PROJECT SOILS OVERVIEW July 15, 2020 EARTHWORK OVERVIEW

• Project features need approx. ~15 to 18 MCYs of soil fill – ~4 to 11 MCYs of RTM will be generated during tunnel boring operations – Remaining fill from ~1.5 MCYs of planned imports and on-site borrow • Effects of hauling and logistical constrictions highlight need to optimize material uses

2 REUSABLE TUNNEL MATERIAL (RTM) OVERVIEW • Tunnel depths expected from approx. 100 - 160 ft below ground • Peats not anticipated • Older soils consisting of sands, silts, and clays w/ occasional buried stream channels • Soils of the Modesto, Riverbank, and Turlock Formation deposits from Pleistocene Epoch – 11,700 – 2.6M years before present

Profile Source: Maier, et al., 2013. Significance of Widespread Quaternary Volcanic Ash (tephra) in the Sacramento-San Joaquin Delta, . USGS Poster Presentation to American Geophysical Union. 3 PROJECT USE OF RTM

– Tremendous need for soil fill and will produce excess quantities of RTM – Project circumstances drive creative thinking about using available resources – Available RTM samples meet State and Federal embankment geotechnical requirements – Biggest issue: moisture content; comes out wet, but have included processes for drying the material before use

4 5 Intake 3 NORTHERN SITES Intake 5 RTM GENERATION SITES EASTERN ALIGNMENT CENTRAL Twin Cities ALIGNMENT Launch Shaft

Eastern Alignment New Hope (Central) New Hope (Eastern) Maintenance Shaft Maintenance Shaft Twin Cities • Staten Island Canal Ranch • Lower Roberts Maintenance Shaft Maintenance Shaft Southern Complex • Launch/ Reception Shaft Reception Shaft

King Island Central Alignment Maintenance Shaft Maintenance Shaft • Twin Cities Lower Launch/ Reception Shaft Bouldin Island • Reception Shaft Upper SOUTHERN Maintenance Shaft • Southern Complex COMPLEX South Delta Pumping Plant Southern Complex Launch Shafts Southern Forebay Southern Conveyance 5 Reception Shafts

South Delta Outlet Control

5 5 Intake 3 NORTHERN SITES Intake 5 ON-SITE BORROW LOCATIONS EASTERN ALIGNMENT CENTRAL Twin Cities ALIGNMENT Launch Shaft

Eastern Alignment New Hope (Central) New Hope (Eastern) Maintenance Shaft Maintenance Shaft Intakes 2 and 3 • Staten Island Canal Ranch • Twin Cities Complex Maintenance Shaft Maintenance Shaft Lower Roberts Island Terminous Tract • Bouldin Island Launch/ Reception Shaft Reception Shaft • Southern Complex Maintenance Shaft Mandeville Island Central Alignment Maintenance Shaft Lower Roberts Island Launch/ Reception Shaft • Intakes 2 and 3 Bacon Island Reception Shaft Upper Jones Tract SOUTHERN Maintenance Shaft • Twin Cities Complex COMPLEX South Delta Pumping Plant Southern Complex Launch Shafts • Southern Complex Southern Forebay Southern Conveyance 5 Reception Shafts

South Delta Outlet Control

6 5

Intake 3 NORTHERN SITES EASTERN ALIGNMENT OVERVIEW Intake 5

Twin Cities FILL MATERIAL (CY) Complex EASTERN SITE NEEDED IMPORTED Comments ALIGNMENT New Hope Intake 3 1,863,000 55,000 Specialty import for levees Maintenance Shaft

Intake 5 1,684,000 55,000 Specialty import for levees Canal Ranch Maintenance Shaft Twin Cities Complex (TCC) 975,000 0 Includes export to shafts

New Hope Tract Maintenance Shaft 32,000 32,000 Soil fill from TCC Terminous Tract Reception Shaft

Canal Ranch Tract Maintenance Shaft 29,000 29,000 Soil fill from TCC King Island Maintenance Shaft Terminous Tract Reception Shaft 63,000 63,000 Soil fill from TCC

King Island Maintenance Shaft 78,000 78,000 Soil fill from TCC Lower Roberts Island Lower Roberts Tract Includes export to shafts & levee Launch/ Reception Shaft 513,000 0 Launch/Reception Shaft repairs SOUTHERN Upper Jones Tract Upper Jones Tract Maintenance COMPLEX 65,000 65,000 From Lower Roberts Maintenance Shaft Shaft South Delta Southern Complex Launch Shaft 155,000 0 From Southern Forebay Pumping Plant Southern Complex Launch Shaft Southern Forebay 5 Specialty import for embankment; Southern Conveyance Southern Forebay 8,518,000 1,373,000 soil fill from TCC Reception Shafts South Delta Outlet Control South Delta Conveyance 616,000 0 7 5 Intake 3 CENTRAL ALIGNMENT OVERVIEW Intake 5 NORTHERN SITES

CENTRAL Twin Cities FILL MATERIAL (CY) ALIGNMENT Launch Shaft SITE NEEDED IMPORTED Comments New Hope Intake 3 1,863,000 55,000 Specialty import for levees Maintenance Shaft

Intake 5 1,684,000 55,000 Specialty import for levees Staten Island Maintenance Shaft Twin Cities Complex (TCC) 1,385,000 0 Includes export to shafts

New Hope Tract Maintenance Shaft 45,000 45,000 Soil fill from TCC Bouldin Island Launch/ Reception Shaft Staten Island Maintenance Shaft 74,000 74,000 Soil fill from TCC

Bouldin Island Launch/Reception Soil fill from TCC; includes levee 519,000 519,000 Mandeville Island Shaft repairs Maintenance Shaft

Mandeville Island Maintenance Shaft 94,000 94,000 Soil fill from TCC

Bacon Island Reception Shaft 124,000 0 Soil fill from TCC Bacon Island Reception Shaft SOUTHERN Southern Complex Launch Shaft 155,000 65,000 From Southern Forebay COMPLEX Specialty import for embankment; South Delta Southern Forebay 8,518,000 1,890,000 soil fill from TCC Pumping Plant Southern Complex Launch Shaft Southern Forebay 5 South Delta Conveyance 616,000 0 Southern Conveyance Reception Shafts

South Delta Outlet Control