The Former Spellman Engineering (Spellman) Site (Site) operated between 1963 and 1969. Spellman performed parts cleaning using Tri-clene solvent, a powerful, all-purpose rust inhibitor removing grease, oils, grime, and dirt that contained trichloroethene (TCE) under a contract with the National Aeronautical and Space Administration (NASA). During operations, Spellman reportedly used Tri-clene on the southeastern portion of the property where an enclosed area that may have been used for a parts cleaning process was present. Accounts of spent solvents being discharged in this area were received during interviews during the assessment activities.
In 1992, groundwater underlying this area was determined to have been contaminated by TCE and was traced back to the Former Spellman Engineering Site. The City proactively sought opportunities to work with United States Environmental Protection Agency (EPA) and Florida Department of Environmental Protection (FDEP) to address the site. Due to community concerns over site stigma, the potential for property values to be impacted, and the uncertainty with the duration for the cleanup, the City of Orlando also requested that EPA not list the site on the National Priority List (NPL). The City and the local community indicated a strong preference for a third-party cleanup using a property divestiture, cleanup, and redevelopment approach. EPA supported this approach, while maintaining that the NPL listing process would move forward if project milestones were not attained.
Since there was no viable responsible party identified, the City conducted a series of voluntary investigations at the site from 1992 to 2004 that defined the extent of the TCE contamination plume, evaluated the potential risks associated with the contamination, and evaluated cleanup alternatives. Key findings included:
- No human exposure to contaminated ground water was occurring.
- The groundwater plume underlay approximately 40 acres.
- An estimated 580 gallons of TCE was present in the subsurface in 2004.
- Migration to the Floridan Aquifer potentially threatened nearby municipal supply wells.
- Contamination could be addressed through an engineered remedy.
- Impacts to the vadose (unsaturated) soils were limited in both magnitude and extend.
The investigations also determined that the area could be redeveloped during cleanup activities and could be cleaned up to meet EPA’s unrestricted use/unlimited exposure criteria.
EPA selected a remedy for the site’s contamination in its 2004 Record of Decision. According to the Record of Decision, the TCE plume originating from the Spellman Site would continue to contaminate the surficial aquifer and the Hawthorne Group intermediate aquifer until remediated, resulting in concentrations remaining the same or increasing.
In 2008, EPA and the City signed the first-ever Contiguous Property Owner agreement. In exchange for EPA resolution of potential liability concerns, the City agreed to implement the site’s estimated $12.9 million remedy. The agreement included a covenant not to sue, which eased liability concerns, and waived EPA oversight costs. Additionally, the EPA did not list the site on the NPL and agreed that as long as cleanup activities were progressing, the site would remain off of the NPL. Implementation of the site’s remedy began in 2011. As part of the remediation efforts associated with the Site, the following technologies were employed at the site between 2011 to 2013:
- Enhanced Reductive Dechlorination (ERD) injections using molasses,
- In‐Situ Chemical Oxidation (ISCO) injections using Sodium Persulfate,
- Bioaugmentation,
- Electrical Resistivity Heating, and
- Groundwater pump and treatment (P&T).
The 2015 groundwater sampling results indicated that the contaminants in the groundwater had been reduced by 90% in target wells, compared to concentrations at the beginning of Remedial Action.
In 2017, the city worked with the EPA to address concerns of the potential for vapor intrusion (VI) near several businesses overlapping the groundwater plume to occur. The assessment conducted by the EPA indicated there were no potential risks to workers in previously identified businesses.
Additional assessments completed between 2017 and 2021 determined that there were isolated areas of TCE present underneath the former Spellman building; however, the structures on the site limited the potential remedial alternatives that could be employed.
The groundwater pump and treat system has remained active and groundwater monitoring has been ongoing since the completion of the preliminary remediation efforts.