Gowanus CanalData Collection for Treatability Testing

February 2012

Data Collection Summary

• Integrated Sampling Approach~NAPL, Geotechnical and ISS Components

• Evaluate NAPL pore fluid saturation and potential mobility• Evaluate geotechnical properties of native sediment• Evaluate geotechnical properties of native sediment

~ISS Component• Evaluate different stabilization recipesp• Strength, permeability, leachability

~Cogeneration Component• Determine thermal value of soft sediment

Key Concepts

•NAPL Mobility• NAPL can be mobilized by upward hydraulic gradient• Upward migration of NAPL can affect performance of active

caps

•Groundwater Discharge Profileg• Groundwater can transport contaminants• Upwelling groundwater can affect active cap performance• Groundwater discharge will be affected by NAPL

•Geotechnical/ISS data• Native sediment needs to support active cap• Native sediment needs to support active cap• Predict hydraulic conductivity change following ISS• Develop performance criteria for native sediment

Groundwater Upwelling Velocities

RTA 1

Average groundwater velocity upward into

RTA 21.58 ft/day

velocity upward into bottom of canal

RTA 3a/b

0.38 ft/day0.09 ft/day

Upwelling velocity i t dincreases toward head of canal

Groundwater Upward Gradient

Vertical groundwater gradients range from 0.02 to 0.03 ft/ft near canalfrom 0.02 to 0.03 ft/ft near canal

Source National Grid Groundwater Modeling Report (Dec 2011)

Investigation Approach•5 transects, varying NAPL impacts, 3 sample locations

per transect

Example Transect

CH2MHILL®

10ft Qj' ;; E

Oft ')( 0 .. 0. 0. c( -10 ft CIO CIO 0

~ -20ft z -Q)

~ c:: -30ft ~ "' > Q)

w

Soft Sediment (4" Vibracore)

Log Core Pocket Pen .. Vane Shear

Grab Sample PFS. TPH. PAHs

Composite Sample from Core

PFS, TPH, PAHs

Composite Sample from Transect

I

Three Locations per Transect Three Cores per Location

•• •

Native Sediment (4" Vibracore)

Log Core Pocket Pen .. Vane Shear

Grab Sample TPH, PAHs

Composite Sample from Core

TPH, PAHs, pH, Als, TOC

Composite Sample from Transect

...L Upper 5 feet or Native

Native Sediment (3" Shelby Tube)

Undisturbed Core NAPL Mobility Package

• • •

Soft Sediment

Native Sediment

Native Sediment (3" Shelby Tube)

Undisturbed Core Strength. Permeability

Testing SummaryAnalysis Analytical Tests Collection Method Sediment Layer Samples

Pore fluid saturation (water, oil) Dean‐Stark, API (1998) Sec. 4.3 Vibracore Soft 30Bulk density (wet and dry) Included with above Vibracore Soft 30Total porosity Included with above Vibracore Soft 30Particle density Included with above Vibracore Soft 30Calorimetry ASTM D240 Vibracore Soft 5TPH‐D,R,O SW 8015 Vibracore Soft 30PAHs SW8270 Vibracore Soft 30Core cutting and preparation API (1998) Sec. 3.5.2 HSA/ Shelby Tube Native 15Core photography API (1998) Sec. 3.4.1, ASTM 5079 HSA/ Shelby Tube Native 15Pore fluid saturation (water oil) Dean‐Stark API (1998) Sec 4 3 HSA/ Shelby Tube Native 75Pore fluid saturation (water, oil) Dean‐Stark, API (1998) Sec. 4.3 HSA/ Shelby Tube Native 75Bulk density (wet and dry) Included with above HSA/ Shelby Tube Native 75Total porosity Included with above HSA/ Shelby Tube Native 75Particle density Included with above HSA/ Shelby Tube Native 75Particle size analysis w/ hydrometer ASTM D422 HSA/ Shelby Tube Native 30Product Mobility  by Water/NAPL Flooding API (1998) HSA/ Shelby Tube Native 15y y / g ( ) / yCompressive Strength (as‐received) ASTM D2166 HSA/ Shelby Tube Native 15Compressive Strength (post S/S Testing) ASTM D1633 Vibracore Native 3Leachability (pre S/S Testing) EPA 1314, 3545 Vibracore Native 3Leachability (post S/S Testing) EPA 1314, 1315 Vibracore Native 3Permeability (pre S/S Testing) ASTM D5084‐03 HSA/ Shelby Tube Native 15Permeability (post S/S Testing) ASTM D5084‐03 Vibracore Native 3pH E150.1/SM4500‐HB/SW9045C Vibracore Native 15Atterberg Limits ASTM D4318 Vibracore Native 15TOC Lloyd Kahn Vibracore Native 15TPH‐D,R,O SW 8015 Vibracore Native 30PAHs SW8270 Vibracore Native 30PAHs SW8270 Vibracore Native 30Groundwater/NAPL Density, Visocity, IFT ASTM D1217, D445, D971 Manual ‐‐ 2

Groundwater Seep Detection

•Distributed Temperature Sensing (DTS):~ Detailed view of seeps over large areas~ Dynamic view, e.g., effects of tides, rainfall,

pumping in time~ Identify locations where flux meters should beIdentify locations where flux meters should be

installed

•Other Methods~ Many seeps not visible to thermography at surface~ Probes investigate few locations

Groundwater Seep Detection

•500 feet long, 90 f t id

RTA 1

90 feet wide•6,000 feet of

DTS CableDTS

CableSample

TransectsDTS Cable(7,000 points)

•10 passes, 10 f t

Cable Transects

approx. 10 feet spacing between

blcables

DTS ExampleSeeps indicated

by cooler temperature

Summary

•This treatability testing investigation will achieve the objectives that National Grid’s set in the Groundwater Model Report for Gowanus Canal Superfund SiteModel Report for Gowanus Canal Superfund Site (December 2011)

• Alteration in groundwater discharge will be analyzed• Water table mounding from remedial measures will be analyzed• NAPL mobilization will be analyzed by mapping groundwater

velocities