View Full Version : Low Pressure Force Main Modeling

January 7, 2015, 10:37 AM
Hello from Snyderville Basin Water Reclamation District. Need a little help here.
In our wastewater collection system we have a handful of residential developments that are served by low pressure sewer force mains. The conveyance for these low pressure sewer force mains is dependent upon private grinder pumps installed on each developed lot. The following display is an example of one such system.

I have been unsuccessful in my search (InfoSewer Help, SWMM blog, and this forum) for a solution in modeling a forcemain / low pressure system sans a public lift station. I have attempted to model the low pressure appurtenances with "Manholes" and again with "Chambers" to no avail. InfoSewer is insistent on including a wetwell / pump station for each force main system.

Is it possible to model a Grinder Pump Low Pressure Sewer Force Main system within InfoSewer? If so, How is it modeled?


Robert Dickinson
January 7, 2015, 02:03 PM
Unfortunately, InfoSewer has rules for Wet Wells / Pumps / Force Mains / Chamber nodes and without adding virtual pumps at your flushing connections it will not solve or run either an EPS or Steady State solution even with the Advanced Force Main Option. Your idea of model simplification is probably the best. For future reference here are the rules

InfoSewer Infographic or Map of Features (http://www.swmm5.net/2014/01/infosewer-infographic-or-map-of-features.html)

A basic Index to @Innovye #InfoSewer (https://twitter.com/search?q=%23InfoSewer&src=hash) for Sanitary and Storrmwater Networks http://twitpic.com/dtwleq (http://t.co/LWlsvYPFuW)

The main features of an InfoSewer Network with labels. This version uses the normal Force Main solution but if the upper grey set of links is added then you have to use the Advanced Force Main Solution.

http://2.bp.blogspot.com/-Q_1RRAuC2j8/Uur64lgKQOI/AAAAAAAAE5w/syNg6s-AIfY/s1600/InfoSewer+InfoGraphic.png (http://2.bp.blogspot.com/-Q_1RRAuC2j8/Uur64lgKQOI/AAAAAAAAE5w/syNg6s-AIfY/s1600/InfoSewer+InfoGraphic.png)

InfoSewer Map of Features

Rules for Force Mains in InfoSewer and H2OMap Sewer (http://www.swmm5.net/2013/12/rules-for-force-mains-in-infosewer-and.html)

The image at the bottom shows the rules for Force Mains in InfoSewer and H2OMap Sewer:
1. Gravity Main
2. Wet Well
3. Pump
4. Chamber Manhole
5. Force Main if you have many force mains the node BETWEEN two force mains has to be a Chamber Manhole
a. The error messages for this are now rigorously enforced and they may not have been in past versions
6. Loading Manhole
7. Gravity Main

http://3.bp.blogspot.com/-g6PRrquX5Jk/UruQoIQZDbI/AAAAAAAAEyg/qZLXeTJpRfU/s1600/image003-768459.png (http://3.bp.blogspot.com/-g6PRrquX5Jk/UruQoIQZDbI/AAAAAAAAEyg/qZLXeTJpRfU/s1600/image003-768459.png)