×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Sewer Inflow and Infiltration Study

Sewer Inflow and Infiltration Study

Sewer Inflow and Infiltration Study

(OP)
I have been asked to help out with a low budget inflow and infiltration study for a sewer system.  This means that we don't have money for sending a camera down sewer mains to find problems.  But what we do have are several portable flow meters.  We will also be monitoring pump run times at pump stations.  Does anyone have advice on how to quickly identify sewer I & I problems so we can determine the best manholes to put our flow meters in?

Thank you,  

RE: Sewer Inflow and Infiltration Study

If you have little funds, you might skip the flow metering and just smoke test to identify major problems. Note that it is very difficult to compare flows over a period of time or storms.

You can also check the construction drawings and determine where the oldest sewers are located. The oldest sewers will probably be in the worst condition.

Prepare budget plans to repair X amount of sewers over X number of years. That is probably the only rational method to proceed. One would suspect that repair funds have not been available over the past years and major funds will not be available in the future.

RE: Sewer Inflow and Infiltration Study

Smoke testing may be done inexpensively depending on what local programs are available.  For example our rural water association asks that you donate any amount you can up to a maximum amount not to exceed actual cost.  Also, I would recommend that you have talks with the wastewater operator to gain his knowledge of where overflows occur, how the collection system handles the spring melt or wet season (if applicable), where backups into homes occur, where they have had or are having root problems, etc.

FYI we just TV'd a sewer system for $1.40/ft...

RE: Sewer Inflow and Infiltration Study

What is smoke testing, and when do you use it?

B+W Engineering and Design
Los Angeles Civil and Structural Engineering
http://bwengr.com

RE: Sewer Inflow and Infiltration Study

When I witnessed it they used some chemically generated smoke and a fan to blow smoke in through the top of a sanitary manhole.  When you start seeing smoke coming up in yards you have an infiltration problem.  Either a crack in the pipe or a missing clean-out cover.  

When I saw it they were having to comply with EPA regs stipulated upon the utility.  Past complaints of overflowing sewers during rain events.  They were photographing insides of manholes and running cameras through all known problem sewers in order to determine problems and design fixes.

RE: Sewer Inflow and Infiltration Study

I agree with Bimr, smoke test is much better and efficient way to know about the major problems in the sewage. As the flows of the sewage vary with time and with different weathers.  

John
http://www.minidiggerhire.ie/#/skip-hire-dublin/4547725214

 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources