How does DEQ calculate reasonable maximum exposure point concentrations?
DEQ uses EPA’s most current version of ProUCL to calculate reasonable maximum exposure point concentrations (RMEPCs). Please note that ProUCL provides the means for calculating RMEPCs for data sets that include non-detects. When ProUCL calculates a RMEPC, it will recommend that an upper confidence limit (UCL) of 95% or greater is the best fit for the data presented (e.g. 97.5% or 99% UCL). DEQ typically requires that the UCL recommended by ProUCL which best fits the data presented be used as the RMEPC. Please note that depending on a specific data set, it may not be appropriate to perform a UCL calculation. This is particularly true for very small data sets or for data sets with less than 5 detections. DEQ will evaluate the ProUCL output including any warnings or recommendations to these must be submitted for review. If you have any questions please contact the project officer for the facility.
