How does sewage back up into homes

SlamDunk

Reading about the damage done in NYC from the heavy rains., some people claimed sewage backed into their homes.

I know there are storm sewers and sanitary sewers and they are separate, I thought.


Just wondering how that happens and how it could be prevented.

Jamie Hall

There are indeed storm sewers and sanitary sewers/ And, in some places, they are separate. However, in most older communities and cities, they aren't. They are combined sewers.

This has lots of consequences in the modern world -- none of them good. It was more or less fine a century or so ago or more, when sewage treatment was mostly "out of sight, out of mind" but as places grew, not so much.

There's not only the problem of sewage backing into houses and buildings, but also the combined flows overwhelming treatment plants and being diverted into rivers and lakes and so on.

It could be prevented by separating the sewers. Sounds so simple, doesn't it? Yeah, right. In practically any community of any size at all, you would have to tear up all the streets and install new sanitary sewers throughout -- and remember, they are gravity flow. While avoiding other utilities. In larger cities... Forget it. It would cost billions and billions, and those billions and billions just aren't there.

Storm overflows can be at least reduced, if not prevented, by building storage facilities for the peak flows, and then treating them later. This also costs billions, but not quite so many billions...

Mad Dog_2

NYC is 95% Combined Sewers...Long Island has "sumps" aka deep recharge basins that that all street catch basins are piped in to.  True separation.  I never saw or heard of a Sump until we moved to "LonGUYland" from Queens.  They also double as sanctuary for teenagers to drink beer 🍻 and play music and get away from adults. They are usually wooded areas.  Mad Dog 🐕 

WMno57

Big problem in Chicago and many of the older Chicagoland suburbs as well. My brother has had personal experience with this in both Arlington Heights and Downers Grove.
Some homeowners have paid to have their homes converted to an overhead sewer connection. This keeps the poo water from coming up through the basement floor drain. Then you need to move the laundry out of the basement, or get a sump pump for the laundry.
Chicagoland has been working on this for 50 years and spent Billions. Still a problem.
https://en.wikipedia.org/wiki/Tunnel_and_Reservoir_Plan
So to all the Big Apple people, the Second City feels your pain. If you need to get away from your current weather woes, consider a vacation to Chicago. We are having dry summer weather here. And our pizza is better.

leonz

Hopefully they will be able to bore out and drive new drainage tunnel legs to another larger TARP tunnel and finally seal off and fill the Chicago Ship and Sanitary Canal to stop the asian carp soon.

The newest Robbins tunnel boring machines are almost 50 feet in diameter now and could bore a straight line tunnel for many tens of mines to store both wastewater and storm water.

They could use the bed rock they mine out for the new TARP tunnel with the tunnel boring machine to fill the Ship and Sanitary canal and the other potential entrance waterways to stop these fish.

They could use a set of elevated locks on the canal route letting the entire lock complex drain into retention basins where the water would be allowed to dry up and any carp and trash fish scooped up and composted into fertilizer.

Any fish trapped in the sealed lock chambers would settle into a drainage trough in the sloped floor and be washed into a common trough where they would be augered into a roll off container in a closed building that would prevent birds from entering it to steal any trash fish to prevent them from spreading fish eggs.

Aluminum sulfate would be a great add on to help sterilize the water and coagulate any semi solids like small trash fish, fish eggs and algae blooms from fertilizer run off.

Mad Dog_2

The FDA officially renamed Food-grade Carp, Silver-Fin. Out of clean waters, carp are excellent to eat.  They could be used to feed the poor, like Donated Venison and the rest can be ground in to fishmeal to feed Starving people around the world. Its wild how they leap out of the water...Mad Dog 🐕 

WMno57

leonz said:

seal off and fill the Chicago Ship and Sanitary Canal to stop the asian carp soon.

How do you propose to accommodate all the barge commerce that currently travels through there between the Great Lakes and the Mississippi?

Jamie Hall

All good thu9ghts, @leonz ! But where, might I ask, is the money to come from to do that?

leonz

Hello WNno57,

As I wrote in my posting a set of elevated locks which would drain to sets of retention ponds that would be drained to land as needed would reduce significantly any chance of the asian carp from entering the Great Lakes system.

Filling in the canal and building a set of elevated locks would prevent the Great Lakes fisheries from becoming damaged by the asian carp and assure that there was solid barrier was created by the elevated locks.

The lower rivers where the carp are known to be present could be electrocuted by first aggravating them in a small boat that has a protected cabin with cyclone fence over the windows and cause them to jump to Identify the carp in these areas and then shock them with medium voltage from a generator and collect them to be composted.

If that single farmer with fish ponds had not broken the levee down river with his boat when his farm property was flooded by the Mississippi River perhaps they would have never entered the lower river system.

Any travel on the canal would have to be suspended or rerouted by rail while it was back filled and the lock system constructed.

The locks would be drained completely at each transit to prevent the carp from migrating by creating a drainage gutter on one side of the each lock chamber using a sloped concrete floor that feeds each gutter
which would have a flow gate.

At every transit each gutter would be flushed out with fire hoses through the flow gate to a collection chamber that would feed to a retention pond that would be drained or pumped to dry land later.

Using electrocution to kill millions of the asian carp each time would be a quicker way of seeing quick results while collecting the dead and live carp in floating gill nets and reducing and chance of harming protected paddlefish or sturgeon in the lower tributaries.



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Hello Jamie,

A new TARP retention tunnel would be paid for just as the original TARP project is being paid for now with bonds and tax money through a bid process as was done for the TARP project with The United States Corp of Engineers as the project manager.

A bored 48 foot diameter tunnel 20 miles long would create 191,000,000 million cubic feet of crushed tunnel rock, slightly over 7 million cubic yards of waste tunnel rock no including the broken rock from the drop shafts and pumping chambers that could be used to back fill the canal in the future to create the base for the elevated lock chambers and add 1.48 billion gallons of waste/storm water storage which is not much in the scheme of things but it would help.

The same type of tunnel would help New York City as well just as it is working in Indianapolis, Indiana.



My thoughts anyway.

MikeAmann

https://makeitright.ca/holmes-advice/home-safety-maintenance/backwater-valves-for-sewage-backflow-prevention/

SlamDunk

Very informative. How would you prevent this? Can this be prevented?

This would be a nightmare for anyone. All the street, curb sewers in my community has "Drains into the River basin" spray painted near them to remind us not to dump chemicals in the street.

However, we also have city grease busters for sanitary sewers. If your home is below street grade, you could have sewage blasted into your house. Above grade, not likely. So, what would be a way to stop this everytime there is a maajor rain event?

pecmsg

How
someone's home is flooded, that puts pressure on the waste piping. As @DanHolohan says “high pressure goes to low pressure”. 

After sandy I installed a slide valve in my BIL’s home in Long Beach to prevent just such an issue. 

SlamDunk

So, knowing flooding rains are coming, he closes it outside the house? That's better than a check valve.

Jamie Hall

The practicalities of closing off and then providing locks on the Chicago Sanitary and Ship Canal -- to give it it's proper name -- are a little more daunting than they might look. The most practical solution to the asian carp problem would be a barrier such as you have suggested, @leonz , just below the Loop area.

This would allow barge shipping to continue as at present (I can hear the wealthy suburbs now if even half that traffic were diverted to rail!), and so far as I know there is no through commercial traffic, although there is through recreational traffic.

However.

What may be not so obvious is the first part of the name: "Sanitary". Where, exactly, do you think waste water from Chicagoland goes? And the first two guesses don't count. It's flushed down that canal, using water from Lake Michigan, and has been for centuries. In fact, that was the main purpose of the canal -- there was a time when it went into Lake Michigan, but that's where the city water comes from and people were getting sick. So -- just flush it away! Simple! You would have to pump that dilutioon water -- and it's a lot -- around any barrier.

Not, mind you, that it would be better not to use the Lake Michigan water that way. The Canadians, if no one else, would be much happier.

WMno57

In Chicagoland it's common to shove a standpipe into the basement floor drain. Plug the drains in the laundry tub. If you keep an eye on the weather forecast, you might avoid a big cleanup. Amazing the amount of basement junk you see curbside after a big rainfall.

WMno57

EdTheHeaterMan

How does sewage back up into homes

I would say with a pungent odor. But that is only a guess, I have never had the pleasure.

leonz

Flooding and sewer backups are a regular occurrence in one neighborhood in Syracuse, N.Y. and 4 inch gate valves in the floor drain piping's sewer connections would be a welcome addition.

In Venice, Italy all the wastewater is dumped in the Lagoon and when there are storms and heavy rain coming off the Adriatic Sea and around the PO River Delta the toilets become fountains since the sea water pressure is so high.

Sadly, Venice will continue to sink as it is on swamp land.

The inflatable permanent lagoon barrier that is finally done and working after many years of fits and starts, bribery, scalping, payoffs and repairs after the installation was finished is working and they have stopped allowing the cruise ships from being towed into the Venice lagoon.

A great number of the residents of Venice have moved away because of the tourists and the flooding and now the majority of the city's commerce is from day trippers and tourism from cruise ships anchored off the coast.

leonz

SlamDunk said:

Very informative. How would you prevent this? Can this be prevented?

This would be a nightmare for anyone. All the street, curb sewers in my community has "Drains into the River basin" spray painted near them to remind us not to dump chemicals in the street.

However, we also have city grease busters for sanitary sewers. If your home is below street grade, you could have sewage blasted into your house. Above grade, not likely. So, what would be a way to stop this every time there is a major rain event?

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With a great deal of New York Cities 5 borough's on "BUILT LAND" or low lying swamp land, the only real solution is deeper mined out storm water drainage tunnels as a solution.

Sediment catch basins would have to be made larger to accept the amount of inflow that will occur in the future.

Building sea walls around NYC and the 5 borough's are not a real option as there is no massive continuous coastline length like the one on Galveston Island take advantage of.

1. pay people for their homes and raze them
2. raise the homes up like they did in Galveston Texas after the 1910 hurricane
3. zoning to prevent building in flood zones
4. move the homes like they did for the construction of the St. Lawrence Seaway
5. smaller 16 foot in diameter long distance storm water storage tunnels that would create 1,061,000
cubic feet of crushed bedrock that could be used to create land mass to lessen the effect of coastal
storms and would store, 7,936795 gallons per mile of storm water tunnel(rounded higher).

The emergence of new oyster beds would have to be taken into account to assure they were not buried by mistake with the crushed granite that would come out of the storage tunnel excavations.

Item No. 5 would be the most effective way to do this, but it would require massive excavations for launch and retrieval pits for the small tunnel boring machine and excavation to connect the existing storm sewers to a storage tunnel.

The deeper you can drive a tunnel boring machine the greater amount of storm water storage you can have by either driving the tunnel longer or excavating a larger diameter tunnel and lining it with precast tunnel lining segments or by using pushing welded steel pipe behind the micro tunneling boring machine that augers the cuttings away from the tunnel face.


None of these are attractive solutions and every one of them has an opportunity cost.



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Our catch basins have "Drains to lake dump no oil" painted on them.

Sal Santamaura

Mad Dog_2 said:

...Out of clean waters, carp are excellent to eat...

As a kid in Yonkers, I biked to the Bronx River for fishing. Carp were what ended up on the hook. It would not have been possible to describe that water as "clean" by any stretch of the imagination; it got worse over time. I took my catch home and buried it as fertilizer under the corn in our garden. My last ever "expedition" to the river saw me cutting the line and abandoning it so as not to foul my rod/reel with all the oil floating on the water.

SlamDunk

I grew up near the Bronx River. Never in my life have I considered fishing it. Too much ick factor.

Down here now, I asked a coworker who caught a carp what does carp taste like? He said, you scale and fillet it, lay it on a cedar plank, add seasoning, some lemon juice and place plank on the grill. When done toss the carp and eat the plank because the plank would go down easier.

SlamDunk

@leonz Sounds like a job for the sand hogs. What you describe sounds like a book I read a long time ago: Trapped under the sea by Neil Swidey

Mad Dog_2

I'll catch and release in almost any body of water.  I like to see whats living in there.  Even horribly polluted water ways like Newtown Creek and The Gowanus canal always have some life in them.  If you see schools of minnows, larger fish are there too! Carp are the hardiest fish out there.  They will survive in mud and breathe oxygen, eat almost anything and can get monstrous.  The fight like A Northern Pike...Like any other fish or crustacean....pristine water 💧...Carp, catfish, suckered and clubs  are mighty fine eatin 😋 .Mad Dog 🐕 

leonz

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SlamDunk said:

@leonz Sounds like a job for the sand hogs. What you describe sounds like a book I read a long time ago: Trapped under the sea by Neil Swidey

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The fiasco with a capital F)(*&^&* lays right at the city of boston's feet because they refused to spend the money on dropping a temporary shaft at the end of the diffuser pipeline for the outfall at Deer Island to open the diffusers in the pipeline.

The genius/fool that was running the show and training the divers that were doing the work to unbolt the plates covering the diffusers before they were opened walked away with no consequences whatso ever.

The fools ended up doing just what was suggested with the dry shaft over the end of the pipeline to begin with. and the diffuser sealing plates inside the tunnel were removed very quickly and the treated effluent pipeline was opened when the plugs over the diffusers were removed and ready to be used quickly shortly after the investigation was completed at the cost of human lives and stupidity and the head honcho that ran things suffered no consequences. If I remember the end of the book right he scurried back to Europe.

All that is left is a monument at the park for those 2 young divers and the families they left behind.