The Mid-Sunset Neighborhood Association, created to serve and support our community, is concerned about the recently discovered chemical contamination on the site where the Tenderloin Neighborhood Development Corporation (TNDC) proposes to build a seven-story affordable housing project. To keep our neighbors informed about this issue, what follows is some background on the situation, how it may impact us, and why it's critical that the community stay engaged.
2550 Irving Street, the address of the proposed TNDC project, is currently the location of the Police Credit Union. Historically, it has also been the site of a gas/service station, a dry cleaner, and more recently, a mortuary.
Across the street at 2511 Irving Street there was a second dry cleaner business that dates from the 1940s until it finally closed in 2015. The Police Credit Union also owns the parking lot that abuts this building.
In 2019 the Police Credit Union initiated a series of environmental investigations at 2550 as well as across the street in the parking lot next to the former Albrite Cleaners building. According to the California Department of Toxic Substances Control (DTSC), the investigation "found elevated levels of PCE in the soil, the groundwater, and
PCE, 'Perc', or Tetrachloroethylene is a common chemical (historically used extensively in the dry cleaning business), and a known carcinogen. Multiple environmental studies have linked PCE to various cancers (kidney, bladder, liver e.g.). PCE has also been shown to be harmful to women and their fetuses during pregnancy. For this reason PCE is heavily regulated and is being phased out of the dry cleaning business (California has banned the use of Perc dry cleaning machines after January 1, 2023).
As a volatile organic chemical, PCE easily vaporizes. If spilled, the PCE liquid can seep below ground and then get trapped in the soil as a vapor. "Soil vapor" moves radially (in every direction) from its source. Normally that's no more than 100 feet. But it can then become mixed with groundwater and as this contamination moves with the groundwater it forms a "plume" in the soil between the water table and the surface. At that point PCE gas can enter commercial buildings and homes via cracks—even too small to see—or through other openings in the foundations. The soil vapors are actually pulled up by the lower pressures found inside. This is called vapor intrusion. (see Figure 1)
AllWest Environmental, the consultant hired by the Police Credit Union to conduct the tests, found concerning levels of PCE in the soil vapor on both sides of Irving Street. Their initial report stated that PCE concentrations in the soil vapor "exceeded the commercial/industrial San Francisco Bay Regional Water Quality Control Board (SFRWQCB) PCE environmental screening level (ESL) for vapor intrusion of 67 μg/m3." 
The levels of PCE were high enough to prompt further investigation and also trigger new testing in front of six houses on 26th and 27th Avenues. These off-site residential soil gas samples were gathered in March 2021, analyzed in April and are now being reviewed by the Department of Toxic Substances Control (DTSC). Eventually this analysis and a full report will be published and made available to the public, most likely in June. We will put a link to this report on our website when it is available.
The findings will help determine if the PCE concentration is increasing, static or decreasing. We also hope to find out how rapidly the plume is moving and how it is spreading through our neighborhood.
Our neighbors who live next to the Police Credit Union are rightly concerned about potential vapor intrusion within their homes, not just in front of them. To support these concerns, we petitioned the Police Credit Union to take responsibility for testing vapor intrusion inside the garages of these six houses that are being monitored outside under the sidewalk. To date, the Police Credit Union has declined to do this.
The need for neighborhood involvement
The Mid-Sunset Neighborhood Association is monitoring this environmental impact story to make sure we are part of the conversation around how this is ultimately resolved. We need full community involvement to ensure that both the Police Credit Union and the developer (TNDC) are not putting their own short term goals above the health of our community.
While we support and are heartened that this investigation is being overseen by the Department of Toxic Substances Control (DTSC), we also recognize that the investigation is covered by a "voluntary agreement" between DTSC and the Police Credit Union and the developer (TNDC). TNDC is also covered by a CLRRA immunity agreement that encourages the developer to make the site safe by offering them immunity during this process. But it is important to remember that "safe" may not always mean the same to the developer as it does to us who live in the Sunset.
Because of the nature of these two agreements, it is critical for the neighborhood to make sure our representatives (from Supervisor Mar to our state representatives) are aware of this investigation, that they know clearly what our concerns are, and are willing to make sure we are protected no matter what happens to the site. How much site remediation (clean-up) is necessary is not always a simple scientific question. Political influence and pressure are a necessary component to the decision of how much of the area will need to be cleaned up and the manner in which it is done. We are not only concerned for our current neighbors but for the project's construction workers, as well as for any future residents living on the site. We welcome Supervisor Mar to come to a Mid-Sunset Neighborhood Association board meeting to discuss these issues and how best to resolve them.
As new information about this environmental investigation comes out, we will update this website. So check back here periodically.
In the meantime, if you are interested in reading the specific reports referenced above, you can find them here:
 - Department of Toxic Substances Envirostor site for 2550 Irving St. "Affordable Housing" investigation
 - AllWest Environmental: "Soil Vapor Investigation Report" November 17, 2020