title: Evaluating two infiltration gallery designs for managed aquifer recharge using secondary treated wastewater.
abstract: As managed aquifer recharge (MAR) becomes increasingly considered for augmenting water-sensitive urban areas, fundamental knowledge of the achievable scale, longevity and maintenance requirements of different options will become paramount. This paper reports on a 39 month pilot scale MAR scheme that infiltrated secondary treated wastewater through unsaturated sand into a limestone and sand aquifer. Two types of infiltration gallery were constructed to compare their hydraulic performance, one using crushed, graded gravel, the other using an engineered leach drain system (Atlantis Leach System(®)). Both galleries received 25 kL of nutrient-rich, secondary treated wastewater per day. The Atlantis gallery successfully infiltrated 17 ML of treated wastewater over three years. The slotted distribution pipe in the gravel gallery became clogged with plant roots after operating for one year. The infiltration capacity of the gravel gallery could not be restored despite high pressure cleaning, thus it was replaced with an Atlantis system. Reduction in the infiltration capacity of the Atlantis system was only observed when inflow was increased by about 3 fold for two months. The performance of the Atlantis system suggests it is superior to the gravel gallery, requiring less maintenance within at least the time frame of this study. The results from a bromide tracer test revealed a minimum transport time of 3.7 days for the recharged water to reach the water table below 9 m of sand and limestone. This set a limit on the time available for attenuation by natural treatment within the unsaturated zone before it recharged groundwater.
authors: CSIRO Water for a Healthy Country Flagship, CSIRO Centre for Environment and Life Sciences, Private Bag No. 5, PO Wembley, Western Australia 6913, Australia. Elise.Bekele@csiro.au
authors: Elise
authors: E
authors: Bekele
authors: Simon
authors: S
authors: Toze
authors: Bradley
authors: B
authors: Patterson
authors: Wolfgang
authors: W
authors: Fegg
authors: Mark
authors: M
authors: Shackleton
authors: Simon
authors: S
authors: Higginson
mesh_terms: D001315:Australia; D003247:Conservation of Natural Resources / Q000379:methods*; D060587:Groundwater / Q000737:chemistry*; D062065:Wastewater / Q000737:chemistry*; D014872:Water Movements; D018508:Water Purification; D014881:Water Supply
chemical_list: D062065:Wastewater