2018 STATE OF HAWAII WATER QUALITY MONITORING AND ASSESSMENT REPORT: Integrated Report to the U.S. Environmental Protection Agency and the U.S. Congress Pursuant to §303(d) and §305(b), Clean Water Act (P.L. 97-117) The Hawaii State Department of Health Clean Water Branch Honolulu, Hawaii Final July 11, 2018 Table of Contents List of Figures and Tables.............................................................................................................. iv List of Acronyms ............................................................................................................................ v EXECUTIVE SUMMARY ............................................................................................................ 1 PART A. INTRODUCTION .......................................................................................................... 1 PART B. BACKGROUND ............................................................................................................ 2 B.1. Scope of Waters in the Integrated Report ............................................................................... 2 B.2. Surface Water Pollution Control Programs ............................................................................. 2 B.2.1. Point Source Pollution Control ............................................................................................ 2 B.2.2. Total Maximum Daily Load Process ................................................................................... 3 B.2.3. Non-Point Source Pollution Control .................................................................................... 3 B.2.4. Hawaii Water Quality Standards .......................................................................................... 4 B.3. Special State Concerns and Recommendations ...................................................................... 5 B.4. Future Monitoring Recommendations .................................................................................... 5 PART C. SURFACE WATER MONITORING AND ASSESSMENT OVERVIEW .................. 5 C.1 Surface Water Monitoring and Assessment ............................................................................. 5 C.2 Assessment Methodology ........................................................................................................ 6 C.3 Assessment Units ..................................................................................................................... 8 CHAPTER 1: MARINE WATERS .............................................................................................. 10 PART A. SCOPE OF WATERS .................................................................................................. 11 A.1. Assessment Units .................................................................................................................. 11 PART B. ASSESSMENT METHODOLOGY ............................................................................. 11 B.1. Recreational Health Assessment ........................................................................................... 11 B.2. Ecosystem Health Assessment .............................................................................................. 12 B.3. Water Body ID (formally Geocode ID) ................................................................................ 13 B.4. Data Sources .......................................................................................................................... 13 B.4.1. Quality Assurance/Quality Control .................................................................................... 13 B.4.2. Laboratory Analytical Support ........................................................................................... 14 B.4.3. Data Storage, Management, and Sharing ........................................................................... 14 PART C. RESULTS ..................................................................................................................... 14 C.1. Marine Water Body Assessment Results .............................................................................. 14 C.2. Watershed Assessment Results ............................................................................................. 15 C.3. Assessment Results Summary ............................................................................................... 16 CHAPTER 2: INLAND WATERS .............................................................................................. 23 PART A. SCOPE OF WATERS .................................................................................................. 24 PART B. MONITORING AND ASSESSMENT ......................................................................... 24 B.1. Basic Assessment Unit .......................................................................................................... 24 B.1.1. Tiered Approach ................................................................................................................. 25 B.1.2. Assessment Unit Rationale and Implementation ............................................................... 25 B.1.3. Application of Criteria to Attainment Decisions................................................................ 25 B.2. Quality Assurance/Quality Control ....................................................................................... 26 B.3. Assessment Methodology ..................................................................................................... 26 B.3.1. Water Body ID ................................................................................................................... 27 B.4. Inland Waters Assessment Results ........................................................................................ 27 B.5. Wetlands Program ................................................................................................................. 29 ii B.6. Public Health Issues .............................................................................................................. 29 CHAPTER 3: 2018 §303(d) and §305(b) WATER BODY ASSESSMENTS FOR HAWAII .... 31 REFERENCES ............................................................................................................................. 34 APPENDIX A: Data Sources...................................................................................................... A-1 APPENDIX B: §305(b) Assessment of State Waters ................................................................. B-1 APPENDIX C: §303(d) List of Impaired Waters ....................................................................... C-1 iii List of Figures and Tables Figure 1. Flow chart of the listing/delisting process for enterococci, TN, NO₃+NO₂, NH₄, TP, PO₄, turbidity, TSS and chlorophyll a. .............................................................................7 Table 1. Enterococci recreational WQS attainment/non-attainment based on frequency, GM and STV .................................................................................................................................12 Table 2. Applicable water body type and WQS for marine water bodies ....................................13 Table 3. Assessed Marine Water Bodies in the 2018 IR Cycle .....................................................15 Table 4. Assessed marine water body attainment (A) and non-attainment (N) of WQS summarized by island .....................................................................................................15 Table 5. Assessed watershed attainment (A) and non-attainment (N) of WQS summarized by island ..............................................................................................................................16 Table 6. Kauai Marine Category Changes .....................................................................................18 Table 7: Lanai Marine Category Changes .....................................................................................18 Table 8: Oahu Marine Category Changes ......................................................................................19 Table 9: Maui Marine Category Changes ......................................................................................20 Table 10: Hawaii Marine Category Changes .................................................................................21 Table 11. Applicable water quality criteria and decision unit boundaries for inland freshwater bodies .............................................................................................................................24 Table 12. Applicable water body type and WQS for inland water bodies ...................................26 Table 13. Assessed Inland Water Bodies in the 2018 IR Cycle ....................................................28 Table 14. Kauai Inland Category Changes ....................................................................................30 Table 15. Oahu Inland Category Changes .....................................................................................30 Table 16. Water body assessment categories ................................................................................32 iv List of Acronyms § Section AU Assessment Unit BEACH Beaches Environmental Assessment and Coastal Health CBD Center of Biological Diversity CCH City and County of Honolulu CCME Canadian Council of Ministers of the Environment CFU Colony Forming Units Ch. Chapter CWA Clean Water Act CWB Clean Water