File:TMDLbaselinesMS4.docx

This document contains information to assist MS4 permittees in determining an appropriate baseline year for all TMDLs approved prior to August 1, 2013. If a year is listed in the “Defined baseline year” column, the TMDL contains an explicitly defined baseline year that must be used. If not, a set of monitoring years, narrative on appropriate baseline year based on details of the model used to set allocations, or both is provided in the following columns. Use best professional judgement when determining a baseline year from a set of monitoring data. MPCA recommends selecting a midpoint or later.