Dan Yates Associate Executive Director

Transcription

1 Dan Yates Associate Executive Director

2 Ground Water Report to the Nation Groundwater & Alternative Water Supplies Why Alternative Water Supplies Matter Adapting to Meet Future Demands Alternative Groundwater Resources Recommended Actions

3 Why Alternative Water Supplies Matter Water levels in Lake Mead (approximately 50 ft below normal pool December 2012) Meeting growing demands has become urgent in many regions. Not just a western states issue. Need to supplement and/or replace existing water supplies. Factors increasing pressures on existing resources include: Climate variability, Population growth, Competition for resources among various users, and Quantity and quality issues associated with current supplies.

4 Meeting Water Demand in a Climate of Uncertainty Unprecedented challenges to maintain current resources and find new resources Groundwater is being tapped more and more for different uses Increasing competition for groundwater among users Climate Extremes Population growth

5 What is considered normal weather? Unpredictable trends result in much uncertainty for water managers. Water systems are stressed by both shortand long-term climate extremes such as: Severe and unseasonable weather, Heavy precipitation and flooding conditions, Extreme heat and drought conditions, Extreme cold, and Hurricanes and tornadoes.

6 Projected Changes in the Water Cycle

7 Population Growth and Migration Factor Supplying water to growing populations has placed stress on existing and aging water infrastructure Census reported a 9.7 % increase from Areas with water availability and sustainability problems are experiencing greater population growth and migration. Net out-migration has been from the Northeast and the Midwest to the South and West, some of the most drought stressed or arid parts of the country.

8 Groundwater-level declines. Red regions indicate areas in excess of 500 square miles that have water-level decline in excess of 40 feet in at least one confined aquifer since predevelopment, or in excess of 25 feet of decline in unconfined aquifers since predevelopment. Blue dots are wells in the USGS National Water Information System database where the measured water-level difference over time is equal to or greater than 40 feet. From: USGS Circular 1323.

9 Adapting to Meet Future Demands U.S. GAO estimates that even under normal conditions, water managers in 36 states anticipate water shortages in localities, regions, or statewide in the next 10 years. Water supply managers must ask themselves what previously untapped resources are available to meet current and future demands? Planning and adequate funding will be critical to address demand.

10 Why Look at Alternative Water Resources? Stresses on traditional freshwater supplies have prompted a search for additional sustainable and affordable supplies Stretching existing resources through conservation is not enough Traditional sources are no longer available Alternative and unconventional water sources can be developed to supplement or provide needed peak capacity To begin to meet the additional demands, planners need to stretch available water resources through system repairs and conservation in combination with using alternative "new" water sources

11 What are the Alternatives? Redirecting Use to "Undesirable" Groundwater Groundwater Desalination Stormwater Harvesting Aquifer Storage and Recovery Water Reuse

12 Best Water for the Use Non-drinking water users can utilize groundwater that meets their quality and quantity needs without treatment Example potential users: Agricultural applications Some industries Cooling water for power generating facilities Various energy-related operations requiring large volumes of water Redirecting Users to Undesirable Groundwater Saline groundwater resources in the US

13 Why Desalinate?

14 USGS Desalination of Ground Water: Earth Science Perspectives, Fact Sheet October 2003

15 Desalination of Brackish and Saline Groundwater El Paso, Texas is the site of the world's largest inland desalination plant. Desalination can be used to tap vast, underutilized groundwater resources Knowledge of aquifer yield and water quality is necessary Desalination is energy intensive Currently evaporation, reverse osmosis, and microfiltration used Blending of treated water with fresher sources can lower cost Concentrate disposal can be costly and requires planning

16 Bioswale in Oregon Stormwater Harvesting Enhances stormwater recharge to the shallow aquifers for future use Prevents flooding and erosion Increases stream base flow from shallow groundwater discharge Uses infiltration techniques such as rain gardens, recharge ponds, infiltration structures, and injection wells

17 Bioswell Rainwater Collection Sand Filtration Unit

18 Stormwater Harvesting Cautions Stormwater may contain sediment, nutrients, metals, salts, microorganisms, fertilizers, pesticides, petroleum, industrial spills, and other organic compounds that could contaminate the groundwater resources. Steps should be taken to protect groundwater quality. BMPs must be used to prevent transfer of pollution from surface water to groundwater resources. Unexpected events, such as chemical spills, can also have a significant impact on recharge water quality. Some types of stormwater harvesting structures are regulated under the UIC Class V program.

19 Aquifer Storage, Recovery, and Management Used to store plentiful water resources underground to be recovered at a later date Used to manage the water quality of an aquifer Storage underground can avoid potential political, environmental, and economic impacts from construction and flooding of new surface reservoirs Stored water not as susceptible to contamination or evaporation as surface sources

20 Aquifer Storage, Recovery, and Management Injection will require planning, testing, and permitting. Sources of water include: Treated Drinking Water, Stormwater, Treated Wastewater, Treated Surface Water, and Treated Groundwater from other aquifers. Target aquifer can be either fresh or saline. To pinpoint areas where ASR can be used, information on aquifer composition and hydrogeologic characteristics which influence the recovery of injected water is needed. The chemical composition of potential receiving aquifers must be identified, and the chemical interaction between the injected water and the aquifer matrix must be understood to avoid retrieved water exceeding a drinking water Maximum Contaminant Level.

21 Wastewater Reuse Treated wastewater can stretch existing water sources and replenish groundwater supplies Can supply nonpotable uses such as irrigation, cooling water, oil and gas exploration, and industrial process water Can be treated to drinking water standards for potable supply Can be used for aquifer recharge, subsidence control, or salt water intrusion barrier maintenance May impact downstream users, environmental flows, and surface water quality standards

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23 A Few Recommended Actions Before investing in these alternatives, conduct a risk and cost-benefit analysis covering: lead times required, funding sources, potential benefits and downsides, what will be needed to adequately characterize the resources, treatment technology, and costs to produce, develop, and provide delivery infrastructure.

24 A Few Recommended Actions Cont. Education is essential for widespread acceptance of alternative water resources. Research is needed to increase the efficiencies of these technologies. Research is needed to identify geographic areas where these technologies are hydrogeologically feasible.

25 Questions?

26 References Alan Plummer and Associates, et. al., 2010, Final Report Stormwater Harvesting Document for the Texas Water Development Board, 220 p. final_rpt.pdf Alan Plummer and Associates, 2010, Stormwater Harvesting Guidance Document Final Report to the Texas Water Development Board, 222 pages. Desalination: A National Perspective, Committee on Advancing Desalination Technology, National Research Council, ISBN: , 316 pages, 6 x 9, (2008), Dragoni, W. and Sukhija, B. S. (2008), Climate change and groundwater: a short review, Geological Society, London, Special Publications, v. 288; p Hightower, Mike, Desalination of Inland Brackish Water: Issues and Concerns, Brackish Groundwater National Desalination Research Facility, Sandia National Laboratories Krieger, R. A., Hatchett, J.L., and Poole, J.L., Preliminary Survey of the Saline-Water Resources of the United States. Geological Survey Paper 1374, U. S. Geologic Survey, Washington, DC. Office of Water - Climate Change and Water Reilly, T.E., Dennehy, K.F., Alley, W.M., and Cunningham, W.L., 2008, Ground-Water Availability in the United States: U.S. Geological Survey Circular 1323, 70 p., also available online at Sánchez-lugo, A., J. J. Kennedy, and P. Berrisford: 2012: [Global climate] Surface temperature [in State of the Climate in 2011 ]. Bull. Amer. Meteor. Soc., 93 (7), S14 S15. Water Resources Western States Water Council, Water Needs and Strategies for a Sustainable Future: Next Steps, June 2008 USEPA Climate Change Impacts and Adapting to Change USGCRP, 2009, Global Climate Change Impacts in the United States Water Resources Chapter (