Talk:San Pedro Creek

Tribune article

Providing a citation of sourcing for my recent edits, is this Pacifica Tribune article:

"Tracking the source of San Pedro Creek's pollution Pacifica Tribune Staff 12/24/2007 01:33:07 PM PST

Pacifica residents as well as surfers and swimmers at Pacifica State Beach have long known about the pollution that washes out of San Pedro Creek. The creek is known to be polluted with fecal bacteria, which has contributed to advisory warnings at Pacifica State Beach. People and their pets have become ill after contact with water potentially contaminated with fecal bacteria.

San Pedro Creek is the only steelhead trout habitat within 30 miles of San Francisco and supports fish more than two feet in length. The creek also serves recreational functions, especially for swimmers, surfers, and small children playing at the creek's mouth at Pacifica State Beach.

Considering the importance of the creek and its value for Pacifica residents, there have been a number of studies to analyze the creek's water quality over the last 10 years. In 1998, the Environmental Protection Agency (EPA) began exploratory testing of the creek's water. At the same time, two Pacifica residents working with the San Francisco Waste Water Plant conducted their own independent study of the creek's water. The EPA and the Pacifica residents' data showed that the creek's bacterial levels were higher than the permissible for recreational purposes for most of the sampling period.

In 1999, a group of concerned Pacifica residents formed the San Pedro Creek Watershed Coalition, a nonprofit 501(c) 3 organization dedicated to protecting, enhancing and maintaining the health of San Pedro Creek and its watershed through monitoring, restoration, adaptive management, and education.

Since 1999, the Coalition, with the assistance of members of the community, has conducted several studies to identify pollution levels in the creek. In 2000, the Coalition supported a comprehensive San Francisco State University Masters study that examined the in-stream physical, chemical and biological characteristics of the creek. Results from this study showed that fecal bacteria levels in the North Fork and Main Stem of San Pedro Creek far exceeded the acceptable levels for recreation as established by the State of California and the EPA.

Efforts to further understand and address water quality concerns continued in 2006 when Coalition members, in collaboration with the San Mateo County Public Health Laboratory (SMCPHL), the Institute of Environmental Health (IEH) in Seattle, Washington, Environmental Microbiology Laboratory (EM Labs) of San Bruno, and the UCSF Biomolecular Resource Center (BRC), conducted a DNA "fingerprinting" (Microbial Source Tracking (MST)) study of the fecal bacteria to estimate the contribution percentage of human and animal sources of bacteria to the overall bacterial load of the creek. Funding for this study was provided through an agreement with the CA State Water Resources Control Board (Proposition 13).

The group established specific sampling sites along the Creek so that each sampling location would accurately pinpoint tributaries and drainage ditches that contribute to the bacteria load of the Creek. Water samples were generally collected every Monday and Tuesday mornings during two sampling windows: in the wet season of 2006 (January, February and March) and in the dry season of 2006 (July and August). On each date, seven sites were sampled starting at the South Fork in San Pedro Valley County Park and finalizing at the Creek outlet (mouth) at Pacifica State Beach. Water samples were cultured at the SMCPHL and EM Labs.

The study also required the Coalition to collect fecal samples from humans, horses, dogs, cats, deer, raccoons, sea gulls and any other animals living in and around the Creek to act as source samples for bacterial source identification. Each fecal sample was cultured under conditions to selectively promote Escherichia coli (E. coli) growth. The UCSF (BRC) and EM Labs then provided E. coli isolates from these fecal samples to IEH, in order that local libraries were comparable for both laboratories.

Study Results

The highest E. coli counts noted in this and earlier studies arise at downstream sites during the highest runoff events in the wet season. Results from the MST study showed that during the wet season, results appear dominated by avian sources, but significant numbers of canine, human, horse, subwild (mostly raccoon), and wildlife (mostly deer) sources were also seen as well.

In the dry season, there remained high percentage counts of avian sources, but raccoons and dogs become more apparent in the data. Since in the dry season the highest E. coli counts are seen at the Arts Center and North Fork sites, the relatively high match rates for humans, dogs and raccoons at these sites suggest that these inputs become relatively more significant at these sites during the low flow periods of late summer.

When comparing rainfall with bacteria sources, rainfall shown to be a significant influence on producing high E. coli counts at downstream sites.

Horse matches appear to be associated with the highest runoff events at most of the sites. Canines and felines also appear to be somewhat associated with high runoff events, yet avian and deer (wildlife) are if anything associated with lower runoff events, probably reflecting their consistent and ubiquitous presence in the data.

There are some general conclusions derived from these data. While avian inputs are most dominant, significant levels of input from horses, humans and dogs point to the need for management changes. Horse E. coli inputs are much more abundant during the wet season, suggesting the need to address horse fecal runoff from stables and trails. Canine inputs are assumed to be from dogs, and are more prominent as a percentage during the dry season. Human inputs are no doubt from leaking sewer lines, and these greatly increase downstream. Even the North Fork has relatively low total counts, so the place to focus future efforts is in downstream neighborhoods where laterals are old and poorly constructed.

The Coalition efforts to protect the Creek and to seek solutions to the pollution problems will not stop because the study is complete. Currently, the Coalition is working with the city, county and state agencies to correct infrastructure deficiencies that cause bacterial contamination such as, leaking sewer mains and laterals, cross-storm/sewer connections, and domestic animal waste storage and disposal.

The Coalition is also working with the public on measures they can take to reduce pollution in the creek and at Pacifica State Beach. The Coalition has organized public meetings, tours and workshops and has created several resources, including its website and a guide for distribution to creekside residents entitled "Pacifica Creek Care, How to live in Pacifica's Watersheds," to help the public to understand the physical and biological processes that exist in our local creek and watershed. These resources also include recommendations on proper disposal of dog, cat, and horse waste, and vehicle care, home care and construction best management practices to protect the creek s water quality.

Many people are not aware that storm drains discharge directly into the creek so most everything that goes into our gutters goes into our creek (and eventually into the ocean) without treatment of any kind. Bacteria, motor oil, antifreeze, discarded paints and pesticides, weed killers and fertilizers wash into the creek with runoff from rainfall. "We can all be part of the solution to reduce impacts to San Pedro Creek," said Christine Chan, Coalition Watershed project coordinator. "There are simple things that we can do, like picking up after our dogs that would significantly reduce pollution and improve the health of the creek. Although we have completed our MST study, we plan to continue to work with the city, county and state agencies as well as Pacifica residents to mitigate and solve the pollution problems affecting San Pedro Creek. The protection of the creek, its water quality and habitat should continue to be a priority for local governments and all Pacifica residents."

For those interested in learning more about the study, the full report will be posted on the Coalition s website at www.pedrocreek.org. The website also provides tips on how you can help to protect San Pedro Creek. "[1] SaltyBoatr (talk) 22:07, 27 December 2007 (UTC)