Water of crystallization degree of hydration can be critical to the resulting chemical properties. For example, anhydrous RhCl is not soluble in water and is relatively useless in organometallic chemistry whereas RhCl•3HO is versatile. Similarly, hydrated AlCl is a poor Lewis acid and thus inactive as a catalyst for Friedel-Crafts reactions. Samples of AlCl must therefore be protected from atmospheric moisture to preclude the formation of hydrates. Crystals of hydrated copper(II) sulfate consist of [Cu(HO)] centers linked to SO ions. Copper is surrounded by six oxygen atoms, provided by two different sulfate groups and four molecules of water. A fifth water resides elsewhere
Water supply and sanitation in the Republic of Ireland 14 November 2002, authorities in Ireland were cited by the European Court of Justice over the microbiological contamination of hundreds of public and private water supplies. The EU's Drinking Water Directive requires an absence of E. coli in drinking water supplies to protect human health. The Environmental Protection Agency's 2011 report on drinking water stated that drinking water quality in public water supplies was continuing to improve. At that time, chemical standard compliance stood at 99.5%. 1.3% of supplies were found to have had E.coli, a reduction of 86% since 2005. 10.2% of private group supplies had E.coli, down from