The Netherlands, almost a fifth of which is covered by lakes, rivers and dikes, may be unable to use surface waters as a source for drinking water by 2050 due to the changing climate and contaminants.
The National Institute for Public Health and the Environment said worsening water quality and drought is affecting the country, whose total area is 41,500 square kilometers (16,000 square miles), slightly larger than the U.S. state of Maryland, 18.4 percent of which necessitate travel by boat.
The issue occurs “during dry years, when water quality standards are exceeded during periods that last from days to months,” the RIVM institute said on its website. Water quality deteriorates in periods of low river discharge as the effect of spills from sewage treatment plants is much larger due to less dilution, the government agency said.
About 40 percent of the Dutch population drink water produced from surface water. Ten water companies in the Netherlands, of which about a quarter is below sea level, make about 1.2 billion cubic meters of drinking water a year, three times that of 1952, according to their trade group, Vewin.
“Water quality standards are already exceeded during very dry years, which may increase in the future,” said the National Institute for Public Health. The extent of the increase will depend on the degree of climate change, RIVM said.
Low Water Discharge
Nearly half of the locations in the Netherlands where surface water is used for drinking water are in branches of canals and rivers with very low water discharge during dry periods, RIVM said. The water level in these sections is maintained artificially at a fixed level and a small variation in discharge may seriously affect the calculated concentrations of substances, the agency said.
“It is therefore recommended that each abstraction point is individually analyzed with all parties concerned,” RIVM said. The risks can then be weighed, it said. Possible remedies may include clamping down on what can be released into water, reducing spills, flushing stagnant zones, extending the drinking water treatment process and building a surplus during wet periods.
“The study is an underpinning of what we’re already doing,” said Marco Zoon, a spokesman for Rijswijk, Netherlands- based Vewin. We’re “constantly looking for new ways to purify water and have large buffers that are sometimes used without anyone noticing.”
RIVM analyzed calculations by Deltares, a Dutch research institute that focuses on delta, coastal and river basins.