Putting Grade ring vs Manhole section when raising the manhole. Need correction

[ANgK]

There is a manhole in the property driveway that was raised by adding 4 meter rings a long time ago, about 24 inches. WE are raising the driving slop and the subcontractor added 3 concrete rings about 30 inches. Totally the manhole was raised 54 inches.

The city public works department inspected the manhole and said it was build incorrectly. Per code, it has to be manhole section instead of ring. They want us to propose a course for remedy and correction.

Replacing all the rings would be a hug cost as well as probably impossible because there is a retaining wall near the manhole with geogrid and replacing the ring would involve tear down the wall.

The manhole is in private property and only connected by the property owner. It is on the side of the driveway next to the retaining wall will never get drived on.

What would be a potential hazard of using ring instead of manhole section? What can we do to satisfy the city without incur too much cost?

Thanks

 

[amlinerrichard]

Is the manhole part of the property owner's connection? Does the property owner own the MH or the city? What is the purpose of the manhole? Can the connection be extended to the outgoing pipe and fill in the MH?

 

[ANgK]

The manhole part of the property owner's connection and the property owner is the only one connect to the manhole. The manhole is in the property but per city, technically the manhole is still belong to public works.

The manhole is dry for more than 20 years. The property owner is building a new house and use the manhole for sewer connection. I don't think there is any other mean for sewer connection

 

[amlinerrichard]

Drive around the city and look for street projects. Look at the manholes to see if City forces/ contractors use lots of grade rings instead of MH sections. You may be surprised at what you find.

 

[ANgK]

I am not sure I understand this " if City forces/ contractors use lots of grade rings instead of MH sections. You may be surprised at what you find."? Do you mean that it is prevalent that contractor using ring instead of section?

I think the problem is the lack of steps to get to the bottom. Is there a way to get the steps/stair to these rings?

 

[GMADS]

I'm confused.

If the MH is on private property, it should be private. If the city claims it's theirs, it's because it's in their right-of-way or in a dedicated easement (which I would assume you or owner would be aware of and I would want to a record of). You say the MH is in the driveway. Is it in the driveway approach (which could be the city ROW), or is it "up in" the driveway - which would seem to be clearly private property (again assuming there's no easement)?

Also, you mention this MH has been dry for 20 years. So it is either the last MH on the upstream portion of the main, or it is a MH on a lateral that is upstream of the main (perpendicular to main). Either way, if it can be shown to be out of their ROW (or no easement), I'd argue that it's private and the owner will be using the MH as a de-facto "oversized clean-out" and why does the city care - they don't have to do the maintenance on the MH. Hopefully, a reasonable city representative would agree. If it hasn't been used in 20 years I would want to TV the line to check its integrity - that may also help with plea to the city as well.

If it IS in a ROW/easement, as new construction, you will have to bring it to current spec. The 18" (sometimes 24") maximum "neck" requirement is pretty typical for most (all I've seen) municipalities. If your municipality is resident friendly, I would still try to sit down with a decision maker and ask for a variance since it is only one service and would be cost prohibitive for the resident/owner. I would ask if they use "waste water access devices/chambers". If they do, I'd say that's basically what you have - a large WWAD.

Your last option could just be a new sewer tap and service if it were cheaper than correcting the MH and removing the retaining wall.

 

[cvg]

"I think the problem is the lack of steps to get to the bottom"

our local agencies no longer allow steps, OSHA confined space entry requires a harness and tripod with ventilation to enter a manhole. no steps needed, plus they increase the maintenance

24" diameter grade rings, 54 inches high will make it significantly more difficult to enter the manhole, especially with the steps installed - regardless of who owns it.