Implementation of Innovative Implementation of Innovative In Situ Biotreatment Technology In Situ Biotreatment Technology

at NWIRP McGregor, Texasat NWIRP McGregor, Texas

Mike Perlmutter

5th Annual Joint Services Pollution Prevention and

Hazardous Waste Management Conference and Exhibition

San Antonio, Texas

August 23, 2000

Presentation OverviewPresentation Overview

Site Description and History Areas of Environmental Concern Interim Stabilization Measures:

Bench- and Pilot-Scale Evaluation– Groundwater– Soil

Conclusions

Site HistorySite History

Operated for More Than 50 Years Under Various Owners and Tenants– United States Army, Navy, and Air Force

Industrial Activities:– Weapons and Weapons Systems

• Bombs, Missiles, and Explosives

– Solid-fuel Rocket Propulsion Systems• Ammonium Perchlorate

AREA H

AREA S

AREA M

AREA L

AREA P

AREA G

AREA A

AREA B

AREA F

AREA R AREA D

AREA C

STATION CREEK WATERSHED

HARRIS CREEK WATERSHED

SOUTH BOSQUE RIVER WATERSHED

Base-outlineSite-outlineBuilding

50FT-CONTOURSBLDGDIRT-ROADRAILROADROADWATER

Subbasin Boundary

gis2//work_dir/mcgregor/simplebase.apr

Site HistorySite History

Area MArea M

750-acre Watershed Perchlorate

Concentrations (ppb)– Surface Water : 5,600– Groundwater: 4 to 91,000– Springs: 22,000

Drainage Pathway• Unnamed Tributary• Station Creek• Leon River/Lake Belton

Interim Stabilization MeasuresInterim Stabilization Measures

Why ISMs?– Migration of Perchlorate-Contaminated

Groundwater and Surface Water from Site– Action Letter from the TNRCC (2/99) Requiring

Migration Abatement Treatment Technology Evaluation Bench-Scale Studies Pilot-Scale Studies

Objective: Evaluate In Situ Treatment of Perchlorate-Contaminated Groundwater

Permeable Reactive Barrier (PRB) PRB Media Evaluation

– Length of Acclimation Period– Reduction Effectiveness – Length of Effectiveness– Hydraulic Characteristics– Feasibility

Bench-Scale Groundwater Study: Bench-Scale Groundwater Study: In SituIn Situ

Experimental Approach– Plastic Bioreactors– PRB Media: 5 to 10% by Mass

• Compost• Canola Oil-Coated Wood Shavings• Cottonseed Meal • Granular Activated Carbon

– Influent Concentration: 5 to 8 mg/L– Flow Rates Similar to Site Groundwater

Bench-Scale Groundwater Study: Bench-Scale Groundwater Study: In SituIn Situ

Compost

Oil-coated Wood Shavings GAC

Cottonseed Meal

Bench-Scale Groundwater Study: Bench-Scale Groundwater Study: In SituIn Situ Medium Phosphate TKN TOC Ammonia Total P

- mg/kg mg/kg mg/kg mg/kg mg/kgcompost 430 23,000 250,000 640 7500wood/oil 31 180 690,000 3.40 28 U

cottonseed meal 42 70,000 500,000 200 10000GAC 15 2,800 970,000 0.69 42

cottonseed - 32,000 440,000 20 4,900

Bench-Scale Groundwater Study: Bench-Scale Groundwater Study: In SituIn Situ

In Situ Bench-scale Study Results: Perchlorate Concentrations

1

10

100

1,000

10,000

0 20 40 60 80 100 120 140 160Time (days)

Pec

hlor

ate

Con

cent

ratio

n (u

g/L

)

Compost Compost (detection) Wood Shavings/Oil

Wood Shavings/Oil (detection) Cottonseed Meal Cottonseed Meal (detection)

GAC GAC (detection) Influent

ISM Pilot-Scale ImplementationISM Pilot-Scale Implementation

Groundwater Cutoff and Collection Trenches

Ex situ Biotreatment System In situ Groundwater Biotreatment Soil Biotreatment

– Anaerobic Landfarming

Cutoff/Collection Trench ConstructionCutoff/Collection Trench Construction

POSSIBLE SOURCE AREA

C-LINE TRENCH

A-LINE TRENCH

B-LINE TRENCH

UNNAMED TRIBUTARY

Cutoff/Collection Trench ConstructionCutoff/Collection Trench Construction

A-line Property Line Cutoff Trench– Extends through

Weathered Limestone Water-bearing Zone

– 30 Inches Wide– Up to 25 Feet Deep– Perforated Collection

Pipe– Drainage Aggregate

Cutoff/Collection Trench ConstructionCutoff/Collection Trench Construction

Cutoff/Collection Trench ConstructionCutoff/Collection Trench Construction

Collection System ModificationCollection System Modification

UNNAMED TRIBUTARY

C1

GAM-10

LSBGWS-10

Clay Clay Clay

Excavated TrenchMaterial

Excavated TrenchMaterial

Excavated TrenchMaterial

Geotextile Geotextile Geotextile

Drainage Aggregate(#57 Gravel)Drainage Aggregate

(#57 Gravel)

Cotton Seed Meal(2 lbs/foot)

GAC(2 lbs/foot)

Cotton Seed(20 lbs/foot)

Compost(15% by volume)

andDrainage Aggregate

(#57 Gravel)

Native Materials Native Materials Native Materials

A-line Trench B-line Trench C-line Trench

Collection System ModificationCollection System Modification

Collection System ModificationCollection System Modification

Groundwater Perchlorate ConcentrationsTreatment System Effectiveness

0

10,000

20,000

30,000

40,000

50,000

60,00022

-Sep

13-O

ct

3-N

ov

24-N

ov

15-D

ec

5-Ja

n

26-J

an

16-F

eb

8-M

ar

29-M

ar

19-A

pr

10-M

ay

31-M

ay

21-J

un

12-J

ul

2-A

ug

Date

Per

chlo

rate

Con

cent

rati

on (

ppb)

Monitoring Well GAM-10 Upgradient of In Situ Treatment System

Lift Station BWithin A-Line Trench

Monitoring Well GWS-10 Downgradient of In Situ Treatment System

Monitoring Point C1Within C-Line Trench

Bench-Scale Soil Study: Bench-Scale Soil Study: Anaerobic LandfarmingAnaerobic Landfarming

Experimental Approach– Nutrients: Nitrogen and Phosphorus– Carbon Sources: Fructose and Citric Acid– Microbes: Acclimated and Indigenous

Findings/Results– Concentrations Reduced From 580 mg/kg

to Detection Limits (0.6 to 1.6 Mg/kg) in 28 Days

Soil Bench-Scale StudyPhase II Results

0

200

400

600

800

1,000

1,200

1,400

1,600

1,800

0 5 10 15 20 25 30 35Date

Per

chlo

rate

Con

cent

rati

on (

mg/

kg) Treatment Cell 1

Treatment Cell 2

Cell 1 - Zero Order

Cell 2 - First Order

Pilot-Scale Soil Study: Pilot-Scale Soil Study: Anaerobic LandfarmingAnaerobic Landfarming

Amendments– Citric Acid– Nitrogen and

Phosphorus– Soda Ash

Flood Cell Monitor

ConclusionsConclusions

VOC Biodegradation In Situ Treatment System Effectiveness

– Projected to Last 8 to 15 Years Perchlorate Mass Leaving Site Reduced

– From 60 to 0.5 Pounds Per Month In Situ Soil Bioremediation Effective Future Applications: Other Onsite Areas

and Offsite