On-Site Incineration of Basin F Liquids at the
Rocky Mountain Arsenal Superfund Site
Commerce City, Colorado

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Incineration at the Rocky Mountain Arsenal Superfund Site
Commerce City, Colorado

Site Name:

Rocky Mountain Arsenal
Superfund Site

Contaminants:

Organochloric and
organophosphoric pesticides
and metals

•	ardrin

•	dieldrin

•	vapona

•	copper

•	zinc

•	arsenic

Period of Operation:

July 1993-July 1995

Location:

Commerce City, Colorado

Cleanup Type:

Interim response

Vendor:

T-Thermal Sub-X® Liqui-
Datur® Incinerator
manufactured by T-Thermal
Incorporated and cross-licensed
by Nittetu Chemical
Engineering, Limited

Technology:

On-Site SQI Incineration

•	High-temperature oxidation in
a down-fired, SQI

•	High-energy venturi scrubber
for particulate emission control

•	Packed tower caustic scrubber
for neutralization of exhaust
gases

•	Residuals transported to off-
site handling facility

Cleanup Authority:

CERCLA and State: Colorado

•	U.S. Army, PRP, and EPA
enter into Federal Facilities
Agreement 2/89 - includes 13
interim response actions

•	ROD signed 12/9/96

•	DoD Lead

SIC Code:

NA

Point of Contact:

Colonel Eugene H. Bishop
Program Manager
Rocky Mountain Arsenal
Commerce City, CO 80022-
2180

(303) 289-0467 - Public Affairs
Office

(303) 286-8032 - SQI
Information Hotline

Waste Source:

Evaporation basin used to store
manufacturing wastewaters

Type/Quantity of Media Treated:

Liquids

• 10.9 million gallons

Purpose/Significance of
Application:

Innovative design used to
capture metal particulates;
250,000 pounds of copper
recovered and recycled

Regulatory Requirements/Cleanup Goals:

• Destruction and Removal Efficiency (DRE) of 99.99% for all constituents of concern as required by
Resource Conservation and Recovery Act (RCRA) incinerator regulations in 40 CFR part 264, subpart
O

Results:

Monitorina and trial burn data indicate that all DRE and emission standards have been met

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Incineration at the Rocky Mountain Arsenal Superfund Site
Commerce City, Colorado

(Continued)

Description:

RMA was established in 1942 and historically has been used for manufacturing and demilitarizating
chemical incendiary weapons. Portions of RMA were leased for the private production of agricultural
chemicals including pesticides from 1947 to 1982. Between 1957 and 1982 an evaporation pond (Basin
F) was used for disposal of various wastewaters from the site's manufacturing process and wastes from
demilitarization activities.

The Army and the on-site chemical manufacturer were designated as responsible parties in a Federal
Facilities Agreement (FFA) entered into in 1989. The FFA specified 13 interim response actions (IRAs),
including the remediation of Basin F. A Record of Decision (ROD) for all operable units at the site was
signed June 11, 1996.

The Army selected SQI to dispose of Basin F liquids. The SQI system included an atomizing liquid
injection system; an incinerator chamber; a quench chamber; a spray dryer; a venturi scrubber for
particulate matter control; a packed-tower scrubber for neutralization of off-gases; and a residuals
handing facility.

Full-scale operation of the SQI began in July 1993, and incineration of approximately 10.9 million
gallons of Basin F liquid was completed by July 1995. The SQI was decommissioned, dismantled, and
sold for parts, per the FFA, upon completion of the project. All applicable and relevant or appropriate
requirements were met throughout the project.

The actual cost for remediation of Basin F was approximately $93,000,000, including $14,800,000 in
capital costs and $78,500,000 in operation and maintenance costs.

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Rocky Mountain Arsenal Superfund Site

Executive Summary

This report presents cost and performance data
for the application of on-site incineration at the
Rocky Mountain Arsenal (RMA) Superfund Site
near Commerce City, Colorado. An on-site
submerged quench incinerator (SQI) was used
from July 1993 through July 1995 to treat liquid
wastes generated at RMA.

The primary contaminants of concern in the liquid
waste included organochloric pesticides
(including aldrin and dieldrin), organophosphoric
pesticides (including vapona), and metals
(including copper, lead, arsenic, and zinc).

RMA was established in 1942 and historically has
been used for manufacturing and demilitarizating
chemical incendiary weapons. Portions of RMA
were leased for the private production of
agricultural chemicals including pesticides from
1947 to 1982. Between 1957 and 1982 an
evaporation pond (Basin F) was used for disposal
of various wastewaters from the site's
manufacturing process and wastes from
demilitarizations.

The Army and the on-site chemical manufacturer
were designated as responsible parties in a
Federal Facilities Agreement (FFA) entered into
in 1989. The FFA specified 13 interim response
actions (IRAs), including the remediation of Basin
F. Standards for Basin F were established in a
1990 Final Decision Document (DD). These
standards included treatment resulting in a
99.99% destruction and removal efficiency (DRE)
of organic constituents. A Record of Decision
(ROD) for all operable units at the site was
signed June 11, 1996.

Remediation of Basin F was conducted in
two parts. The first part consisted of removal
and temporary storage of liquid, and removal
and stockpiling of solids and sludges. The
second part consisted of disposal of the
stored liquid. The remainder of this
document addresses the disposal of Basin F
liquids, unless otherwise stated.

The Army selected SQI to dispose of Basin F
liquids. The SQI system included an
atomizing liquid injection system; an
incinerator chamber; a quench chamber; a
spray dryer; a venturi scrubber for particulate
matter control; a packed-tower scrubber for
acid neutralization of the exhaust gases; and
a residuals handing facility.

Full-scale operation of the SQI began in July
1993, and incineration of approximately 10.9
million gallons of Basin F liquid was
completed in July 1995. The SQI was
decommissioned, dismantled, and sold for
parts, per the FFA, upon completion of the
project. All applicable and relevant or
appropriate requirements (ARARs) were met
throughout the project.

The actual cost for remediation of Basin F
was approximately $93,000,000. This
consisted of approximately $14,800,000 in
capital costs and $78,500,000 in operating
and maintenance costs.

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Rocky Mountain Arsenal Superfund Site

Site Information

Identifying Information

Treatment Application

Rocky Mountain Arsenal Superfund Site
Commerce City, Colorado

Type of action: Interim response (on-site
SQI incineration)

CERCLIS #: NA

ROD and DD Date: A Decision Document for
the Basin F IRA was issued May 1990. A single
ROD for all on-site OUs, including Basin F, was
signed June 11, 1996.

Background

Period of full-scale incinerator operation:

July 1993 through July 1995

Quantity of material treated during
application: 10.9 million gallons of liquid
hazardous waste

Historical Activity that Generated
Contamination at the Site: Manufacture and
demilitarization of chemical munitions and
manufacture of pesticides

Waste Management Practice that Contributed
to Contamination: Disposal of manufacturing
wastewater into an evaporation basin

Site History:

RMA was established in 1942 for the
manufacture of chemical and incendiary
munitions as well as demilitarization of
chemical munitions. Pesticides were
manufactured at the site from 1947 through
1982.

The RMA site is located on approximately
17,000 acres 10 miles northeast of
metropolitan Denver, Colorado and directly
east of Commerce City.

From 1943 through 1950, stocks of
Levinstein mustard gas were distilled, several
million rounds of mustard-filled shells were
demilitarized, and mortar rounds filled with
smoke and high explosives were test-fired.

In 1947, portions of RMA were leased for
production of chlorobenzene, DDT,
naphthalene, chlorine, and fuzed caustic.

In 1951, another manufacturer assumed
the lease and produced pesticides until
1982.

Through 1956, waste streams from the
above manufacturing operations were
discharged to unlined evaporation basins
(Basins A through E).

In 1956, Basin F was designed and
constructed as an evaporation basin to
receive various manufacturing wastes.
The basin had a surface area of 93 acres
and a capacity of approximately 243
million gallons. The basin was
constructed using an asphalt liner
covered by a 1-foot layer of sand.
Between August 1957 and December
1981, Basin F was the only evaporative
wastewater disposal location in service at
RMA.

Basin F was located in the northeast
section of RMA and was used to dispose
of wastes containing organochloric and
organophosphoric pesticides and various
metals.

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Rocky Mountain Arsenal Superfund Site

Site Information (Cont.)

Background (Cont.l

In 1986, the Department of Interior, the
Department of Health and Human Services,
the Department of Justice, and the U.S. EPA
(EPA ef a/.,); and the potentially responsible
parties (PRP) at the site agreed (via the
Basin F Memorandum of Understanding) to
undertake a removal action to address
threats to human health and the environment
posed by liquids and contaminated soils and
sludges in Basin F. Part One of the removal
action (completed in December 1988)
included the removal of liquids from Basin F
to storage tanks and a surface
impoundment, and the removal of soil and
sludge to a double-lined waste pile. Part
Two included incineration of the Basin F
liquid that was stored in the holding tanks and
surface impoundment.

In February 1989, EPA et al., and the PRPs
entered into a FFA for all of RMA, including
remediation of Basin F.

In May 1990, the Army issued a Final
Decision Document for Basin F Liquids which
specified remediation via SQI with a
venturi/packed-tower scrubber.

Timeline

Table 1. Timeline

Date

Activity

1942

RMA established for manufacture and demilitarization of chemical and incendiary munitions.

1943- 1950

Chemical munitions manufactured and demilitarized; explosives test-fired.

1947

Portions of RMA leased; manufacture of chlorobenzene, DDT, naphthalene, chlorine, and fuzed
caustic begins.

1951 - 1982

PRP assumes lease and manufactures pesticides.

1957- 1982

Basin F is used as an evaporation pond for various RMA manufacturing process discharges.

1986

U.S. Army, another PRP, and EPA et al., agree to Basin F Memorandum of Understanding, outlining
Basin F IRA

July 1987

RMA placed on the NPL

May 1988 - December
1988

Part One of Basin F IRA conducted (removal and temporary storage of wastes).

September 1988

Part Two of Basin F IRA initiated (characterization of liquid waste, selection of treatment alternative,
testing of treatment technology, design of treatment process).

February 1989

U.S. Army, another PRP, and EPA et al., enter into a FFA that includes 13 IRAs at RMA (including a
two-part IRA for remediation for Basin F liguid, sludges, and soils).

December 1989

Final Treatment Assessment Report describing the preferred alternative for treatment of Basin F
liguids.

May 1990

Final Decision Document for Basin F liouid treatment issued.

U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Solid Waste and Emergency Response
Technology Innovation Office

Between July 1993 and July 1995, the
SQI processed 10.9 million gallons of
Basin F liquids, meeting the standards
established in the FFA.

Regulatory Context: In February 1989,
EPA et al., the Army and the second PRP
entered into a FFA that stated RMA is subject
to the cleanup standards in Section 121 of
the Comprehensive Environments Response,
Compensation, and Liability Act (CERCLA)
and provisions of the National Contingency
Plan for Oil and Hazardous Substances
(NCP).

Remedy Selection: On-site submerged
quench incineration (SQI) was selected as
the remedy for Basin F liquids at RMA based
on the results of feasibility studies, a
preliminary risk assessment, and treatability
studies (laboratory and pilot-scale testing);
economic considerations; and input from the
public.

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Rocky Mountain Arsenal Superfund Site

Site Information (Cont.)

Table 1. Timeline

Date

Activity

September 1992

Trial Burn Plan submitted.

May 20-25, 1993

Two Mini-Burns conducted (to establish interim limits).

June 10-12, 1993

Trial Burn conducted.

July 1993-July 1995

Full-scale operation of SQI conducted.

December 1993

Trial Burn Summary Report completed.

May 1996

SQI decommissioned, dismantled and sold for parts.

Site Loaistics/Contacts

U.S. Army Contact:

Colonel Eugene H. Bishop
Program Manager
Rocky Mountain Arsenal
Commerce City, CO 80022-2180
(303) 289-0467 - Public Affairs Office
(303) 286-8032 - SQI Information Hotline

Treatment System Vendor and Operator:

T-Thermal Sub-X® Liqui-Datur® Incinerator
manufactured by T-Thermal Incorporated
and cross-licensed by Nittetu Chemical
Engineering, Limited

SQI system operated by Weston Inc.

Matrix Description

Matrix Identification

Type of Matrix Processed Through the
Treatment System: Liquid waste from pesticide
manufacturing processes

Contaminant Characterization

Primary Contaminants: Organochloric and	found at concentrations ranging from

organophosphoric pesticides and metals in	0.11 to 0.89 mg/L.

solution

Several metals were detected, including
The contaminants of greatest concern	copper, zinc, and arsenic at maximum

include pesticides (aldrin, dieldrin, and	concentrations of 210 mg/L, 0.95 mg/L,

vapona) and metals (copper, zinc, and	and 3.0 mg/L, respectively,

arsenic).

Several organochloric pesticides were
detected, including vapona at a maximum
concentration of 2.40 mg/L.

Several organophosphoric pesticides were

Site Management: DOD-Lead

Oversight: EPA with input from Colorado
Department of Health, U.S. Fish and Wildlife
Service, and Tri-County Health Department

Remedial Project Manager:

Laura Williams
U.S. EPA Region 8
999 18th Street, Suite 500
Denver, Colorado 80202
(303) 312-6660

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Office of Solid Waste and Emergency Response
Technology Innovation Office

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Rocky Mountain Arsenal Superfund Site

Matrix Description (Cont.)

Matrix Characteristics Affecting Treatment Costs or Performance

The Basin F liquid was sampled and
analyzed and determined to be corrosive,
according to RCRA regulations in 40 CFR
261.22. The higher heating value of Basin F
liquid was measured to be 37 BTU/lb.

Specific gravity and pH of the liquid were
measured to be 1.2 and 6.02,
respectively.

Treatment System Description

Primary Treatment Technology

Submerged quench incineration system
including:

Atomizing liquid injection system
Submerged quench incinerator
Quench chamber
Spray dryer

System Description and Operation

Supplemental Treatment Technology

Post treatment (air):

High-energy venturi scrubber for
particulate matter control
Packed tower caustic scrubber for acid
neutralization of the exhaust gases

The incineration system at RMA consisted of
high-temperature oxidation in a down-fired,
SQI followed by a high-energy venturi
scrubber for particulate emission control and
a packed tower caustic scrubber for acid
neutralization of the exhaust gases. A
schematic of the incineration system is
presented in Figure 1.

During operations, liquid waste was fed to the
flame zone of the down-fired incinerator
through an atomizing spray nozzle. Molten
salts (residuals from combustion) flowed
down the sides of the incineration vessel and
fell into a quench tank with water circulation.
Combustion gases were bubbled through the
quench tank and routed to the APCS. The
quench tank liquid (brine), which contained
dissolved salts and residual heavy metals,
was transported first to the residuals storage
facility and ultimately off-site where the
metals were removed and recycled to a
smelter.

the quench tank gases and primary
treatment for the discharge air from the
residuals handling facility. The packed-
tower scrubber system consisted of an
absorber section, a mist eliminator, and
an exhaust stack.

Combustion gases were drawn through
the SQI and APCS by an induced-draft
fan and were exhausted through a 30-
meter reinforced, concrete stack.

Typical exit gas velocity was 14.7 meters
per second.

The SQI was developed by T-Thermal,
Inc. The SQI design operating
parameters are presented in Table 2.

The APCS included of a mechanical venturi
scrubber for removal of particulates in the
off-gases from the quench tank. The APCS
also included a caustic (packed) tower
scrubber used as secondary treatment for

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Rocky Mountain Arsenal Superfund Site

Treatment System Description (Cont.)

Table 2. Summary of Design Operating Parameters

Parameter

Value

Combustion chamber capacity

30 million BTU/hr

Gas temperature after quench

200 °F

Residence time

2 seconds

MOIST. TREATED AIR TO ATMOSPHERE - ^

LIME FftOM MSm P LKMMOft TANK

Figure 1. Conceptual Schematic of the Submerged Quench Incineration System
(prepared by Woodward-Clyde Consultants)

Treatment System Performance

Cleanup Goals/Standards

The cleanup goals and standards specified in	• The required DRE for POHCs was

the FFA were consistent with the	99.99%.

requirements in Section 121 of CERCLA and
the provisions of the NCP.

The maximum acceptable concentrations of
contaminants corresponded to a 1 x10~6
excess lifetime cancer risk and a hazard
index of 1.00.

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Rocky Mountain Arsenal Superfund Site

Treatment System Performance (Cont.)

Treatment Performance and Compliance

Two mini-burns were conducted at RMA May
20 through May 25, 1993, and a full trial burn
was conducted from June 10 through June
12,1993. The burns were designed to
operate the incineration system at conditions
that would reflect worst- case destruction and
removal of all constituents of concern.
Monochlorobenzene and carbon
tetrachloride were selected as POHCs for the
trial burn at RMA. The POHC feed rate,
stack gas emissions rate, and calculated
DREs are shown in Table 3. Interim
operating limits were then established based
on results of the mini-burns. These interim
limits were used until approval of final limits.

Table 3. Average Destruction and Removal Efficiencies from Trial Burn

POHC

Average POHC Feed Rate'1
(Ibs/hr)

Average POHC Stack Gas
Emissions Rate (Ibs/hr)

DRE(%)

Vlonochlorobenzene

8.81

1.87 x 10"6

>99.9990

Carbon Tetrachloride

8.12

2.91 x 10"6

>99.9988

The SQI operated within the operating
limits established during the mini burns
and trial burn, signifying that all
emissions requirements were met or
surpassed. Trial burn and interim
operating parameters are shown in Table
4.

"Neither POHC was detected in the waste feed.

Table 4. Operating Parameters [4]

Parameter

Trial Burn '1,

Interim'

Waste Feed Rate

176 Ib/min

< 166 Ib/min

Emission Rate:





Particulate - @7% 02

- @12% C02

0.0214 grains/dscf
0.0320 grains/dscf

< 0.08 grains/dscf
<0.10 grains/dscf

HCI

0.2291 Ib/hr

< 4Ib/hr

CO (HRA)

51.5 ppm

< 100 ppm

THC

8.25 ppm

NA

NOx

131 ppm

NA

S02

55.6 ppm

NA

HCI

2.50 ppm

NA

Operating Conditions:





Minimum SQI Chamber Temperature

1836°F

1825°F

Minimum Residence Time

2.72 sec

2.7 sec

Minimum Excess Oxygen

3.50%

3%

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Rocky Mountain Arsenal Superfund Site

Treatment System Performance (Cont.)

Table 4. Operating Parameters [4]

Parameter

Trial Burn '1,

Interim'

Minimum Quench pH

5.12

4

Minimum Scrubber pH

5.76

5.25

Maximum Venturi Recycle Flow Rate

126.7 gal/min

100 gal/min

Maximum Venturi Differential Pressure

90 inches w.c.

80 inches w.c.

Maximum Liquid/Gas Ratio

11.1 gal/kcf

9.3 gal/kcf

Maximum Scrubber Recycle Rate

285.7 gal/min

270 gal/min

Natural Gas Flow Rate

438 scfm

NA

Total Combustion Air

7,107 scfm

NA

SQI Chamber Pressure

3.97 psig

NA

"Average measured value of three runs conducted at identical conditions during trail burn.

bone half the detection limit for individual non-detect results was used to determine the average values.

'Interim limits established during two "mini-burns" conducted May 20-25,1993. These values were used as limits until approval of
the limits proposed during the trial burn.

dscf - Dry standard cubic feet	psig - Pounds per square inch, gauge

HRA - Hourly rolling average	scfm - Standard cubic feet per minute

kef - Thousand cubic feet	NA - Not available

w.c. - Water column

Performance Data Completeness

Complete results of Basin F liquid testing can
be found in the Summary Report for
Incineration of Basin F Wastes [1] and the
Trial Burn Summary Report [4].

Complete risk assessment results can be
found in the Final Human Health Risk
Assessment [5].

Performance Data Quality

According to site personnel, Quality
Assurance and Quality Control (QA/QC) for
all testing and associated analyses,
evaluation of all data, and the complete
decision making process was followed in
accordance with the FFA.

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Rocky Mountain Arsenal Superfund Site

Treatment System Cost

Procurement Process

IT and Weston, Inc. were contracted to
commission, test, and operate the SQI at the
site.

Cost Data

The total project cost of $93,337,779 was
reported by Rocky Mountain Arsenal in terms
of capital costs and operation and
maintenance costs. The capital costs for the
incineration system were $14,829,318 and
operation and maintenance totaled
$78,508,461. The total costs for thermal
treatment were reported as $58,145,681. A
total of 10.9 million gallons of liquid waste
were incinerated. This corresponds to a total
unit cost of $9 per gallon, and a unit cost for
thermal treatment of $5 per gallon. Tables 5
and 6 show the operation and maintenance
costs for incineration.

Table 5. Capital Costs

WBS Number

Description

Cost

331

01

Mobilization and preparatory work

$8,923,728

331

02

Monitoring, sampling, testing, and analysis

$3,505,590

331

03

Sitework

$2,400,000





Total Capital Costs

$14,829,318

Table 6. Operation and Maintenance Costs

WBS Number

Description

Cost

342

14

Thermal Treatment (Incineration) which includes:
Equipment
Labor

Direct operating costs
Overhead

$58,145,681

342

18

Disposal

$18,936,616

342

22

General Requirements

$1,426,164





Total Operation and Maintenance Costs

$78,508,461

Cost Data Quality

Actual capital and operations and
maintenance cost data are available from
Rocky Mountain Arsenal.

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Rocky Mountain Arsenal Superfund Site

Observations and Lessons Learned

Observations and Lessons Learned

Unexpected weather conditions caused delays
in the start-up of the incinerator. A heavy
rainfall classified as a 25-year/24-hour event
significantly increased the volume of liquid in
the open holding pond just before the start of
the project. This necessitated construction of
a special double-lined holding pond for
additional storage capacity. Additionally, a
tornado touched down near the tanks and
holding pond, requiring inspection and
subsequent repair of equipment.

Public Involvement

An extensive Community Relations program
was developed in 1988 at RMA that addresses
public concern relating to the entire site. This
program included the establishment of an on-
site information center, providing speakers for
local clubs and organizations, attending
conventions, public meetings, and open
houses.

A 24-hour telephone hotline was established
and a monthly publication (the Rocky
Mountain Arsenal SQI Update) was
developed.

In addition, a Restoration Advisory Board,
including members of local governments and
the public, was established to obtain input on
the remedial approach from various parties.

According to site personnel, these actions
helped to alleviate public concern related to
the on-site remediation action.

The draining of liquid from Basin F and
the subsequent drying of soils,
sediments, and the Basin F liner was
identified as a significant odor concern by
nearby residents. Air purifiers were
distributed to affected homes to help
alleviate the odors. Toxicologists from
various agencies identified the
compounds causing the odors and
determined that they did not present
acute health effects.

References

1.	Summary Report for Incineration of Basin F
Wastes at Rocky Mountain Arsenal. Volume
1; September 1988.

2.	Final Decision Document for the Interim
Response Action, Basin F Liquid Treatment,
Rocky Mountain Arsenal, Volume I - Text;
May 1990.

3.	Interim Response Action. Basin F Liquid
Incineration Project, Implementation
Document, Volume I; January 1992.

4.	Trial Burn Summary Report for the
Interim Response Action, Basin F
Submerged Quench Incineration Project,
Volume I; December 1993.

5.	Interim Response Action, Basin F Liquid
Incineration Project, Final Human Health
Risk Assessment, Volume I; March 1994.

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Office of Solid Waste and Emergency Response
Technology Innovation Office

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