cornerstone enVIronmental Mot-:5 - 4 Wu! 4 ma ?burr?3p;- - .1.st away-w 1. cm) 100 Run Road, Suite 101. Middletown. NY. 10941 845.595.0200 - 845.692.5894 August 30, 2017 Mayor Richard Thomas City of Mount Vernon City Hall 1 Roosevelt Square Mount Vernon, NY 10550 Re: Memorial Field Material Characterization City of Mount Vernon DEC Case No. R3-20160119-6 Dear Mayor Thomas: On behalf of City of Mount Vernon, Cornerstone Environmental Group, LLC (Cornerstone) is pleased to provide the New York State Department of Environmental Conservation (NYSDEC) with this report on the results of the test pit investigation and characterization of the stockpile located on the east side of Memorial Field at the intersection of Garden Avenue and East Sanford Boulevard, in Mount Vernon, New York. A Site Location Map is included as Figure 1. The test pit investigation was performed in accordance with the Memorial Field Material Characterization Plan (Cornerstone, June 2016), the Characterization Plan Conditional Approval (NYSDEC, July 13, 2017), and emails from David Pollock, PE, of NYSDEC between July 13 and July 20, 2017. Background The stockpile on the east side of Memorial Field is the result of the placement of soil and other materials following the cessation of use of the field with aerial photographs showing material being placed on site beginning in 2012. The City of Mount Vernon was not aware of the source or sources of the material, although a number of citizens reported seeing municipal and private equipment moving the material to and around the site. Much of the material reportedly is related to water system projects within the City, though no documentation exists. In January and November 2015, NYSDEC collected samples of the stockpiled material, 2 of which were submitted for laboratory analysis in February 2015. The NYSDEC Reports (April 2015 and November 2015) both identified the presence of coal, ash, and slag within the material sampled, and reported concentrations of polyaromatic Page 1 of 262 Mayor Richard Thomas August 30, 2017 Page 2 hydrocarbons (PAHs) and lead above the NYSDEC Unrestricted Use Soil Cleanup Objectives (SCO) in the April report. The stockpile is approximately 120 feet wide by 280 feet long and ranges in height from a couple of feet to 15 feet high. It is estimated that approximately 12,000 cubic yards of material are present. Tennis courts have been constructed on the northern portion of the stockpile. The material is in a former sports stadium that the City plans to renovate. There are no wetlands or waterbodies on the site. The Hutchinson River is located approximately 200 feet from the project area, to the east of Highland Avenue. Adjacent properties to the east and north are residential, and some of the material appears encroach on some of these properties. As shown on Figure 2, the soils underlying the Memorial Park area are classified as Urban land. Typically, the Urban land consists of areas covered by buildings, streets, parking lots, and other structures that make it impossible to identify the soils. The natural soil layers have been altered or mixed with manufactured materials, such as bricks, broken concrete, or Cinders.1 Test Pit Investigation Results Fifteen test pits were excavated through the stockpiled material between July 19 and 25, 2017 with the City of Mount Vernon providing the equipment and operator, with Cornerstone and NYSDEC provided oversight. The excavated material was visually characterized for evidence of staining or waste, and for volatile organic compounds (VOCS) using a photoionization detector (PID). Soil samples were obtained from 11 of the 15 test pits for chemical analysis. Observations made in the field found most of the material in the test pits to be soil with cobbles and boulders. Debris, including concrete, asphalt, brick and brick fragments, metal rebar, glass, wood, tree branches, some plastic debris, and/ or piping, were identified at every test pit location. No significant odors or visual signs of contamination was encountered, although ?eld screening detected elevated PID readings in soils from 4 of the test pits, including and Soil samples were obtained from these test pits from the soil intervals where the elevated VOCs were detected based on the ?eld screening. The soil samples were submitted to York Laboratories in Stamford, Connecticut under chain-of-custody and on ice for analysis. All samples were analyzed for VOCs by EPA Method 826GB, semi?volatile organic compounds (SVOCs) by EPA Method 8270C, pesticides by EPA Method 8081A, PCBs by EPA Method 8082, and metals. No VOC exceedances were detected in any of the test pit samples. A trace level of telrachloroethylene (TCE) was reported at an estimated concentration of 0.003 mg kg in the sample from and 2-butanone was reported in the samples from and both at 0.008 mg/ kg. All concentrations were well below the Unrestricted Use SCO of 1.3 mg/ kg Soil Survey of Putnam and Westchester Counties, New York. US Department of Agriculture- September 1994. - MEMORIAL FlELDWroject Fitcs?Mcmorili Field Report EDIT-01140 dour Page 2 of 262 Mayor Richard Thomas August 30, 2017 (cornerstone environmental Page 3 and 0.1 mg kg, respectively for TCE and 2-butanone. Acetone, a common laboratory contaminant, was also reported in a number of samples, including in TP-10 at 0.092 kg above the Unrestricted Use SCO of 0.05 mg/ kg. Its detection is likely due to laboratory artifact. No other VOCs were detected in the soil samples from the test pits. A summary of the VOC results can be found on Table 1. Table 2 presents a summary of the semi-volatile organic compound results from the test pit investigation, as well as the results reported by NYSDEC in April 2015. aromatic hydrocarbons (PAHs) were detected at concentrations above the Residential SCO in 4 of the 11 samples collected in the July investigation. Benzo(a)anthracene and were also reported at concentrations above the Impact to Groundwater SCO in the 4 samples. The same compounds were reported in the samples of the stockpiled material collected by YSDEC in 2015, however the concentrations reported by NYSDEC were significantly higher than the concentrations found during this investigation. While these compounds have low SCOs, they are quite ubiquitous in the modern urban environment. PAHs result from the incomplete combustion of fossil fuels and typically disperse from non?point sources through road run-off and atmospheric deposition of particulate air pollution, are often found in historic fill material, and in the coal, ash, and slag identified in the samples collected by NYSDEC. With the exception of the SCO for the Residential and Impact to Groundwater SCOs for the PAHs in exceedance are based on New York State rural soil background concentrations for those compounds. The Pesticide and PCB results are presented in Table 3. Trace level concentrations of DDT were detected in 3 of the samples, one of which also had and DDE. These pesticide concentrations exceeded the Unrestricted Use SCOs. All concentrations reported are more than 2 orders of magnitude below the Residential SCOs for these compounds. A trace level concentration of PCBs was detected in the sample from at 0.042 mg/ kg, below the Unrestricted Use SCO of 0.1 mg/ kg. Table 4 presents the metals results. As shown on the table, 1 sample had an exceedance of the Residential SCO for barium. Selenium was reported above the Impact to Groundwater 8C0 of 4mg/ kg in 3 samples at concentrations of 4.1 to 4.9mg/ kg. Lead was reported above the Unreslricted Use SCO in 8 of the samples, as well as the 2 NYSDEC samples from 2015, as was nickel in 2 samples and zinc in 4 samples. All of the metals were reported at concentrations that were well below the respective Residential SCO, other than the 1 barium sample and the exceedances are a result of the Ecologic SCO. Since there are no water bodies or other ecological receptors to these subsurface materials, the Ecological SCOs should not be considered applicable. Copies of the laboratory reports are included in Attachment A. While not included in the original work plan, soil samples were collected for physical waste characterization analysis, although the samples were not submitted to a laboratory for analysis. As the test pit program got under way, the NYSDEC oversight personnel questioned whether or not the physical analysis would be performed. It was decided in the - MEMORIAL FlELWrojecl FileslMemor'uI Held Repo? 201150840 doc: Page 3 of 262 Mayor Richard Thomas 30, 2017 (message Page 4 field and with consultation with the City that the samples would be held for potential physical analysis based on observations made and the results of the chemical analysis, since if it were decided to remove the material for disposal off site, the cost of $424 per sample would not need to be spent. Part allows for the beneficial use of recognizable, uncontaminated concrete and concrete products, asphalt pavement, brick, glass, soil and rock placed in commerce for service as a substitute for conventional aggregate?. The physical waste characterization analysis performed on the samples collected by NYSDEC in 2015 reported the presence of coal, ash, slag, and plastics at concentrations ranging between 2.6% and 12.6% of the sample and as a result, both reports stated that the material ?did not meet the de?nition of Uncontaminated under 6 NYRR Part In addition, as described above, the samples were found to have PAHs and lead at concentrations above SCOs. While coal, ash, and slag were not identi?ed in the field in the July 2017 test pits, these materials identified in the NYSDEC samples were in the 2?6 mm fraction of the samples and would be hard to discern without processing. NYSDEC, while overseeing the test pitting, requested that at least 1 test pit be excavated within the tennis court area in the northern portion of the property. After discussions with an individual associated with the tennis program it was learned that a subsurface irrigation system exists beneath the courts to keep soil moisture at proper levels for stable footing. As such, no sampling was performed in the tennis courts area in the northern portion of the Memorial Field property. A review of historic aerial photographs of the area show that the tennis courts on the northern portion of the property were present in 1974, as were handball courts at the northern end of the stockpile area where new court had been constructed on the stockpiled material. Both the tennis courts and the handball courts appear to be in good condition and operational based on their appearance in the aerial photos through 2011. The photograph from November 2012 shows that the handball courts were gone, the tennis courts were in disrepair and no longer in use, and fill material was being stockpiled in the southeast portion of the property. The 2014 photographs show that by April the small retaining wall on the scuth and east sides had been constructed and by October the reconstructed tennis courts had been surfaced. Conclusions The results of the test pit investigation demonstrated that the material present is not hazardous and nor is it sigr?ficantly impacted, with no exceedances of the Commercial SCO. Based on the data, this material should be able to be used as fill material, though a deed restriction would be required to be placed on the property and, if used on site to raise grades, areas where the material remains would have to be capped with clean fill or pavement to prevent direct contact. Additionally, if the City was inclined to consider using this material either at Memorial Field or elsewhere as part of a Brownfield project, the physical analysis on the samples would likely be required. Whether the material remains on site or is removed, it is recommended that the City remove any stockpile material that has encroached onto adjacent properties. KAPROJECTWT - MEMORIAL FIELWroject Field Reporl 2017-03-30 docx Page 4 of 262 Mayor Richard Thomas August 30. 2017 Page 5 NYSDEC has estimated that there are 12,000 cubic yards of material on site, which may be low. Using the 12,000 yard volume and a weight of 1.5 tons per yard, an estimated 18,000 tons of material is stockpiled on site. The undocumented dumped material should be removed and properly disposed. Estimated costs for Transportation and Disposal to a prOper disposal facility could be $90 per ton or $1,620,000. Based on the above estimated volume of material, it could take 1 to 3 months to remove the material from the Site and cost in excess of $2,000,000 for the excavation, handling, and loading of the material, the transportation and disposal of the material, and for the oversight and documentation that the work is properly completed. Actual costs and an anticipated schedule to complete the removal of all the undocumented material from Memorial Field would have to be obtained from solicited contractors. We hope that the above information is helpful. If you have any questions, comments, or require additional information, please do not hesitate to contact us. Sincerely, CORN NC NEERING AND LAND SURVEYING, PLLC Richard Calog RP Richard A. Peluso, RE. Senior Project Manager President cc. David Pollock Joseph Nigro - DPW Commissioner VERNOMIGOSES - MEMORIAL FlELiject Filcs?LMunDrial Field Report ZUI 7438?30 doc: Page 5 0f262