12-04-2016, 07:28 AM
If you give the bacteria time and space to consume the waste products then the water getting to the water table is not a problem. A properly functioning septic tank and leach field does a good job and is all you need. In some cases you must build up a mound of the properly sized sand and gravel above the surrounding grade to get the proper conditions of percolation and aeration required by the bacteria, plus distance from the water table if needed, but it is surprising how few feet of aerated soil is required to treat normal sewage when designed right. The problem with cesspools is not that they return water to the soil. It is that they seem almost designed to speed the wastewater past the aerobic zone without treatment.
So yes a sawdust toilet and a compost heap does a pretty good job mostly because it does not create wastewater. If rain leached through the heap and ran along the surface that would be a problem. Covering the heap is not a bad idea but I don't normally and I often dig into the heap and find dry spots. When it is cooking right heaps of the size that most of us build are self-aerating. One consequence of this is that the movement of air through them coming in cold and leaving warm drys them out. The steepness of the pile also tends to create a thatched roof effect.
So yes a sawdust toilet and a compost heap does a pretty good job mostly because it does not create wastewater. If rain leached through the heap and ran along the surface that would be a problem. Covering the heap is not a bad idea but I don't normally and I often dig into the heap and find dry spots. When it is cooking right heaps of the size that most of us build are self-aerating. One consequence of this is that the movement of air through them coming in cold and leaving warm drys them out. The steepness of the pile also tends to create a thatched roof effect.