Omer Uppal

Senior Project Manager / Engineer - Remediation Technology

REMEDIAL SYSTEM

OPTIMIZATION

PRESENTATION OUTLINE:

Remedial Optimization Concepts

Air Sparge Implementation for Treatment of VOCs, SVOCs, and Arsenic

Integrated SVE and VM for Complex Building Foundations

Pump and Treat Implementation for Containment of a PCE Plume in Bedrock

Implementation of Hydraulic Optimization for Groundwater Recovery System

ISCO of TCE-Impacted Groundwater in Bedrock Through an Enhanced Fracture Network

OPTIMIZATION – WHAT DOES IT MEAN?

Efforts vs. Time with Remedial Optimization

(U.S. Navy 2003, ITRC 2004)

Efforts vs. Time in Typical Remedial Actions

(U.S. Navy 2003, ITRC 2004)

Goal: “Reduce the cost as well as time to meet remedial objectives and remain protective of

human health and the environment”

WHY OPTIMIZE?

OBJECTIVES Reduce Capital Costs

Reduce OM&M Costs

Reduce Remedial Timeframe

Increase Remedial Efficiency

Increase Performance

Increase Protectiveness – Reduce Risk

Improve Sustainability

Improve Quality

All or a Combination of Above Multi-Objective Decision Making

OPTIMIZE WHEN?

REMEDY OPTIMIZATION PROCESS Track 1 - Optimize During Planning

Track 2 - Optimize During Implementation Planning

Phase

Implementation Phase

Long-Term

Optimization

(NAVFAC Optimization Workgroup Website: https://www.navfac.navy.mil/navfac_worldwide/specialty_centers/exwc/products_and_services/ev/erb/wg/opt.html)

OPTIMIZE HOW?

PROCESS ELEMENTS

Review and evaluate RA objectives and conceptual site

model (CSM)

Evaluate remediation effectiveness

Evaluate cost efficiency

Evaluate remediation alternatives

Evaluate technology alternatives

Develop and prioritize optimization strategies

Prepare optimization report

Implement optimization strategy

TRACK 1 - OPTIMIZE DURING PLANNING

PLAN

Upfront planning for the life-cycle of remedy

STRATEGIZE

Concurrent or sequential use of multiple remedial technologies targeting various sections of a source / plume

Use of several different unit processes within a single treatment system

Integrated / hybrid remedial technology use

DESIGN

Design for the entire life of the cleanup, not just the initial conditions

Allow room for future upgrades or upgrade now for future needs

(NAVFAC Optimization Workgroup, November 2012)

DESIGN CONSIDERATIONS

Evaluate pulsing

Use mass flux calculations

Use F&T models for better prediction of remedy

performance

Use pneumatic models

Lease/purchase equipment

Design mobile systems

Use of passive delivery systems

Use standard designs and parts

Plan for intermittent operation

Evaluate process control options

Consider sustainability during design phase

Apply multiple remedial technologies, where

applicable

TRACK 2 - OPTIMIZE DURING IMPLEMENTATION

EVALUATE

Evaluate remedy performance

Determine the need for system optimization or remedial approach

Optimization alternatives analysis

Perform cost/benefit analysis

IMPLEMENT

Optimize the exit strategy, or

Optimize the remedial system, or

Optimize the monitoring program, or

All of above

MONITOR

Track improved performance

Track cost benefits

Track time to completion

Typical Remedial Progress Curve

(NAVFAC Optimization Workgroup, November 2012)

OPTIMIZE LONG-TERM MANAGEMENT

PROCESS ELEMENTS

Program goals

Monitoring point locations

Monitoring frequency

Monitoring parameters

Sample collection methods

Data evaluation and presentation

Regulatory acceptance

(NAVFAC Optimization Workgroup, November 2012)

AIR SPARGE

IMPLEMENTATION

FOR TREATMENT OF

VOCs, SVOCs,

AND ARSENIC

SITE BACKGROUND

Former manufacturing facility with active lagoon operations through 1954 and backfilled between 1967 and 1970

Benzene, VOCs, SVOCs, and heavy metals (i.e., Arsenic) in soil and groundwater

Former biosparge system operation from 2002 through 2012 - Model predicted cleanup time frames >> 50 years

GW Flow Direction

AIR SPARGE TARGET AREA

REMEDIAL OPTIMIZATION STRATEGY

EXCAVATION

Removal and off-site disposal of approximately 2,200 tons of NAPL impacted soil - October 2012

PULSED AIR SPARGE SYSTEM

VOCs / BTEX

Volatilization / Stripping

Aerobic biodegradation

PHARMACEUTICALS (Phenol) and ALCOHOLS (Ethanol)

Aerobic biodegradation

METALS (Arsenic)

Co-precipitation with dissolved minerals (i.e., iron and calcium)

Sorption on metal / iron oxy-hydroxides SEM images of Fe-Al-Si oxy-hydroxide

precipitate formed in

groundwater

(EDS analytical spectra)

MAY 2013 AIR SPARGE PILOT TEST

Remedial Technologies Tested:

Biorespiration

Air Sparge/Helium Tracer

SVE/Point Permeability

Test results indicated favorable

conditions for air stripping.

PNEUMATIC MODELING

Modeling resulted in a more cost-

effective optimization strategy.

OPTIMIZATION DESIGN STRATEGY

DESIGN COMPONENTS

53 multi-level air sparge wells

41 horizontal vapor collection wells

17 vapor vent wells

11 chimney wells

2 dry wells

3-ft Clean Fill Cap

Pulsing Strategy

OPTIMIZATION BENEFITS

System Construction Ongoing

Startup planned for January 2015

Anticipated Cleanup Timeframe - 3 to 5 years

• Reduced Cleanup Timeframe

• Cost Savings

• More innovative, cost effective, and sustainable in-situ

remediation technology than excavation

INTEGRATED SVE AND VM FOR COMPLEX

BUILDING FOUNDATIONS

INTEGRATED SVE AND VM, MANHATTAN, NYC

SITE BACKGROUND

Active dry cleaning facility through June 2013

Residential dwellings located on floors two through five

Indoor air assessment - PCE and TCE in exceedance of

NYSDOH Vapor Intrusion Guidance Matrix

2-6 inch thick concrete slab with granite bedrock beneath

Limited space/access constraints

Possible demolition of building during operation period

OPTIMIZATION STRATEGY

Pilot test and pneumatic modeling

Integrated SVE and VM approach

Equipment was sized so that the system can be

expanded in the future, if warranted.

Operational sub-slab vacuums >> 0.004 IWC

Total VOC Mass Removed = 260 lbs (February 2013 through April 2014)

Optimization Benefits:

Effective vapor mitigation and remediation through one system

Cost savings

SYSTEM OPERATION

INTEGRATED SVE AND VM, NORTHERN NJ

SYSTEM IMPLEMENTATION

Pilot test and pneumatic modeling

Equipment sizing for potential system expansion

System activated in September 2014

Operational sub-slab vacuums >> 0.004 IWC

Initial VOC mass removal rate = 0.25 lbs/day

OPTIMIZATION BENEFITS

Effective Vapor Intrusion Mitigation

Source Mass Removal

Cost Savings

Reduced Remedial Timeframes

PUMP AND TREAT

IMPLEMENTATION FOR

CONTAINMENT OF A

PCE PLUME IN

BEDROCK

Municipal Well

RW-1

RW-2

RW-3

RW-4

RW-5

RW-6

SITE BACKGROUND

SYSTEM DESIGN

OPTIMIZATION STRATEGY PCE plume containment in a complex

geology – Interbedded Shale and

Sandstone lenses

Mass Removal

Equipment sizing for potential future

expansion

Vapor Pressure > 1.0 mm Hg

PCE 14 TCE 58

P&T EQUIPMENT COMPONENTS

IMPLEMENTATION OF HYDRAULIC

OPTIMIZATION FOR GROUNDWATER

RECOVERY SYSTEM

GROUNDWATER MODEL CONSTRUCTION

Regional Groundwater Model Grid

(Nine model layers encompassing

an area of 130 square miles)

Close-up of refinery property

NORTH

River

50x vertical exaggeration

River

1 Mile

Refinery

BENZENE MT3D SIMULATION, CURRENT CONDITIONS

B

B’

OPTIMIZED SYSTEM PUMPING RATES

PW-52

PW-51

RW-28

RW-6

RW-22

PW-49

PW-48

PW-50

RW-23

RW-5A

OPTIMIZATION BENEFITS

Effective Containment

Reduced Pumping Rates

Reduced OM&M Costs

ISCO OF TCE-IMPACTED GROUNDWATER IN

BEDROCK THROUGH AN ENHANCED FRACTURE

NETWORK

SITE BACKGROUND

TCE plume occupies an area of approximately 3 million ft2.

Poorly connected fractures form a complex network with low hydraulic connectivity

DNAPL Source Zone Pilot Tests

Implementation of SVE Pilot Test – 2003

Implementation of ISCO Pilot Test – 2003

9 blast fracture trenches and 327 blast/injection

boreholes totaling approximately 21,400 linear

feet installed to facilitate chemical oxidant

injections – 2006

NOVEMBER 2005

JANUARY 2008

51,024 GALLONS (31,320 LBS.) OF 2.5% POTASSIUM PERMANGANATE & 10% SODIUM PERMANGANATE SOLUTION

INJECTED FROM 2003 TO 2009

SEPTEMBER 2011

REMEDIAL OPTIMIZATION IMPLEMENTATION

Additional injections October through November 2011

Mitigate the residual “source” of TCE groundwater plume with

concentrations greater than 1,000 ppb

43,200 gallons (9,151 lbs.) 2.5% Potassium Permanganate solution

injected into 32 intermediate injection wells and 8 deep injection wells

6 deep injection wells and 1 intermediate injection well were hydro-

fractured to facilitate chemical oxidant injections.

Overnight gravity feed to facilitate improved injection rates.

OPTIMIZATION BENEFITS

Source Treatment

Reduction in size of groundwater

plume

Reduction in average TCE

concentrations by 88%

Technical Impracticability

Waiver

Substantial Cost Savings

REMEDIAL ACTION RESULTS:

INTERMEDIATE ZONE

CONCLUSIONS

Upfront planning for the life-cycle of remedy is critical: Design for the entire life of the

cleanup, not just the initial conditions.

Establish performance objectives for each component of treatment train.

Define effective operational range of technology: Identify when to discontinue use of

a specific technology once it’s no longer operating within its pre-determined cost

effective range.

Pulsing of Air Sparge / SVE / MPE / P&T systems can result in improved remedial

efficiency and sustainability under mass transfer limiting conditions.

Cost-effective remediation will likely require transitioning between multiple treatment

technologies.

Optimization can result in substantial cost savings, reduce cleanup timeframe, and

increase protectiveness of a remedial system.

QUESTIONS??