AWRA 2008 Annual Symposium – April 18, 2008
Afternoon Breakout Session B1 – Environmental and Energy Implications
Summarized by Seth M. Turner, PE
The AWRA symposium afternoon session titled “Environmental and Energy Implications” focused on the environmental implications of water and energy development and emphasized the importance of monitoring and data collection. The session began with two student presentations.
Ana Ruiz of the Colorado School of Mines discussed the bioremediation of acid mine drainage in Clear Creek County (Figure 1). The project is utilizing passive treatment systems, which are ideal for remote sites due to their simple design and monitoring. Water flows through the treatment systems by gravity, eliminating the need for energy inputs. The treatment systems consist of 1,500 gallon tanks containing a substrate of corn stover, walnut shells, and manure. The objective of the treatment process is to decrease sulfate reduction in Clear Creek; reducing sulfate causes other metals (e.g., Fe, Cu, Zn) to precipitate.
|Figure 1. Anna Ruiz Scholarship Recipient Presentation|
Andrew Payton of Western State College presented a summary of a multi-disciplinary study of the Henson Creek Watershed. Acid mine drainage is prevalent in the basin, and a 1972 dam breach released heavy metals that had been stored. The class evaluated a number of key parameters, including background geology, metals concentrations, and biological indicators. The various datasets were collected into a comprehensive 179-page report for use by stakeholders in the basin.
Attorney Robert Wigington of the Nature Conservancy (Figure 2) spoke about efforts to integrate the conservation and preservation of freshwater biodiversity with the need for water supply adaptation in the face of climate change.
|Figure 2. Robert Wigington of the Nature Conservancy|
Klint Reedy, a water supply planner with Black & Veatch, talked about emerging research to assess the carbon footprint of water development. “Carbon footprint” is defined as an estimate of the amount of greenhouse gases released to or removed form the environment by human activities. The EPA estimates that water and wastewater facilities account for approximately 1/3 of municipal energy use; the agency is now implementing an Energy Star program for these treatment facilities. Assessing the carbon footprint is an 8-step process in which activities associated with water development are converted to CO2 equivalent. While the analysis of the carbon footprint of water development is a relatively new area of research, it represents a positive step towards sustainability.
Jason Turner of White & Jankowski and Ken Watts of the USGS discussed coal bed methane (CBM) development in Colorado (Raton Basin) and Wyoming (Powder River Basin) and the associated impacts on groundwater resources. CBM is methane that is trapped in coal seams and usually requires the pumping of groundwater before the gas can be extracted. Between 1999 and 2007, approximately 2.93 billion barrels (377,720 AF) of water were pumped from CBM wells in Colorado. The pumped groundwater (about 1.4% of annual groundwater use in Colorado) is typically disposed of through (1) deep injection (53.9%), (2) lined evaporation pits (27%), or (3) surface disposal.
The jurisdiction and legal status of the water pumped from CBM wells varies. The Division 7 water court ruled that water pumping from CBM wells was a diversion and a beneficial use. Another recent case in Colorado sought a ruling requiring the State Engineers Office to regulate the CBM well pumping. A Wyoming CBM task force suggested application of the “duty of water”; if no gas is produced after a certain volume of water is pumped, then the well should be shut down. Ultimately, the protection of water resources without unduly burdening the oil and gas companies requires monitoring and data collection.