Cleaning Sanitary Sewers

[bank]

We recently had a clean and television inspection (CTV) done on sanitary sewers in a large neighborhood. The CTV mechanism shoots a water jet ahead of the camera to clean out debris so you can assess the condition of the pipe.

Even after the water jet there were still pipe segments with heavy grease accumulations attached to the pipe walls. Does anyone know of a method the city can adopt to thoroughly clean small-diameter (less than 12" diameter) sewers?

 

[bimr]

Typically, there will be light cleaning or heavy cleaning. Heavy cleaning involves operations such as:

a. Mechanical Cleaning (Heavy Cleaning Equipment): Bucket machines shall be in pairs with sufficient power to perform the work in an efficient manner. Machines shall be belt operated or have an overload device. Machines with direct drive that could cause damage to the pipe will not be allowed.
b. Power rodding machines shall be either sectional or continuous type capable of holding a minimum of 750 feet of rod. The rod shall be heat-treated steel. To ensure
safe operation, the machine shall have a fully enclosed body and an automatic safety throw-out clutch or relief valve.
c. Chain knockers may be used in a back and forth motion to loosen heavy deposits of material. Chain knockers may be used in ductile iron pipe ONLY.
d. Contractor may recommend other heavy cleaning equipment for use with the approval of the Engineer.

Multiple cleaning passes may be required.

Refer to the attachments.

 

[bimr]

Here is another spec.

 

[Hoagie]

Bimr's gives good stuff.

Just in case you need a reference, know that there are established guidelines for cleaning. Check NASSCO Specification Guidelines for Sewer Collection System Maintenance and Rehabilitation.

 

[msquared48]

Call R*(*-R**(#@ and you'll see how quick your drains are trouble-free... R*(*-R**(#@!

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[Ron]

Subtle, Mike...subtle

 

[msquared48]

And who says that marketing jingles don't work?

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[ChipperB]

You can cut grease with high pressure water. Make sure your contractor turns up the pressure and has a grease cutting nozzle on the hose. As BIMR says multiple passes will be required. Expect the contractor to ask for more money if multiple passes or heavy cleaning has not been negotiated in advance.

 

[dicksewerrat]

There are some chemical degreasers out there for sewers. You mix the water and chemicals in the jet truck and go at it. Follow the grease problem upstream to see if there is one especially bad contributor to the problem. SWEPCO I think makes one. There is a trade show in late Feb., early March, Pumper and Cleaner Show . This is a good tradeshow to get lots of different vendors names and products without having a parade through your office.

http://WWW.pumpershow.com.

This year it is the first week of March in Louisville, KY

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[joengr]

A guy I know uses a partially deflated soccer ball with a rag wrapped around it. He tied the ball to a rope which he uses to drag through the pipe.

He works from manhole to manhole fishing wire through the pipe first in order to lead the rope.

I assume if you tied a second rope to the ball and had a guy in each manhole you could essentially 'floss' the pipe clean.

 

[SewerEng]

Vac-Con with hydro jetter nozzle for high pressure / grease cleaning works well.