South Basin Groundwater Remedial Investigation and Feasibility Study
The South Basin Groundwater Remedial Investigation and Feasibility Study focuses on a two-square-mile portion of the groundwater aquifer located under Irvine, Santa Ana and Tustin.
The South Basin is contaminated near the surface with volatile organic compounds (VOCs) left behind from decades-old manufacturing. In this area, the geology is different and the migration rates of the pollutants are a little slower than in the North Basin. One water supply well has been removed from service because contaminants reached elevated levels. OCWD is embarking on a comprehensive plan to control the spread and eventually remove these chemicals that have migrated beyond their original pollution sources and now threaten the deeper aquifers from where drinking water is drawn. Regulatory oversight is provided by the Department of Toxic Substance Control (DTSC) and the Regional Water Quality Control Board (RWQCB). These two state agencies are working closely with OCWD and some cooperative potentially responsible parties to map the occurrence of the contaminants, identify appropriate remedies and implement groundwater cleanup.
South Basin Remedial Investigation & Feasibility Study documents
- South Basin remedial investigation work plan
- Community involvement plan (CIP)
- Preliminary remedial investigation report
- Prelim appendix A - monitoring well logs
- Prelim appendix B - cone penetrometer logs
- Prelim appendix C - source site information
- Prelim appendix D - time series charts
- Prelim appendix E - analytical database
- Prelim appendix F - cone penetrometer pore pressure dissipation logs
- Prelim appendix G - CPT assessment analytical reports
- Prelim appendix H - split sample analytical results
- Prelim appendix I - detailed contour maps
- Quality assurance project plan (May 2012)
- Field sampling plan and quality assurance project plan addendum (May 9, 2017)
- Field sampling plan addendum 1 (Feb. 5, 2018)
- Data gap memo (June 6, 2017)
- Groundwater modeling scope of work and cost estimate (Oct. 2, 2017)
- Health and human risk assessment work plan (April 26, 2018)
- Applicable or relevant and appropriate requirements (draft) (Oct. 24, 2017)
- South Basin stakeholder letter
- South Basin community survey
- June 15, 2016 OCWD board of directors meeting
- May 18, 2016 OCWD board of directors meeting and status report
For all items pertaining to the project, please search our meetings and agendas page.
- South Basin Remedial Investigation & Feasibility Study neighbor letter (May 3, 2017)
- South Basin GPP fact sheet (July 2017)
- Plume map - coming soon!