Sub-surface Urban Heat Island (SSUHI) - Sources and effects on drinking water

“Sub-surface Urban Heat Island. Is UHI only the tip of the iceberg? What about the sub-surface UHI?
In the Netherlands water is distributed without chlorine. 25°C is the maximum allowed temperature at the customer’s tap. In 2006 1% of random sampling > 25°C. With climate change more samples may exceed 25°C.”

(Citaat: Agudelo-Vera, C.M., Blokker, E.J.M. – Sub-surface Urban Heat Island (SSUHI) – Sources and effects on drinking water – Pan-European Symposium Water and Sanitation Safety Planning and Extreme Weather Events, Bilthoven, 7 april 2017)