Lots of very interesting thoughts in the comments section. Many wondered why the water at El Polin Springs was not potable. While lots of answers were given, the principle reason is that the spring is not protected at the source from contamination by mammals, wild and domestic. The spring is fairly low flow, easily contaminated by coliform bacteria and therefore, not good to drink.

Great to see this project receiving some good press and congratulations to Allison for the interview.

–Doug Kern

…three makers of artificial turf deliberately failed to disclose that their products contain lead.

It turns out that lead is used to give the green color to artificial turf. According to the article:

lead,…,has been identified by state agencies as a chemical that can cause cancer, damage to male and female reproductive systems, and birth defects in developing fetuses.

The article does indicate that excessive lead was not found in all of the artificial turf samples from the three companies.

However, it was noted that:

Although artificial turf presents little or no danger when it is new, lead levels rise to potentially harmful levels as it gets older, said Deputy Atty. Gen. Dennis A. Ragen, the state’s lead attorney on the lawsuit.

The lead in artificial turf is a serious issue as the field ages and the dust from the material comes off on children’s hands, which they then put in their mouths. Lead contaminated dust could wash off the field and into the environment. Any installation of artificial turf at the Presidio should be carefully considered in the light of this information.

–Doug Kern

Guided Project Tours at El Polin Springs in the Presidio’s Tennessee Hollow Watershed 

• Saturday, September 6, 10:30 am–Noon
• Saturday, September 13, 10:30 am–Noon
• Meet at the picnic tables at El Polin Springs, off MacArthur Avenue, in the Presidio. RSVP/Directions (415) 561-5357.
• Sponsored by the Presidio Trust 

Restoration of the Tennessee Hollow watershed is now continuing at El Polin Springs, a place remarkable for nature and wildlife as well as for its extraordinary human history.

Beginning in September 2008, habitat restoration will begin to return ecological richness to the wetland area surrounding the springs. As a first phase, 60 eucalyptus, cypress, and pine trees will be removed from around El Polin Loop. Habitat will then be restored with plants and trees grown in the Presidio Nursery, including coast live oak and California buckeye, as well as wax myrtle, toyon, willows, and native grasses.

Later, a number of improvements will showcase the history of the area and welcome visitors. El Polin Loop will be transformed into a boardwalk and trail with a new picnic area, public restrooms, and benches. The stone channels and well will be restored, and interpretive gardens and other features will share the long history at the springs.

For complete project details, visit the Presidio Trust website on the Tennessee Hollow Project.

Artist’s conceptual rendering of boardwalk and restored habitat around El Polin Springs. Illustration by Art Zendarski.

She refers to this July 27 article by Harold Gilliam, the Chronicle’s environmental columnist for three decades, that gave her hope for a green vision of the Presidio, “a vision to stir our blood.” Reflecting on the Presidio of San Francisco, Mr. Gilliam asks,

So what happened to the original vision? And now that green is the color of the day, the year and hopefully the century, isn’t it high time we revive that vision?

–Doug Kern

The short term work to smooth the top of the slide area to prevent toppling failure will occur next Wednesday (May 21st). The work is anticipated to take one day. Equipment will mobilize to site on May 20th. The beach will be cleared and personnel stationed there during the smoothing work to advise beachgoers of the activity, and monitor for safety.

Comments welcomed.

– Doug Kern

During the course of bird surveying this Saturday in the Presidio I came upon a person with a leashed dog on the Batteries to Bluffs trail.  Being that this trail is one on which dog walking is not allowed, I approached the individual to inform him of this fact. Much to my surprise, I recognized the dogs handler as an off duty employee of the US Park Police, stationed at the Presidio.  I know this individual to be a very conscientious and dedicated employee and one who would never knowingly violate any of the Parks rules.  After a greeting and some discussion, I learned that this Presidio law enforcement officer was not aware that the Batteries to Bluffs trail is off limits to dogs.  

This indicates to me that the trailside signage is inadequate, as is GGNRA interagency communication. If the employees of the GGNRA and the other federal agencies working within the GGNRA are not aware of the laws pertaining to pets in the park, how in the world can we expect the general public to know and abide by the rules?

This is yet another indicator that the outreach, education and enforcement efforts regarding pets in the Park are too soft and, consequently, are not as effective as they need to be.

Your thoughts?

– Doug Kern

While we do understand and support the benefits of using synthetic turf, UWP remains concerned about water quality impacts from this surface downstream of proposed ballfield sites. We would like to see that potential impacts are studied prior to installation and that the synthetic turf presents no danger to downstream receptors.

I’d still like to know whether maintenance of the field will introduce problem chemicals to the environment and restored creeks below the site.  For example, what is applied to clean and disinfect the field?  Fabric softeners?

While potential water quality impacts remain a major concern, what about the human health impacts?  Check out the April 17, 2008 video below from ABC News looking at the potential health impacts from synthetic turf. I certainly support further investigation into synthetic turf prior to its use at the Presidio. 

– Doug Kern

– Doug Kern

– Doug Kern