Parameter Grouping Function
A function that groups parameters that represent the same pollutant, and selects the parameter that best represents the total pollutant load, to avoid double counting in the Loading Tool. Double counting can be contributed to NPDES permits that may require a facility to measure a pollutant in more than one way. For example, a facility may report both total lead and dissolved lead. The function will select the total lead if reported instead of dissolved lead, to calculate the lead load. The EZ Search automatically uses this function, but users can turn it off in the Advanced Search. Section 3.2.2 of the Technical Users Background Document for the DMR Pollutant Loading Tool describes how the Loading Tool uses the parameter grouping function.
Search Considerations: The Loading Tool uses parameter codes in ICIS-NPDES and PCS and a parameter selection hierarchy to group loadings for parameters that represent the same pollutant. The parameter grouping hierarchy is available in the Technical Users Background Document for the DMR Pollutant Loading Tool.