quarz media

[ozfish]

I have emptied a sand filter which was used as a final stage for treating potable water. At the base the medi was large chunks of quartz - why would this be used - particularly the quartz in lieu of other smooth gravels?

Regards

 

[johnd43]

I recommend Stevenson's book again. Ref the discussion thread on WT History.

 

[bimr]

The material is probably the filter media support gravel. Support gravel was commonly supplied in 3 or 4 different sizes. The gravel was layered by the size of the gravel over the underdrain laterals. The gravel is used to hold the filter media in the vessel. The holes in the underdrain laterals are typically larger dia. than the filter media. Without the gravel, the filter media will travel through the underdrain and out with the effluent.