Issue link: https://read.dmtmag.com/i/55888
Resource Extraction Thematic maps illustrating parcel-sampling progress and the latest sample date of each water supply loca- tion can keep project managers informed in near real time, allowing them to shift resources ahead of the drilling schedule to ensure sampling-program objec- tives are met. Modeling Impoundments and Well-Site Restrictions In Pennsylvania, the PAMAP Program (www.dcnr.state. pa.us/topogeo/pamap/index.aspx), administered by the Department of Conservation and Natural Resources, acquired statewide high-resolution one- and two-foot-pixel color digital orthophotography and 3.2-foot grid-cell raster elevation data using light detection and ranging (LIDAR) technology. These datasets are being used to map well- site locations and model potential impoundments for collecting and storing water for hydrofracking. GIS watershed-modeling tools delineate very-high- resolution drainage channels and calculate the drain- age area at each drainage-network junction. The ability to delineate a high-resolution drainage network using watershed-modeling tools far exceeds stream-channel mapping available from a typical high-resolution National Hydrologic Dataset (NHD) produced from 1:24,000 USGS Topographic Quadrangles. The magenta drainage network in Figure 1 was derived from watershed modeling, where each upstream chan- nel drains a quarter-acre area. The blue lines reflect the high-resolution NHD drainage network for the same area. Note the significant amount of additional drain- age detail created by the model and the preciseness of fit to the topography visible in the shaded-relief ter- rain model created from PAMAP LIDAR data. Using the watershed drainage area, historical annual precipitation data, channel slope and impervious-surface characteristics within the watershed, it's possible to identify sections of stream channel that could be impounded to achieve a desired reservoir-storage capacity (5 million gallons is the typical requirement to hydrofrack one Marcellus gas well). Subsequent analysis of geologic, cultural and environmental fac- tors can be applied to refine the preliminary selection of candidate sites identified though hydrologic-modeling techniques. A high-resolution hydrologic network also can be applied to regulatory compliance. For example, Pennsylvania Department of Environmental Protection regulations state that well sites can't be located within 100 feet of streams or wetlands that are one or more acre in size, within 200 feet of a water supply and with- in 200 feet of a home or workplace (the July 22, 2011, Governor's Marcellus Shale Advisory Commission Report recommended increasing the wellbore setback distance from streams and water bodies to 300 feet, from private water wells to 500 feet and from public water systems to 1,000 feet). Figure 2 illustrates the use of GIS buffering tools to reflect the 300-foot setback distance from streams, the 200-foot setback around homes and workplaces, and the location of existing Marcellus wells in the area. As new well-site locations are acquired using GPS tools, these setback buffers can be reviewed to ensure regulatory compliance. Buffering has a variety of additional uses for map- ping setbacks and distance thresholds stipulated in well siting and notification regulations. Figure 3. Silverlight Web GIS mapping includes embedded charting functions. 16 GEO W ORLD / FEBRUAR Y 2O12 Interactive Web Mapping Interactive Web mapping is being used extensively to publish information about Marcellus well permits, drilled wells and production data. Energy companies and firms providing support services (e.g., lease acquisition, pre-drill water-quality sampling and right- of-way surveying) are implementing secure Web GIS services to publish well sites; existing and planned gathering; and midstream pipeline right-of-way align- ments, water-sampling sites, and properties and associated lease holdings for access by clients and staff in remote offices. Sharing GIS data is critical for coordinating well-permit and drilling activities across a large geographic area and responding to field emergencies.