Groundwater quality: measuring the invisible

Cape Town, South Africa, is highly reliant on groundwater for its rapidly growing population. But one of the main sources under the city, long in the spotlight for its dwindling water supplies, is at serious risk of being polluted.

Run-off from small-scale farms, landfills, cemeteries, factories and informal settlements risks leaching into the Cape Flats aquifer, which lies under much of Cape Town, found a recent study from the United Nations Environment Programme (UNEP).

Cape Town isn’t the only major city struggling with groundwater contamination. Urban centres from Pakistan to the United States have in recent years seen pollution creep into important aquifers, potentially threatening water supplies for millions of people.