Groundwater Quality

Indian town of Mhaismal

Groundwater provides almost half of all drinking water worldwide but we still do not know sufficient about the state of groundwater resources globally and we do not manage aquifers well enough. Especially when it comes to groundwater quality. At the same time, human activities and climate variability are increasing the pressures on groundwater resources and serious pollution problems are reported for many parts of the world.

What is the status of groundwater quality globally and what are the trends? According to the recent World Bank report (2019) Quality Unknown: The Invisible Water Crisis is the impact of the worsening water quality much wider and uncertain than previously thought. Uncertainty is in particular over groundwater quality, due to insufficient information in many parts of the world.  

Laguna Verde, Bolivia, has high arsenic levels

There are very few global studies on groundwater quality so far and even fewer of those freely accessible through on-line information systems. A brief overview can be found in the book: Groundwater around the World. IGRAC  has produced a few overviews in the past, dedicated to arsenic and fluoride, saline and brackish groundwater and nitrate, EAWAG has developed a comprehensive global model of arsenic and BGS did an extensive study on emerging contaminants.  

The United Nation Agenda 2030 shows a strong dependence of Sustainable Development Goals (SDGs) on groundwater quality; this holds in particular for SDG6 (Water and Sanitation), but also for SDGs on food security, poverty eradication, sustainability of human settlement and even climate change. Yet, only a few parameters are being collected globally (per country) to provide a baseline for the SDG Target 6.3: Water quality and wastewater. It is far from certain whether the collected data will be sufficient to provide a correct indication of groundwater quality worldwide.

Open sewer, by: Red Hand Records

Hence, enough reasons for the World Bank to organise a session on Groundwater Pollution: Challenges and Opportunities for Action during the World Bank Water Week in Washington DC (in April 2019). Requested by the organisers, IGRAC participated and contributed to this session.  

Already in November 2018, the UN Environment organised a kick off meeting of the World Water Quality Assessment (WWQA), at the WMO headquarters in Geneva. During the meeting, groundwater specialists  “Friends of Groundwater”, identified the main challenges and are preferable actions related to global groundwater quality assessment.  The 2nd workshop of WWQA was held on 16-18 September 2019 at the EU Joint Research Centre in Ispra, Italy. Based on a presentation from the Friends of Groundwater and the outcomes of breakout group on groundwater, a draft work plan for groundwater quality was proposed.

On IGRAC initiative, Friends of Groundwater also organised a side event at the 10th International Groundwater Quality Conference (GQ2019) in Liège, Belgium, informing the conference participants on various global groundwater quality activities, providing a floor for discussion beyond cocoons and to encouraging collaboration across the scales and borders. This collaboration with the Friends of Groundwater has resulted in a dedicated groundwater quality website ( and perspective paper.

Saline/brackish groundwater

This year, EAWAG and IGRAC connected the on-line platforms Groundwater Assessment Platform (GAP) and Global Groundwater Information System (GGIS) by sharing some groundwater quality maps. 

Also in 2019, IGRAC started an overview of national groundwater quality monitoring programmes and this work will be continued in the new year. At the time of writing, IGRAC is participating in the first meeting of new IAH Commission on Groundwater Quality, taking place at UNESCO in Paris. The year 2019 was very promising one for global groundwater quality, hopefully this pace will continue, there is a lot to catch up.