EXECUTIVE SUMMARY

The 2016 Annual Ocean, Harbor and Bay Water Quality Report provides an updated analysis of bacteriological water quality data for Orange County’s recreational waters and includes data on sewage spills and related ocean, harbor and bay water closures. The annual report also describes year-to-year variability and trends representing the 17-year period (2000 – 2016) that Assembly Bill 411 (AB 411) Ocean Water-Contact Sports Standards for bacteriological water quality have been in place. In addition, the annual report incorporates historical sewage spill and associated ocean, harbor and bay water closure information during the most recent 30-year period from 1987 – 2016.

• The total number of sewage spills reported to the Ocean Water Protection Program in 2016 was 129, continuing a steady decline and down 68.3% from the peak record of 408 spills set in 2002.

• During 2016, the total number of sewage spills resulting in beach closures (9) remained 52.6% below the 30-year average of 19 beach closures per year.

• The total number of Beach Mile Days (BMD’s) due to sewage spill closures was 14.0 and is 33% below the 18-year average of 27.4 BMD’s from 1999 through 2016.

• Pipeline blockages continue to be responsible for the majority of sewage spills resulting in beach closures. Since 1999, blockages have resulted in 61.5% of all closures and over half of these blockages (56.2%) were caused by infiltration of roots or deposition of grease.

• Total Beach Mile Days posted due to bacteriological water quality standards violations during the AB 411 period (April 1 to October 31) were 29.1 which is 92% below the record high of 366 recorded in 2002. The continuing trend of record lows over the last 4 years is likely due to drought and less runoff impacting the beach.

• The new South County Unified Regional Monitoring Plan completed its second AB 411 monitoring season (April 1 to October 31). This new regional monitoring plan was implemented at south county beaches in April 2015 and requires “point zero” monitoring at locations where urban runoff physically enters the ocean. Second year monitoring results during the AB 411 period showed 15 out of the 28 point zero stations were in 100% compliance with state ocean water health standards. See Appendix 6 for additional information about point zero monitoring results.

• During the summer of 2016, HCA/Environmental Health continued collaborating with Stanford University and Heal the Bay on a Predictive Modeling pilot study. One of the three chosen pilot locations in Southern California was at San Juan Creek in Doheny State Beach. The pilot used a computer model to determine if water quality at selected beach locations would exceed state health standards on any given day to determine if the beach should be posted. A continuation of the pilot study is planned for the 2017 AB 411 period.

• Thirteen (13) Rain Advisories were posted during 2016 for a total of 51 days and represents a 25% increase over the previous 3-year ’s drought-impacted average of 38 days. The current number is still 18% below the (pre drought) average of 62 days and may continue to contribute to better water quality due to less urban runoff flowing to the ocean.