Background on Contaminant Migration and Exposure Pathways - PowerPoint PPT Presentation

Background on Contaminant Migration and Exposure Pathways Presentation to the LTMS August 28, 2007 By: Brian Ross, USEPA

Figure 7-1. Illustration of locales or conditions for volatile emissions from CDFs

Delta Island Hydrology & Dredged Sediment Chemistry Presentation to the LTMS August 28, 2007 By: Steven Michelson Applied Water Resources Corporation Walnut Creek, CA 925 938 1600

Remedy for Sediment Dilemma (adapted from Jeffery Steevens, ERDC) � Management � “Use science to tell us the right level” � Regulatory Agencies � “Let’s look at the regulations” � Scientists � “It depends…” � Environmental Groups � “No level is low enough” � Politicians � “Any level is OK, if this problem will only go away” August 28, 2007

Outline (science approach) � Delta Island Hydrology � Delta Island Ground Water � Delta Island Drainage Ditch Water � Sediment characterization � Based on Roberts No. 1 and adjacent Deep Water Ship Channel August 28, 2007

DELTA Stockton Deep Water Ship Channel Roberts Island Rough and Ready Island August 28, 2007

August 28, 2007

Schematic – delta island hydrology August 28, 2007

Deep Water Ship Channel Roberts No. 2 San Joaquin Pump House River Black Slough Roberts No. 1 Burns LOWER Cutoff ROBERTS Mokelumne ISLAND Aqueduct ROUGH & READY ISLAND August 28, 2007

August 28, 2007 Roberts No. 1

Roberts Island Drainages near RN1 August 28, 2007

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Ground Water Quality August 3, 2006

August 28, 2007 Background Transect

August 28, 2007

August 28, 2007

Specific Conductance in RN1 Peat Layer Monitor Wells Background Transect includes all field measurements since 9/05 7000 6000 5000 Specific Conductance (µS/cm) 4000 3000 2000 1000 MW-9p MW-10p MW-11p 0 0 500 1000 1500 2000 2500 3000 Distance from River (feet) August 28, 2007

Specific Conductance Sand Layer Wells, Background Transect - includes all field measurements since 9/05 5000 4500 4000 3500 Specific Conductance (µS/cm) 3000 2500 2000 1500 1000 500 MW-9s MW-10s MW-11s 0 0 500 1000 1500 2000 2500 3000 Distance from River (feet) August 28, 2007

Specific Conductance in RN1 - All Peat Layer Monitor Wells includes all field measurements since 9/05 7000 6000 5000 ) ens/cm icrosiem 4000 onductance (m MW-5p MW-7p 3000 MW-8p pecific C MW-9p MW-10p MW-11p S MW-13p 2000 MW-15p MW-16p MW-17p MW-18p 1000 MW-19p MW-20p 0 0 500 1000 1500 2000 2500 3000 Distance from River (feet) August 28, 2007

Specific Conductance in RN1 Sand Layer Monitor Wells, All Transects includes all field measurements since 9/05 5000 4500 4000 Specific C onductance (microsiemens/cm) 3500 9s, 10, 11s MW-5s 3000 MW-6s MW-7s 6s, 13s, 20s, 7s 2500 MW-8s MW-9s 2000 MW-10s MW-11s 18s, 19s, 8s MW-13s 1500 MW-15s MW-16s 1000 MW-17s MW-18s 500 MW-19s Edge of sediment MW-20s 0 0 500 1000 1500 2000 2500 3000 Distance from River (feet) August 28, 2007

Island Drainage – Water Quality August 3, 2006

Agricultural Irrigation Ditches at RN1 SW-1 SW-2 August 28, 2007 SW-3 SW-4 Main drain

Ditch Water and Ground Water 30 MW-6d MW-14d 25 SW-3 Main Island Drainage 20 Water Quality Goal 15 10 5 0 Arsenic Lead Sodium Sulfate SC (µg/l) (µg/l) (mg/l/10) (mg/l/10) (µS/cm/100) August 28, 2007

Sediment Chemistry August 3, 2006

Source of Sediments… � River sediment naturally eroded from foothills and Sierra Nevada � Deposited throughout Central Valley and Delta � Anthropogenic impacts � Mining ‐ (Hg …) � Agricultural ‐ (pesticides, herbicides, nitrates, organic carbon) � Industrial ‐ (you name it…) � Municipal Storm Water ‐ (petroleum, metals…) August 28, 2007

ARSENIC : in Sediment and Ground Water 90 80 70 Concentration (µg/l, ppb) 60 50 40 30 20 10 WQG = 10 µg/l AG = 100 µg/l 0 REF (1) POS WC DWSC 04, S4 Seds (5) Roberts Isl MW-9P MW-10P, MW-9S MW-10S, Docks (10) 05, 05 (30) No.1 (21) 11P 11S DI WET DI WET DI WET DI WET GW Background Peat Background Sand RIVER PREDREDGE DREDGED ISLAND GROUND WATER Arsenic

BARIUM : in Sediment and Ground Water 1000 900 800 Concentration (µg/l, ppb) 700 600 500 400 300 200 100 WQG = 10 µg/l AG = 100 µg/l 0 REF (1) POS WC DWSC 04, S4 Seds (5) Roberts Isl MW-9P MW-10P, MW-9S MW-10S, Docks (10) 05, 05 (30) No.1 (21) 11P 11S DI WET DI WET DI WET DI WET GW Beckground Peat Background Sand RIVER PREDREDGE DREDGED ISLAND GROUND WATER

COPPER : in Sediment and Ground Water 70 60 Concentration (µg/l, ppb) 50 40 30 20 10 WQG = 10 µg/l AG = 100 µg/l 0 REF (1) POS WC DWSC 04, S4 Seds (5) Roberts Isl MW-9P MW-10P, MW-9S MW-10S, Docks (10) 05, 05 (30) No.1 (21) 11P 11S DI WET DI WET DI WET DI WET GW Beckground Peat Background Sand RIVER PREDREDGE DREDGED ISLAND GROUND WATER Copper

LEAD : in Sediment and Ground Water 20 18 16 Concentration (µg/l, ppb) 14 12 10 8 6 4 2 WQG = 10 µg/l AG = 100 µg/l 0 REF (1) POS WC DWSC 04, S4 Seds (5) Roberts Isl MW-9P MW-10P, MW-9S MW-10S, Docks (10) 05, 05 (30) No.1 (21) 11P 11S DI WET DI WET DI WET DI WET GW Beckground Peat Background Sand RIVER PREDREDGE DREDGED ISLAND GROUND WATER Lead

NICKEL : in Sediment and Ground Water 100 90 80 Concentration (µg/l, ppb) 70 60 50 40 30 20 10 WQG = 10 µg/l AG = 100 µg/l 0 REF (1) POS WC DWSC 04, S4 Seds (5) Roberts Isl MW-9P MW-10P, MW-9S MW-10S, Docks (10) 05, 05 (30) No.1 (21) 11P 11S DI WET DI WET DI WET DI WET GW Beckground Peat Background Sand RIVER PREDREDGE DREDGED ISLAND GROUND WATER Nickel

ZINC : in Sediment and Ground Water 200 180 160 140 Concentration (µg/l, ppb) 120 100 80 60 40 20 WQG = 10 µg/l AG = 100 µg/l 0 REF (1) POS WC DWSC 04, S4 Seds (5) Roberts Isl MW-9P MW-10P, MW-9S MW-10S, Docks (10) 05, 05 (30) No.1 (21) 11P 11S DI WET DI WET DI WET DI WET GW Beckground Peat Background Sand RIVER PREDREDGE DREDGED ISLAND GROUND WATER Zinc

SUMMARY � Delta Island Hydrology � Rivers recharge GW � GW flows inland and is returned via ditches to river � Delta Island Ground Water � GW becomes more saline with distance inland � GW in dredged sediments is similar to GW adjacent to river � GW in dredged sediments is of better quality than inland GW � Delta Island Drainage Ditch Water � Of lower quality than GW in River and dredged sediments � Sediment characterization � DI WET tends to over ‐ predict potential impact to GW August 28, 2007

August 28, 2007 END