PARENT SESSION
TP7 - Water Quality Criteria
Chair: Canton, Steve¹, ¹ Chadwick Ecological Consultants, Littleton, CO
2:10 PM to 5:30 PM - Tuesday, 19 November 2002
Room Ballroom A

(462) Review and Correction of the US EPA Water Quality Criteria for Aluminum.

Latimer, Henry^*,1, Canton, Steven¹, ¹ Chadwick Ecological Consultants, Littleton, CO, USA

ABSTRACT- A review of the 1988 US Environmental Protection Agency (US EPA) Water Quality Criteria (WQC) for Aluminum revealed one error in the acute toxicity database and a chronic value based solely upon two studies of questionable applicability. An error was made in transcribing the acute value for the flatworm, Dugesia, from the original data memorandum presenting the data to the US EPA to the acute toxicity database in the WQC database. The acute value for this genus was listed as >23,000 g/L in the WQC document, however the correct value is actually >16,600 g/L. Correction of this error resulted in Dugesia becoming one of the four most sensitive genera in the acute database. Following this correction, the acute criterion increased from 750 to 825 g/L. The current chronic value of 87 g/L is based upon two unpublished studies using Salvelinus fontinalis and Morone Saxatilis. Neither of these studies were determined to be suitable for inclusion in either derivation of the acute-to-chronic ratio or inclusion in the chronic toxicity database. The 87 g/L value is based upon no effect levels determined for both species. Current methodology dictates that the chronic value for a species is calculated as the geometric mean of the no effect and lowest effect concentrations. Calculation of a chronic value for these species using this methodology results in a chronic value of 122 to 123 g/L for both species. This review indicates that in addition to the changes noted above, preliminary updates of the toxicity databases demonstrate that sufficient new data exists to justify an update of the current WQC.

Key words: Aluminum, Toxicity, Water Quality Criteria, Correction