View Full Version : Backflow Valve Advice

08-31-2012, 08:35 PM
Hi to everyone out there, i'm new to the forum! I have read alot posts lately and everyone gives great advice and i was looking for some as well.

I am from Chicago, I have lived in my house for the last 6 years and my basement has flooded 4 times (3 times 8 up to eight inches and two years ago 4 feet). We were lucky that our county was declared a federal disaster and received assistance to replace our furnace and washer/dryer. Everytime my basement has flooded it was due to the citys sewers not being able to handle the amount of rain.

It happened again Sunday night, it rained pretty constantly and we got 8 inches in our basement. I had eliminated the floor drain in the basement and installed a clean out instead. Thinking that would keep water coming in but all that did was force the water to come out thru cracks in the sewer line under my slab (due to roots from a huge @rs tree in front of my house).

I was wondering what my options are as to installing a backflow valve on my main sewer line (clay).

I have read "SewerRatz" posts and he recommends a flood control system and I believe I may have one that the previous owner messed up trying to open it back up.

I took a picture of the system that's in front of my house, i will try to post a better quality one tomorrow. Can someone please help me out?

Thanks in advance everyone!


Gary Swart
08-31-2012, 10:19 PM
With all due respect and with the realization you are trying to do this for cheap, this really is not a DIY job. It does sound like you have a drain that is not in the best of condition, and it would be prudent to have a professional evaluate it and advise you on the best course of action.

09-01-2012, 08:59 AM
A better picture would tell us if that is an effective "flood protection" system. IF done properly, it could be. A Chicago pump company made a very effective flood protection system in the 50s. It was an inline device with a backflow valve, and bypass pumps to control seepage and household water usage, but I do not remember their name and don't know if they are even still in business. As a practical matter, however, with a clay sewer you are probably jousting with the wind by trying to prevent flooding.

09-01-2012, 09:19 AM
Thanks for your reply, i will post a better picture. I do hope that it is a type of flood protection and that the previous owner messed up the valve by rodding the line.

It does feel like ive been jousting with the wind these last years. I've installed*sump pumps that haven't kept up with the flow of the water coming in from the city or to see the power go out. Eliminating my floor drain only caused the water to seep in other cracks. But if a valve can some how be installed within that pit then if the water were to seep out it would do it before my basement. Since that pit is in front of my house.

Thanks again for your help

09-01-2012, 02:39 PM
quote; I do hope that it is a type of flood protection and that the previous owner messed up the valve by rodding the line.

IF he rodded the line, he either damaged the valve or his snake is still in there, because it would act like a ratchet allowing the snake to go out, but NEVER pull back without breaking the valve's gate.

09-02-2012, 07:06 PM
Hi Danny, I lived and worked in the Chicago area from 1980-1987. For most of that time period a huge underground tunnel was built (under Cook County and miles long). I think it was called the deep tunnel project where the mix of rain and septic water could be stored during heavy rains when the system was overwhelmed. The affluent would processed at a later time before discharging into Lake Michigan. Before the tunnel, untreated water would be discharged into the lake causing high bacteria counts. Your problem still shows that these old cities have a long way to go to get the drainage system disconnected to the waste systems.

Other than taking the suggestions from the plumbers, the next time you have to replace your furnace and water heater, get them off the floor. A tankless water heater (wall mounted) and the furnace mounted on a base one or two feet off the floor is doable. It will cost more but far less when the sewer system backs up.

Gary Swart
09-02-2012, 09:36 PM
In southern Florida, they build houses on stilts because the tropical storms will flood the ground floors. That's all well and good for south Florida, but you are dealing with sewage backups. It would be a wiser choice to prevent the problem from occurring in the first place. I do not see this as an inexpensive thing to do, nor is it a DIY job.

09-03-2012, 06:47 AM
quote; Before the tunnel, untreated water would be discharged into the lake

Milwaukee and Racine discharge into the lake, most, if not all, of Chicago's water goes into the Chicago River and eventually winds up in the Mississippi River.

09-03-2012, 07:41 AM
In southern Florida, they build houses on stilts because the tropical storms will flood the ground floors.

Only in the Keys are houses required to be on stilts and maybe some areas around the swamps and preserves, but nearly all homes in the state are on slabs. ISAAC dumped 12 plus inches (Palm Beach County) of rain last week in about a 24 hour period and we stayed fairly dry. Only the roads stay flooded for a few days. Other area named the Acreage and Loxahatche did get very bad.

Thanks HJ for the correction. 112 years ago the river flow was reversed so the affluent would not dump into the lake where the city gets it drinking water.

The problem for Danny is he probably has a home more than 50 years old and more likely 100. City code requires cast iron pipe and there maybe a clay pipe under ground to the main trunk. He stated that if he capped off the floor drain water would seep in because of a damage pipe under the floor. With or without a back flow device there is water pressure build up that these old pipes can no longer handle. The sewage water might stop at the back flow but if there are cracks in the pipe on the outside of the foundation, water will seep along the perimeter of the pipe and work itself under the floor of the basement, and eventually come up through the floor. Also hydro-static pressure from groundwater after heavy rains can work itself into the basement. He has to install a back flow device, replace his under ground plumbing and get the appliances off the floor for the best protection. Maybe the foundation walls need to be sealed. All expensive. Chicago has thousands of beautiful brick cottages but they are old and needing upgrade.

09-03-2012, 02:07 PM
Many books have been written about chigago's sewers - quite a story.


Kenosha is far ahead of chicagos mixed rain and crap that goes partially treated into the rivers - Kenosha de-chloribates before putting it back in the lake, but chicago has the distinction of dumping know coliform in the river.
Probably wont be long before the farmers start fighting to get irrrigation water from the lake too. When the chinese carp get to the lake, all bets are off.


09-03-2012, 02:38 PM
Thanks for all the replies, unfortunately i know first hand about how far Chicago lags in terms of the combined sewer system. I will no don't call a licensed Plummer but i just needed some sort of advice beforehand. Before i'm told that they need to demo my house to install the back flow valve.

09-03-2012, 02:59 PM
If your piping under the slab leaks, you'd need to install something closer to the street where you may have solid pipe, or replace the pipe you have (difficult under the slab). I don't know if they can reline the existing pipe or even if they can, how well it would work on tile, but it may be part of the answer. Easier than tearing up the slab.

09-19-2012, 10:01 AM
"WorthFlorida" Thanks for your insight.

I was out of town but i recently washed out the pit and here is a better picture. It looks like indeed it's a "Flood Control System". Hopefully the valve is just stuck open. 17303

09-19-2012, 01:26 PM
IT is a pretty "small' system in that case. The pump and one pipe has to be ebtween the house and the "backflow valve" and the discharge has to be "after" the BFV, but your two pipes are too close together to have a BFV between them and if it were there it would have an access cover to service it, and also a way to maintain the pump.

09-19-2012, 01:48 PM
Yes Sir, you are right.

I will have to stick my "wifes" :D cell phone down the stack and take a picture to see if there is evidence of a valve.

04-22-2013, 09:40 AM

Thanks to everyone that helped me out with my issue. There in fact was a Backflow valve which was deteriorated and stuck partially open. I was able to find the exact 6" cast iron valve and finally installed it 2 weeks ago. Just in time too because of all the flooding that the storms caused last week here in Illinois. All I have to do is install the new sump pump which I will do on my next day off.

04-22-2013, 12:35 PM
Sorry I have not been around much. The backflow valve is right under the cover the 2" pipe ties into. This cover needs to be opened and the flapper serviced every year to ensure proper operation. The open pipe is an over flow tee, which is on the house side of the backflow valve. When the city sewer backs up and closes the flapper your water usage from the house over flows from the tee into the pump pit. The pump then pumps this water into the closed side of the valve. During the yearly service check to ensure the pump is working properly as well.

04-23-2013, 05:49 AM
Thanks! I did read some of your previous posts concerning these types of valves. Your posts were extremely helpful. It looks like the previous owner never did any maintenance at all, the flapper was detoriorated and stuck open, the screws were so brittle that they snapped off when i tried to clean them. Thanks again!