Headloss through filter pack

[Sowega]

Need help figuring headloss through a groundwater well filter pack. I'm thinking it would be something like headloss through a sand filter but I can't find a formula that quite fits.

 

[fattdad]

I think there are tables/graphs in this publication.

http://armypubs.army.mil/eng/DR_pubs/dr_a/pdf/tm5_818_5.pdf

f-d

¡papá gordo ain’t no madre flaca!

 

[tkall]

Sowega:
Your question made me remember I had the same question several years ago. I had a bright engineer working with me and we decided to build a model of the filter pack/well in the office and measure the headloss as a function of pumping rate. It worked great and accurately predicted the response of the actual well in the field.

 

[dgillette]

Just curious, tkall, how did the head loss through the filter compare with head loss through the well screen? What do you use for allowable velocity through the screen? I think somebody told me 0.2'/s for permanent wells, and 0.5'/s for temporary dewatering wells, but that was a few years ago.

Thanks,
DRG

 

[tkall]

dgilette:
It was a long time ago and I don't remember the details. We built an exact replica of the well on a barrel added a pump and measured the headloss. Pretty basic but instructive.