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Home My WebLink AboutNC0026573_Biosolids Investigation_20170227t; Water Resources Environmental Quality February 27, 2017 Brad Boris City of Morganton — Department of Water Resources P.O. Box 3448 Morganton, NC 28680 RE: Biosolids Investigation Permit No. NCO026573 Catawba River Pollution Control Facility WWTP Burke County Dear Mr. Boris, ROY COOPER Gove-nor MICHAEL S. REGAN Secretary S. JAY ZIMMERMAN Directoi- The Division of Water Resources (DWR) has reviewed the September 30, 2016 report by S&ME concerning a hand -auger survey of suspected biosolid disposal areas immediately surrounding the wastewater treatment works. DWR issued a letter on November 17, 2014 requiring the City of Morganton to review historical aerial photographs to determine if additional disposal areas are present onsite. The impetus for the latest survey was based on two historical aerial photographs (E.g. May 1982 & March 1987) submitted by Freese and Nichols, Inc. in a memo dated April 8, 2015. Figure 1 shows four areas of concern generally referred to as Area 1, Area 2A, Area 213, and Area 2C. The hand -auger survey completed a total of eight borings (E.g. A through H) within three of the four areas of concern. Total auger depths ranged from 2.5 feet below ground surface (BGS) to 7 feet BGS. Based on field observations and further review of the soil samples, the S&ME report concluded that suspect biosolids materials were not present in the borings completed. To assist with review of the subject report, the Asheville Regional Office (ARO) created an ARC GIS project that incorporates three historical aerial photographs (E.g. February 1983, March 1987, and March 2014) and the locations of eight hand -auger borings. The coordinates for the borings were provided by Robert Vinay of Freese and Nichols, Inc. Figure 2 is a 1983 orthophoto showing the locations of two suspected biosolid disposal areas referred to as Area 1 and Area 2B. The presence of biosolids in Area 1 was previously identified during the construction of the equalization basin in 2013. Area 2B was investigated during the latest survey with three hand -auger borings referred to as F. G, and H. Total depths for the Nothing Cornpares:'_:_ State of North Carolina I Environmental Quality I Water Resources 2090 U.S. Highway 70, Swannanoa, North Carolina 28778 828-296-4500 Brad Boris February 27, 2017 Page 2 of 8 three borings ranged from 4 feet BGS to 7 feet BGS. The ARC GIS project shows three borings near the edge of the waste boundary. A site visit conducted on December 2, 2016 provided additional evidence that these borings may be located outside of the waste boundary for the potential disposal area. Figure 3 is a 1987 orthophoto showing the location of two suspected disposal areas referred to as Area 2A and Area 2C. A third potential disposal area is located less than 100 feet east of Area 2C. Area 2A was investigated in the latest survey with three auger borings referred to as C, D, and E. Total depths for the three borings ranged from 4 feet BGS to 6.5 feet BGS. Area 2C was investigated with two auger borings referred to as A and B. Total depths for the two borings ranged from 2.5 feet BGS to 7 feet BGS. One observation is that the borings do not appear to coincide with any potential disposal areas visible on the 1987 orthophoto. Furthermore, the boring depths for Area 2A appear to be too shallow for an area that was historically used for the disposal of soil and other construction debris. Figure 4 shows the disposal of soil within area 2A. You will be required to further investigate the three potential disposal sites visible on the February 1983 and March 1987 orthophotos. Figure 5 identifies these areas as 2A, 213, and 2D. You should be prepared to construct borings that may extend beyond a depth of 10 feet. You will also be required to fully delineate the horizontal and vertical extent of biosolids should they be encountered. Borings can be terminated upon identification of residual soil and/or saprolite. You will also be required to install three groundwater monitoring wells downgradient of Area 1 as proposed in the April 8, 2015 memo by Freese and Nichols, Inc. These monitoring wells will be referred to as TW-4, TW-5, and TW-6. Water samples should be analyzed for ammonia, arsenic, barium, cadmium, chloride, chromium, fecal coliform bacteria, iron, lead, manganese, mercury, nitrate, nitrite, phenols, selenium, silver, sulfate, total coliform bacteria, and zinc. During a site visit on December 2, 2016, 1 observed that a temporary monitoring well (TW-1) was never properly abandoned. The borehole is currently open and is acting as a conduit for surface water contamination, which is a violation of 15A NCAC 02C .0113 (e). Any well which acts as a source or channel of contamination is required to be repaired or permanently abandoned within 30 days of receipt of notice from the Department. According to 15A NCAC 02C .0113 (d), all wells other than water supply wells including temporary wells, monitoring wells or test borings greater than 20 feet in depth or that penetrate the water table shall be abandoned by completely filling with a bentonite or cement -type grout. Please provide this office with a work plan and a tentative schedule for the installation of three monitoring wells (E.g. TW-4, TW-5, &TW-6) and the investigation of three potential disposal areas. You will also be required to notify this office when the temporary monitoring well is properly abandoned. I am available if you have any additional questions or concerns. I can be reached at (828) 296-4681 or brett.laverty@ncdenr.gov. Brad Boris February 27, 2017 Page 3 of 8 Sincerely, Water Quality Regional Operations Asheville Regional Office Ec: ARO File Jann C. Bryan - Freese and Nichols, Inc Brad Boris February 27, 2017 Page 4 of 8 Figure 1: Boring location map for hand auger survey. Taken from SWE report dated September 30, 2016. KEY - APPROXIMATE TEMPORARY MONITORING WELL LOCATION - APPROXIMATE GEOTECHNICAL SOIL TEST BORING LOCATION - APPROXIMATE HAND AUGER LOCATION � NY , Brad Boris February 27, 2017 Page 7 of 8 Figure 4: November 2011 aerial photograph showing disposal of soil within area 2A. Brad Boris February 27, 2017 Page 8 of 8 Figure 5: Three potential disposal areas requiring further investigation.