Environmental Concerns at "1 Sierra" in Moss Beach

MidPen Housing is in the process of purchasing the 11-acre undeveloped property on the border of Moss Beach and Montara, across Highway 1 from Point Montara Lighthouse. The property has been used as open space parkland by the community for several decades, and is home to numerous species of animals and trees, and possibly two federally protected endangered species. The site is large enough to support nesting, feeding, and breeding habitats for these species, and may be its own self-sustaining ecosystem for many of the species present. The military history of the site also indicates the possibility of toxic contamination, which must be investigated and remediated prior to any development.

Photo courtesy of San Mateo GIS services

Endangered Species

There are reports of at least two endangered species on the property: The California Red Legged Frog (Rana draytonii), and the San Francisco Garter Snake (Thamnophis sirtalis tetrataenia). Both species are very rare and are on the verge of extinction. California red-legged frogs are the largest native frogs in the Western United States. Despite their robust size, the frogs have disappeared from over 70% of their former range1 and are deemed to be endangered by the Fish and Wildlife Service (www.fws.gov).

Other Species

Red foxes (Vulpes vulpes, right), have been seen on the property numerous times by local residents and have been photographed hunting, as shown here. There are many other species seen regularly on the property. For example, hawks (right) are often seen in the trees, looking for prey, such as rodents and snakes. There are other raptor species on the property, including barn owls (Tyto alba).

Other species residing or hunting in the open space include mountain lions, deer, coyotes, as well as various rodents, insects, and plants.  Due to the size of the area and the variety of species present (including several top-level predators), the area is believed to be its own self-contained ecosystem. Development of the area will displace a great many species that contribute to the beauty and environmental health of the coastside.

Trees of Special Significance

There are at least 20 “significant Trees” on the property, which are “…necessary for the health and welfare of the citizens of this city in order to preserve the scenic beauty; maintain property values; prevent erosion of topsoil; protect against flood hazards and the risk of landslides; counteract the pollutants in the air; maintain the climatic balance and decrease wind velocities; and relieve the public costs of installing and maintaining storm water drainage systems.”3 Significant trees are also large enough to provide nesting habitats for raptors, vultures, and other large birds.

The San Francisco Garter Snake has a very small habitat, confined to the Peninsula between San Francisco and San Jose. Deemed “one of the “most beautiful snakes in Northern California” by the Environmental Protection Agency (www.epa.gov), the snake has been protected by the federal government since 19672.  The snakes have a beautiful blue/green stripe which complements the deep red and black coloring typical for this snake family. The snake also has the same blue/green color on its underside.

1 Sierra Street was once a top-secret naval training facility during World War II. It has since been an open space public park.

Environmental Hazards

The 1 Sierra property was home to a Navy anti-aircraft training facility during WWII. Buildings constructed during this era typically utilized both asbestos and lead materials, which have since been deemed hazardous for human health. Additionally, dumping, burying, and burning of fuels, solvents, and other wastes was standard Department of Defense procedure in this era. It is possible that contaminants such as asbestos, lead, arsenic, mercury, dioxin, and PCBs are still present on the site. Any activities that disrupt the soils on the site (excavation, clearing and grubbing, grading, etc.) are likely to create exposure pathways to residual contaminants. Such activities may also release potential toxins into the air and cause run-off of potential toxins into the adjacent Montara Creek and subsequently into the federally-protected Fitzgerald Marine Reserve.

Health effects of lead exposure include developmental disabilities, causing the CDC to conclude that “No safe blood level in children has been identified.”4 Asbestos is known to cause lung cancer and mesothelioma.5 Adverse health effects of arsenic, mercury, dioxins and PCBs are also well documented.6


An informed environmental assessment must include the above assumptions and any others indicated via a thorough review of specific military records and any other records relevant to the environmental history of the site. Any suggested remedial action should be approved and monitored by the relevant responsible environmental agency to assure that environmental and human health is protected.