On July 1, 2020, the 2018 IGP Amendments will go into effect. So, what is new in the 2018 Amendments and how do they build on the 2015 requirements? The 2018 Amendments apply to the following areas: sufficiently sensitive analytical methods, total maximum daily loads (TMDLs), alternative compliance options, and change to the SMARTS database to accommodate the Amendments (see SWRCB answers frequently asked questions about the amendments). The California State Water Resources Control Board (SWRCB) Industrial General Permit 2014-0057-DWQ (IGP) requires that each industrial facility conduct a pollutant assessment to determine which pollutants were present at the facility. The facility pollutant monitoring requirements are based on this assessment and depending on the pollutant an instantaneous exceedance, numeric effluent limit (NEL), or an annual average, benchmark limit, are applicable. The sufficiently sensitive methods change requires that labs use approved methods that can detect concentrations of analytes to accurate levels in order to demonstrate permit compliance. Most labs have provided their certification information in regard to EPA standards and this can be found on their websites. If you want to be certain, you can request that your labs confirm that they are compliant with ELAP and are using EPA-approved test methods. TMDLs are only applicable to specific areas and only to pollutants that were identified in your pollutant assessment. Let’s break down how to determine whether TMDLs are applicable to your facility: As discussed in a previous blog that you can review for more details, the TMDLs are developed based on individual watersheds to achieve a target water quality in that receiving water. The TMDLs only apply to your facility if you are in a watershed that has a TMDL established. How do you know if your facility is in a TMDL watershed? The waterboard has provided an Industrial Stormwater General Permit Map Tool which allows a user to input her facility to determine if the facility is in a TMDL watershed. The SWRCB has provided a handy flow chart for determining TMDL applicability and we’ll walk through a couple of examples here.