R2018-94 Authorizing 2nd Amendment to Agreement between the City of Decatur and MDA Properties LLC

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-- Bwk: 45158 Page: 496 September 30, 2015 Mr. Billy Tyus Focused Phase II ESA- 151 West Main Street/152 West Wood Street Page 3 Property where contaminants of concern would most likely be encountered, if present.A Site Plan depicting the locations of the soil borings and temporary groundwater monitoring well, is included as Attachment 2. All field and sampling activities were performed in accordance with the City of Decatur's USEPA-approved Quality Assurance Project Plan(QAPP)and the submitted Sampling and Analysis Plan (SAP). Environmental Setting Regional Physiographic Conditions Regional topography was determined by review of the United States Geological Survey(USGS) Decatur Quadrangle Map,dated 2015. According to the topographical map reviewed, the Property is approximately 660 feet above mean sea level(MSL). Regional Geology Based on the Illinois State Geologic Survey(ISGS)Berg Circular,Potential for Contamination of Shallow Aquifers from Land Burial of Municipal Waste, the Property is located in an area rated as D2. In general, a D2 rating area contains uniform, relatively impermeable sandy till at least 50-feet thick with no evidence of interbedded sand and gravel. Based on the borings conducted, the geologic profile of the Property consists of intervals of sandy-silts and silty-sand matrices until a depth of approximately 1-10 feet below ground surface (bgs), which were immediately underlain by a dense glacial till to the maximum boring depth of 25 feet bgs.As such, the geology of the Property is consistent with the documented geological sources. Soil Investigation Either a wheel-mounted Geoprobee 420M hand cart or a track-mounted hydraulically powered Geoprobee Model 7822 DT was used to advance a 2-inch diameter steel drive point to the top of the desired sampling interval.Soil cores were extracted from soil borings using a 3 or 5 foot tong Macrocore®or Dual Tube Samplere equipped with disposable polyethylene sample liners. Samplers were attached to the leading end of extension probe rods and driven downward until desired target depths were reached.After the desired depth interval was obtained, the sampler was extracted and the polyethylene liner opened,field logged and screened, and subsequently sampled in accordance with Fehr Graham Standard Operating Procedures (SOPs),as presented in the City's USEPA-approved QAPP. Soil borings associated with soil and groundwater sampling activities were advanced between 15.25 feet bgs depending on field conditions observed by Fehr Graham staff or the limitations of the drilling equipment used.The extracted soil cores were immediately field screened at 1- foot intervals by Fehr Graham staff with a MiniRae 3000 photoionization detector(PID) equipped with a 10.6 eV lamp. The PID was calibrated to 100 parts per million (ppm) isobutytene and 0 ppm fresh air calibration prior to use.The PID is designed to detect the presence of volatile organic compounds(VOCs)emanating from soil pores.The soil cores, as extracted, were visually examined, and the physical observations were logged by Fehr Graham staff in a field notebook.The soil sample intervals at each boring were selected for laboratory analysis based on registered PID readings, any physical evidence of contamination such as odors or staining, and/or from typical contaminant migration characteristics.