 737

Tue Nov 01, 2016 7:42 pm

A sanitizing solution will be put in the tank and drawn through all the lines and coffee makers. It has to sit I think for at least an hour like that( not sure the sit time I have not done one in years). The tank is drained and refilled with fresh water and the lines are flushed until they test fresh again. I always flushed the tank twice with fresh water.

I would never drink any water that comes out of these systems. That includes the coffee makers. Most mechanics feel the same. There is simply no reason to, why take the chance.
 
ozark1
Topic Author
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Re: potable water systems on 737

Tue Nov 01, 2016 9:43 pm

That is really interesting. Thanks very much.
 
AA737-823
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Re: potable water systems on 737

Tue Nov 01, 2016 9:43 pm

Veetwo wrote:
I was under the impression that you shouldn't drink the potable water on any aircraft except for the coffee as it has been boiled.


That's a longstanding misnomer that's mostly obsolete.
Clearly, the poster after you feels the same way.
But as someone who has spent many, many hours sanitizing the potable water tanks on 737s, and who is fully aware that they're routinely tested for water quality, I don't hesitate to drink onboard water.

NOW... I won't drink out of a lavatory faucet. But that's not because of the water... it's because the faucet is physically located in the lavatory.

Also, the water going into potable water systems is locally sourced tap water. So if you're willing to drink it out of the tap....

I don't apply this rule to any aircraft that is based outside of the USA. I assume EASA has similar water quality rules, but I don't know for sure.
 
Veetwo
Posts: 218
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Re: potable water systems on 737

Wed Nov 02, 2016 2:46 am

AA737-823 wrote:
Veetwo wrote:
I was under the impression that you shouldn't drink the potable water on any aircraft except for the coffee as it has been boiled.


That's a longstanding misnomer that's mostly obsolete.
Clearly, the poster after you feels the same way.
But as someone who has spent many, many hours sanitizing the potable water tanks on 737s, and who is fully aware that they're routinely tested for water quality, I don't hesitate to drink onboard water.

NOW... I won't drink out of a lavatory faucet. But that's not because of the water... it's because the faucet is physically located in the lavatory.

Also, the water going into potable water systems is locally sourced tap water. So if you're willing to drink it out of the tap....

I don't apply this rule to any aircraft that is based outside of the USA. I assume EASA has similar water quality rules, but I don't know for sure.


Interesting. I know some private planes have a UV filter integrated in the supply. Has that made its way into the commercial airplane market? Is it even needed? Has there been any sort of fleet wide study on the quality of water?
Airline employee and Crohn's sufferer.
 
Apprentice
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Re: potable water systems on 737

Sat Nov 05, 2016 1:50 pm

Hi, problems with potable water system is normally traced to outstations w/ no so strict control rules.
Gays that operates Potable Water trucks &Toilet trucks, in many ocasions are not trained at all by their handling companies, there is nothing like a antidesease training or license, and by definition, this positions are low payed ones and frequently changing personnel.
It's very uncommon to find a company to requieres mechanic to be available and control water system / toilettes servicing. (AF & Luffthansa down here are the only I can remember), since this will make operation more costly... In many cases, when a/c is on overnight stop, water/toilet servicing is conducted after mec had finished maintenance service and gone, cause handling companies are short of trucks-people and prioritize planes which will depart over the ones on overnight stop.
After so many years, I don't even drink coffee on board, only bottle water..
Rgds

Rgds
“An4; IL18; IL6; Tu5; D10; MD11; MD83; B32; B34: B37; B744; B748; B752; B763; B772; B773; B77W; A320; A332; A333; A342; A343.
"A NO" is a positive answer., "DON'T KNOW" is not. My Tutor (a wise man)
“CUBANA” 90 years Flying”
 
Dalmd88
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Re: potable water systems on 737

Sat Nov 05, 2016 2:02 pm

I agree, water service is done by a very low paid employee or contractor. I don't trust all of them to do it right. One day in our hangar we stopped a couple of cabin support mechanics just before they leak checked the lav tanks they had just installed. They were dragging the blue potable water service hose to the plane. Just before they hooked it to the lav service port we yelled at them. These two guys had been using that hose and many like it to put water in the lav system to check for leaks in every bay in our hangar. Even after explaining the cross contamination possibility to them they didn't get it. Only when we demanded they lick the lav service port did they get it.

There are too many idiots out there. It is not worth it to me to even drink the coffee on planes.
 
Wacker1000
Posts: 279
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Re: potable water systems on 737

Sat Nov 05, 2016 4:20 pm

Apprentice wrote:
Gays that operates Potable Water trucks &Toilet trucks, in many ocasions are not trained at all by their handling companies


Ummmmm
 
Apprentice
Posts: 778
Joined: Sat Jan 19, 2013 12:51 pm

Re: potable water systems on 737

Sun Nov 06, 2016 1:14 am

[quote=Ummmmm[/quote]

Well, in many places this job is considerd as a non important one. First day they "teach" the new comer on 2 or 3 planes and them is up to him. This quick OJT, is only how to do, and what problems he/she will encountered if any plane got a delay for water/toilet services issues, nothing about health concerns.
Rgds
“An4; IL18; IL6; Tu5; D10; MD11; MD83; B32; B34: B37; B744; B748; B752; B763; B772; B773; B77W; A320; A332; A333; A342; A343.
"A NO" is a positive answer., "DON'T KNOW" is not. My Tutor (a wise man)
“CUBANA” 90 years Flying”
 
LH707330
Posts: 2439
Joined: Fri Jun 15, 2012 11:27 pm

Re: potable water systems on 737

Sun Nov 06, 2016 5:45 am

“In wine there is wisdom, in beer there is Freedom, in water there is bacteria.” -Ben Franklin

This thread merely confirms centuries-old wisdom.
 
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HAWK21M
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Re: potable water systems on 737

Sun Nov 06, 2016 1:41 pm

Trust me Ive been working out here for last 27yrs & my advice is DO NOT DRINK from the Aircraft potable water system.
Use packaged water bottles instead.

Just to add the Water supplied to the Toilet & basins [Potable] are from two seperate tanks.
Nowadays most toilets use the vaccuum type but there is a little liquid sprayed prior to the vaccuum flush.
I may not win often, but I damn well never lose!!! ;)
 
Newbiepilot
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Joined: Tue Aug 30, 2016 10:18 pm

Re: potable water systems on 737

Sun Nov 06, 2016 4:30 pm

Apprentice wrote:


Well, in many places this job is considerd as a non important one. First day they "teach" the new comer on 2 or 3 planes and them is up to him. This quick OJT, is only how to do, and what problems he/she will encountered if any plane got a delay for water/toilet services issues, nothing about health concerns.
Rgds


I will give you he benefit of the doubt and assume that you didn't notice the typo where you typed GAYS rather than GUYS.

In general I will drink the coffee but never tap water. I am hesitant to drink the coffee on domestic flights in places like India but I am a bit hypocritical and will drink coffee on widebodies that may have been in India in the last couple of days.

The flushing process is usually done at least in heavy check. Cleaning is important. Some new planes like the 787 have disinfecting systems for potable water system as the water enters the plane.
 
jetstar
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Re: potable water systems on 737

Sun Nov 06, 2016 8:40 pm

One time a few years ago as I was waiting to board my AA flight at LGA, I watched a ground support person roll out a water hose and attach it to the water fill port of an MD-88, after the servicing was completed he unhooked the hose and let it drop onto the tarmac and then went to the water hose reel and reeled in the hose, dragging the nozzle on the tarmac as it was reeled it.

Water from the onboard water supply, including the water used to brew coffee, even though it is boiled during the brewing process which may kill the bacteria, any contaminates in the water that entered though a dirty water hose connection may not be removed by the onboard filter system.

For me I never drink any potable water on an airplane, only soda or juices, it’s not worth the ever slight chance of drinking contaminated water.

JetStar
 
737tanker
Posts: 399
Joined: Fri Dec 30, 2005 2:47 am

Re: potable water systems on 737

Sun Nov 06, 2016 10:22 pm

Drinking water on WN is safe as it is served from cans. The water for the coffee however still comes from the potable water system.
 
CanadianNorth
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Re: potable water systems on 737

Mon Nov 07, 2016 12:49 am

Several years of experience working on 737s here.

The toilets each have their own tank of "blue juice", 100% independent of the potable water supply. Consider them an outhouse with a filtered recirculating pump.

The lavatory sinks, coffee makers, and hot water taps, are all sourced from a potable water tank right behind the back wall of the aft luggage pit, basically underneath the aft galley. This tank is generally filled from city tap water or equivalent, so if you are willing to drink the tap water then you should be fine drinking the water in the tank.

In our system every 30 days a scheduled maintenance task comes up to sterilize the potable water system. Essentially you fill the tank and associated plumbing with the Boeing specified sterilizing solution, let it sit for however long the instructions say to, drain it, then flush several times with regular drinking water.

There is also another scheduled task that comes up regularly (I can't remember the interval off the top of my head, but it's reasonably frequent) that calls for taking two samples, one from a randomly selected coffee maker and one from a randomly selected lavatory sink and then send them away for testing. I haven't seen one fail yet but if one does MELing the potable water system does sound like a logical way to let the airplane carry on flying while a proper fix is arranged.

It sucks having no coffee for the day but usually things like that are a simple case of we want to fix it, but the time and hangar space might not be available that night due to more important issues, and it would be silly to cancel a days worth of flying just because the coffee makers are unserviceable. The MEL is there for a reason so might as well make use of it.

As a side note I've been wrenching on 737s for several years and drinking the coffee from them for even more years, and never had a problem.
HS-748, like a 747 but better!
 
737tanker
Posts: 399
Joined: Fri Dec 30, 2005 2:47 am

Re: potable water systems on 737

Thu Nov 10, 2016 5:38 am

On the 737NGs there is no more blue juice for the toilets. They use a vacuum not system along with potable water. If a 737NG is out of potable water we have to close off the lava as they can't be flushed.
 
INFINITI329
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Re: potable water systems on 737

Fri Nov 11, 2016 4:33 am

737tanker wrote:
On the 737NGs there is no more blue juice for the toilets. They use a vacuum not system along with potable water. If a 737NG is out of potable water we have to close off the lava as they can't be flushed.


I can tell you at my airline, blue juice is still used on our 737NGs
 
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HAWK21M
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Re: potable water systems on 737

Wed Nov 23, 2016 5:03 pm

737tanker wrote:
On the 737NGs there is no more blue juice for the toilets. They use a vacuum not system along with potable water. If a 737NG is out of potable water we have to close off the lava as they can't be flushed.

Both Recirculation type & Vaccum type exists on the B737NG as per customer configuration needed.
I may not win often, but I damn well never lose!!! ;)

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