Can I drill a 1 3/4” hole through a manhole cover

[Roger Feeley]

We have a manhole in our back yard that goes to a rain sewer. I want to back flush the in ground pool ont the sewer. I can lift the cover every time but what I really want is to have a hole with 1 1/4” sch40 pvc through it so I don’t have to mess with it.

I can drill it fairly easily with a 1/4” twist drill. I got out my Milwaukee hole saw and was a littl surprised that it made some progress before the pilot drill snapped.

I can rent one of those magnetic drill presses for $55/day but the rental place has no bits.

suggestions?

[Sam Force]

No clue of the legality of what you are wanting to do. Should be no different than flushing into the driveway or street. I would think with a clean pilot hole and plenty of lubricant it should drill fine. I suspect you wandered off vertical some which caused pilot bit to break. If enough of a grove were cut prior to breaking it I would give it a try without a pilot bit

[Tom M King]

A magnetic drill press can use the holesaw you have. It needs a substantial thickness of metal under the base to grab. Even if it doesn't grab strongly enough to hold it to drill with a lot of force, it should still be stable enough if you feed it slowly, and will be easier than you expect. I bought one for working on a tractor, thinking I'd sell it when I finished that job, but I liked it so much I kept it, and have been glad several times that I did.

I needed to drill a 3/4" hole through three layers of 1/4" steel to put a lifting ring on the front of a mower. About an inch and a half below that metal was some pretty expensive parts of the steering system. It was easy to control, and cut like butter.

The mower weighs 1800 pounds, but the marine lifting ring is rated for 5500 pounds. I can pull it straight up in the air, and sit it on the big flat back end to swap blades. Picture was just first test lift.

[Malcolm McLeod]

... what I really want is to have a hole with 1 1/4” sch40 pvc through it so I don’t have to mess with it.

...

Realizing that you probably don't move the manhole cover everyday, even to back flush, but you may still need to move it. I'd be sure to insert a union in that 1-1/4", so I can disassemble/move the PVC without a sawzall.

I'll make the leap of faith you have determined who owns the manhole, and the right-of-way its sitting in, and have permission.

Oh, and +1 on the mag-base drill.:cool:

[Bruce Wrenn]

The way I resolve snapping off pilot bits is to use a piece if 1/4" rod in hole saw in place of bit. Using 1/4" bit, drill a pilot hole first.

[Kev Williams]

--do you/don't you have a drill press?

[Roger Feeley]

--do you/don't you have a drill press?
I do have a drill press. I just didn’t think about carting the heavy manhole cover to the basement and then somehow supporting it while I drill. Maybe I should give that a try. That and substituting a piece of 1/4” rod for the pilot bit.

[Jim Koepke]

We have a manhole in our back yard that goes to a rain sewer.

Is this manhole your property or does it belong to a local entity?

You may be able to get them to replace the cover with a grate. Maybe don't tell them you want to use it to drain your pool.

jtk

[Alex Zeller]

The way I resolve snapping off pilot bits is to use a piece if 1/4" rod in hole saw in place of bit. Using 1/4" bit, drill a pilot hole first.

I second this. If a tooth on the hole saw bites in it forces the flute of the pilot bit into the metal in the side of the pilot hole. That'll cause the pilot bit to snap. Switch to a 1/4" rod and it's like magic. Also after starting the actual cut with the hole saw stop and drill a 1/4" hole in the hole saw cut so metal has a place to go as you cut the hole since I wouldn't use oil (environmental reasons). Manhole covers are most likely cast iron of some sort so making a hole shouldn't be hard.

[Tom M King]

What drill were you using to spin the hole saw?

[Roger Feeley]

What drill were you using to spin the hole saw?
I have a Milwaukee 3107-6 right angle drill with gobs of power. Pre-drilling the pilot hole was easy.

[Tom M King]

That should be no problem. I'd rather use a spade handle, but a right angle will work fine. I had an 18v cordless drill come all to pieces in my hands trying to drill a hole with a holesaw once. I knew I was pushing my luck, but it was the only drill I had in the truck at the time. I thought it might just lock up, and I positioned myself for that possibility, but the handle broke into multiple pieces when it did.

[Roger Feeley]

I’m thinking that the tooth geometry is the problem. The hole saw I have has teeth that are Hooke to bite into wood. I ordered a carbide saw where the angle of attack is much more vertical.

[Matt Day]

Haven’t heard about the legality of this yet. Is the storm drain the property of the AHJ? If so you likely shouldn’t be tapering with it without at least asking first.

[Roger Feeley]

I realized that I am approaching this wrong. Instead of cutting a hole through the cast iron, maybe I should replace the cover with a plastic one. This is next to a fence in our back yard. No one will ever want to drive over it so it just has to be able to support a person. The light weight presents a security issue for the children. I would need to screw it in place. Drilling and tapping cast iron is easy.

https://www.amazon.com/dp/B00JEKKPNY/ref=emc_b_5_t

[Matt Day]

Could you please tell us if you own this storm drain? How is it not the property of the city/county?

[Roger Feeley]

Could you please tell us if you own this storm drain? How is it not the property of the city/county?
It’s the city’s. No problem now. I ordered a plastic one. I’ll just put the cast iron one aside someplace.

[Mitch schiffer]

In case your plastic cover doesn't work i would suggest an annular cutter in a mag drill that is by far the best way I have found to cut big holes in thick steel.

[Bill Dufour]

The way I resolve snapping off pilot bits is to use a piece if 1/4" rod in hole saw in place of bit. Using 1/4" bit, drill a pilot hole first.
Exactly what I was going to say.
Bill D.

[Bill Dufour]

Invert cover to see where the support ribs are located. Drill center hole from the backside so as not to cut support ribs. Flip lid right side up and drill with a hole saw. Use heavy gloves and place leg to stop reaction force of drill or keep legs and arms out of the way. Use vegetable oil for lube if needed.
If you lived in the west water laws would probably outlaw dumping poisioned water into flowing water where the chlorine will kill life.
Bill D

[George Yetka]

The Manhole cover isnt your property so no as far as legality. What you could do is excavate a little on the side and drill through the concrete that its most likely in.
If you do go through with drilling the cover use a pvc Union right next to it so if needed they can get into it.
You shouldnt need a mag drill its very soft steel.

I made the mistake when I was young of using blind flanges to make a shooting target. Sat at the bench 200 yds out and didnt see them swing or here them. 223 ripped through 1-1/4 of the same soft steel

[Roger Feeley]

In case your plastic cover doesn't work i would suggest an annular cutter in a mag drill that is by far the best way I have found to cut big holes in thick steel.

the plastic cover is really made for a well or septic tank. I don’t think it would have any trouble supporting a person. It even has two blank spots in the honey comb for attaching pipes.

[Tony Zona]

Tampering with that heavy sewer cover could put you directly in line for responsibility in any future loss of life caused by your action.

If kids figure out how to unscrew and remove your light cover, and one ends up in the hole and drowns, will you be able to look in the mirror or face a sobbing mother? A heavy cover is put there for a reason. It’s wise to leave it alone, no matter how inconvenient.

The city itself may be willing to assist you with your problem. Just ask the proper authority.

[Ole Anderson]

Cast iron is easy to drill, think of it like a very hard wood. No lubricant is necessary. Just follow the previous suggestions of using a solid 1/4" pilot. And a quality bi-metal hole saw.

[Roger Feeley]

Tampering with that heavy sewer cover could put you directly in line for responsibility in any future loss of life caused by your action.

If kids figure out how to unscrew and remove your light cover, and one ends up in the hole and drowns, will you be able to look in the mirror or face a sobbing mother? A heavy cover is put there for a reason. It’s wise to leave it alone, no matter how inconvenient.

The city itself may be willing to assist you with your problem. Just ask the proper authority.

I see your point, Tony. If this was a full size rain sewer under our property, I would leave the cast iron cover in place. This particular manhole isn’t really a manhole. It only goes down a few feet to an 18” galvanized pipe that eventually feeds into a real rain sewer.

far more dangerous is a well in the front of the property. There’s a (about) 24” diameter section of concrete sewer pipe sunk verticall in the ground. The only cover is a chunk of slate or bluestone that weighs a lot. I can slide it aside but our grandkids can’t…yet. I would like to fill it in with something but I just haven’t taken the time to look into it.

[Mike Henderson]

One of my college profs asked the class, "Why are manhole covers round?" Do you know?

Mike

[Jerry Bruette]

One of my college profs asked the class, "Why are manhole covers round?" Do you know?

Mike
So they don't fall through the hole.

[Sam Force]

Round, with a lip is the only geometric shape that will not at some cross section be smaller than the longest cross section

[Michael Schuch]

Annular cutters are perfect for such projects!

https://www.amazon.com/Annular-Cutters/b?ie=UTF8&node=340028011

You can usually pick up odd sizes on ebay for cheap.

If you don't want to rent the magnetic drill press try securing a piece of plywood to the man hole lid (a couple of clamps). Then drill through the plywood which will then act as a guide for the Annular cutter or hole saw to keep it from running all over the top of the cast iron. A magnetic drill press would still probably be my preference though. I would also recommend some kind of cutting fluid (or even just dirty engine oil).

[Michael Schuch]

One of my college profs asked the class, "Why are manhole covers round?" Do you know?

Mike

I would answer... because the hole they are covering is round! ;)

[Mike Henderson]

So they don't fall through the hole.

Absolutely correct. Most other shapes can fall completely or partially (a triangle) through the hole.

Mike

[Bill Dufour]

far more dangerous is a well in the front of the property. There’s a (about) 24” diameter section of concrete sewer pipe sunk verticall in the ground. The only cover is a chunk of slate or bluestone that weighs a lot. I can slide it aside but our grandkids can’t…yet. I would like to fill it in with something but I just haven’t taken the time to look into it.[/QUOTE]

Plugging a well is a legal process that if done wrong can have massive consequences. Sure you can fill it in with dirt and hope for the best. But if ground water leaks into the aquafier and contaminates it you are legally on the hook for remediation costs. Probably not a huge issue where it rains a lot.
Bill D

[Ronald Blue]

As for the well check with your local health department. At least here since they do water testing and approve septic systems etc they also tell you how they require a well to be filled. I believe they require bentonite to fill it and seal it. That's the people to start with anyway. They might defer to someone else but it's a starting point.

[Richard Coers]

If that is storm water drain, I really doubt the city wants water with chemicals coming in. You will likely be fined for modifying the drain and dumping unknown water down it. It may go directly to a stream or creek. Please be a good citizen and check on the ecologically impact. I turned in my neighbor when I saw him draining the oil out of lawn mower into the storm drain in his back yard. Each person impacts the health of our planet!

[Frank Pratt]

hat is I turned in my neighbor when I saw him draining the oil out of lawn mower into the storm drain in his back yard.
Yikes! Hard to believe someone would do that.

[Jim Koepke]

Yikes! Hard to believe someone would do that.

The human race may be an intelligent species but individuals, including groups of individuals, can be idiots when thinking only of their own needs and/or convenience.

jtk

[Roger Feeley]

Thanks for all the great advice. I barely got my solution installed when I got a letter from the city saying that I can’t pump chlorinated water into the rain sewer. So I had to take it out. Now I’m back in my former dilemma. The place in our yard where we pumped it before got pretty swampy. I need to figure out a way to put it on our yard without over-watering.

[Ole Anderson]

Let your pool sit until the chlorine level tests zero then you should be ok to dump into the storm sewer.

[Malcolm McLeod]

... we pumped it ...

Does this pump produce 25-30psi? If so, run it to a dedicated geared sprinkler head or maybe a good ol' fashion impact head that will throw it in a 35-40ft radius. Maybe tie pump into existing sprinkler circuit if you have such, just make sure you have check valves to prevent backflow.

Last casa had code-required fire sprinklers. Annual test dumped water out a 3/4" line on the side of the house. Rather than 'puddle' the test water in the flower beds, test tech screwed on a 180deg sprinkler head :: testing watered that area of the lawn.

[Roger Feeley]

Let your pool sit until the chlorine level tests zero then you should be ok to dump into the storm sewer.
pumping it down for the end of the season isn’t the problem. It’s the 100 gallon back flush that we do at least weekly.

[Bill Dufour]

Back flush into a rubbermaid stock trough. Let it sit a few days for the chlorine to dissapear ten sump pump to water the lawn. Actually most plants can withsand some chlorine.
Sounds like too much back flushing. Do you wait for filter pressure to double before back flushing or at least get to 20 PSI? Normally a clean filter should run about 10 PSI. Back flush when it gets to 20 PSI.
I just replaced my pump with a Black and Decker variable speed pump. Saves a ton of energy. I run it at about 100 watts 12+ hours a day.
Bill D

[Frank Pratt]

Will your sanitary sewer (there's an oxymoron) not handle the back flush? 100 gallons isn't that much.

[Roger Feeley]

Will your sanitary sewer (there's an oxymoron) not handle the back flush? 100 gallons isn't that much.
the unique layout of the property puts any clean out too far away. If I want to drain into the sanitary sewer, the shortest route would be to run a pipe through a crawl space into the cellar.

I rerouted the discharge hose to the back yard where it will empty out on the grass. I can move it around to avoid a swamp.

[Jerome Stanek]

Let your pool sit until the chlorine level tests zero then you should be ok to dump into the storm sewer.

Tap water is allowed to be 4 parts per M and pool water is between 1 to 3 parts per m

[Maurice Mcmurry]

I did a very similar hack in a nearly identical setting. It was for a 4 inch PVC downspout drain with a sump pump discharge teed into it. I went down stream from the manhole cover and un-earthed the 12 inch ductile iron pipe and drilled through the top of that with a 4 3/8 Lenox bi-metal hole saw in the SDS drill with plenty of cutting oil. It is a city owned storm drain on private property within a utility easement. My friend was the chief engineer for the contractor that installed the inlet with manhole cover and pipe 10 years earlier. My engineer friend saw what I did and said "You better hope nobody ever finds out that you did that"

479158

[Bill Dufour]

In the San Francisco are when a home is sold they pump smoke into the sanitary sewer. Any leaks out of the ground or downspouts connected must be fixed before sale can go through.
Bill D

[Brian Elfert]

In the San Francisco are when a home is sold they pump smoke into the sanitary sewer. Any leaks out of the ground or downspouts connected must be fixed before sale can go through.


The city I previously lived in replaced everyone's water meter. Here in Minnesota they are all inside the houses. As part of the water meter replacement project the city also inspected to be sure sump pumps were not dumping into city sewers. I recall they would not install your meter if you failed the sump pump check. The city would give you a grant to pay 50% of the cost to remedy the problem I think up to $500. You had to fail the first inspection to get the grant.

I failed the sump pump inspection and spent a lot of time installing a 2" poly line about 200 feet to a spot where the water would drain into a small lake. I had to do some calculations to verify my sump pump could pump that far. I calculated I was pumping around 1,000 gallons per day which was much more than the ground could absorb. I had previously tried a small dry well which didn't work and just resorted to dumping the water into the sewer.

[Matt Day]

Maybe my standards are too high but I can’t believe you went ahead with this without knowing if you were legally allowed to.

[Bill Dufour]

Good thing you got the warning letter before they fined you.
The problem with dumping into the the sewer system is a big rain will overflow the sewer treatment plant and flood untreated sewage out. You sewer bills have to pay for the fines when that happens, tens of thousands of dollars a day.
Bill D