Responding to evidence that arsenic poisoning is becoming a serious global problem, Koch Membrane Systems Inc., of Wilmington, Mass., is offering its Fluid Systems products to successfully reduce arsenic in drinking water. The World Health Organization, the European Union and the USEPA have proposed more stringent drinking water safety standards. A natural part of the Earth’s crust, arsenic enters groundwater in trace amounts by percolating through certain rock types, particularly sandstones.