Fate of Natural Gas Brine Constituents Released to Roads and Soils Christopher Guerrero, Steven Pacenka, Tammo Steenhuis Department of Biological and Environmental Engineering, Cornell University (Summer 2011) Materials and Methods Background Wastewater from the hydraulic fracturing of natural gas wells is currently being discharged into the surface environment. Releases include the intentional spreading of brine on roads for ice/dust control and the accidental spilling of fracturing water. Depending on the location and rock type, the formations from which the natural gas is derived can contain high concentrations of salt and metals. These brine constituents are potentially harmful to not only human health, but also ecosystems. Moreover, as upstate New York lays on the verge of intensive gas well development, the production and handling of brine and fracturing wastes is expected to expand tremendously over the next few years. The object of this research project is to examine the environmental fate of natural gas brine constituents. By determining the concentrations of salts and metals in the brine and roadside sediment, one can assess the effects of accidental spills and brine spreading by comparing these results to current quality standards. Analyzed using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Results of Sediment Analyses Discussion 14 Brine Analysis 12 10 Brine Analysis Collected in Cherry Creek and South Dayton, NY. Diluted 25, 50, 100, 500 and 1000 times. For the 25 times dilution, 2 mL of filtered brine was added to 48 mL of 5% (v/v) Nitric Acid. Sediment Analysis Collected in Boutwell Hill State Forest, NY. Sampled at three sites at the top and slope of the hill. Sampled a strata at 3, 5, 7, 12 in. below the surface. Background samples were taken 20 ft. into the forest next to each roadside. After air-drying and sieving, samples were digested with 4 M Nitric Acid in a hot water bath for an hour. 8 B/b BA/b L/b 6 4 Roadside Strata Analysis 2 0 Ca Mg Na Sr Figure 1. Division of salt concentrations in roadside ditch samples averaged at each of the three sites (B, BA, L) by the background sample (b) Together 3 2.5 B/b L/b BA/b 1.5 1 0.5 0 Ba Parameter mg/L Medina Brine Composite Medina Brine Individual Well Sodium (Na) 58800 66800 Calcium (Ca) Magnesium (Mg) 21000 23200 Cu Ni Pb Figure 2. Division of trace metal concentrations in roadside ditch samples averaged at each of the three sites (B, BA, L) by the background sample (b) 1760 1780 Potassium (K) 1080 1040 Iron (Fe) 130 129 Manganese (Mn) 70 85 Calcium, strontium, magnesium and sodium are highest to lowest salts and barium, copper, nickel and lead are highest to lowest trace metals. Lead concentrations were consistently lower than the background in both the strata and roadside ditch results. Future work 9 3360 Strontium (Sr) The roadside ditches and strata had higher calcium, magnesium, sodium, strontium, barium, copper and nickel values that the background soil. 10 8 3000 The salt and trace metal results for the strata showed a downward trend in their salt content with the sample at three inches below the surface (BH3) being the highest and the sample at twelve inches below the surface (BH12) being the lowest. 3.5 2 Table 1. Chemical characteristics of brine from traditional Medina wells analyzed by the New York Department of Environmental Conservation While lead may not be present in our brine samples, one possible explanation as to why lead was not detected in the brine is because at low dilutions, high salt concentrations interfere and at high dilutions, the lead concentration fails to surpass its detection limit. 7 6 BH3/b BH5/b BH7/b BH12/b 5 4 Results of Brine Analyses 3 2 Parameter mg/L NYDEC Deep Gas Brine Cherry Creek Brine South Dayton Brine Nickel (Ni) 3.6 3.1 Lead (Pb) 2.5 2.2 Zinc (Zn) 1.2 0.6 Sodium (Na) 61003 36100 44200 Copper (Cu) 0.6 0.6 Calcium (Ca) 29880 34500 34200 Strontium (Sr) 1400 1200 1230 0 Mg Na Develop a method to isolate any lead present in the brine for analysis. Research history of roadside strata analyzed to determine types of soil present and composition of brine spread. 1 Ca While this preliminary work gives some insights into the environmental fate of natural gas brine constituents, we are considering several possible next steps: Sr Figure 3. Division of salt concentrations in the strata samples averaged at each of the four heights (BH3, BH5, BH7, BH12) by the background sample (b) 5 4.5 Research salt and metal concentration differences in brine from newly drilled Marcellus Shale wells. Compare effects of brine and commercial road salt on roadside ditch salt and metal concentrations. 4 Magnesium (Mg) 4240 3270 3200 3.5 3 Objectives Barium (Ba) 89 145 144 BH3/b BH5/b BH7/b BH12/b 2.5 2 Locate towns in Western NY where brine is used in the summer for dust control. Test production brine from the towns’ holding tanks. Sample roadside ditches and backgrounds on roads where brine is currently applied in these towns to gather data on short-term effects of brine application. Sample strata in a roadside ditch to gather data on long-term effects of brine application. Lead (Pb) 2.68 ND ND 1.5 1 Copper (Cu) 2.4 0.39 0.5 2.66 0.23 0.23 Table 2. Comparison of chemical characteristics from New York reports to the Cherry Creek and South Dayton brines used in this study. Funding from Engineering Learning Initiatives Shree Giri, Tigist Tebebu, Carla Ferreira from the BEE Soil and Water Lab 0.5 0 Nickel (Ni) Acknowledgments Ba Cu Ni Pb Figure 4. Division of trace metal concentrations in the strata samples averaged at each of the four heights (BH3, BH5, BH7, BH12) by the background sample (b) David Orr and Lynne Irwin from Cornell Local Roads Program George Spanos, Director, Chautauqua County Department of Public Facilities