System Optimization During System Design and Operation...

System Optimization During System Design and Operation to Enhance Conventional Remediation Technologies

Chuck Whisman, PE

cwhisman@gesonline.com

Sr. VP of Engineering – Groundwater & Environmental Services, Inc. (GES)

Exton, PA - USA

Remediation System Optimization

Definition:

> To evaluate and monitor remediation systems to detect and respond to changes in system performance

> To determine if system enhancements are needed to meet remedial objectives or improve system operation

Benefits:

> Reduced O&M duration

> Project life-cycle cost savings

The Optimization Process …

Cost savings realized for each month of O&M reduced:

> Labor (field and office)

> Materials (filters, carbon, …)

> Utilities and fuel

> Monitoring (system and wells)

> Equipment lease/rental

> Off-site disposal fees

> Administrative costs

How Much $ Can Effective System Optimization Save?

Typical Remediation System Typical Optimized System

Design $ 10,000 $ 12,000

Installation $ 150,000 $ 165,000

Year 1 O&M $ 70,000 $ 75,000

Year 2 O&M $ 70,000 $ 75,000

Year 3 O&M $ 70,000 $ 75,000

Year 4 O&M $ 70,000 ---

Year 5 O&M $ 70,000 ---

TOTAL $ 510,000 $ 402,000

Does not include post-remediation monitoring/closure costs.

Annual O&M costs include groundwater monitoring and utility costs.

The Optimization Process During Design

• Effective site characterization and feasibility testing will

minimize design assumptions.

• Optimization features can be designed into the system

(i.e., remote monitoring controls, specific equipment,

sampling locations).

The Optimization Process During Design

Examples of design modifications to provide more effective

optimization

> Remote monitoring systems - view data & adjust operation

> Using high-efficiency extraction/injection wells

> Utilizing individual lines to injection/extraction wells (improves

data review and ability to modify system)

> Equipment selection (i.e., redundant transfer pumps, positive

displacement transfer pumps, VFD-controlled motors)

Inspect O&M Data

Recommendations:

• Site-specific O&M forms or use real-

time data acquisition

• Dedicated O&M technicians and

optimization engineers

• O&M data to evaluate:

> system pressures and flow rates

> concentration data

> pump cycling

> treatment system retention time

Determine the degree of system effectiveness

Determine if design goals are met. Examples:

• Are SVE wells providing an effective ROI?

• Can groundwater pumps be lowered or the flow rate increased?

• Are pumping wells providing adequate capture?

• Can different equipment be used?

• Can increased vacuum levels enhance groundwater capture?

Compare the actual concentration reductions versus predicted

concentration reductions.

RW-1 Groundwater Concentrations

0

20,000

40,000

60,000

80,000

100,000

120,000

140,000

Jun-00 Oct-00 Jan-01 Apr-01 Jul-01 Nov-01 Feb-02 May-02

Date

Gro

un

dw

ate

r C

on

ce

ntr

atio

n (

pp

b)

BTEX (ppb)

MTBE (ppb)

Determine the degree of system effectiveness

Information to evaluate includes:

• Concentrations over time

• Treatment equipment removal efficiencies

• Compare actual concentrations to predicted.

BTEX Removal Efficiency

85.00

90.00

95.00

100.00

15-Jul-02 25-Jul-02 4-Aug-02 14-Aug-02

Date

Re

mo

va

l E

ffic

ien

cy (

%)

Actual Removal Efficiency (%)

Review Mass Recovery, Contaminant Reduction, O&M Costs

VAPOR-PHASE CONCENTRATION DATA AND MASS REMOVAL

0

2,000

4,000

6,000

8,000

1-Apr 29-Aug 26-Jan 25-Jun 22-Nov 20-Apr 17-Sep

DATE

VA

PO

R-P

HA

SE

>C

4-C

10 H

C

CO

NC

(P

PM

V)

0

2,000

4,000

6,000

8,000

10,000

12,000

14,000

TO

TA

L P

OU

ND

S

OF

VA

PO

R-

PH

AS

E C

4-C

10

HC

RE

CO

VE

RE

D

vapor-phase >C4-C10 HC conc (ppmv)

pounds of vapor-phase >C4-C10 HC

• Do increasing mass recovery trends occur following system adjustments?

• Has the technology reached it’s endpoint?

• Are other technologies available?

• What is the mass recovery in each phase?(adsorbed, dissolved, separate)

Separate-Phase Product Recovery Over Time

0

200

400

600

800

1000

1200

30-Mar

30-May

30-Jul

30-Sep

30-Nov

30-Jan

30-Mar

30-May

30-Jul

30-Sep

30-Nov

30-Jan

Date

Cum

ula

tive S

epara

te-P

hase P

roduct R

ecovere

d

(gallo

ns)

• Compare dissolved concentrations over time

• Estimate contaminant mass during remediation to determine contaminant reduction and mass remaining

Well ID

Dissolved Concentrations

Pre-RemediationFollowing 12 months of

Remediation

Benzene (ppb)Total BTEX

(ppb)

MTBE

(ppb)Benzene (ppb)

Total

BTEX

(ppb)

MTBE

(ppb)

OW-1* 860 4,490 110 ND ND ND

OW-2* 13,000 60,300 5,500 ND ND 25

RW-1 5,200 6,650 14,000 6 6 89

RW-2* 13,000 20,800 16,000 ND ND ND

RW-3* 4 9 7 ND ND ND

Mass RecoveryPre-

remediation

Following 12 months

of remediation

Dissolved

Phase MassBTEX (lb)

24.80 0.02

Adsorbed-

Phase Mass

BTEX (lb) 826.70 0.70

TPH (lb) 3,240.0 9.33

Adsorbed-Phase BTEX Mass % Decrease 99.92%

Review Mass Recovery, Contaminant Reduction, O&M Costs

BTEX

(μg/l)

5

500

1,000

2,000

4,000

8,000

12,000

16,000

20,000

Before

Remediation

BTEX

(μg/l)

5

500

1,000

2,000

4,000

8,000

12,000

16,000

20,000

After 16

Months of

Remediation

Visual Comparison of Dissolved Concentrations

OPERATING COST PER POUND OF HYDROCARBONS

RECOVERED

$-

$100

$200

$300

$400

$500

Ap

r

May

Ju

n

Ju

l

Au

g

Sep

Oct

No

v

Dec

Jan

Feb

Mar

Ap

r

May

Ju

n

Ju

l

Au

g

Sep

Month

Opera

ting C

ost

Per

LB

of

Hydro

carb

ons

Recovere

d• Determine operating cost / pound of contaminant recovered

• Data should show frequent fluctuations as efficiencies are realized

Review Mass Recovery, Contaminant Reduction, O&M Costs

Evaluate System Up-time and Down-time

• System shut-downs should be evaluated to determine cause of shut-

down

• Shut-downs should be addressed immediately to maximize system

operation and up-time

• Telemetry units and remote monitoring controls can be used to alert

of a system shut-down (via phone, fax, e-mail)

Identify capital costs for upgrades and modifications

• Upgrades/modifications that improve system operation include

> add more extraction/injection wells

> upgrade existing equipment

> install more efficient wells / develop existing wells

> reduce pipe headloss

> change recovery or treatment technologies

Ways to evaluate and justify the need for system

upgrades/modifications

• Perform life-cycle cost analyses

• Conduct additional site characterization activities

• Perform additional remedial feasibility tests

• Use modeling applications or predictive tools

Why is Remote Monitoring Helpful?

• Decreases response time if problem arises

• Can identify problems prior to shutdown

• Increases system up-time

• Decreases # site visits required

• Data logging provides accurate tabular data -decreases reporting

time

• Analysis of logged data enables one to troubleshoot complex

system problems

• Added health & safety control

Remote Monitoring Systems

Data

Processing

Local

Monitor

Panel

Monitor

Analog

Inst.

Digital

Switches

Local Data

Storage Computer Data

Storage

Web Server

Data Storage

• Liquid level transducers installed to measure drawdown.

• Flow transducers measure groundwater recovery rate from each trench/well.

• Electrical submersible pumps controlled automatically via VFDs.

• Adjust flow rates via VFDs/valves to achieve optimal drawdown.

Remote Monitoring - Examples

Remote Monitoring Computer Interface

Remote Monitoring Computer Interface

Soil Vapor ExtractionIdeas for Optimization

• Review system and individual well vacuum levels, mass recovery,

and flow rates

• Analyze which wells to use and

vacuum levels to operate

• Analyze screen interval versus

DTW and applied vacuum

• Evaluate system vacuum losses

Example SVE Data and Review

SVE Well flow vacuum mass recovery

RW-1: 40 scfm 10 iw 15.7 lb/day

MW-4: 28 scfm 45 iw 32.0 lb/day

RW-2: 60 scfm 3 iw < 2.0 lb/day

MW-10 1 scfm 45 iw < 2.0 lb/day

MW-11 60 scfm 8 iw 45.0 lb/day

SVE blower can do 200 scfm @ 50 iw

Low mass recovery

RW-2: High flow, low vac, and low mass recovery – broken line?

MW -10: Low flow, high vac, and low mass recovery – water or clog in line?

Turn off SVE wells with low mass recovery to focus on high-mass SVE wells!!!!

Example SVE Data and Review

SVE Well flow vacuum mass recovery

RW-1: 40 scfm 10 iw 15.7 lb/day

MW-4: 28 scfm 45 iw 32.0 lb/day

RW-2: 60 scfm 3 iw < 2.0 lb/day

MW-10 1 scfm 45 iw < 2.0 lb/day

MW-11 60 scfm 8 iw 45.0 lb/day

SVE blower can do 200 scfm @ 50 iw

Low mass recovery

RW-2: High flow, low vac, and low mass recovery – broken line?

MW -10: Low flow, high vac, and low mass recovery – water or clog in line?

Turn off SVE wells with low mass recovery to focus on high-mass SVE wells!!!!

Automated SVE Optimization

In-Line PID

(Cycles to each leg)

Vacuum Transducer

Flow Transducer

Processes

Data

SmartVAC

SVE

System

System Controls/

PLC

^ ^ ^

O O O

Adjusts valves to change

vacuum/ flow from each well

X X X

1 2 3

Automated SVE Optimization

Groundwater Recovery & TreatmentIdeas for Optimization

• Track pressure drops and concentrations through

system equipment over time

• Evaluate drawdown via hydrographs – compare

drawdown to pump intake level (potential to

adjust lower / raise pumps)

• Evaluate retention time through system

• Check all pumps/equipment/wells for fouling and

proper operation

Total-Phase Vacuum ExtractionIdeas for Optimization

• Evaluate well and straw vacuum levels and ensure there is not significant vacuum loss

• Compare recovered flow rates (vapor and gw) from system versus pilot test data

• Ensure LRP is not operating at a vacuum level that could be too high or too low for the pump

• Periodically perform individual well extraction tests during O&M (compare vapor/gw flow, PID, vacuum)

Air SpargingIdeas for Optimization

• Obtain flow/pressure data at each

point (can change on a daily basis

and should be re-adjusted)

• System cycling preferred – use

O&M data to determine cycling

durations/frequencies

• Obtain DO, mounding, pressure

influence data routinely

• Review pressure data at each point

to ensure that AS points are not

silting/fouling

• Check for short-circuiting or high

flow points

Optimization Examples

Example 1 - Former petroleum terminal with gw/product recovery:

• Limited product recovery (270 gal in 2006; 140 gal in 2007).

• Optimization work included cleaning/refurbishing pumps.

• Results: approx. 1,300 gal product recovered in just over 6 months since optimization work performed (> 10x increase in NAPL recovery).

Example 2 - Service station site:

• Vacuum-enhanced groundwater extraction (VEGE system reached asymptotic mass recovery levels in 2006).

• Performed feasibility testing in 2007 using multiple technologies. Air sparging showed positive results.

• Added air sparging equipment to existing system in 2007System deactivated following 5 months of air sparging after clean-up goals achieved.

Other Optimization Ideas: VFDs and Redundant Pumps

• Variable frequency drives

(reduce power load)

• Redundant transfer pumps,

SVE blowers, or other

equipment

Ozone w/ Air & OxygenHydrogen Peroxide

maximum ROI

Groundwater

Flow Direction

Hydrogen Peroxide

Other Optimization Ideas: Ensure Proper ROI – and Enhance ROI as-needed

Product Recovery Enhancement Ideas: Vacuum? Flushing? Surfactants? Ozone?

Gas Movement in a

Recovery Trench

Ozone Injection

Point

Impacted soil going

back to original

appearance

View appearance changes in soil, water, NAPL

GP-11

pre-remediation10’ to 11’ bgs

GP-11B

after 3 weeks

10’ to 11’ bgs

GP-4

pre-remediation

24’ to 26’ bgs

GP-4B

after 3 weeks

24’ to 26’ bgs

View appearance changes in soil, water, NAPL

GP-6

pre-remediation

12’ to 13’ bgs

GP-6B

after 3 weeks

12’ to 13’ bgs

GP-6

pre-remediation

13’ to 14’ bgs

GP-6B

after 3 weeks

13’ to 14’ bgs

View appearance changes in soil, water, NAPL

View appearance and viscosity changes NAPL

Visualize Concentration Data – Pre-Design and During System Operation

Injection Point Locations Selected Following LIF Investigation

Pre-Remediation 3 Weeks Into Remediation Post Remediation (after 8 weeks)

Visualize Concentration Data – During System Operation (Soil Headspace Readings Shown)

2

20

100

300

500

1000

2000

3000

19000GT4

50 100 150 200 250 300 350 400 450

50

100

150

200

250

300

350

BTEX Concentration Reductions

BTEX (ug/L)

After Three Injections

Oct ‘05

GT4

50 100 150 200 250 300 350 400 450

50

100

150

200

250

300

350

Pre-HypeAir

Mar ‘04

Short-Term ISCO: Adjustments and Evaluations Pre and Post Injection Events (BTEX Site in NY)

Pre-Remediation After 2 Injection Events

Short-Term ISCO: Adjustments and Evaluations Pre and Post Injection Events (ETU Remediation Site in FL)

GERMANTOWN PIKE

FORMER EXXON

SERVICE STATION

MW-7

OIL UST

WASTE

VALL

EY

FO

RG

E R

OAD

GRASS

GRASS

MW-2

MW-3

MW-1

RW-2

TANK FIELD

MW-6

MW-4

RW-1

RW-1A

FUEL

OIL TANKMW-5

PUMPS

PUMPS

PLA

NTE

R

SEPTIC

pre-remediation

April 2003

GERMANTOWN PIKE

FORMER EXXON

SERVICE STATION

MW-7

OIL UST

WASTE

VA

LLEY

FO

RG

E R

OA

D

GRASS

GRASS

MW-2

MW-3

MW-1

RW-2

TANK FIELD

MW-6

MW-4

RW-1

RW-1A

FUEL

OIL TANKMW-5

PUMPS

PUMPS

PLA

NTE

R

SEPTIC

September 2003

0

50

100

150

200

250

300300

250

200

150

100

50

20

MTBE (µg/l)

GERMANTOWN PIKE

FORMER EXXON

SERVICE STATION

MW-7

OIL UST

WASTE

VALL

EY F

OR

GE

RO

AD

GRASS

GRASS

MW-2

MW-3

MW-1

RW-2

TANK FIELD

MW-6

MW-4

RW-1

RW-1A

FUEL

OIL TANKMW-5

PUMPS

PUMPS

PLA

NTE

R

SEPTIC

October 2004

MTBE Concentrations vs. Time

0

500

1000

1500

2000

2500

Mar-

03

Aug-

03

Jan-

04

Jun-

04

Nov-

04

Apr-

05

Sep-

05

Feb-

06

MT

BE

(u

g/L

) MW-7

MW-8

MW-12

RW-1A

Dissolved MTBE Concentrations (ug/l)

Short-Term ISCO: Adjustments and Evaluations After Each Injection Event

Dissolved BTEX Concentrations (ug/l)

% Reduced

Since April

2003Well ID 4/03 7/03 8/03 10/03 1/04 4/04 8/04 10/04 10/05

MW-3 312.2 748.1 10.9 76.5 3.5 ND(5) ND(5) ND(5) ND(5) 100%

MW-4 3.6 ND(5) ND(5) 2.5 ND(5) ND(5) ND(5) ND(5) ND(5) 100%

MW-6 793.6 687.4 708.9 302.4 287.9 221.4 201.5 159.3 ND(5) 100%

RW-1A 771.8 87.6 92.9 23.9 284.3 43.5 ND(5) ND(5) ND(5) 100%

RW-1 ND 118.8 47.5 42.9 2.6 47 98 30 ND(5) 100%

AVERAGE 100%

Injection event

Prior to each injection event, the injection plan was modified for optimal injection.

Short-Term ISCO: Adjustments and Evaluations After Each Injection Event

Dissolved Oxygen (9/20/09)Dissolved Oxygen (7/31/09)

Note: The majority of pre-remediation source area DO levels were less than 1.78 mg/l

Dissolved Oxygen Contours During Remediation (9/20/09)

5

10

10

15

20

P

P

23.28

15.7

13.98

11.61

13.45

7.01

15.08

11.93

11.62

14.5

14.75

ISCO: Visualize Performance Data – During System Operation (Oxygen Influence During Ozone Injection Shown)

GRASS

GRASS

ASPHALT

ASPHALT

EDGELY ROAD

MIL

L C

REEK R

OAD

MW-1

MW-3

MONITORING WELL

%%uLEGEND

FORMER

DISPENSER

ISLAND

FORMER

DISPENSER

ISLAND

THREE BAY

GARAGE

BUILDING

FORMER

UST FIELD

MW-5

VAPOR EXTRACTION POINT

INJECTION WELL

SVE-1

IW-1

IW-2

WATER LINE

UNDERGROUND ELECTRIC LINE

UNDERGROUND TELEPHONE LINE

MW-4

MW-2

60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440

40

60

80

100

120

140

160

180

200

220

240

260

280

300

105 feet

4 days after 3rd Event

– 10/10/06

0.1

0.5

1

2

5

10

30

Dissolved

Oxygen (DO)

concentration

(mg/L)

IW-3

IW-4

IW-5

GRASS

GRASS

ASPHALT

ASPHALT

EDGELY ROAD

MIL

L C

REEK R

OAD

MW-1

MW-3

MONITORING WELL

%%uLEGEND

FORMER

DISPENSER

ISLAND

FORMER

DISPENSER

ISLAND

THREE BAY

GARAGE

BUILDING

FORMER

UST FIELD

MW-5

VAPOR EXTRACTION POINT

INJECTION WELL

SVE-1

IW-1

IW-2

WATER LINE

UNDERGROUND ELECTRIC LINE

UNDERGROUND TELEPHONE LINE

MW-4

MW-2

60 80 100 120 140 160 180 200 220 240 260 280 300 320 340 360 380 400 420 440

40

60

80

100

120

140

160

180

200

220

240

260

280

300

80 feet

39 days after 3rd Event

– 11/14/06

IW-4

IW-3

IW-5

Short-Term ISCO: Visualize Performance Data – Post Injection (Oxygen Influence Shown)

August 1, 2009 August 24, 2009Naphthalene

Concentration

µg/L

September 10, 2009 September 20, 2009

ISCO: Visualize Concentration Data For Source Area (Naphthalene Concentrations Shown)

Benzene

Concentration

µg/L

Jan 10, 2010

Post Remediation

Aug 1, 2009

Pre-Remediation

ISCO: Visualize Concentration Data For Entire Site as Well as Source Area (Benzene Concentrations Shown)

5

5

RESIDENTIAL AREA

RESIDENTIAL AREA

RESIDENTIAL AREA

ALLEY

P

P

10.14.63

17.87

1.56

0.311.762.1 3.07

2.92

4.18

1.91

8.05

0.97

0.08

0.110.22

3.470.11

0.2

3.49 0.03

0.44

3.020.64

1.84

0.41

7.5

6.76 0.14

4.2

July 31, 2009 September 20, 2009 January 15, 2010

5

10

15

RESIDENTIAL AREA

RESIDENTIAL AREA

RESIDENTIAL AREA

ALLEY

P

P

23.28

15.713.98

11.6113.45

7.0115.08

11.9311.62

14.5

14.75

5.73

1.39

7.45 0.18

5

5

10

15

RESIDENTIAL AREA

RESIDENTIAL AREA

RESIDENTIAL AREA

ALLEY

P

P10.54

1212.51

1.215.93

0.36

9.82

10.8910.23

3.62

13.92 12.89

0.51

0.86

0.31

1.01

0.9

7.91

3.98

7.72

27.57 0.37

5

10

15

20

25

Dissolved Oxygen

(mg/L)

ISCO: Visualize Influence Data For Entire Site as Well as Source Area (DO Shown)

It’s never too late to re-look at the source or perform a proper feasibility test!

Thank you.Chuck Whisman, PE

Sr. VP of Engineering – GES

cwhisman@gesonline.com

www.MAX-OX.com