Overview of the issue
Many of the Sanctuary's beaches are regularly closed or posted by county health departments as showing elevated levels of contamination from coliform bacteria. This is termed a beach closure if the source is a recognizable sewage spill, and it is an advisory beach posting if the source of the contamination is unknown. Coliform contamination can serve as an indicator of human fecal matter that can contain an array of potential pathogens, although there are other potential sources of natural coliform contamination.

These beach closures or postings have obvious impacts on recreation, including surfing, diving and swimming, as well as impacts on tourism and aquaculture operations. Pathogens in human sewage may cause health impacts for those who come in contact with the contaminated water, including the spread of diseases such as ear infections, nausea, and rashes. There is also evidence of human gastrointestinal pathogens in the sea otter population that resides in nearshore Sanctuary waters, and concern that such contamination may be a factor in the decline of that population.

Sources of coliform contamination
Possible contributions from human sources include clogs, sewage overflows and spills, as well as improper designs, cracks, root invasions and leaching in aging storm drain and sanitary (sewage) system infrastructure. Other contributing factors include illicit connections between the two systems, septic system leaching, lack of runoff control in coastal developments, sewage dumpage from recreational vehicles or boats, and homeless encampments. Recognized clogs and spills can occur due to inappropriate contributions to the sanitary system, such as foam, diapers and grease.

Some contamination may also be due to wildlife such as marine mammals and birds, pet droppings, and small livestock facilities. A useful initial step in effectively addressing this issue is better identification and tracking of the sources to distinguish among wildlife, domestic animals and human contributors.

How is the Sanctuary involved?
The Sanctuary's involvement in this issue has included working with the cities on addressing urban runoff, including coliform contamination, and investigating and jointly pursuing potential funding opportunities for local communities to better identify sources of coliform contamination and improve infrastructure systems. The Sanctuary Citizen Watershed Monitoring Network is involved in monitoring coliform contamination in the watersheds and stormdrain systems at various times of year to help identify sources. We have also facilitated public access to beach closure information by including links to each county's beach closure notification process on our website. However, the Sanctuary does not yet have a comprehensive plan for addressing beach closure issues.