Envirosafe Services of Ohio, Inc. (ESOI) owns and operates a hazardous waste treatment, storage, and disposal facility located in an industrialized area of Oregon, Ohio.
The facility occupies approximately 133 acres. Undeveloped areas border the facility to the east and northeast, and industrial developments border the facility to the north, south and west. ESOI owns a non-contiguous 50-acre piece of property to east of the facility and uses this property primarily to store clay for cell construction.
The facility is divided by a public roadway, York Street, which divides the facility into northern and southern sections. The northern section has several closed RCRA disposal areas, namely Cells F, H, G, and I all of which have undergone final closure. Also located in the northern section are old solid waste disposal areas developed by the previous operators of the site. Envirosafe is currently evaluating these old areas as part of a RCRA Facility Investigation (RFI) as required by its permit. Also located on the north side of York Street is the Facility's truck scale, maintenance building, laboratory and offices
The southern portion of the facility contains the only active disposal area, Cell M, as well as a state-of-the-art containment building where waste unloading and treatment take place. In addition to Cell M and the Stabilization Containment Building (SCB), on the south side of York Street Envirosafe has leachate storage tanks capable of holding up to 100,000 gallons of leachate prior to off-site shipment for treatment.
ESOI'S FACILITY PLAN
The facility is characterized by sediments deposited in glacial and post-glacial environments. The upper most stratum of soil is a layer of lacustrine soils. These soils comprise 10 to 20 feet of lake deposits, layered silt, and thin clay deposits. When this layer is encountered during construction of a cell, it is removed and replaced with clay that has a lower hydraulic conductivity, (i.e., less permeability).
Below the lacustrine soils is the Upper Wisconsin Till, also known as Ohio Blue Clay, which is 40-50 feet thick and has occasional isolated sand deposits. Below this layer is the Lower Wisconsin Till (hardpan) which is 15 to 20 feet thick; and below this till is bedrock. The bedrock begins at a depth of 70 feet to 100 feet below the surface and has been identified as a dolomitic limestone formation of the Silurian age, known locally as the Greenfield Formation.
ESOI'S GEOLOGIC FENCE DIAGRAM
ESOIís Groundwater Monitoring Program is a comprehensive plan which ensures the protection of groundwater by providing a method of early detection in the unlikely event a leak were to occur at the facility. The program involves the following areas: Hydrogeologic investigation, sampling, laboratory analysis, quality assurance/quality control, statistical analysis and regulatory review.
ESOI monitors three hydrogeologic zones at the facility. These include the contact between the lacustrine clays and the Upper Wisconsin Till, the contact between the Upper Wisconsin Till and the Lower Wisconsin Till, and the bedrock aquifer underlying the site.
The Lacustrine material, deposited in the deep, quiet water of post glacial lakes covering the area, is 10-20 feet thick with hydraulic conductivity ranging from 2.0x10-7 cm/sec to 3.8x10-8 cm/sec, (i.e., water will move through these materials at a rate of 0.4-2.0 feet every 10 years.) The upper till represents a period of several minor glacial advances and retreats. Thickness range from 35 to 50 feet thick and hydraulic conductivities are comparable to the lacustrine sediments. The lower till lies directly over the bedrock aquifer and is approximately 12 - 30 feet thick with hydraulic conductivity up to 1.0x10-9 cm/sec or 1 foot every 1000 years. Underlying these "aquitards" is the bedrock aquifer, which is the only unit below the site capable of producing usable amounts of water. The bedrock aquifer consists of Silurian and Devonian age limestones and dolomites. A total of 119 wells were installed as part of the monitoring system; 24 wells will monitor the bedrock formations, with other monitoring wells installed at the two contact zones discussed above.