Tuesday, May 15, 2012

Emergency Plugging of Sewer Backflow

         I had promised, after a series of six posts which consider a US financial collapse to post something else here.  This is an important, though not a pleasant subject.    In an emergency, a flood or a failure of an urban or suburban municipal water and sewer systems backflow of sewage will occur into a home through toilets, sink or shower drains.    This method will also stop backflow from a malfunctioning septic tank system, also in an emergency.    In some emergencies, most often floods, the contents of the local sewer can backflow into a house, and the result can be disastrous. Homes can be rendered too unsanitary in which to live, or the water and other contents themselves can actually destroy drywall, wood floors, or basements and the things stored there.  There are two potential nightmares here.  One is called backflowing where sewer liquids are actively flowing up into your home from the sewer.  The other is called backed up.  In backed up, nothing is flowing down the drains from your house, and as a result, the sewage from your house is then backflowing through the lowest drain in your house.  (I have seen this in the 80s at a house with a failed septic, which turned out not to really exist, at all.)  THERE IS NO VALVE THAT SIMPLY TURNS OFF A SEWER.  So, you must prepare for this possibility in advance.


This is what the test plug looks like  (Photo: Petersons)

You need:

1.    An inflatable sewer line test plug which matches the size of the sewer line.  I am told that in most applications in the US, this is 4 inches.  This may be found in the plumbing section of your hardware store, or at a plumbing supply house.  Please get one now, before everyone you know gets one, they are all sold out, and they are back-ordered for a year !
    If you must order one via mail or internet, you need a single diameter model without a bypass port.  While you are getting one, get TWO. ***

2. . A hand operated pump to inflate the device   (like a bicycle pump)

3. A large wrench or pliers to remove the clean out cap, as marked in the picture below in red.

Assemble your kit now, and put it in a conspicuous place.

(This photograph and markings is the work product of: http://www.disaster-survival-guide.com/plug-sewer.html, and we are extremely grateful for this photograph)

Procedure to plug your sewer or septic:

1. Locate the Main Cleanout at your house.  It looks like the picture above.  These are often in basements, some homes with septic tanks have them located out of doors, and hidden.  It's good to look for this, draw this out, and know about it in advance.  Check to see that there are no drains afterward, because if there are, these must be plugged too.  (Some homes need an additional 1.5 inch drain plug also.)  The test plug should be located below the blue line above.
2. Next, make alternate arrangements for where people will use the toilet. Inform everyone that nothing can be flushed down the toilet until furthur notice.
3. Make sure that water supplies to all sinks and toilets are turned off  Do this at the Primary Water Valve of your house.
4. Remove the clean out cap using a large wrench or pliers if you don't have a wrench that large.  It is circled above in red.
5. Tie a rope to the sewer plug you purchased. (So that it can come out when you eventually need it to.)
6. Insert the plug beyond the blue line above in the direction in which the drainage would normally flow.
7. Inflate the plug as per directions using a hand bicycle pump.  Repeat procedure for any other drains below the main drain, as there can be some variation in plumbing set ups.
8. Use an alternative toilet until the problem is resolved.
9. Making tape shut the lids on your toilets to remind children and others who might forget that there is nowhere for urine and feces to drain at the moment.

Although the above process is most often used for a city or municipal water sewer system, it can also be employed for a normal septic tank, which do occasionally back up.  You can plug a conventional septic in the same manner until it is repaired.


I cannot stress how important it is to find all of these items in your home in advance of such an emergency.
You may wish to print this out and keep it in a safe place.

*** To order a sewer or septic plug of single diameter model without a bypass port:


In Canada or other nations:

I am unsure of the size (and for that matter the location) of the main clean out to our place in Canada.  Make sure you verify the size of the one you would need there.  Although it is often 4 inches in the US, this may not always be the case.
If you are in another nation, the UK, or others for example, take the time to find out how your system works, how it should be plugged, and what size plug you would need and where to get one.  A plumber would likely be your best source, although a savvy homeowner might also know.

References and additional information:





Gorges Smythe said...

When my wife lived in Illinois with her deceased first husband, their sewers apparently emptied into the storm sewers for the streets. SO, when their neighborhood flooded, their basement got more than just storm water. It only had to happen once for them to look into drain plugs. There crazy neighbor insisted that them plugging theirs made everybody else get flooded worse. They told him to plug his own, but he was too stubborn to ever do it!

JaneofVirginia said...

I think I would plug mine without telling anyone else ! Of course, this is why we were an apartment dwellers for one year, suburban homeowners for four, and have lived in an intensely rural area ever since. I might have to be a team player at work and in general, but I don't have to have sewage backing up in my house because the neighbor dislikes my using a plug ! LOL Thanks for posting.

aaa-auger said...

Hello All,
You have created a very interesting concept. You may need to plug your sewer line during a disaster as a back flowing sewer can cause considerable property damage and pose health hazards. Thanks......
Houston Plumbing Supply

Virginia Lawrence said...

Thanks for the post. Sewer backflow in schaumburg can be quite a problem. So thanks for sharing!

JaneofVirginia said...

Virginia, It can be quite a problem many places ! Thanks for making people in that region aware, and for providing additional alternatives through your link.

Dexter Morgan said...

This is some great information about the sewer backflow in Schaumburg. Thanks for posting this here.

Gelo D said...

Thank you for posting this. Backflow inspection is one of the things that we should always remember for our backflow device in order to ensure that it is always in good condition to avoid water contamination.

JaneofVirginia said...

You are very welcome. This is important information, and I found some difficulty in assembling the correct septic backflow kit for my own home. It seems the Lowes and Home Depot did not stock this here. Eventually, I went to a plumbing supply house.

kathryn gomez said...

This can be within the particular water system part of your components shop, or even at a water system present home. Make sure you get a single at this point, ahead of every person you recognize will get a single,backflow

JaneofVirginia said...

Kathryn, Thank you for your post. my original post was referring to the prevention of sewer backflow in an emergency, where suburban sewer systems were off for some reason, or for times when a home with a septic tank is enduring temporary backflow.
The system to which you have linked relates to fire systems in industrial buildings. I have left your post should it be of interest to someone here.

kathryn gomez said...

We are a Fire Sprinkler Company in Miami offering automatic fire sprinkler installation,
fire sprinkler inspections, 24 hour emergency repair and more.
fire backflow

JaneofVirginia said...

Kathryn, The subject of this post was the emergency plugging of a sewer or septic line in order to avoid backflow into a house during emergencies. Emergency fire sprinklers in a residential structure is another subject entirely ! I have left your post up for anyone who has an interest in the Miami area, but sprinkler systems in residential homes is only very rarely done because the water in such systems tends to stagnate and become a source for disease. In commercial buildings, schools, and even hospitals it is mandated by law that these exist, and the maintenance for such can be expensive and laborious, however in a fire it's better to have them rather than not. I looked into these in some detail before we built our last home. Thanks for your post.