Quantifying aquifer water balance and salinity dynamics to minimise environmental impacts of a land-based effluent treatment system in China

This paper presents a groundwater modelling framework to assess the hydraulic loading and salinity impacts on the underlying groundwater system of a large-scale land-based effluent treatment system for treating urban sewage of Yanggao County in the north of Shanxi Province, China. This land-based treatment system is called "Filtration and Irrigated cropping for Land Treatment and Effluent Reuse" abbreviated as FILTER. The FILTER operations include intensive irrigation of crops with urban effluent, filtration through the soil matrix, and pumping and reuse of improved quality drainage water. Three sizes of FILTER were simulated using groundwater modelling techniques to (i) upscale the operations and benefits of an experimental FILTER site to a larger FILTER system to handle the larger volume of effluent and to (ii) assess the potential effects on the regional groundwater. The boundary flux analysis carried out to quantify the net impact of FILTER on the surrounding areas indicated that a well-designed and managed vertical drainage system can be used in a catchment-scale FILTER system for productive and environmentally friendly management of domestic wastewater in peri-urban areas. Results of this innovative and cost-effective technology from the field trials in Australia and China are promising for wider applications. Copyright © 2009 John Wiley & Sons, Ltd.