Water Disposal / Groundwater Recharge
The use of the surface water body, whether it is for industry, recreation, spawning habitat, etc., will influence the quality and quantity of treated wastewater that can be introduced without deleterious effects.
Alternatively, water can be discharged into aquifers. Groundwater recharge is increasing in popularity as groundwater resources deplete and as saltwater intrusion becomes a greater threat to coastal communities. Although the soil is known to act as a filter for a variety of contaminants, groundwater recharge should not be viewed as a treatment method. Once an aquifer is contaminated, it is next to impossible to reclaim it.
It is necessary to ensure that the assimilation capacity of the receiving water body is not exceeded, i.e. that the receivingbody can accept the quantity of nutrients without being overloaded Parameters such as turbidity, temperature, suspended solids, BOD, nitrogen and phosphorus (among others) should be carefully controlled and monitored before releasing any water into a natural body. Local authorities should be consulted to determine the discharge limits for the relevant parameters as they can widely vary (see also policies and legal framework). For especially sensitive areas, a post-treatment technology (e.g., chlorination, see also post treatment methods) may be required to meet microbiological limits.
The quality of water extracted from a recharged aquifer is a function of the quality of the wastewater introduced, the method of recharge, the characteristics of the aquifer, the residence time, the amount of blending with other waters and the history of the system. Careful analysis of these factors should precede any recharge project. See also surface groundwater recharge and subsurface groundwater recharge to read more on typical methods how to recharge groundwater.
The adequacy of discharge into a water body or aquifer will entirely depend on the local environmental conditions and legal regulations. Generally, discharge to a water body is only appropriate when there is a safe distance between the discharge point and the next closest point of use (see also policies and legal framework, water pollution and pathogens and contaminants). Similarly, groundwater recharge is most appropriate for areas that are at risk of saltwater intrusion or aquifers that have a long retention time. Depending on the volume, the point of discharge and/or the quality of the water, a permit may be required.
Generally, cations (Mg2+, K+, NH4+) and organic matter will be retained within a solid matrix, while other contaminants (such as nitrates) will remain in the water. There are numerous models for the remediation potential of contaminants and microorganisms, but predicting downstream or extracted water quality for a large suite of parameters is rarely feasible. Therefore, potable and non-potable water sources should be clearly identified, the most important parameters modelled and a risk assessment completed.
Operation & Maintenance
Regular monitoring and sampling is important to ensure compliance with regulations and to ensure public health requirements (see also policies and legal framework,water pollution and pathogens and contaminants). Depending on the recharge method, some mechanical maintenance may be required.
ARGOSS (Editor) (2001): Guidelines for Assessing the Risk to Groundwater from On-Site Sanitation. Keyworth: British Geological Survey. URL [Accessed: 30.09.2013]. PDF
SEILER, K.P.; GAT, J.R. (2007): Groundwater Recharge from Run-off, Infiltration and Percolation. Dodrecht: Springer.
WHO (Editor) (2006): Guidelines for the safe use of wastewater excreta and greywater. Volume III. Wastewater and Excreta Use in Aquaculture. Geneva: World Health Organisation. URL [Accessed: 26.02.2010]. PDF
TILLEY, E.; ULRICH, L.; LUETHI, C.; REYMOND, P.; SCHERTENLEIB, R.; ZURBRUEGG, C. (2014): Compendium of Sanitation Systems and Technologies (Arabic). 2nd Revised Edition. Duebendorf, Switzerland: Swiss Federal Institute of Aquatic Science and Technology (Eawag). PDF
This is the Arabic version of the Compendium of Sanitation Systems and Technologies. The Compendium gives a systematic overview on different sanitation systems and technologies and describes a wide range of available low-cost sanitation technologies.
BRISSAUD, F. (1999): Groundwater recharge with recycled municipal wastewater: Criteria for health related guidelines. France: Hydrosciences, MSE, Univ. Montpellier II, 34095 Montpellier Cedex 05. PDF
This article aims to highlight some principles related to aquifer recharge with recycled water, and to propose a simple approach to health related guidelines that take into account existing water regulations and guidelines.
FAO; GEF; IAH; IHP; World Bank (2012): Management of aquifer recharge and discharge processes and aquifer storage equilibrium. Food and Agriculture Organization (FAO). URL [Accessed: 08.04.2013]. PDF
This paper draws attention to case studies from a range of hydro-geological, climatic and societal settings where innovative management has been successful in reversing groundwater storage declines (or increases). Informing and engaging stakeholders in governance has resulted in more resilient outcomes that take better account of local needs. Importantly, in many settings local action by motivated communities has run ahead of state and national policies and been highly effective in managing groundwater storage, increasing farm incomes and protecting the environment.
IWMI (Editor) (2002): Innovations in Groundwater Recharge. Water Policy Briefing. IWMI-TATA Water Policy Program. Vallabh Vidyanagar: International Water Management Institute. URL [Accessed: 15.04.2011]. PDF
This brochure gives an overview on different low-cost aquifer recharge solutions based on the results from a 10-year pilot project in Uttar Pradesh. It indicates a practical and low-cost way to conserve and rejuvenate falling groundwater reserves.
MEKDASCHI STUDER, R.; LINIGER, H. (2013): Water Harvesting. Guidelines to Good Practice. Bern/Amsterdam/Wageningen/Rome: Centre for Development and Environment (CDE), Rainwater Harvesting Implementation Network (RAIN), MetaMeta, The International Fund for Agricultural Development (IFAD). URL [Accessed: 01.10.2013]. PDF
Water harvesting has been practiced successfully for millennia in parts of the world – and some recent interventions have also had significant local impact. Yet water harvesting’s potential remains largely unknown, unacknowledged and unappreciated. These guidelines cover a wide span of technologies from large-scale floodwater spreading to practices that collect and store water from household compounds.
This is a chapter on a rainwater-harvesting manual from the Public Health Engineering Department in India. It gives an extensive overview on different groundwater recharge technologies and approaches.
ASANO, T. ; COTRUVO, J. (Editor) (2004): Groundwater recharge with recycled municipal wastewater: health and regulatory considerations. Davis: Department of Civil and Environmental Engineering, University of California. URL [Accessed: 15.04.2011]. PDF
This case study on groundwater recharge with recycled wastewater focuses on quantifying possible health implications.
http://www.unep.or.jp/ [Accessed: 15.04.2011]
This website provides the online-version of the Sourcebook of Alternative Technologies for Freshwater Augmentation of the United Nations Environmental Programme (UNEP).