maximum drop depth allowed in the sewage manhole 1

[mdrehansk]

Hi all,
can any one have the idea about the maximum drop depth allowed in the sewage manhole with 1000 mm pipe, please provide references for the same.

Regards,

 

[bimr]

One would have to contact the local sewer agency that you are working with. Different agencies may have slightly different interpretations as there is no universal standard.

 

[gbam]

bimr hit it on the nose check with local waste water agency.

 

[mdrehansk]

Thanks

 

[rconner]

As others have noted it is always wise (or imperative) to check with local authorites, and particularly any AHJ's. I am aware however, ASCE MOP No. 60/old WPCF FD-5 gravity Santary Sewer Design and Construction does cite multiple problems that may occur as a result of drops and deep drops, and it says of drop manholes, "Drop manholes should be used sparingly and, generally, only when it is not economically feasible to steepen the incoming sewer. Some engineers eliminate drops by using vertical curves. It would appear that this should be a general rule for elevation differnces of less than about 1 m (3 ft) and often for larger drops as well."

 

[mdrehansk]

Thank you rconner, it is very helpful.

 

[bimr]

Attached is a typical detail for a drop manhole. Drop manholes are typically required if you are taking more than 2 ft of drop inside the manhole. If you have a drop manhole, then the drop outside the manhole may be much larger.

 

[hokie66]

Long drop? Start from here.

http://travel.cnn.com/sydney/life/long-drop-australias-outback-dunnies-291535/

 

[mdrehansk]

thank you bimr

 

[mdrehansk]

Dear rconner can you share the code ASCE MOP No. 60/old WPCF FD-5 gravity Santary Sewer Design and Construction

 

[rconner]

fyi

http://ascelibrary.org/page/books/s-mop

(and copywrighted ASCE manuals of practice are not really "codes", but are as explained at that web page or the front matter of the various MOP's)

 

[dicksewerrat]

Are you laying a new pipe? If so, put it in at the flow line of existing manhole. Dropping helps get the H2S to come out of the sewage. This will corrode your manhole. Another thing is that us guys that do or did go into live manholes don't like the "Drop Manhole" idea. Have to take a shower in clean water afterwards.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com