ASTM E1527-05, the most recent guidance for conducting Phase 1 Environmental Site Assessments (ESAs), provides environmental consultants across the country a clear standard for performing environmental due diligence. Still, many clients look to environmental professionals who have an intimate working knowledge of a particular region, and with good reason.  Due to each particular area’s unique history and distinguishing environmental features, it is often crucial to have local assessors familiar with the area conduct the Phase 1 ESAs, as they often have a better understanding of particular regional issues.  Integrating thorough regional knowledge into the Phase 1 Environmental Site Assessment provides clients with a superior due diligence product.

The City and County of San Francisco is no exception, having a unique history in relation to other cities on the West Coast. 

San Francisco History

The City of San Francisco has a rich history.  Due to the gold rush in the mid-1850’s development in San Francisco occurred rapidly due to the booming population and the need for business and industry to meet the inhabitants’ needs.  Many factories and industrial operations sprouted up to meet the growing demand, including rail yards, fuel terminals, ship yards, and tanneries.  Many of these operations were primarily along the waterfront, especially in the areas South of Market, China Basin, and Bay View/Hunters Point.  After the devastation of the 1906 earthquake and fire, reconstruction occurred rapidly and much of the existing shoreline was reclaimed from the bay for real estate development through the use of undocumented fill, which included debris from the 1906 earthquake – more on this particular concern below.  The City of San Francisco continued to grow and be a center of commercial and industrial development.  Another area with a history important to environmental site assessments is the San Francisco Shipyard, which was originally constructed in the late 1800’s and was home to Union Iron Works.  The area was later acquired by the US Navy at the beginning of World War II and then became known as the Hunters Point Naval Shipyard, which has been shown to have documented cases of contamination that can impact redevelopment and real property transactions.  Understanding the industrial development of San Francisco, and the awareness of the undocumented fill material, is helpful when conducting Phase 1 Environmental Reports.

1906 Earthquake and Regional Impact Area

The Maher Ordinance Area is an area of San Francisco that was filled following the 1906 earthquake and requires an investigation of hazardous materials in soil if a building project will result in the disturbance of more than 50 cubic yards of soil.  The Maher Ordinance is now identified in San Francisco Public Health Code, Article 22A and is designed to identify hazardous materials in artificial fill materials prior to a proposed development to protect workers or the public.  The artificial fill material is a mixture of manmade debris, sand, clay, and bay muds and can contain contaminants that can be harmful to human health and/or the environment, including petroleum hydrocarbons and heavy metals. The required tests for the Maher Ordinance include inorganic VOCs, PCBs, pH, Cyanides, Methane, TPHs, and semi-volatile compounds.  Although the Maher Ordinance doesn’t directly impact existing improvements and the Phase 1 ESA scope of work from a regulatory standpoint, it is important to know if the subject property is situated within the Maher Ordinance Area and to request any information regarding previous development projects and any resulting site investigation activities that may have occurred and to identify the potential for undocumented fill material to be present at the subject property. 

Heating Oil Tanks in San Francisco

Although much more associated with east Coast development, heating oil was used extensively during early industrial development in the City of San Francisco.  Many of the commercial office buildings and hotels downtown, in addition to residences throughout San Francisco, were previously equipped with heating oil tanks.  Many of these are vaulted tanks either within an encased concrete vault or with earthen floors.  The majority of the heating oil tanks are out of use and/or have been removed; however, due to historical use, an Environmental Professional (EP) must be aware that the potential for heating oil USTs exists in San Francisco and it is important to carefully view basement and ground level areas and review records from both the San Francisco Fire Department as well as the Department of Public Health, both of which may maintain old heating oil tank records.  For more info on the hunt for USTs in San Francisco, check out my colleague Matt Pheanis’s blog.   

Urban Environment

San Francisco is a densely populated region that encompasses an approximate area of forty-nine square miles.  As in any urban environment, the regulatory database report researched as part of the ESA process will often have a large number of regulatory listings that will take careful consideration and will need to be addressed within the Phase 1 Environmental Report.  Because San Francisco is so densely populated, evaluation of the regulatory database report will require more effort than an Environmental Site Assessment conducted in a more suburban, rural, or more recently developed area.   However, an environmental consultant can quickly group many of the regulatory listings together based on nature of the listing and specific factors encountered in an urban environment, and, thereby creating a concise discussion and eliminating what might appear to be a number of concerns at first glance.  However, the EP must evaluate the regulatory listings keeping in mind potential issues associated with vapor encroachment and/or vapor intrusion.  

Vapor Intrusion in San Francisco

Vapor intrusion occurs when contaminated soils or groundwater release vapors into the air and potentially into a structure, posing a health concern.  Vapor intrusion has been talked about in the environmental due diligence industry for some time and ASTM first published a vapor intrusion standard in 2008, which was subsequently replaced by E2600-10 in 2010 that provides a standard for screening for vapor encroachment.  This standard can be incorporated into the Phase 1 ESA.  A vapor encroachment condition (VEC) as defined by ASTM is the presence or likely presence of chemicals of concern (COC) vapors in the subsurface of the target property caused by the release of vapors from impacted soil or groundwater either on or near the target property. 

As with any older urban environment with densely packed mixed land uses, there is potential for vapor intrusion concerns from various sources of contamination in San Francisco.  One major source of vapor intrusion concerns are neighborhood dry cleaning facilities.  What are perhaps even more concerning than existing facilities are older dry cleaning facilities.  The vapors from perchlorethylene (PCE), a common dry cleaning solvent, can migrate up through the ground surface through the cracks and fissures in the concrete foundation and represent an inhalation risk to humans.  The Environmental Protection Agency (EPA) formally concluded on February 10, 2012, that PCE should be classified as a likely human carcinogen. According to a study of groundwater contamination incidents from old dry cleaners conducted by the Santa Clara Valley Water District, the average plume length among national case profiles was reported to be 1,270 feet.  With multiple utility conduits in an urban environment, there is a potential for vapors to extend even further. 

San Francisco has many dry cleaning facilities throughout the city and can be densely packed in some areas.  The Presidio Trust, which provides water for residences of The Presidio in San Francisco, must monitor for PCE in the drinking water supply, which primarily comes from a local surface water source, Lobos Creek, due to the concentration of dry cleaners in the adjacent Richmond District.  In addition, old industrial sites and military sites in San Francisco can present vapor intrusion risks, as well as gasoline station sites and other petroleum hydrocarbon impacted properties. 


These are just some of the examples of how San Francisco’s unique history and development impact how environmental professionals in the Bay Area conduct environmental due diligence, and why it is so important to have local Phase 1 Environmental Professionals that are familiar with these local issues.