standard or low rate, and high rate.
hydraulic head between the lowest
The application of sewage at higher
liquid level in the dosing chamber and
rates and the recirculation of a
the center of the rotary distributor
portion of the effluent constitute the
arm is 10 to 12 inches. If sprinkler
nozzles are used, head should be
operation of a high rate filter and
sufficient to discharge the maximum
that of a standard rate filter.
flow at the low water level in the
This usually requires a
(1) Design procedure.
6- to 10-foot head from the high water
of the filter bed is determined on the
level in the dosing tank to the