City of Morro Bay and Cayucos Sanitary District OFFSHORE MONITORING AND REPORTING PROGRAM 2015 ANNUAL REPORT Pt. Piedras Sea Surface Temperature Blancas 21 October 2015 25°C 24 Estero Bay 23 22 21 Pt. Buchon 20 19 18 17 16 15 Pt. Arguello Marine Research Specialists 3140 Telegraph Rd., Suite A Ventura, California 93003 Report to the City of Morro Bay and Cayucos Sanitary District 955 Shasta Avenue Morro Bay, California 93442 (805) 772-6272 OFFSHORE MONITORING AND REPORTING PROGRAM 2015 ANNUAL REPORT Prepared by Douglas A. Coats Submitted by Marine Research Specialists 3140 Telegraph Rd., Suite A Ventura, California 93003 Telephone: (805) 644-1180 Telefax: (805) 289-3935 E-mail: [email protected] March 2016 TABLE OF CONTENTS Page LIST OF FIGURES ......................................................................................................................................... v LIST OF TABLES ......................................................................................................................................... vii LIST OF ACRONYMS .................................................................................................................................... ix EXECUTIVE SUMMARY .................................................................................................... ES-1 1.0 INTRODUCTION .............................................................................................................. 1-1 1.1 REPORT ORGANIZATION ............................................................................................ 1-1 2.0 TREATMENT PLANT PERFORMANCE ..................................................................... 2-1 2.1 WASTEWATER TREATMENT PLANT ........................................................................... 2-2 2.1.1 Operations ................................................................................................................ 2-3 2.1.2 Plant History ............................................................................................................ 2-7 2.1.3 Regulatory Setting ................................................................................................. 2-11 2.1.4 Description of the Treatment and Outfall System .............................................. 2-14 2.1.5 Pollution Prevention Program ............................................................................. 2-15 Industrial Waste Survey ..................................................................................... 2-15 Public Outreach .................................................................................................. 2-17 Source Identification .......................................................................................... 2-18 2.2 WASTEWATER CHARACTERIZATION ....................................................................... 2-19 2.2.1 Flow Rate ............................................................................................................... 2-19 2.2.2 Suspended Solids, Turbidity, and Settleable Solids ........................................... 2-22 2.2.3 Biochemical Oxygen Demand ............................................................................... 2-25 2.2.4 Oil and Grease ....................................................................................................... 2-26 2.2.5 pH ........................................................................................................................... 2-27 2.2.6 Temperature .......................................................................................................... 2-28 2.2.7 Ammonia ................................................................................................................ 2-29 2.2.8 Residual Chlorine .................................................................................................. 2-29 2.2.9 Coliform Bacteria .................................................................................................. 2-30 2.2.10 Toxicity ................................................................................................................... 2-32 2.2.11 Nutrients ................................................................................................................. 2-32 2.2.12 Chemical Compounds ........................................................................................... 2-34 Trace Metals ....................................................................................................... 2-35 Selenium ............................................................................................................. 2-35 Radionuclides ..................................................................................................... 2-36 Phenolic Compounds .......................................................................................... 2-36 2.3 BIOSOLIDS ................................................................................................................. 2-36 2.3.1 Solids Treatment Process ...................................................................................... 2-37 2.3.2 Chemical Compounds ........................................................................................... 2-38 i TABLE OF CONTENTS (Continued) Page 3.0 RECEIVING WATER QUALITY ................................................................................... 3-1 3.1 MONITORING PROGRAM ............................................................................................ 3-1 3.1.1 Objectives of Sampling ........................................................................................... 3-1 3.1.2 Scope of Monitoring ................................................................................................ 3-2 3.1.3 Sampling Station Design ......................................................................................... 3-5 3.1.4 Navigation ................................................................................................................ 3-7 3.1.5 Sampling Equipment and Methodology ................................................................ 3-8 Auxiliary Measurements ...................................................................................... 3-8 Instrumental Measurements .................................................................................. 3-8 3.2 PLUME DISPERSION .................................................................................................. 3-10 3.2.1 Zone of Initial Dilution.......................................................................................... 3-11 3.2.2 Critical Initial Dilution Ratio ............................................................................... 3-12 3.2.3 Regional Oceanographic Processes ...................................................................... 3-13 3.2.4 Ambient Seawater Properties ............................................................................... 3-16 3.3 COMPLIANCE EVALUATION ...................................................................................... 3-20 3.3.1 Screening for Applicability ................................................................................... 3-20 Measurement Location ....................................................................................... 3-20 Presence of Wastewater Constituents ................................................................. 3-21 Natural Variation ................................................................................................ 3-22 3.3.2 Numerical Limits ................................................................................................... 3-23 COP Objectives .................................................................................................. 3-23 Basin Plan Limits ............................................................................................... 3-25 3.3.3 Other Lines of Evidence ........................................................................................ 3-26 Mixing Performance ........................................................................................... 3-27 Limited Discharge Volume ................................................................................ 3-28 Effluent Quality .................................................................................................. 3-28 3.3.4 Visual Observations .............................................................................................. 3-30 3.4 BENEFICIAL USE ....................................................................................................... 3-30 4.0 MARINE SEDIMENTS AND BENTHIC BIOTA .......................................................... 4-1 4.1 MONITORING PROGRAM ............................................................................................ 4-1 4.1.1 Scope of Monitoring ................................................................................................ 4-1 4.1.2 Sampling Station Design ......................................................................................... 4-3 4.1.3 Benthic Sample Collection and Processing ........................................................... 44- Equipment ............................................................................................................ 4-4 Physicochemical Samples .................................................................................... 4-5 Infaunal Samples .................................................................................................