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

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

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

Groundwater Quality Concerns

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

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.”

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

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

Who is Responsible for Groundwater Quality?

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

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

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

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

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

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

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

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)

Well… Any Questions?