Daily Archives: December 20, 2014

Volcanic Eruptions “Force” Changes in Climate

“Mount Gamalama in North Maluku province of Indonesia erupted at 13:41 UTC on Thursday, December 18, 2014, sending ash and rocks 2 km into the sky and¬†forcing the authorities to close an airport and issue warnings to planes. Nine people were injured while running to escape the eruption.¬†One person is still unaccounted for, authorities said.” article here

Review of USEPA Secondary Drinking Water Standards

Dietrich AM, Burlingame GA. Critical Review and Rethinking of USEPA Secondary Standards for Maintaining Organoleptic Quality of Drinking Water. Environ Sci Technol. 2014 Dec 17.

Consumers assess their tap water primarily by its taste, odor and appearance. Starting in 1979, USEPA promulgated Secondary Maximum Contaminant Levels (SMCLs) as guidance for contaminants with organoleptic effects and also to maintain consumers’ confidence in tap water. This review assesses the basis for the 15 SMCLs (aluminum, chloride, color, copper, corrosivity, fluoride, foaming agents, iron, manganese, odor, pH, silver, sulfate, total dissolved solids, zinc) and summarizes advances in scientific knowledge since their promulgation. SMCLs for aluminum, color, pH, silver, sulfate, total dissolved solids, and zinc are appropriate at current values and remain consistent with sensory science literature. Recent advances in sensory and health sciences indicate that SMCLs for chloride, copper, fluoride, iron, and manganese are too high to minimize organoleptic effects. The SMCLs for corrosivity and foaming agents may be outdated. The SMCL for odor requires rethinking as the test does not correlate with consumer complaints. Since current stresses on source and treated waters include chemical spills, algal blooms, and increased salinization, organoleptic episodes that negatively impact consumer confidence and perception of tap water still occur and may increase. Thus, adherence to SMCLs can help maintain production of palatable water along with consumers’ confidence in their water providers.

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