Groundwater Sustainability: The National Ground Water Association’s

PositionKevin McCray, CAE

Chief Executive Officer

September 12, 2016

Old News

Los Angeles Times,

November 27, 1952

What is groundwater sustainability?• Groundwater sustainability is the development and use of

groundwater resources to meet current and future beneficial uses without causing unacceptable environmental or socioeconomic consequences. (USGS Circular 1186)

What is water resource resilience?• Resilience is the capacity of a groundwater (or water-resources)

system to withstand either short-term ‘shocks’ (e.g., drought) or longer term change (e.g., climate change).

• When discussing resilience, the timeframe under consideration should be defined.

• Resilience applies to both water quantity and quality and may be an important concept as part of groundwater sustainability.

Groundwater sustainability

•Essentially the end result of public acceptance of

the tradeoffs of development

•Groundwater hydrologists provide information on

the long-term consequences of groundwater

pumping that can be used in helping make societal

decisions

Sustainability is in the eye of the beholder

•Different professions may define sustainability differently:

•Ecologists might consider sustainability as use of resources that allows perpetual survival of existing ecosystems

•Economists view it more as an allocation of resources that leaves future generations no worse off than present generations

•Need to consider management practices in defining sustainability

Reasons to focus on groundwater sustainability• Surface waters allocated or fully used –

demand for groundwater increasing

• 2010 irrigation use of groundwater in US is 148% greater than in 1950

• 16-year drought across Western US

• Groundwater use along coasts continues with result of saltwater intrusion

• Demand for water in energy production continues

• Oil & Gas industry produced brines need alternative disposition

• Population growth increases demands for drinking water and food production

How we use groundwater in the U.S.

Agricultural Irrigation – 49.5 bgd (65% of all groundwater extracted)

Drinking water – 19.24 bgd (25.4% of all groundwater extracted

Source: van der Gun, J., A. Aureli, A. Merla.

Enhancing Groundwater Governance by

Making the Linkage with Multiple Uses of the

Subsurface Space and Other Subsurface

Resources. Water 2016, 8, 222;

In some groundwater systems, depletion of a small part of the total volume of groundwater in storage can have large effects on surface water, water quality, or subsidence which become limiting factors to development.

Upper San Pedro Basin,

AZ

Houston, TX

Edwards Aquifer, TX

Republican River Basin,

CO, KS, NE

Trends in total groundwater use

0.42% decline between 2005 and 2010

Groundwater withdrawals for U.S. agricultural irrigation

“Economic forces, such as changing commodity

prices or production costs are likely to induce farmers to shift marginal

land in and out of production.”

- Economic Research Service, USDA, September 2006

Reason to discontinue irrigation by wells

• Shortage of groundwater• Cited for 1,284 farms in 2013

• 86% increase from 2008

• 690 farms in 2008 • 36% decrease from 2003

• 1,082 farms in 2003

Year Electricity Natural Gas

LP, Propane,Butane

Diesel Gasoline or Gasohol

2003 $42.65 $57.25 $27.21 $25.09 $11.50

2008 $57.60 $93.03 $38.72 $54.20 $84.98

2013 $59.59 $55.38 $36.91 $45.51 $48.29

Energy costs in dollars per irrigated acre, associated with irrigation well pumps, 2003- 2013

Source: 2013 Census of Agriculture, USDA, National Agricultural Statistics

Service

Public supply• 15.7 bgd

• 20.7% of total groundwater extraction

• 33.3% of total public supply water

• 87,100,000 American residents served by 39,000 community water systems

• 88,000 wells serving community water systems

Trend in public supply use

U.S. populations served by public water systems using groundwater

U.S. households served by wells: 1997 - 2013

Source: American Housing Survey, U.S. Census

X 1,000

13,093,00015,200,000 in 1990

Loss of 2.107 million

households in 16 years

New construction in recent 4 year period - households on wells: 1997 - 2013

Units are classified as new construction if the unit

was constructed 4 years or less from the date of

the interview by Census employees.

965,000 in 1997

179,000 in 2013

81% decline between 1997 and 2013

Source: American Housing Survey, U.S. Census

Some Groundwater Sustainability Drivers

Groundwater and energy• Shale Gas

• Geologic carbon sequestration

• Biofuels

• Solar energy

• Nuclear waste

Source of water for existing and proposed thermoelectric cooling systems

Groundwater and climate

• More emphasis on unsaturated zone and shallow groundwater

• Greater groundwater use

• Distinguishing climate from pumping

Saline groundwater as a resource

Additional drivers• Groundwater governance

• Harmonizing SW and GW laws and regulations

• Endangered Species Act (GW dependent ecosystems)

• Exempt wells

• Water use estimation

Texas – a lesson for the nation?• Arid climate• Vast farming area• Large population

• Increase by more than 80% by 2060

• 1997 Water Plan• Gap between supply and demand of

over 8 million acre-feet by 2060• $53 billion investment in new water

supply strategies needed

• $2 billion revolving loan fund• 20% for conservation and reuse• 10% for rural areas

Technology solutions for groundwater sustainability

• Improvements in data and monitoring

• Guarding against saltwater intrusion into fresh groundwater

• Use of recycled or reclaimed water

• Conjunctive use of groundwater and surface water

• Managed aquifer recharge

Baton Rouge - protecting groundwater from saltwater intrusion

• Layne Christensen of Bloomington, Indiana, and Owen and White of Baton Rouge, Louisiana, designed and constructed an innovative, sustainable infrastructure project for the Baton Rouge Water Co. to mitigate the impact of saltwater intrusion into one of the city’s primary wellfields.

• Saltwater intrusion is a growing concern for water utilities located in coastal regions of the United States. In some localities, brackish water contamination has forced the closure of wellfields, resulting in pumping moratoriums and expensive infrastructure to maintain hydraulic barriers. While desalination is an option, treatment systems require significant capital and are expensive to operate. Moreover, disposal of the waste stream produced by desalination can be costly.

• The constructed project relies on two “scavenger” wells that achieve in situ separation of brackish water and freshwater due to the hydraulic interference between the wells.

Photo courtesy of Baton Rouge Water Co.

Phoenix – ASR wells to stabilize local aquifer• Based on the City of Phoenix’s 2010 groundwater

management plan, the project was developed to install three aquifer storage and recovery (ASR) wells to stabilize the local aquifer levels, which had been dropping 3 feet to 4.5 feet a year. Phoenix services about 1.5 million people and although most of the city’s water supply comes from surface water sources, groundwater is critical to meet drought shortages and system outages, as well as to provide reliability to the supply system.

• Using the three large ASR wells, excess potable water is pumped into the aquifer (recharge) during periods of low water demand (winter months) and pumped back out as needed during periods of high water demand (summer months). The city now has a total aquifer recharge capacity of 4.5 million gallons a day.

• It is estimated that theses ASR wells will:

• Reduce the city’s water well rehabilitation costs by $110,000 to $115,000 a year

• Reduce well rehabilitation work time from 30 to 40 days a year to 3 to 4 days a year.

• Working closely with the city were Carollo Engineers, Clear Creek Associates, Weber Water Resources LLC, and ASR Systems.

Photo courtesy of Clear Creek Associates

Managed aquifer recharge research questions• Changes in permeability (dissolution and clogging)

• Efficiency of injection/withdrawal cycles

• Long-term storage and recovery

• Introduced micro-contaminants

• Mobilization of trace elements

• 3D flow and transport simulation

• Fate and transport of pathogens

• Role of dissolved organic matter

• Disinfection byproducts

• Monitoring techniques

• Regional impacts

• Land deformation

• Economics

Importance of data to understanding sustainability and resilience• Increased federal funding for cooperative groundwater quantity data

collection is the most useful action the federal government can take, according to groundwater professionals around the country.

• Federal support of cooperative data collection of water quality, aquifer mapping, and pertinent scientific research is also important.

• Data and research provide the underpinning for sound local water management decision making that advances the well-being of the nation’s citizens, economy, and environment.• National Groundwater Monitoring Network

National Groundwater Monitoring Network• Design

• Inventory

• Guidance:• Field Methods

• Data Elements, Standards, & Mgt

Drought-proofing groundwater• Explicit recognition of climate variability

• Build climatic variations in models and project groundwater conditions over years to decades

• Raise awareness about maintaining groundwater as a reserve• Monitoring water use and water levels are key components

• Recognition of managed aquifer recharge as a critical component

• Increase groundwater rights during droughts with more restrictive use during the intervening periods when surface water is more available

• Make use of large volume of groundwater in storage through a conjunctive groundwater and surface water system

NGWA Principles for Groundwater Resource Sustainability

1) Collaborate with adjacent local and regional jurisdictions within

and among states and nations.a. Recognize groundwater flows under jurisdictional boundaries

b. Develop mutually a common understanding of the groundwater resource and influential factors

c. Conduct a local and state groundwater

resource audit and develop a water budget

d. Share water plans, objectives and data

for local and state water management

NGWA Principles for Groundwater Resource Sustainability

2) Set groundwater resource objectives and forecast water demand.a. Establish publicly vetted aquifer objectives for groundwater

availability in future usesb. Adopt aquifer management/groundwater use rules, codes, and

lawsc. Evaluate future water uses

and compare with available

groundwater and alternatives

NGWA Principles for Groundwater Resource Sustainability

3) Incorporate the hydrologic cycle and natural processes in groundwater management.a. Store water underground to reduce evaporative loss and protect groundwater

qualityb. Facilitate recharge by use of green infrastructure and native-vegetated

landscapesc. Maintain groundwater levels to avoid

non-recoverable land subsidencea. Preserve groundwater levels, flow, and

quality for ecosystem biodiversity

NGWA Principles for Groundwater Resource Sustainability

4) Minimize the carbon footprint of groundwater infrastructure and

production.

a. Evaluate water supply alternatives for minimizing life-cycle footprint

and costs

b. Use most efficient pumps, equipment, and production processes

c. Reduce water loss in storing and

delivering groundwater

d. Promote conservation and reuse

of water as alternate sources for

future use

NGWA Principles for Groundwater Resource Sustainability

5) Implement source water protection and remediation for private and public groundwater uses.a. Eliminate or reduce sources

of contaminationa. Protect usable groundwater

from future contaminationthrough practices and laws

c. Remediate contaminated groundwater

NGWA Principles for Groundwater Resource Sustainability

6) Measure, report, and share resource status data with residents and

other jurisdictions.

a. Monitor groundwater levels,

quality, and use

b. Report on achievement of

groundwater resource objectives

NGWA Principles for Groundwater Resource Sustainability

7) Prepare to avoid disruption from extreme events affecting reliable safe groundwater supply.

a. Consider effects of extreme weather events and human interventions

b. Identify and address water supply

vulnerabilities of infrastructure and

operations

c. Establish processes for timely recovery

of water services to communities

* Picture Source: pubs.USGS.gov/gip/70/

NGWA Principles for Groundwater Resource Sustainability

8) Reassess groundwater management on regular intervals.

a. Evaluate availability, source, protection, provision, use, and resilience alternatives

b. Conduct life-cycle assessments of natural and constructed infrastructure

c. Adjust codes, laws, and practices for cost-effective provision of safe sustainable water

Technology alone is not the answer• How likely Washington, DC’s checkbook will return to the practices of

the 1970s when the federal government accounted for nearly 75% of drinking water and sewer infrastructure investments?

• Restructuring our nation’s water use will require:• Changing laws, policies, and incentives that guide water use at all levels

It is time to take action to develop public understanding of the:• Factors affecting groundwater supplies and use

• Methods that promote the wise use of groundwater supplies

• Need to determine strategies that promote groundwater sustainability

• Need for cooperative efforts to fill data gaps and undertake priority research

• Need for increased collaborative educational efforts.

• The National Ground Water Association calls upon the federal government to assist states, local agencies, and the groundwater professions in meeting this call to action.