1. Desirable Results Since 1998
Managing Groundwater Quality
Where does the plume end and the basin begin?
Uncommon Dialogue
Groundwater Quality and Management Under the Sustainable Groundwater Management Act Stanford University June 11, 2018
John Woodling
Executive Director
Sacramento Groundwater Authority
Desirable Results Since 1998

2. Presentation Overview
SGA Background
GW Quality Concerns
Defining Sustainability
Authorities and Responsibilities
Successful Approaches
Conclusions

3. SGA Background Joint powers authority formed in 1998
Use police powers of 3 cities and county
195 square mile area under north Sac County

5. Groundwater Quality Concerns

6. Groundwater Quality Concerns
Long remediation times of known plumes – 200 years or more
Changing water quality standards – CrVI, As, 1,2,3-TCP, PFAS, etc.
Conflicts between basin operation and remediation
Regulators often have a “plume chasing” mentality
Orphan sites
Views of pump, treat and serve

7. What is Sustainability?
Sustainability goal – “… operated within its sustainable yield.”
Sustainable yield – “means the maximum quantity of water…without causing an undesirable result.”
Sustainable groundwater management – “means the management and use of groundwater…without causing undesirable results.”

8. What is Sustainability?
Undesirable results include the following, if occurring at significant and unreasonable levels and caused by groundwater conditions occurring throughout the basin
Chronic lowering of groundwater levels
Reduction in groundwater storage
Land subsidence
Seawater intrusion
Degraded water quality, including the migration of contaminant plumes that impair water supplies.
Depletion of interconnected surface waters

9. SGMA Authorities for GSAs
Conduct Investigations
Levy fees to conduct groundwater management activities
Require registration of groundwater extraction facilities
Require metering and reporting of groundwater extraction volumes
Control extractions from wells
Set spacing requirements for new wells
Not really a lot of “authority” here with respect to sustaining groundwater quality

10. Who is Responsible for Groundwater Quality?

11. Roles and Responsibilities
RWQCB, DTSC, USEPA – order and oversee investigation and remediation
County Env. Health – oversee smaller cleanups, well permitting
RPs and PRPs – financial responsibility for cleanup
SWRCB – regulate drinking water quality
Water Suppliers – comply with MCLs, treat water
GSA’s – mitigate/avoid undesirable results

12. Successful Approaches
Coordination
Regional Contamination Issues Committee
County (as well permitting authority)
Investigation
Regional vulnerability study
PCE investigation

13. Coordination - RCIC Formed in 2004 in response to
Additional discovery of Aerojet contamination north of the American River
Claims by McClellan that recovery of groundwater levels due to conjunctive use were interfering with remediation timetable (adding 100s of years)
Includes representatives of impacted water suppliers, regulators overseeing sites, and responsible parties

14. Coordination – RCIC (continued)
Has met on a quarterly basis
Intent has been to
find areas of common interest to improve efficiency for all participants
identify emerging regional water quality concerns early on
GET L-A facility at Ancil Hoffman Golf Course
600 gpm remediation plant
First direct reuse of remediated groundwater in region

15. Regional Vulnerability Investigation – Simulated Potential Movement of Known Plumes
Year 0
Year 50

16. Regional Vulnerability Investigation – Susceptibility of Aquifer
Combined PCAs and DRASTIC into single layer
Added known plumes
Added individual well water quality information
Provided results to water agencies for future planning

17. PCE Investigation
Purveyor experienced PCE/TCE contamination in rapid succession and brought this to the RCIC
Study
evaluated potential sources
constructed monitoring wells and conducted additional sampling
Resulted in eliminating several potential sources and better definition of plume extents and concentrations
Allowed purveyor to develop treatment and operations plan

18. Conclusions
Groundwater contamination is a serious threat to sustainable supplies
GSAs clearly do not explicitly have all the tools they need to sustainably manage GW quality
GSAs can still achieve success by
actively coordinating the regulatory community, water suppliers, and responsible parties
exercising the limited authorities that they possess under SGMA (e.g., conduct investigations)

19. Well…
Any Questions?