# Presentation: 597027

## Remedial Strategy for Perchlorate-bearing Commingled Plumes at an Explosives Test FacilityEPA Technical Support Project MeetingOctober 21, 2004Speaker: Vic Madrid

**Remedial Strategy for Perchlorate-bearing ****Commingled Plumes at an Explosives Test Facility**EPA Technical Support Project MeetingOctober 21, 2004Speaker: Vic Madrid

**Lawrence Livermore National Laboratory****Environmental Restoration Division**
**UCRL-PRES-207684**

**This work was performed under the auspices of the U.S. Department of Energy by the**
**University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48.**

## Location Map

**Site 300 **
**location map**

**Site**
**300**

- Courtesy
- Kevin Mayer,
- US EPA, Region 9

## Site 300 Raw Chemicals

- _High explosives_
**	**RDX or cyclonite: C3 H6 N6 O6
- 	HMX or octogen: C4 H8 N8 O8
- 	Potassium perchlorate: KClO4
- 	Ammonium perchlorate: NH4ClO4
- 	Mock Explosives: Ba(NO3)2
- 	Nitric acid:  HNO3
- _Radionuclides_
- 	Tritium: 3H
- 	Depleted uranium (235U/238U < 0.007)
- _Solvents & heat exchange fluids_
**	**TCE
- 	Silicon oil (TKEBS/TBOS)

## Site 300 Technical Operations

## Site 300 Technical Operations

- Environmental
- Test Facility

- TCE used as
- heat exchange fluid

## Data from CERCLA investigations

-  1,000+ boreholes
- 	 ~ 70% continuously cored
- 	 > 50% geophysical logs
- 	 up to 550 ft depth
- 600+ ground water monitor wells
- 	15 years of ground water monitoring data
- 	 hydrographs covering drought to El Niño conditions
- 	 broad range of chemical data including isotopes

## Site 300’s commingled plumes

- 8 Operable Units
- 12 commingled plumes
- Low levels of  perchlorate detected in nearly all plumes

**Notes:**
At our site, perchlorate usually exists with different contaminants across the site.  Therefore, we need to develop strategies that deal with multiple areas that have multiple contaminants--and this pushes us to use smaller, portable treatment units and often systems in tandem with each other.

Distributed plumes drive the need for portable units and the reuse of these treatment units once done at one area, for the next area.

## Summary of perchlorate data

- From 1965 to 1975 about 2 tons of perchlorate were used at Site 300
- Perchlorate monitoring began in January 1998 at the request of the RWQCB
- 2,520 ground water samples have been collected from 380 monitor           	wells and analyzed for perchlorate at 4 μg/L detection limit
- 730 perchlorate detections in 122 monitor wells
- Maximum result = 65 μg/L detected down gradient of a landfill pit
- The most widespread perchlorate contamination is located beneath the 		HE Process Area where it is commingled with VOCs, RDX, & 		elevated nitrate.
- In the northern part of Site 300 perchlorate is commingled with tritium, 		depleted uranium, and elevated nitrate.

## Major geologic structures

## Pit 7 complex – tritium plume

## Extent of pit inundation by shallow

- ground water during 1998 El Niño

**Dec  ‘97**

**Feb  ‘98**

**Mar  ‘98**

**Apr ‘98**

**May  ‘98**

**Jul  ‘98**

## Hydrogeologic Cross-section through the landfill pits 

- Pit 7

- Pit 5

**Pit 7**

**Pit 5**

## Extent of depleted uranium in ground water

- Bedrock
- aquifer

- Alluvial
- aquifer

- Pit 3

- Pit 5

- Pit 7

## Perchlorate detections in Pit 7 area

**11**

**14**

**8**

## Proposed remedial alternatives for perchlorate-bearing commingled plume

- Multi-component remedial alternatives to remove depleted uranium and perchlorate, prevent pit inundation, & recycle tritium
-   1) Hydraulic diversion system
-   2) *In situ* (PRB) using cow bone char or apetite & ion exchange resin
-   3) *Ex situ* (funnel & gate) using cow bone char or apetite & ion exchange resin
-   4) Recirculation of tritium-bearing effluent
- 	for *ex-situ* option

*in situ*

*ex situ*

- Draft Final Pit 7 Remedial Investigation/Feasibility for the Pit 7 Complex at Lawrence Livermore National
- Laboratory Site 300, December, 2004 UCRL-AR-202492-DR

## Tnbs2 Aquifer Conceptual Model

**Notes:**
Indicate gw flow direction

## Tnbs2 TCE (μg/L)

- Tnbs2 TCE (μg/L)

- 50

- 20

- 5

- 10

- 30

- 40

- TCE μg/L

- 5

- 10

- 20

- 30

- 40

- 50

- Former
- W-S Well 6

- Mass Est. = 13 kg

- TCE source

## Tnbs2 RDX (μg/L)

**45**

**1**

**90**

**45**

**10**

- TCE μg/L

- 5

- 25

- 50

- 75

- 50

- 25

- 5

- RDX μg/L

- 100

- Mass Est. = 3 kg

- RDX source

- 50

- 25

- 5

- 5

- 25

- 50

## Tnbs2 NO3- (mg/L)

- Tnbs2 NO3**-** (mg/L)

**10**

- Mass Est. =       100,000 kg

- Possible nitrate source

**45**

**60**

**90**

## Nitrate (mg/L) along cross-section A-A’

**97**

**120**

**130**

**100**

**100**

**70**

**90**

**80**

**35**

**15**

**62**

**58**

**ND**

**12**

**3.6**

**ND**

## Dissolved O2 (mg/L) along cross-section A-A’

**4.6**

**4.1**

**7.6**

**5.8**

**7.2**

**0.8**

**0.2**

**< .2**

**0.3**

**1.0**

**1.1**

**1.4**

## Isotopic signatures of nitrate in groundwater and in potential source materials

- Harry R. Beller, Vic Madrid, G. Bryant Hudson, Walt W. McNab, and Tina Carlsen “Biogeochemistry and
- natural attenuation of nitrate in groundwater at an explosives test facility”  Applied Geochemistry 19 (2004).

## Excess N2 along cross-section A-A’

- Harry R. Beller, Vic Madrid, G. Bryant Hudson, Walt W. McNab, and Tina Carlsen “Biogeochemistry
- and natural attenuation of nitrate in groundwater at an explosives test facility”  Applied Geochemistry 19 (2004).

## Tnbs2 ClO4- (μg/L)

## Perchlorate (μg/L) along cross-section A-A’

**ND**

**ND**

-  > 8 μg/L
-  4 - 8
- ND < 4

**ND**

**ND**

**ND**

**ND**

**ND**

**5.8**

**9.8**

**9.2**

**ND**

**9.2**

**ND**

**8.7**

**5.7**

**11**

**ND**

## Ongoing ground water cleanup activities

- Currently operating 13 ground water treatment facilities
- 7 facilities treating perchlorate
- 2 new facilities planned for FY’05 will treat perchlorate

## Key question...

- Given large-scale, dilute, multiple constituent  plumes in low-yield aquifers, how do we develop cost-effective strategies for ground water extraction and treatment using available remedial technology and effluent disposal options?

## Treatment options

## Effluent disposal

## Does GAC remove perchlorate?

- W-817-03

- GAC_1

- GAC_2

- GAC_3

- GAC_1
- influent

- GAC_2
- influent

- GAC_3
- influent

- effluent

- TCE   = 14-29 μg/L
- RDX   =  5-10 μg/L
- ClO4-  = 17-33 μg/L
- NO3-    =  70-90 mg/L

- W-817-03

- ClO4-
- break
- through

## GAC profiling results

- Treated 50,000 gallons @ 1-2 gpm flow rate using solar-powered GAC treatment unit
- ClO4- breakthrough after 20,000 gallons
- 		Effluent @_ __	_
- _	__	_perchlorate
- 	       	_breakthrough__	_   _GAC Profile __	_
- TCE 	=  	 <0.5 μg/L	  < 0.5 μg/L
- RDX 	=    	 <1.0 μg/L	  < 0.3 mg/kg
- ClO4- 	=   	  7.0 μg/L	     47 μg/kg
- NO3-	 =    	   56 mg/L	  178 mg/kg
- Sorption capacity of GAC for ClO4- based on this test =
- 	~ 18 mg/kg or ~ 2 grams per 55 gallon drum of GAC

## GAC perchlorate removal data

## Fixed film bioreactor

- Fixed-film bioreactor
- Designed to treat nitrate using denitrifying bacteria.
- Influent  nitrate = 90 mg/L ( as NO3-)
- Flow rate = 1-2 gpm
- Effluent  nitrate < 1 mg/L at peak efficiency
- 8-hr residence time
- Acetic acid used as main nutrient source.
- Minimizes nitrate loading on IX resin.

**Notes:**
Given the realities of our site, we need to design the treatment facilities to meet all requirements of all contaminants in the aquifer.  Therefore, our treatment facilities tend to be tandem systems.  Here, for the perchlorate, we use the Bioreactor and the Ion Exchange unit (for insurance, in case any perchlorate breaks through).

## Low-cost, solar powered treatment train with containerized wetland (CW)

- Solar-powered treatment train consisting of GAC, CW, & IX operates 10 to 15 hrs / day depending on sun angle.
- CW uses local indigenous plants to remediate nitrate and perchlorate.
- Influent = 10 to 15 μg/L ClO4- & 45 mg/L NO3-
- Flow rate = 1 gpm
- CW Effluent =  < 4 μg/L ClO4- &
- 	< 10 mg/L NO3- at peak efficiency
- 15-hour CW residence time
- Avoid creating wetland habitat.
- Ion exchange polishing used to ensure compliance with effluent discharge requirements.

**Notes:**
Using solar(free) energy (to pump water out of the wells) and gravity--also free (to feed the water through the containerized wetlands).
The solar treatment unit has a Granulated Activated Carbon unit (GAC) or Aqueous Phase GAC.  
Ion exchange unit is for ensuring that no discharges occur to the infiltration trench.  In reality, system consists of STU/GAC, BTU/wetland and that’s it folks.

BTU = Bioremediation treatment unit
STU = Solar treatment unit
Acetate = microbial food source for bioactivity

## B854-PRX Perchlorate Performance Data

## Ion exchange

- Sybron SR-7: nitrate-specific ion exchange resin
- Higher affinity for perchlorate than nitrate (i.e., selectively removes perchlorate from nitrate-bearing water).
- Influent = 40μg/L ClO4- & 100 mg/L NO3-
- Flow rate = 3 gpm
- Effluent =  < 4 μg/L ClO4- & 20 mg/L NO3-
- Perchlorate-laden resin is extremely difficult to regenerate, so it is disposed of as hazardous waste.

**Notes:**
When deploying industry standard remedial technology, we optimize it for the location and conditions within which we’re deploying it.  Environmental factors impact the performance of it negatively, so we’ve found it very important to look at the performance and to figure out ways to optimize that performance.

## Commingled plume treatment train

**Notes:**
Given the realities of our site, we need to design the treatment facilities to meet all requirements of all contaminants in the aquifer.  Therefore, our treatment facilities tend to be tandem systems.  Here, for the perchlorate, we use the Bioreactor and the Ion Exchange unit (for insurance, in case any perchlorate breaks through).

## B815-SRC Perchlorate Performance Data

- Replace
- IX resin

- IX polish

- Detection
- Limit

## Extraction well field management priorities

- 	  Prevent plumes from migrating offsite
- 	  Contain source areas
- 	  Cost efficiency
- 	  Preserve resource

## Capture zone analysis of extraction well field

## Remedial Strategy

- Balance site boundary pumping with up gradient pumping.
- Hydraulically contain source areas.
- Minimize nitrate loading on IX resin to reduce waste disposal costs.
- Strategically inject treated effluent
- 	- reverse natural gradient at site boundary
- 	- flush source areas
- 	- preserve resource
- Demonstrate technical basis for MNA of nitrate.

## Final well field design

- Final well field design

**817-PRX**

**815-PRX**

**815-DSB**

**817-SRC**

**815-SRC**

**Extraction  well**

**Injection  well**

## Acknowledgements

- Project Manager: Leslie Ferry
- Hydrogeology:  Zafer Demir, Mike Taffet, & Walt McNab
- Analytical chemistry: Brad Esser, Bryant Hydson, & Jean Moran
- Microbiology: Harry Beller
- Environmental engineering: Rolf Halden*, Bill Daily Jr, & Matthew Verce
- Phytoremediation: Paula Krauter & Tina Carlsen
- * Johns Hopkins Bloomberg School of Public Health

- References for more information:
- Burge, Stephany and Rolf Halden, “Nitrate and Perchlorate Removal from Groundwater by Ion Exchange” UCRL-ID-135639, September 8, 1999.
- Paula Krauter, Bill Daily Jr., Valerie Dibley, Holly Pinkart, and Tina Legler.  Perchlorate and Nitrate Remediation Efficiency and Microbial Diversity  in a Containerized Wetland Bioreactor. Submitted to International J. of Phytoremediation June 17, 2004. UCRL-JRNL-204756.
- Harry R. Beller, Vic Madrid, G. Bryant Hudson, Walt W. McNab, and Tina Carlsen “Biogeochemistry and natural attenuation of nitrate in groundwater at an explosives test facility”  Applied Geochemistry  19 (2004).