Stormdrain outlet and ponded water underneath the Santa Monica Pier - the most likely source of the fecal bacteria to the Pier beach. Photo: Heal the Bay.

West end of ponded area beneath the Santa Monica Pier. Photo: Heal the Bay.

Aerial view of the Santa Monica Pier showing sampling locations used in the study. Image: Heal the Bay.

In Heal the Bay’s 2006 Annual Beach Report Card, the Santa Monica Pier had the fifth worst water quality in the state.  Since the storm drain underneath the Pier is diverted during the dry summer months, the source of the pollution was a mystery.

In order to determine the source(s) and possible remedies to this poor water quality at the pier, the City of Santa Monica partnered with Heal the Bay to conduct a bacterial source identification study this past summer.

The Study

The five-week study was designed to determine if fecal bacteria sources were offshore or onshore, were related to tidal cycle or current direction, and/or were localized near the stormdrain, leaky pipes, bird populations, or other sources.

Heal the Bay staff took ocean water samples from 10 locations at the Pier, three times a week for five weeks (from 7/10/06 through 8/10/06), and analyzed those samples for three types of indicator bacteria (the same way our Beach Report Card samples are analyzed). 

Bacteria levels at two different depths of water—ankle and waist depth—and at different distances from the Pier were analyzed. Also, additional information was recorded such as ocean water temerature, quantity of birds in the immediate area, and the presence of any water leaking from the Pier onto the beach (leaking pipes, etc).

Most telling, however, was a large pond of still water at the mouth of the storm drain under the Pier.  The level in this “pond” seemed to rise and fall, indicating a source of water.  When the water in this pond was analyzed, the bacteria levels were sky high. Also, samples taken from sites closest to this pond consistently had the highest levels of bacteria of all the samples analyzed. 

All signs pointed to residual storm water coming through the storm drain (despite the dry weather runoff diversion) that was pooling in front of the drain, creating a large source of fecal bacteria to the ocean.  This ponded, sheltered nuisance runoff could also lead to bacterial regrowth—meaning a source of bacteria could multiply in these conditions.

UCLA Tests the Sand

To better understand the impact that the ponded stormwater was having on beach bacteria densities, Professor Jenny Jay with UCLA, as a favor to Heal the Bay, collected sand samples and analyzed those samples for the same fecal bacteria. 

The sand closest to the pond area had the highest levels of fecal bacteria, while those samples further away displayed decreasing bacteria levels.  As the sampling sites got closer to the high tide line, the bacteria levels tapered off, and the sites north and south of the pond had no fecal bacteria at all.

Conclusions

The predominant source of fecal bacteria to the Santa Monica Pier beach is from onshore and most likely the pond in front of the pier stormdrain. Although pigeons, leaky pipes and homeless people are potential fecal bacteria sources, the evidence demonstrates that the pond is the most likely major source of fecal bacteria to the beach.  

Recommendations and Action

Heal the Bay provided extensive recommendations to the city of Santa Monica to clean up the Pier beach, the strongest of which is to repair the storm drain diversion and fill in the ponded area with sand, thus eliminating the bacteria laden pond.  We also recommend deterring pigeons from roosting under the Pier, and repairing all leaky pipes.

The city of Santa Monica has started implementing these recommendations.  For example, the polluted water has been pumped out of the pond and the area filled with clean sand. Also, a contractor will be hired to complete a thorough investigation of the stormdrain infrastructure, the runoff diversions and the Santa Monica Urban Runoff Reuse Facility to identify problems and solutions to the water quality problems.

We feel these measures will have a large impact on improving water quality at the Santa Monica Pier, and will help keep local beachgoers safe and healthy.