Pathways and Environmental Impacts of Methane Migration: Case Studies in the Marcellus Shale, USA

Figure 12

(a) A time series plot of dissolved CH₄ concentrations from homeowner (HO) water wells 1–10 sampled in the study region near Sugar Run in Lycoming County, PA. Plotted data for water well HO8 include two water wells (a, b) sampled on the same property. The vertical dashed and dotted lines indicate the spud date and hydraulic fracturing date, respectively, for gas well Harman Lewis 1H. Horizontal dashed lines represent Immediate Action and Warning Levels [59]. (b) A time series plot of dissolved C₂H₆ concentrations for wells HO6, HO5, HO4, HO3, and HO2 from data reported online (Range Resources LLC 2013), by the PA DEP (http://www.depgis.state.pa.us/emappa), or in Woda et al. [15].