George ~ It sounds like you have some major problems in your area with your
possum aftermath .   The system in our area is 4 ft. deep buried under the
ground. Being underground we have no needs for Zone antifreeze, ours cant freeze.
It sounds like your system needs some upGRADING. Are you still using that
brown down spout and gutter to move your possum belly waste to your above ground
Cement pond.  I just saw the weather forcast for your area it tis to go down
to 12 degrees Sunday night. You better get a few extra gallons of Zone lifetime
antifreeze. remember you cant be having your oze freeze . If it would help
you any Wallmart has winter Lifetime warrantyCement pond covers on sale !!  They
say that it will help cut the ungodly smell by 50%  They say if your
neighbors turn their noses up to you ,your system needs upgrading.
  hAVE A NICE DAY gEORGE
Don @ DVW