SEWAGE DEPARTMENT TRAINING PROGRAM
How to Build an Elevated Sandmound Sewage Disposal System
When purchasing the aggregate, get the cleanest material possible. Washed stone is preferred.
When aggregate is stockpiled, rock dust filters through the pile so that the material at the bottom of the pile has more fine material. If this material is used, the rock dust can clog the sand causing the system to fail.
Try to have the loader take the aggregate from the upper portions of the pile (at least 3 feet up) and not along the ground surface.
This material was taken from the bottom of a stockpile. Had it not been removed from the system, the elevated sandmound would surely have failed shortly after use.
