Environmental Overview: 39 th Avenue Greenway. What We ll Cover: Denver s Environmental Investigation Process Environmental Concerns Identified

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1 What We ll Cover: Denver s Environmental Investigation Process Environmental Concerns Identified Recognized Environmental Conditions VB/I-70 Superfund Site (OU-1, OU-2) Planned Investigations Next Steps Questions Environmental Overview: 39 th Avenue Greenway

2 Environmental Investigation Process Cast a wide net Identify what might potentially be of concern Review records and investigate Narrow based on findings Some potential concerns will go away Examples (business was properly managed, wastes were properly managed, business didn t use substances of concern, etc.) Further investigations where needed Plan and respond where concerns are substantiated Cast wide Cast wide net net Identify potential concerns Narrow investigation based on findings Identify potential concerns Further investigate Address substantiated concerns

3 Denver s Environmental Investigation and Cleanup Process Investigate all properties All City and County of Denver land transactions All major CCOD construction projects Investigation and cleanup steps Review available information and identify Recognized Environmental Conditions Phase I/Phase II environmental investigations (we are here) Identify clean-up needed Prepare cleanup plans Conduct cleanup Work with appropriate regulatory agencies throughout Inform public throughout

4 Recognized Environmental Conditions Vasquez Boulevard/I-70 Superfund Site Operable Units I, II, III Operable Unit I Residential Soils Operable Unit II Coliseum Property (location of former Omaha-Grant Smelter) Not part of 39 th Avenue Greenway Operable Unit III (location of former Argo Smelter) Not part of 39 th Ave. Greenway

5 VB/I-70 Operable Unit II Coliseum Property Arsenic and lead in soils and groundwater Investigations present Cleanup: Plan not yet selected Removal Action will be conducted for Globeville Landing Outfall U.S. EPA and CDPHE Oversight Under Administrative Order on Consent Construction under way for removal Next steps: Community Advisory Group process Work toward selecting final remedy Insert map of OU II

6 VB/I-70 Operable Unit I Only included residential properties (no industrial/commercial) Arsenic and lead in surface soils Investigations , cleanup All residential properties addressed 4700 sampled and cleaned where necessary Approximately 50 refused access Notices placed on deeds Annual notification to homeowner and occupant Insert map showing residential properties of OU 1

7 REC Reports Methodology Methodology Reviewed historical land uses in and around the project Reviewed physical setting to evaluate how contaminants might move Reviewed compliance history of facilities within and in proximity of the area Conducted field visits to evaluate concerns Montclair Study Area

8 Vazquez Boulevard/I-70 Superfund site Potential for metals in surface soils Areas of buried trash and debris Potential impacts to soil, groundwater Potential asbestos-contaminated soils Potential for landfill gases Historical railroad Potential heavy metals and/or polyaromatic hydrocarbons (PAHs) in surface soils Recognized Environmental Conditions 39 th Avenue Greenway

9 Numerous former auto repair facilities Former gas station Former transformer production potential for polychlorinated biphenyls (PCBs) Product manufacturing businesses potential for petroleum spills Former foundry potential for metals, PCBs and PAHs. Known perchloroethylene (PCE) plume present south of alignment (dry-cleaner) Recognized Environmental Conditions 39 th Avenue Greenway

10 Initial Subsurface Investigation Soil Borings Seven soil borings advanced to 20 feet below ground surface (bgs) Twelve soil borings advanced to 29 feet to 45.5 feet bgs Soil cores collected from each soil boring Inspected and logged Some fill and debris found at four locations Field screened for volatile organic compounds (VOCs) Odor and PID Some odors found at two locations

11 Initial Subsurface Investigation Soil sampling Composite soil sample composed of soil collected between 5 and 20 feet bgs Additional targeted discrete soil samples collected Shallow soil samples collected zero to 1.5 feet bgs from every third boring Soil samples analyzed for: VOCs Metals Polynuclear aromatic hydrocarbons (PAHs)

12 Initial Subsurface Investigation Constituents in soil PAHs (exceed residential screening levels) Arsenic (all less than VB/I70 70 ppm Std)

13 Current Status Conducting Phase I investigations at 29 properties Acquisitions (full or partial) Due to be complete Spring 2017 Potential for Phase II investigations if identify RECs of concern Potential additional soil sampling

14 Planned Next Steps Current Investigations Phase I Environmental Site Assessments (ESA) on property proposed for acquisition records review, site visit, historical photos, insurance records, property ownership, etc. Began November 2016 Future Investigations Phase II on properties where Phase I ESA identified recognized environmental conditions (RECs) Phase II ESAs begin Winter 2016 Field investigations, sampling Develop cleanup plans and monitoring strategies where needed Conduct cleanup where needed Cast wide net Identify potential concerns Narrow investigation based on findings Further investigate Address substantiated concerns

15 Questions? Questions? Contact: Celia VanDerLoop Dave Erickson