The City has intermittently discharged wastewater containing total recoverable aluminum at levels that would have exceeded the new 87 micrograms per liter ( ug/l ) monthly average limitation placed into effect on August 1, 2009. This Order requires the City to complete surface water sampling that will either confirm that the 87 ug/l limit is appropriate or will support site-specific criteria development and a NPDES Permit modification request to revise the limit. The Order also requires the City to determine what additional source controls and treatment measures will be investigated, and recommendations for short-term and long-term corrective measures including a schedule for implementation. The implementation schedule as amended by EPA will be incorporated into the Order by letter. The Order also includes interim limits for total recoverable aluminum.