pump station peak factor

[deeman]

Does anyone have any information on ideal peak factors to use for sewer pump station design flows. Ten States has a chart for peak factors based on population but this is excessive and seems to be more aclimated to large plant flows. The state regulators here are now requiring a minimum of 4.0 factor and this is causing problems with long detention times in wet wells. I have researched many other cities and have found that factors range 2.5 to 4.0.

 

[RWF7437]

Peak factors of 2 to 4 are very commonly used, as you already know. Although higher factors may be warranted for small populations. If you have, or can get, actual water use peaks for those months when irrigation is not a major water use, these will probably give you the best estimates. Developing a diurnal curve for water use is well worth the effort IF you can get the data.

good luck

 

[bimr]

Have you thought about changing the float levels in the lift station? Changing the levels will change the detention time.

 

[deeman]

Yes I have thought about this and it does help to some extent, but we'd like to keep the operating range to at least 1.5 feet and this can still cause a problem when using a peak of 4.0.