Purolite A860 is a Macroporous Type I strong base anion exchange resin with an acrylic matrix. The acrylic matrix ensures excellent removal of organic matter from a water supply in conjunction with their reversible removal upon regeneration. This resin is regenerated very efficiently with lower levels of sodium hydroxide than those required for a polystyrene based type I resin, and yet it has a comparable ability to remove weaker acids including carbonic acid and silica. Its use in combination with a polystyrene based resin (for instance in a mixed bed positioned after the anion unit) can often result in the removal of a wider spectrum of organic compounds than either type of anion resin alone, and is particularly resistant to organic fouling, even where loadings are relatively high.