| The primary goal of this research was to evaluate the performance of on-site subsurface drip irrigation systems, analyze system failures, and recommend improvements and further research studies. This study was funded by the Texas On-Site Wastewater Treatment Research Council.;Soil type, effluent type and geography were considered in selecting the 18 study sites. Soil and water samples, and other field measurements were taken. Landowners and the county health officers were interviewed to determine the status of on-site systems.;The soil was analyzed for texture, swell shrinkage, bulk density and moisture. The effluent was analyzed for COD, BOD5, pH, Total Phosphorous, Kjeldahl Nitrogen, Nitrite, Nitrate and Fecal Coliforms. Effluent flow rates were estimated from the number of occupants or bedrooms. The hydraulic conductivity of the soil at different locations in the drip field were determined through permeability tests.;A multi-regression analysis was carried out to get the relationship between failure of system, loading rate, and other parameters such as soil type, clay content, and swell shrinkage. Removal efficiencies of the drip system were: BOD5 (56–68%), COD (41–53%), Fecal coliforms 49.5%, Total Phosphorous 80.5%, Nitrite 90.3%, Total Suspended Solids 95%. |
