this pit is pumped up to the top, rather than the bottom, of the

sand filter. The effluent is pumped to the top of the sand filter

in this system because we felt that since we have to pump it up to

the sand filter we may as well allow it to run through the filter

rather than pumping it directly to the bottom.    The effluent from

the sand filter is then pumped to the top of the sand filter, the

septic tank, and the dosing chamber which in turn pumps it to the

mound system.

3.4 Denitrification System Monitoring

     In addition to the original design of the denitrification

systems, temperature probes have been placed in the two systems.

The temperature probes are made out of type T thermocouple wire

which have been soldered together at the bottom end and sealed with

a Silicone Rubber Adhesive Sealant.       An omega HH21 hand held

microprocessor   digital   thermometer   is  used  to   record   the

temperatures from these thermocouple wires.

      At Site 1, four groups of these thermocouples were placed in

the sand filter as shown in figure 3.6.     Each group consists of

four thermocouple wires with the wires extending about 2.2 ft, 1.2

ft, 0.2 ft, and 0.0 ft below the surface of the sand in the sand


      At Site 2, only one group of four thermocouples was placed in

 the sand filter at the same depths.   We only placed one group in
 this system because the sand filter is deeper in the ground than

 the sand filter at Site 1 and thus we felt that temperature may not

 play as important a role on the nitrification and denitrification