East Fork Little Miami River Basin Total Maximum Daily Load Development
Total Page:16
File Type:pdf, Size:1020Kb
Loading Analysis Plan and Supporting Data Acquisition Needed for the East Fork Little Miami River Basin Total Maximum Daily Load Development Ohio EPA Technical Report AMS/2012-EFLMR-3 Division of Surface Water Assessment and Modeling Section November 2020 TMDL DEVELOPMENT | AMS/2012-EFLMR-3 Draft Loading Analysis Plan – East Fork Little Miami River Basin November 2020 Table of Contents Aquatic Life Use .......................................................................................................................................................................................................... 3 Evaluation of Biocriteria ................................................................................................................................................................................... 3 Proposed Actions ...............................................................................................................................................................................................11 Enrichment - Nutrients .................................................................................................................................................................................13 Linking impairment to TMDL pollutants ...........................................................................................................................................13 Modeling methods .......................................................................................................................................................................................14 Proposed Targets to Address Aquatic Life Use Impairment ...............................................................................................................20 Enrichment - Nutrients .................................................................................................................................................................................20 Recreation Use ..........................................................................................................................................................................................................20 Evaluation of Criteria .......................................................................................................................................................................................21 Proposed Actions ...............................................................................................................................................................................................21 Atrazine .............................................................................................................................................................................................................22 Algae (nutrients) ............................................................................................................................................................................................22 Linking impairment to TMDL pollutants ...........................................................................................................................................22 Modeling methods .......................................................................................................................................................................................27 Proposed Targets to Address Public Drinking Water Use Impairment ..........................................................................................27 Atrazine .............................................................................................................................................................................................................27 Algae (nutrients) ............................................................................................................................................................................................28 Nonpoint Source efforts ..................................................................................................................................................................................29 Wastewater treatment plant upgrades ....................................................................................................................................................30 Special Considerations for the New Vision .......................................................................................................................................................31 Nutrient TMDLs Based on Multiple Uses of Impairment .....................................................................................................................31 Stakeholder Involvement ................................................................................................................................................................................32 Water Quality Source Trading ......................................................................................................................................................................32 References ..................................................................................................................................................................................................................33 Appendix A .................................................................................................................................................................................................................35 2 AMS/2012-EFLMR-3 Draft Loading Analysis Plan – East Fork Little Miami River Basin November 2020 Introduction This document provides an overview of the information considered in proposing the strategy to address water quality impairments in the East Fork Little Miami River (East Fork LMR) watershed. These recommendations are based on data collected as part of a biological and water quality study in 2012. A description of the project area, sites, data types, methods and results can be found in the Biological and Water Quality Study of the East Fork Little Miami River and Select Tributaries, 2012 (Ohio EPA, 2014a) technical report document at (epa.ohio.gov/Portals/35/documents/East_Fork_LMR_TSD_2014.pdf). In December 2013, U.S. EPA announced a new “Vision” for the Clean Water Act (CWA) Section 303(d) program to provide an updated framework for implementing responsibilities under the impaired waters program (for additional information see: epa.gov/tmdl/new-vision-implementing-cwa-section-303d-impaired-waters- program-responsibilities). U.S. EPA recognized that “… there is not a one-size-fits-all approach to restoring and protecting water resources.” Under the new Vision, states will be able to develop tailored strategies to implement the 303(d) program in the context of their water quality goals. Ohio EPA has picked the East Fork LMR watershed as a pilot project for implementing the new Vision approach. This is due to the watershed’s unique circumstances of aquatic life and public water supply uses. These conditions provide the opportunity to integrate these uses into an alternative Total Maximum Daily Load (TMDL) framework that offers improved remediation and protection outcomes to existing methods. This alternative approach also provides direct engagement with the priorities of the well-established East Fork Watershed Cooperative (EFWCoop) stakeholder group; see: epa.gov/water- research/east-fork-watershed-research-and-cooperative. Research efforts undertaken by EFWCoop, led by U.S. EPA’s Office of Research and Development (ORD), have been extensive in the East Fork LMR watershed. Ohio EPA intends to tap into many of these research projects as noted throughout this plan. Much of ORD’s focus of this research has been to understand the feasibility and mechanics of water quality source trading in the watershed. Ohio EPA is focusing on developing a TMDL report that will incorporate/facilitate water quality trading as much as possible within the Agency’s legal authority. This focus on stakeholder engagement and attention to adaptive management alternatives is another aspect of the East Fork LMR TMDL report being a new Vision project. Sites in the East Fork LMR watershed were assessed for aquatic life use, recreation use, and public water supply use. The attainment of aquatic life and recreation use is based on specific restoration targets. Public water supply use attainment is based on atrazine and algal toxin thresholds. This document examines those targets and thresholds and lays out proposals for addressing each impairment. Where appropriate, methods are outlined to develop TMDLs for specific pollutants. Aquatic Life Use Evaluation of Biocriteria Attainment of Ohio EPA’s biocriteria are based on fish and macroinvertebrate scores, as measured by the Index of Biotic Integrity (IBI), Modified Index of well-being (MIwb) and Invertebrate Community Index (ICI). Further explanations of Ohio EPA’s biocriteria can be found in Ohio Administrative Code (OAC) Chapter 3745-1-07 and additionally at epa.ohio.gov/dsw/bioassess/BioCriteriaProtAqLife. Goals for those indices in the East Fork LMR watershed are shown in Table 1. The attainment status for each site is shown in Figure 1 and the scores for impaired sites are shown in Table 2. Note that Table 2 includes impairments that are outlined in the East Fork LMR biological and water quality report (Ohio EPA, 2014a) based on assessment site and overall watershed assessment