13 C14-2025-0090 - West Martin Luther King Jr Blvd and Nueces Street; District 9 - Neighborhood Postponement Request — original pdf

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13 C14-2025-0090 - West Martin Luther King Jr Blvd and Nueces Street; District 91 of 613 C14-2025-0090 - West Martin Luther King Jr Blvd and Nueces Street; District 92 of 613 C14-2025-0090 - West Martin Luther King Jr Blvd and Nueces Street; District 93 of 6January 16, 2026 To Whom it May Concern Sent by email only to: Megan Meisenbach at Subject: Environmental Evaluation of Former Jack Brown Cleaners Site 615 W. Martin Luther King, Jr. Blvd.; Austin, Texas Dear Ms. Meisenbach: As you requested, this letter report summarizes the results of my evaluation of environmental conditions and potential human health effects due to releases of dry cleaning chemicals from the former Jack Brown Cleaners (JBC) property (Site) located at 615 W. Martin Luther King, Jr. Blvd in Austin, Texas. I summarize background information regarding the Site history, presence of dry cleaning chemical contamination in soil and groundwater at the Site and at nearby properties, regulatory status with the Texas Commission on Environmental Quality (TCEQ), and environmental risks if the Site is redeveloped for commercial or residential use. Summary and Conclusions From my review of the JBC Site VCP documents, I draw the following conclusions: ▪ The Site soil and groundwater are contaminated with high concentrations of the dry cleaning chemical Tetrachloroethylene (PCE) and its degradation by-product chemicals, including Trichloroethylene (TCE) and Vinyl Chloride (VC). The chemicals are present at levels exceeding indoor air human health limits for vapor migration into current and future buildings. Further, PCE in groundwater has exceeded TCEQ limits for outdoor air exposures. It is notable that the U.S. Environmental Protection Agency is sufficiently concerned about PCE’s toxicity (and that of TCE and VC) that the agency is phasing out nearly all uses of this chemical. ▪ It is my opinion that the Texas Commission on Environmental Quality (TCEQ) inappropriately approved JBC’s request to cease Site cleanup and monitoring. The Voluntary Cleanup Program (VCP) Certificate of Completion granted to JBC means that they and future property owners have no further obligations to cleanup and protect on-site residents, visitors, and workers from cancer risks despite the potential that indoor and outdoor air quality could exceed human health safe limits. ▪ Regardless of TCEQ’s previous actions, future development plans for the JBC property should address these potential human health risks that likely will remain for decades unless the Site is properly remediated or building measures incorporated to prevent migration of toxic chemical gases into the buildings. In addition, the property owner should prevent outdoor air exposures, especially to workers who could contact contaminated soil and groundwater and breathe toxic vapors. Operational and Environmental History of the Site Dry cleaning operations under various business names are reported to have begun in 1950 and continued for an unknown period but at least until 2003 when JBC enrolled the Site into the VCP. The dry-cleaning facilities used chemical solvents, including the known human carcinogen Tetrachloroethylene (PCE, perc). PCE can 13 C14-2025-0090 - West Martin Luther King Jr Blvd and Nueces Street; District 94 of 6 Environmental Evaluation of Former Jack Brown Cleaners Site January 16, 2026 Page 2 degrade and be transformed by bacteria into degradation by-products such as Trichloroethylene (TCE) and Vinyl Chloride (VC), which likewise are known to cause cancer from exposure to very low environmental concentrations in water, air, and skin contact. PCE and associated chemicals were discovered at the Site in 2003 during an environmental assessment conducted by a possible purchaser of the property. JBC subsequently performed additional soil and groundwater investigations to define the horizontal extent of soil and groundwater contamination on their own property and on neighboring properties to the east and south. They claimed that chemical releases to the subsurface originated from chemical storage tanks in the Site basement. Their studies showed that soil and groundwater concentrations on-site exceeded TCEQ limits even under the relaxed standards for groundwater that was deemed to not be a potential source of drinking water (known as a Class 3 groundwater). TCEQ did not require JBC to evaluate the potential that contaminant vapors could migrate from soil and underlying groundwater into indoor air within buildings present then or in the future. I believe this omission was an inappropriate oversight by TCEQ and that building indoor air vapor migration risks should have been assessed due to the highly toxic nature of PCE, TCE, and VC for human inhalation and because of the high concentrations in soil and groundwater. JBC’s own vapor monitoring data from vent points in the basement showed very high vapor concentrations of over 900 parts per million. Further, groundwater lab data provide strong evidence that PCE is present in groundwater, not only dissolved in the water but also as a separate- phase PCE liquid. Consequently, it is my opinion that PCE will continue to dissolve into groundwater and volatilize (i.e., evaporate) vapors into subsurface air space for decades into the future. PCE, TCE, and VC groundwater concentrations at the Site have exceeded U.S. Environmental Protection Agency (EPA) Resident Vapor Intrusion Screening Levels (VISLs). TCE in groundwater also exceeded TCEQ limits for outdoor air exposure. JBC removed the basement concrete floor and excavated contaminated soil and weathered limestone bedrock underneath, which they hauled off-site for disposal. Because contamination remained in the soil and bedrock following excavation, JBC installed a perforated pipe vapor venting system to remove contaminant vapors. A new basement concrete floor was installed over the vapor collection system. They also collected and analyzed groundwater samples periodically from monitoring wells installed on-site and off-site. The groundwater lab data showed little reduction in concentrations over time, although transformation to degradation by-products is evident, including VC which is even more toxic than PCE. TCEQ Site Status JBC enrolled the Site into TCEQ’s Voluntary Cleanup Program (VCP) as Site No. 1658. The VCP affords successor property owners with legal protections against TCEQ enforcement provided the Site is remediated or controlled to the TCEQ’s satisfaction under relevant agency rules and guidance. In 2020, JBC reevaluated the groundwater classification from Class 3 to “non-groundwater bearing unit”, which had the effect of allowing JBC to terminate all ongoing cleanup activities. As a result, JBC received a VCP Certificate of Completion (COC) from TCEQ indicating that no further action was required at the Site. 13 C14-2025-0090 - West Martin Luther King Jr Blvd and Nueces Street; District 95 of 6 Environmental Evaluation of Former Jack Brown Cleaners Site January 16, 2026 Page 3 I believe TCEQ should not have issued the Certificate without addressing the vapor indoor migration risk or the risk of outdoor air exposure, as described above. Potential Effects on the Site if Redeveloped If a property owner develops the Site for occupancy by residences or commercial buildings, it is my opinion that physical barriers and/or an air venting system beneath the foundation may be necessary to prevent toxic vapor migration into buildings and other enclosed breathing spaces. Additionally, it is my opinion that TCEQ should have required JBC to apply land use controls to the property deed and a site management plan to prevent contamination exposure to on-site workers via contact with vapors in work spaces and contact with groundwater, such as in subsurface excavations (note that groundwater is very shallow at less than 2 feet deep at times). As indicated above, there may be an ongoing potential risk to human health at the Site from inhalation of TCE vapors in outdoor air, a risk that, in my opinion, has not been adequately addressed by JBC and TCEQ. Brad Snow, P.E., P.G. Qualifications and Experience My professional background consists of 43 years of environmental experience focused on investigation, human health and ecological risk assessment, and cleanup of industrial and commercial properties contaminated with a wide variety of chemicals throughout the U.S. and internationally. I am a licensed Professional Engineer and Professional Geologist in multiple states, including Texas. I earned B.S. and M.S. degrees in Geological Engineering from the Missouri University of Science & Technology. _________________________________________________________________________________________ If you have any questions about this letter, please do not hesitate to contact me at 512.705.0010 or brad@snowenv.com. Thank you. Sincerely, Snow Environmental Solutions, LLC Brad L. Snow, P.E., P.G. Senior Consultant and President (Signed 1/16/2026) 13 C14-2025-0090 - West Martin Luther King Jr Blvd and Nueces Street; District 96 of 6