International Journal of Soil Science1816-4978xxxx-xxxxAcademic Journals Inc.10.3923/ijss.2011.249.258HumphreyC.P. O`DriscollM.A. 4201164On-site wastewater treatment systems require aerated soil beneath the disposal field trenches for adequate effluent treatment and protection of groundwater quality. Low chroma colors are used as a reference point for the depth to the seasonal high water table. The study objective was to assess the frequency of water table saturation and cumulative saturation of soil at depths typical for disposal field trenches (30 to 60 cm shallower than low chroma soil colors). Groundwater monitoring wells were installed at 11 sites with 4 different soil series in mainland Carteret County, North Carolina. Soil profile descriptions and the depth to low chroma colors were recorded during the well installation process. Automated water level loggers were placed in the wells and programmed to record water table depths every 0.5 h. The depths to low chroma soil colors and 30-60 cm shallower were compared to groundwater levels for a one year period (December 2006 to January 2008) to determine the frequency and cumulative saturation of soil at these depths. Data indicated that the soil cumulative saturation and frequency of water table inundation was greater at depths 30 cm above chroma 2 colors relative to 45 and 60 cm above chroma 2 colors. Increasing the vertical separation distance requirements from on-site wastewater system disposal field trenches to low chroma colors by 15 cm could reduce the frequency of saturation and the cumulative groundwater table saturation of disposal field trenches by 25 and 67%, respectively. Water quality could be improved by increasing separation distance requirements by 15 cm or more from the current standards.]]>Al-Jlil, S.A. and O.A. Alharbi,20104400406Al-Jlil, S.A.,20098473477Bouwer, H. and R.C. Rice,197612423428Brady, N.C. and R.R. Weil,20042nd Edn.,Cahoon, L.B., J.C. Hales, E.S. Carey, S. Loucaides, K.R. Rowland and J.E. Nearhoof,200622319327Carlile, B.L., C.G. Cogger, M.D. Sobsey, J. Scandura and S.J. Steinbeck,19811981Daghrah, G.A. and R. Al-Sa'ed,200925870Day, P.R.,19791979pp: 545-567pp: 545-567Fear, J., T. Gallo, N. Hall, J. Loftin and H. Paerl,200461491506Genthner, M.H., W.L. Daniels, R.L. Hodges, and P.J. Thomas,19981998Hassannezhad, H., A. Pashaee, F. Khormali and M. Mohammadian,20083149156He, X.,20002000He, X., M.J. Vepraskas, D.L. Lindbo and R.W. Skaggs,200367961969Heath, R.C.,19981998Hoover, M.T., T.A. Daisy, M.A. Pfeiffer, N. Dudley, R.B. Mayer and B. Buffington,19961996Humphrey, Jr. C.P. and M.A. O'Driscoll,20116103113Humphrey, C.P., M.A. O'Driscoll and M.A. Zarate,20106214481455Humphrey, C.P. Jr., M.A. O'Driscoll and M.A. Zarate,2011Escherichia coli contributions to shallow groundwater in coastal North Carolina.]]>63789795Hussain Chattha, T., K. Mateen ul Hassan and L. Muhammad Imran,20054345348Laghari, A., S.N. Chandio, M.Y. Khuhawar, T.M. Jahangir and S.M. Laghari,20044314316Laghari, A., S.N. Chandio , M.Y. Khuhawar, T.M. Jahangir and S.M. Laghari,20044317322Lindbo, D.L., D. Rashash and M.T. Hoover,20052005Mensah, E., H.E. Allen, R. Shoji, S.N. Odai, N. Kyei-Baffour, E. Ofori and D. Mezler,20083243251Microsoft Corporation,20072007Momba, M.N.B., M. Sibewu and A. Mandeya,20099648654North Carolina Climate Office,20082008North Carolina National Estuarine Research Reserve,20032003Onset Computer Corporation,20072007Severson, E.D., D.L. Lindbo and M.J. Vepraskas,200873189196Solinst Canada Ltd.,20072007Stall, C.J.,20082008Vepraskas, M.J. and S.P. Faulkner,20002000pp: 85-107pp: 85-107Vepreskas, M.J. and L.P. Wilding,198347280285Galavi, M., A. Jalali, S.R. Mousavi and H. Galavi,2009S. bicolor Speed feed).]]>8489494