The Other Side Village (TOSV) Environmental Information
Background
Salt Lake City owns a 70-acre parcel located at 1850 W Indiana Avenue. This parcel is a historical municipal landfill that accepted waste from 1923 to 1962. In the late 1970s, the landfill was bisected by the construction of I-215, creating a West Pile and an East Pile. Since the development of I-215, Salt Lake City has used portions of the East Pile and surrounding land for processing green waste; however, municipal dumping stopped in the 1960s.
The Other Side Academy (TOSA) has obtained approval to develop The Other Side Village (TOSV) pilot project within an 8-acre area in southeastern corner of the site, which is the area least impacted by past landfill activities. To accommodate the development, the City Council approved a rezone of the development site on October 18, 2022. On May 10, 2023, the Planning Commission approved TOSA’s Planned Development. For more background on the City’s Zoning and Planning processes and approvals, visit the Salt Lake City Council’s page and Planning’s virtual open house page.
The pilot project will provide housing and supportive services for those experiencing homelessness and struggling with substance abuse, mental illness and/or physical disability. This innovative project is a step toward creating more affordable housing choices and options for residents to thrive.
To ensure the area is safe for residents, the City entered the site into the Utah Department of Environmental Quality’s (DEQ) Voluntary Cleanup Program (VCP). Under the VCP, the City worked with regulators and TOSA to investigate the pilot area and develop a remediation plan to make the area safe for residential use. The remedial action plan was accepted on August 15, 2023 and construction began in October 2023. See below for more information.
TOSA anticipates the residential units will be ready to be occupied in winter 2024. The City will only allow residents to occupy the site after verification that the improvements to date meet the requirements of the remedial action plan.
Summary of Environmental Conditions
Several environmental investigations have been conducted at this parcel since the 1990s, but these investigations were focused primarily on the areas used as a landfill and not the pilot project area. Since the TOSV project started being considered in 2021, additional investigations have been conducted in the pilot area. This section summarizes the results of the pilot project area investigations since 2021.
Characterization of the site has included the collection of soil samples, groundwater samples, and soil gas samples for analyses of all potential environmental impacts associated with former landfills. Characterization and sample analyses have been conducted in coordination with the DEQ to ensure all potential impacted media, contaminants, and exposure pathways are identified and evaluated. After analyzing samples for an extensive list of potential contaminants, the following impacts were identified:
- Fill material was found to be impacted by one polycyclic aromatic hydrocarbon (benzo(a)pyrene) and two metals (arsenic and cadmium). Samples of native materials beneath the fill have reported impacts from arsenic; however, benzo(a)pyrene and cadmium have not been reported.
- Groundwater was found to be impacted by 1,4-dioxane (a volatile organic compound), PFAS compounds (known as an emerging contaminant), and two metals (arsenic and hexavalent chromium).
- Soil gas samples reported elevated concentrations of chloroform.
All compounds reported are chemicals that are commonly identified at residential, commercial, and industrial sites in developed cities.
Source: Site Characterization Report Redwood Road Dump Pilot Phase Project, Terracon, January 18, 2023
Remediation Plan and Notices
A remediation plan was developed to address the environmental concerns in the pilot area. This plan was approved and accepted by VCP regulators on August 15, 2023. The approval process included a 30-day public comment period from June 23, 2023 – July 23, 2023.
Remediation strategies and exposure pathways were carefully addressed to make development of this community safe for anyone living, working, or visiting the site. The primary remediation strategies are:
- Excavate impacted soils and dispose offsite at a permitted facility
- Install vapor intrusion mitigation systems under buildings to prevent soil gas infiltration
- Implement institutional controls and engineering controls to manage any impacts remaining on site post-remediation, such as fencing, signage, routine groundwater monitoring, and inspections to ensure integrity of remedial actions
Visit the DEQ Public Notice Webpage to access the full plan (project documents are under Redwood Road Dump, VCP Site C121 in 2023).
With an approved RAP (Remedial Action Plan), TOSA was able to proceed with site remediation and development after receiving the appropriate permits and agreements from the City. Construction began in October 2023.
Construction and Site Development
- Construction and remediation began in October 2023, after receiving the appropriate permits and agreements from the City and the DEQ. By the end of October, initial removal of contaminated soil completed.
- In winter 2023, elevated levels of groundwater at the site caused significant delays to construction. TOSA received Treated Groundwater Discharge Permits from the DEQ and Salt Lake City Public Utilities in March 2024. Dewatering began in March and was completed June 2024. No additional dewatering is anticipated.
- In August 2024, the last area with contaminated soil was remediated. A vapor mitigation system was installed beneath the Neighborhood Pavilion (laundry room and community space) and this building will be completed in November 2024. The vapor mitigation system was inspected and certified to meet required design standards.
- Foundations for the modular homes have been installed and these homes are anticipated to be installed October through December 2024. These are elevated structures that do not require vapor mitigation systems.
- TOSA is seeking City approval to allow occupancy at the modular homes and Neighborhood Pavilion. Prior to receiving approval, TOSA must submit to the City and DEQ verification that the improvements to date meet the requirements of the remedial action plan. This is currently in progress.
Overview of Timeline and Next Steps
An overview of the environmental milestones and next steps for the TOSV project is provided below. This timeline is for informational purposes only and is subject to change.
Activities to Date:
- March 2023 – Additional sampling to define extent of soil contamination completed, Site Characterization Report finalized.
- April/May 2023 – Proposed Remedial Action Plan submitted to the DEQ for approval.
- June 2023 – Remedial Action Plan published for public comment.
- August 15, 2023 – Remedial Action Plan (RAP) is accepted by the DEQ.
- October 2023 – Construction and remediation began after receiving the appropriate permits and agreements from the City and the DEQ.
- August 2024 – Last of the contaminated soil was removed. Building installation and excavation for foundations of some residences begins. Begin installation of vapor mitigation systems installed as required by the RAP.
Next Steps:
- Fall/Winter 2024 – TOSA will submit documentation verifying that improvements have been made as required by the RAP. The City will issue Certificate of Occupancy for the housing units completed to date.
- Winter/Spring 2024 – Construction of additional housing units and services facilities will continue with vapor mitigation systems installed as required by the RAP. Completion of other remediation components will continue (such as installation of groundwater monitoring wells, fencing, and signs).
- Spring 2024 – A Remediation Completion Report and Site Management Plan will be prepared and submitted to DEQ for approval. The Site Management Plan will describe the routine monitoring and inspections that will be conducted to verify the effectiveness of the remedy, as well as any reporting requirements and other site management activities.
Resources
Project files related to the VCP efforts can be found on the DEQ’s website: http://eqedocs.deq.utah.gov/
If you have any questions on the environmental work at this site, contact Catherine Wyffels in Sustainability (Catherine.wyffels@slc.gov)