C. 2. c. EFFLUENT VERSUS ABSORPTION AREA WATER QUALITY DURING THE RESEARCH STUDY

C. 2. c. EFFLUENT VERSUS ABSORPTION AREA WATER QUALITY DURING THE RESEARCH STUDY Hydrogen ion concentrations (pH), EC values, and chloride ion concentrations remained consistent between effluent and subsystems samples each year. Effluent nitrate-N concentrations were lower and ammonium-N concentrations higher than those concentrations found within either subsystem in the absorption area. This was due to nitrification that occurs under the aerobic conditions in the subsystems (Reneau et al., 1989). The phosphate-P concentration was also higher in the pump chamber effluent than in the subsystems, as expected. Nitrate-N increased by as much as 182 times, ammonium-N decreased by as much as 20 times, and phosphate-P decreased by as much as 157 times from the effluent determinations to those determined from subsystems 1 and 2. The pump chamber operates under anaerobic conditions and ammonium-N from the human waste accumulates. When the effluent from the anaerobic pump chamber is dosed into an aerobic subsystem, ammonium-N is transformed to nitrate-N through nitrification and phosphate-P is immobilized on soil colloids (Degen et al., 1991). Although the effluent was of overall weak strength, all the quality parameters were at greatest values/concentrations in 1991, the third and last year of the research study, however, subsystem values/concentrations varied little during the study period. Both subsystems appeared to handle the effluent load with consistent performance, regardless of effluent quality.