City of Morro Bay and Cayucos Sanitary District OFFSHORE MONITORING AND REPORTING PROGRAM 2010 ANNUAL REPORT Pt. Piedras Sea Surface Temperature Blancas 28 July 2010 21:59:55 PDT Estero Bay 18°C Pt. Buchon 17 16 15 Pt. Arguello 14 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 2010 ANNUAL REPORT Prepared by Bonnie Luke and Douglas A. Coats (Marine Research Specialists) and Bruce Keogh (Morro Bay/Cayucos Treatment Plant Manager) 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 2011 marine research specialists 3140 Telegraph Rd., Suite A • Ventura, CA 93003 • (805) 644-1180 Mr. Bruce Keogh 31 March 2011 Wastewater Division Manager City of Morro Bay 955 Shasta Avenue Morro Bay, CA 93442 Reference: 2010 Annual Monitoring Report Dear Mr. Keogh: Enclosed is the referenced report. It documents the continued effectiveness of the treatment process, the absence of marine impacts, and compliance with the discharge limitations and reporting requirements specified in the NPDES discharge permit. Please contact the undersigned if you have any questions regarding this report. Sincerely, Bonnie Luke Project Manager Enclosures (4 Reports) I certify under penalty of law that this document and all attachments were prepared under my direction or supervision in accordance with a system designed to assure that qualified personnel properly gather and evaluate the information submitted. Based on my inquiry of the person or persons who manage the system, or those persons directly responsible for gathering the information, the information submitted is to the best of my knowledge and belief, true, accurate and complete. I am aware that there are significant penalties for submitting false information, including the possibility of fine and imprisonment for knowing violations. Mr. Rob Livick Acting Director of Public Services City of Morro Bay Date 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 .............................................. 2-13 2.1.5 Pollution Prevention Program ............................................................................. 2-14 Industrial Waste Survey ..................................................................................... 2-14 Public Outreach .................................................................................................. 2-16 Source Identification .......................................................................................... 2-18 2.2 WASTEWATER CHARACTERIZATION ....................................................................... 2-19 2.2.1 Flow Rate ............................................................................................................... 2-21 2.2.2 Suspended Solids, Turbidity, and Settleable Solids ........................................... 2-21 2.2.3 Biochemical Oxygen Demand ............................................................................... 2-24 2.2.4 Oil and Grease ....................................................................................................... 2-25 2.2.5 pH ........................................................................................................................... 2-26 2.2.6 Temperature .......................................................................................................... 2-27 2.2.7 Ammonia ................................................................................................................ 2-27 2.2.8 Residual Chlorine .................................................................................................. 2-28 2.2.9 Coliform Bacteria .................................................................................................. 2-28 2.2.10 Toxicity ................................................................................................................... 2-29 2.2.11 Nutrients ................................................................................................................. 2-30 2.2.12 Chemical Compounds ........................................................................................... 2-32 Trace Metals ....................................................................................................... 2-34 Bis(2-ethylhexyl) phthalate (DEHP) .................................................................. 2-34 Radionuclides ..................................................................................................... 2-34 Dioxin ................................................................................................................. 2-35 2.3 BIOSOLIDS ................................................................................................................. 2-36 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 ......................................................................................... 3-4 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 ............................................................................... 3-17 3.3 COMPLIANCE EVALUATION ...................................................................................... 3-20 3.3.1 Lines of Evidence ................................................................................................... 3-20 Completion of Initial Dilution ............................................................................ 3-21 Presence of Wastewater Constituents ................................................................. 3-21 Detection Threshold ........................................................................................... 3-23 Natural Variability .............................................................................................. 3-24 Downstream Transport ....................................................................................... 3-24 Ongoing Initial Dilution ..................................................................................... 3-25 Seafloor Turbidity Layer .................................................................................... 3-25 Effluent Source ................................................................................................... 3-27 3.3.2 Numerical Limits ................................................................................................... 3-27 COP and Thermal Plan Allowances ..................................................................