I have been involved with  water and wastewater process equipment for 35 years. My passion is package and custom potable treatment systems. The municipal granular filtration bed design has remained relatively unchanged since the invention of "Multi" or "Tri" media design many years ago. After that technologies for reducing the load on the filter as well as extending the life of the actual filter bed evolved. Auxiliary Wash and many designs for "Gravel-Less" underdrain emerged. I can help you determine if you have enough 22 & 24 and condition of them. Does your 20 need skimming? Depending on the integrity of your 42 source and your type of 66, the 44 structure could be disturbed. This will cause loss of your 22 & 24 down through the 44 structure into your 40. (Diagram may differ in some area's).

Seriously, I grew up being involved with companies that in my opinion were the most influential in municipal filtration technologies over the past 100 plus years.


Technology Today

The onset of higher rate media designs sparked the need as well as the development of pretreatment technologies. The invention of inclined settling surfaces in some instances more than doubled conventional sedimentation basin flow per square foot. Further hybrid technology addressed the high chemical need (relatively) to percipitate floc in low turbidity waters as well as further reduce footprint. More troublesome sources required advannced consideration. Oxidation to promote settling, introducing micro bubbles to collect floc at the surface, as well as specalty media / chemicals were among the solutions.


Most filter upsets are due to the gradations of gravel being displaced from original placement. This displacement can render a perfectly acceptable filter structure deficient and reduce production efficiencies greatly depending on the amount of upset. This performace degradation is due to change in the planular hydraulics of your filter bed. I refer to this as "Plug The Hole Syndrome". Making this "hole" produce can over time gum up the rest of the media due to increased dose and uneven planular hydraulics.

Silica gravel is the least expensive material in a filter. Typically during removal retainage of fluidizable material (the filter) from the gravel is cost prohibitive...   UNTIL NOW!

If the media is deamed reusable (say because a coatings failure causes early filter life issues) I have a process that removes the fluidizable media seperate from the non fluidizable, retains, washes, and after repairs are done returns the filter media.