Soil Treatment

Although technologies favored for use in the decentralized concept can produce effluent of sufficient quality to meet discharge limits in many situations, regulatory authorities everywhere frown upon the concept of a multitude of small discharges. While it can be argued that this perspective is questionable – I've often said, not completely tongue-in-cheek, that the real point of so-called “regional” wastewater plants was to gather this stuff together in one place where it can REALLY do some damage – soil dispersal will doubtless remain the norm for on-site/small-scale “waste” water systems. It is important, therefore, to have a thorough understanding of just what happens to effluent when it enters the soil system. It does not go “away”—which seems to be the focus of soil dispersal system “design” in many quarters. There is no “away”. Wherever it goes, the water remains in some part of the hydrologic system. Thus, there is no such thing as a “disposal” system—that word should be stricken from the lexicon of the wastewater management field. All “disposal” fields are really dispersal systems, and the aim of their design should be to provide optimum conditions for the required treatment to be accomplished in the soil system.


Soil Treatment Mechanisms - An Analysis of the Potential Public Health and Environmental Impacts of Soil Dispersal Systems

A review and discussion of the mechanisms by which “waste” water is treated in the soil system to assimilate or eliminate pollutants before any water which percolates reaches a limiting condition—a point where essentially no further treatment can be expected before the water enters groundwater or a surface watercourse. This information is used to analyze how dispersal mechanisms can be designed to take best advantage of whatever soil resources are available.

NOTE: A revision of this paper is being prepared.. The original version of this paper is displayed in the meantime.


Drip Irrigation Dispersal System Design Manual for High Quality Effluent

As described in the "Soil Treatment Mechanisms" paper, drip irrigation is the dispersal method that practically maximizes the treatment capability of any soil. This paper is a manual describing design principles and practices for drip irrigation dispersal systems when the "waste" water fed into the drip system has been pretreated to high quality, such as that provided by the high performance biofiltration system.
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