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ORSANCO Proposes Revisions to Pollution Control Standards


On May 11, 2012, the Ohio River Valley Water Sanitation Compact (ORSANCO) released proposed revisions to its pollution control standards for public comment.  ORSANCO will accept public comment on the standards until July 20, 2012.  ORSANCO is revising its water quality standards to update information and incorporate new science.

One important change under consideration is the establishment of a temperature criterion for protection of human health from exposure to contact with water to prevent burns.  ORSANCO is proposing a maximum temperature of 110ºF that would apply inside and outside a mixing zone.  Thus, a maximum temperature of 110ºF would become an end-of-pipe standard.  ORSANCO is also proposing to revise the temperature criteria for aquatic life protection to update the seasonal in-stream temperature limits.  ORSANCO indicated that the proposed revisions are based upon more recent scientific data on temperature end points for aquatic life and more recent ambient temperature data for the Ohio River.

Finally, ORSANCO is considering eliminating the acute aquatic life criterion for selenium of 20 ug/l.  It would retain the chronic aquatic life criterion of 5 ug/l.  The basis of the proposed changes in the selenium standard is that EPA is close to issuing new criteria and current science does not support the stringency of the existing acute criterion.  Because selenium may be present in discharges associated with the mining and combustion of coal, revisions to the selenium criteria will likely be controversial.  ORSANCO expects to take final action on the proposed revisions in October 2012.

To view a complete PDF of the May/June 2012 issue of the Environmental Letter, click HERE.

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