Sewer Inflow and Infiltration Study

[davyheat]

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,

 

[bimr]

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.

 

[CrazyHorse81]

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...

 

[brandonbw]

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

B+W Engineering and Design
Los Angeles Civil and Structural Engineering

http://bwengr.com

 

[sam74]

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.

 

[johnabcd]

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