The quality and safety of our water supply is also closely monitored with weekly checks to maintain safe drinking water standards. (tflats.com)
It was considered a model of successful recycling of coal combustion waste until tests of nearby groundwater wells discovered arsenic and lead levels exceeding drinking water standards, according to city water tests. (scientificamerican.com)
Some hypothetical vertical farms have even been designed to recycle processed sewage (pdf), turning waste into water that meets drinking water standards. (discovermagazine.com)