title: Assessment of the impact of traditional septic tank soakaway systems on water quality in Ireland.
abstract: One of the key threats to groundwater and surface water quality in Ireland is the impact of poorly designed, constructed or maintained on-site wastewater treatment systems. An extensive study was carried out to quantify the impact of existing sites on water quality. Six existing sites, consisting of a traditional septic tank and soakaway system, located in various ranges of subsoil permeabilities were identified and monitored to determine how well they function under varying subsoil and weather conditions. The preliminary results of the chemical and microbiological pollutant attenuation in the subsoil of the systems have been assessed and treatment performance evaluated, as well as impact on local surface water and groundwater quality. The source of any faecal contamination detected in groundwater, nearby surface water and effluent samples was confirmed by microbial source tracking. From this, it can be seen that the transport and treatment of percolate vary greatly depending on the permeability and composition of the subsoil.
authors.affiliation: Department of Civil, Structural & Environmental Engineering, Trinity College Dublin, Ireland E-mail: keeganm2@tcd.ie.
authors.forename: Mary
authors.initials: M
authors.lastname: Keegan
authors.affiliation: Department of Microbiology, School of Natural Sciences and Ryan Institute, NUI, Galway, Ireland.
authors.forename: Kate
authors.initials: K
authors.lastname: Kilroy
authors.affiliation: Department of Civil, Structural & Environmental Engineering, Trinity College Dublin, Ireland E-mail: keeganm2@tcd.ie.
authors.forename: Daniel
authors.initials: D
authors.lastname: Nolan
authors.affiliation: Department of Civil, Structural & Environmental Engineering, Trinity College Dublin, Ireland E-mail: keeganm2@tcd.ie.
authors.forename: Donata
authors.initials: D
authors.lastname: Dubber
authors.affiliation: Department of Civil, Structural & Environmental Engineering, Trinity College Dublin, Ireland E-mail: keeganm2@tcd.ie.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Johnston
authors.affiliation: Department of Civil, Structural & Environmental Engineering, Trinity College Dublin, Ireland E-mail: keeganm2@tcd.ie.
authors.forename: Bruce D R
authors.initials: BD
authors.lastname: Misstear
authors.affiliation: Department of Microbiology, School of Natural Sciences and Ryan Institute, NUI, Galway, Ireland.
authors.forename: Vincent
authors.initials: V
authors.lastname: O'Flaherty
authors.affiliation: Department of Microbiology, School of Natural Sciences and Ryan Institute, NUI, Galway, Ireland.
authors.forename: Maria
authors.initials: M
authors.lastname: Barrett
authors.affiliation: Department of Civil, Structural & Environmental Engineering, Trinity College Dublin, Ireland E-mail: keeganm2@tcd.ie.
authors.forename: Laurence W
authors.initials: LW
authors.lastname: Gill
mesh_terms: D001419:Bacteria / Q000235:genetics; D004269:DNA, Bacterial / Q000032:analysis; D005243:Feces / Q000382:microbiology; D005618:Fresh Water / Q000382:microbiology*; D060587:Groundwater / Q000382:microbiology*; D007494:Ireland; D012987:Soil / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000295:instrumentation* / Q000379:methods; D062065:Wastewater / Q000382:microbiology; D060753:Water Quality
chemical_list: D004269:DNA, Bacterial; D012987:Soil; D062065:Wastewater