HAZARD RANKING SYSTEM (HRS) DOCUMENTATION RECORD COVER SHEET

Name of Site : Macon Naval Ordnance Plant

EPA ID No. : GAD003302676

Contact Persons

Documentation Record : Cathy Amoroso , National Priorities List Coordinator U.S. Environmental Protection Agency, Region 4 61 Forsyth Street, S.W., 11 th Floor Atlanta, Georgia 30303 (404) 562 -8 637

Donna Seadler, Remedial Project Manager

U.S. Environmental Protection Agency, Region 4 61 Forsyth Street, S.W., 11 th Floor Atlanta, Georgia 30303 (404) 562

- 8870

Quinn Kelley, Site Manager Tetra Tech EM, Inc. 1955 Evergreen Boulevard Duluth, Georgia 30096 (678) 775

- 3101

Pathways, Components, or Threats Not Scored

The ground water migration, soil exposure, and air migration pathways , as well as the surface water pathway drinking water threat

, were not scored in this Hazard Ranking System (HRS) documen tation

record . These pathways are of concern to EPA and may be considered during future evaluation. T he

human food chain and environmental threats for the surface water migration pathway are sufficient to qualify the site for the National Priorities List (NPL).1 HAZARD RANKING SYSTEM (HRS) DOCUMENTATION RECORD

Name of Site: Macon Naval Ordnance Plant

EPA Region: 4

Date Prepared: March 2012

Street Address of Site*: 600 Guy Paine Road

City, County, State: Macon, Bibb County, Georgia, 31206

General Location in the State: Central Portion of the State

Topographic Map: Macon West, Georgia, 198 5

Latitude: 32° 46 ′ 39

. 57 ′′ North

Longitude: 83° 38 ′ 22

. 83 ′′ West

The coordinates listed above for the former Macon Naval Ordnance Plant were measured from t he approximate location of surface soil sample MNOP

- 04

- SF, collected during the EPA June 2011 Supplemental Sampling Event (Ref. 4)

.

* The street address, coordinates, and contaminant locations presented in this HRS documentation record identify the general area where the site is located. They represent one or more locations the U.S. Environmental Protection Agency (EPA) considers part of the site based on the screening information EPA

used to eva luate the site for National Priorities List (NPL) listing. EPA lists national priorities among the known “releases or threatened releases” of hazardous substances; thus, the focus is on the release, and not on precisely delineated boundaries. A site is defined as an area where a hazardous substance has been “deposited, stored, placed, or otherwise come to be located.” Generally, HRS scoring and the subsequent listing of a release represent the initial determination that a certain area may need to be addressed under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). Accordingly, EPA contemplates that the preliminary description of facility boundaries at the time of scoring will be refined as more information is developed a bout where the contamination has come to be located.

Pathway Pathway Score
Ground Water Migration Not Scored
Surface Water Migration 97 .94
Soil Exposure Not Scored
Air Migration Not Scored

HRS SITE SCORE 48 .972 WORKSHEET FOR COMPUTING HRS SITE SCORE

S Pathway S 2 Pathway

Ground Water Migration Pathway Score (S gw ) Not Score d Not Scored

Surface Water Migration Pathway Score (S

sw ) 97.9 4 9,59 2. 2436

Soil Exposure Pathway Score (S

s ) Not Scored Not Scored

Air Migration Pathway Score (S

a ) Not Scored Not Scored

S 2

gw + S 2

sw + S 2

s + S 2

a 9,592.2436

(S 2

gw + S 2

sw + S 2

s + S 2

a ) / 4 2,398.0609 √ (S 2

gw + S 2

sw + S 2

s + S 2

a ) / 4 48 .973 Table 4

- 1

– Surface Water Overland/Flood Migration Component Scoresheet

Factor Categories and Factors Maximum Value Value Assigned

Drinking Water Threat

Likelihood of Release:

1. Observed Release 550 550 550
2. Potential to Release by Overland Flow:

2a. Containment 10 NS

2b. Runoff 25 NS

2c. Distance to Surface Water 25 NS
2d. Potential to Release by Overland Flow [lines 2a(2b + 2c)] 500 NS
3.Potential to Release by Flood:
3a. Containment (Flood) 10 NS
3b. Flood Frequency 50 NS
3c. Potential to Release by Flood (lines 3a x 3b) 500 NS
4. Potential to Release (lines 2d + 3c, subject to a maximum of 500) 500 NS
5. Likelihood of Release (higher of lines 1 and 4) 550 550

Waste Characteristics:
6. Toxicity/Persistence (a) 10,000
7. Hazardous Waste Quantity (a) 10,000

8. Waste Characteristics 100 NS
Targets:

9. Nearest Intake 50 NS
10. Population:

10a. Level I Concentrations (b) NS

10b. Level II Concentrations (b) NS

10c. Potential Contamination (b) NS
10d. Population (lines 10a + 10b + 10c) (b) NS

11. Resources 5 NS
12. Targets (lines 9 + 10d + 11) (b) NS
Drinking Water Threat Score:
13. Drinking Water Threat Score [(lines 5x8x12)/82,500, subject to a maximum of 100] 100 NS

Human Food Chain Threat

Likelihood of Release:
14. Likelihood of Release (same value as line 5) 550 550

Waste Characteristics:
15. Toxicity/Persistence/Bioaccumulation (a) 500,000,000
16. Hazardous Waste Quantity (a) 10 0

17. Waste Characteristics 1,000 320
Targets:

18. Food Chain Individual 50 204 Table 4

- 1

– Surface Water Overland/Flood Migration Component Scoresheet (Continued)

Factor Categories and Factors Maximum Value Value Assigned
19. Population

19a. Level I Concentration (b) 0

19b. Level II Concentration (b) 0

19c. Potential Human Food Chain

Contamination (b) 0. 0 003
19d. Population (lines 19a + 19b + 19c) (b) 0. 0 003
20. Targets (lines 18 + 19d) (b) 20 .0003

Human Food Chain Threat Score:

21. Human Food Chain Threat Score [(lines 14x17x20)/82

, 500, subject to maximum of 100] 100 42

. 6 6

Environmental Threat

Likelihood of Release:
22. Likelihood of Release (same value as line 5) 550 550

Waste Characteristics:
23. Ecosystem Toxicity/Persistence/Bioaccumulation (a) 500,000,000
24. Hazardous Waste Quantity (a) 100

25. Waste Characteristics 1,000 320
Targets:

26. Sensitive Environments

26a. Level I Concentrations (b) 0

26b. Level II Concentrations (b) 25

26c. Potential Contamination (b) 0.9 15
26d. Sensitive Environments (lines 26a + 26b + 26c) (b) 25

. 9 1 5
27. Targets (value from line 26d) (b) 25 .9 1 5

Environmental Threat Score:
28. Environmental Threat Score [(lines 22x25x27)/82,500 subject to a maximum of 60] 60 55.28
Surface Water Overland/Flood Migration Component

Score for a Watershed

29. Watershed Score c (lines 13+21+28, subject to a maximum of 100) 100 97.9 4
Surface Water Overland/Flood Migration Component Score

30. Component Score (S of ) c (highest score from line 29 for all watersheds evaluated, subject to a maximum of 100) 100 97.9 4

Notes:

a Maximum value applies to waste characteristics category

b Maximum value not applicable

c Do not round to nearest integer

NS Not scored"Former" Macon NavalOrdnance Plant/01,000500FeetMAP SOURCE:USGS, MACON WEST, GATOPOGRAPHIC QUADRANGLE, 1985PROPERTY BOUNDARY SOURCE:MACON-BIBB COUNTY BOARD OF TAXASSESSORS.REFERENCES 8; 17, pp. 5, 171:12,000LEGENDProperty Boundary Date Saved: 1/17/2012 9:19:34 AM User: dale.vonbuschBIBB COUNTY,GEORGIAUnited States Environmental Protection AgencyMACON NAVAL Path: C:\GIS_Workspace\TTEMI-05-003-0127_Macon_Naval_Ordnance_Plant\Figures\GIS\MXDs\Site Location Maps\FMNOP SITE LOC MAP 1-17-12.mxdORDNANCE PLANTMACON,BIBB COUNTY,GEORGIATDD No.TTEMI-05-003-0127FIGURE 1PROPERTY LOCATION

5gW G u y P a i n e R o a d M e a d R o a d

A l l i e d I n d u s t r i a l R o a d

Ennis BoulevardMIXING/BLENDINGHOUSESBUILDING 109WWTP DISCHARGEWASTE WATERTREATMENT PLANTBUILDING 105 - ASSEMBLY

B U I L D I N G 5

M E T A L P L A T I N G F A C I L I T YLegendgWWWTP DischargeFormer Waste WaterTreatment PlantFormer Macon Naval OrdnancePlant StructuresFormer Macon Naval OrdnanceExplosives Handling andStorage AreasNew StructuresProperty Boundary0 300 600150Feet/1:7,200Note:Aerial Photograph: Bing Maps, 2009References 6; 8; 13, pp. 52, 54; 17, p. 25 Date Saved: 11/17/2011 8:38:39 AM User: dale.vonbuschUnited States Path: C:\GIS_Workspace\TTEMI-05-003-0127_Macon_Naval_Ordnance_Plant\Figures\GIS\MXDs\Site Layout Maps\MNOP PROP LAYOUT 8.5x11 1 1-17-11.mxdMACON,BIBB COUNTY,GEORGIARAILCARUNLOADINGEnvironmental Protection AgencyMACON NAVAL ORDNANCE PLANTTDD No. TTEMI-05-003-0127FIGURE 2PROPERTY LAYOUT

6Legend""))

G u y P a i n e R o a dMNOP-01-SFJune 2011 Sample Locations#*Sediment Sample")Soil Sample##**Background WetlandSediment SampleMNOP-04-SF""))Background Soil Sample")Map Features"Former" Macon NavalOrdnance PlantCreekDrainage Ditch"Former" Macon Naval##**PEMPFO/PSS R o c k y C r e e k

D

r a i na

g e D

i t c h

1

R o c k y C r e e kMNOP-W-01-SDPFO/PSS

D r a i n a g e D i t c h 2 D r i a#*#*#*#*#* D r a i n a g e D i t c h 4PEMPFO/PSSPFO/PSSPFO/PSS

n a g e D i t c h 3 R o c k C r e e kRocky CreekMNOP-D4-07-SDMNOP-D4-04-SDMNOP-D4-02-SDMNOP-D4-W-09-SDMNOP-D4-W-08-SD(PPE 1)Rocky CreekWater ReclamationFacilityMap Source:Aerial Photograph -Bing Maps, 2009.Property Boundary -Macon-Bibb County Board ofTax Assessors.Wetlands - U.S. Fish and Wildlife Service NationalWetlands InventoryReference 9, pp. 1, 3Notes:D -Drainage DitchHg - MercuryMNOP -Macon Naval Ordnance PlantPPE - Probable Point of EntrySD -Sediment SampleSF - Surface Soil SampleW - Wetland/0 500 1,000FeetOrdnance PlantWetland AreasFreshwater PalustrineEmergent WetlandFreshwater PalustrineForested/Shrub Wetland1:12,000 D ate Saved: 11/17/2011 8:53:13 AM U ser: dale.vonbuschFIGURE 3SAMPLING LOCATIONSMACON NAVAL ORDNANCE PLANTMACON,BIBB COUNTY,GEORGIATDD No. TTEMI-05-003-0127United StatesEnvironmental Protection Agency Path: C:\GIS_Workspace\TTEMI-05-003-0127_Macon_Naval_Ordnance_Plant\Figures\GIS\MXDs\HRS Sampling Maps\MNOP SELECT SMPLS 8.5x11 11-17-11.mxd

78 REFERENCES

1. U.S. Environmental Protection Agency (EPA). Hazard Ranking System, Title 40 Code of Federal Regulations Part 300, 55 Federal Register 51532. December 14, 1990. 138 Pages. A complete copy of the Hazard Ranking System is available at: http://www.epa.gov/superfund/sites/npl/hrsres/index.htm#HRS Rule.

2. EPA. Superfund Chemical Data Matrix (SCDM). January 2004 , Updated December 2011 . Excerpt,

75 Pages. A complete copy of SCDM is available at: http://epa.gov/superfund/sites/npl/hrsres/tools/scdm.htm

.

3. Tetra Tech EM Inc. (Tetra Tech). 15

- Mile Surface Water Migration Pathway wi th NWI Wetlands

. U.S. Geological Survey (USGS) 7.5 Minute Series Topographic Maps of Georgia Quadrangles: Macon West ( 198 5 ), Macon East ( 198 5 ), Warner Robins NW ( 1986 ), Warner Robins NE (1985). 1 Map.

4. Tetra Tech. Project Note to File with Attachment. Subject: Coordinates for Macon Naval Ordnance

Plant . Attachment: Google Earth Map. November 2, 2011

. 2 Pages.

5. EPA

, Envirofacts Warehouse

. Macon Naval Ordnance Plant. Quer y : Comprehensive Environmental Response, Compensation, and Liability Information System (CERCLIS) (Data

Extracted August 15, 2011 )

. Accessed on August 31, 2011

. 2 Pages. CERCLIS Accessed on- line at http://iaspub.epa.gov/enviro/cerc lisquery.get_report?pgm_sys_id=GAD003302676

.

6. Tetra Tech. Project Note to File with Attachments. Subject: Macon

- Bibb County Parcel Maps and Property Cards for the Former Macon Naval Ordnance Plant Property

. Attachment: Parcel Maps and Property Cards. September 7, 2011

. 64 Pages.

7. Tetra Tech. Final Expanded Site Inspection Report. Allied Industrial Park, Macon, Bibb County, Georgia. September 29, 2009. Excerpt: 197 Pages.

8. Department of the Navy, Bureau of Yards and Docks. U.S. Naval Ordnance Plant, Macon, GA. Master Shore Station Development Plan, Part II Section 2, General Development Plan

– Existing. Approved March 19 , 1965. 1 Page.

9. Tetra Tech. Project Note to File with Attachments. Subject: June 2011 Supplemental Sampling Event. Attachments: Figure and Logbook Notes. September 1, 2011. 10 Pages.

10. Tetra Tech. Draft Quality Assurance Project Plan, Macon Naval Ordnance Plant. June 20, 2011. 20 Pages.

11. EPA, Region 4 Science and Ecosystem Support Division (SESD). Final Analytical Report, Project

No. 11

- 0536. August 1, 2011. 24 Pages.

12. Science Applications International Corporation (SAIC). Draft Hazardous Site Response Act (HSRA) Compliance Status Report, Former Macon Naval Ordnance Pla nt, Allied Industrial Park, Macon, Georgia. Prepared for the U.S. Army Corp of Engineers ( USACE ) , Savannah District. August 2000. 1,626 Pages.

13. RUST Environment and Infrastructure Inc. Site Investigation Report, Allied Industrial Park Site, Macon, Georgia. Prepared for the USACE, Savannah District. May 1997. 390 Pages.

14. Environmental Science & Engineering, Inc. (ESE). Final Engineering Report, Confirmation Study of Former Macon Naval Ordnance Plant, Macon, Bibb Co., Georgia. Prepared for the Defense Environmental Restoration Program, USACE, Mobile District. September 1990. 129 Pages.9 15. Tetra Tech. Project Note to File. Subject: Allied Industrial Park Property Owners Internet Search

. September 9, 2011

. 1 Page.

16. Tetra Tech. Final Expanded Site Inspection Report. Former Macon Naval Ordnance Landfill, Macon, Bibb County, Georgia. September 29, 2009. Excerpt: 135 Pages.

17. EPA, Environmental Sciences Division. Aerial Photographic Analysis Former Macon Naval Ordnance Plant Landfill Site, Macon, Georgia. November 1999. 57 Pages.

18. RUST Environment and Infrastructure Inc. Final Site Investigation Report, Former Naval Ordnanc e Plant Landfill (FMNOL) Site, Macon, Georgia. Prepared for the Savannah District, U.S Army Corps of Engineers (USACE). September 1997. 142 Pages.

19. Georgia Environmental Protection Division , Hazardous Waste Management Branch. Preliminary Assessment, Ar mstrong World Industries, Inc. Prepared for the U.S. EPA. August 10, 2007.

18 Pages.

20. SAIC. Final Phase I Remedial Investigation Report, Former Macon Naval Ordnance Plant Landfill Site, Macon, Georgia. Prepared for the USACE, Savannah District. October 2000. 483 Pages.

21. SAIC. Letter to the U.S. Army Corps of Engineers. Subject: Monitoring Report for Post

- Test Groundwater Sampling (October

- November 2004), Pilot

- Scale Alternatives Assessment and Implementation Plan for Groundwater VOC Reduction at the Former Macon Naval Ordnance Plant. January 19, 2005. 240 Pages.

22. Georgia Environmental Protection Division (EPD). Preliminary Assessment, Former Macon Naval

Ordnance Landfill and Allied Industrial Park, Macon, Bibb County, Georgia. February 1992. 21 Pages.

23. Department of the Army. Technical Manual TM 9

- 1300

- 214, Military Explosives. September 1984. Most Recent Revision: September 1990. 355 Pages.

24. EPA, Region 4 SESD. Operati ng Procedure for Soil Sampling, Number SESDPROC

- 300

- R1. November 1, 2007. 22 Pages. Accessed on

- line at http://www.epa.gov/region4/sesd/fbqstp/Soil

Sampling.pdf

.

25. EPA, Region 4 SESD. Operating Procedure for Sediment Sampling, Number SESDPROC

- 200

- R2. September 8, 2010. 23 Pages. Accessed on

- line at http://www.epa.gov/region4/sesd/fbqstp/Sediment

- Samplin g.pdf

.

26. EPA , Region 4

. Macon Naval Ordnance Plant, Chain of Custody Record No. 06/30/11

- 0001. Project No. 11

- 0536. July 1 , 2011. 2 Pages.

27. EPA, Region 4 SESD, Analytical Support Branch. Laboratory Operations and Quality Assurance Manual. January 6, 2011. 205 Pages.

28. Tetra Tech. Project Note to File. Subject: Data Review, Validation, and Verification Conducted at the Science and Ecosystem Support Division (SESD), Analytical Support Branch. January 6, 2009

. 1 Page.

29. Tetra Tech. Record of Telephone Conversation. Subject: Definitions of Minimum Reporting Limit, Minimum Quantitation Limit, Contract Required Quantitation Limit, and Sample Quantitation Limit. Between Shanna Davis, Environmental Scientist, and Charlie Appleby, Quality Assurance Section, SESD, Management and Technical Services Branch, EPA Region 4. July 9, 2008. 1 Page.10 30. Tetra Tech. Project Note to File with Attachments. Subject: Soil Map for Macon Naval Ordnance

Plant. Attachments: Soil Map, Map Legend, and Map Unit Legend. September 2, 2011. 4 Pages.

31. Tetra Tech. Project Note to File with Attachment. Subject: Summary of J

- Qualified Data.

Attachment: J

- Qualified Data. September 6, 2011. 2 Pages.

32. EPA, Office of Emergency and Remedial Response. Using Qualified Data to Document an Observed Release and Observed Contamination. Quick Reference Fact Sheet EPA

- 540 -F- 94

- 028. November 1996. 18 Pages.

33. Tetra Tech. Project Note to File. Subject: June 2011 Supplemental Sampling Event Observations. September 2, 2011. 1 Page.

34. EPA, Region 4 SESD. Final Analytical Report, Project No. 09

- 0441. August 22, 2011. 181 Pages.

35. EPA, Region 4 SESD. Final Analytical Report, Project No. 09

- 0441. August 22, 2011. 155 Pages.

36. U.S. Department of the Interior, Fish and Wildlife Service. National Wetlands Inventory Maps of Georgia: Macon West, Macon East, Warner Robins NE, Warner Robins SE. 1995. 4 Maps.

37. Tetra Tech. Record of Telephone Conversation. Subject: Fishing on Rocky Creek in Macon, Bibb County, Georgia. Between Qu inn Kelley, Environmental Scientist, and Steve Schleiger, Biologist, GADNR, Wildlife Resources Division. September 9, 2011 . 1 Page.

38. Tetra Tech. Project Note to File with Attachment. Subject: Stream Flow Data for Tobesofkee Creek and the Ocmulgee River in Macon, Bibb County, Georgia. Attachment: USGS 2010 Water

- Data Reports for Tobesofkee Creek and the Ocmulgee River. September 6, 2011

. 17 Pages.

39. Tetra Tech. Project Note to File with Attachment. Subject: Ocmulgee Watershed Stream Evaluations. Attachment: 2002 Georgia Section 303(d) Listed Streams, Ocmulgee River Water Management Plan, Table 2

- 6. September 9 , 20 11 . 3 Pages.

40. GADNR, Environmental Protection Division. Water Quality in Georgia 2008

- 2009

. Approved November 10, 2010

. 50 5 Pages. Accessed on

- line at http://www.gaepd.org/Documents/305b.html

.

41. Macon

- Bibb County Planning and Zoning Commission. Comprehensive Plan 2030, Community

Assess ment. February 2006. 415 Pages. Accessed on

- line at http://www.maconbibbpz.org/artman2/uploads/1/CP2030_1.pdf

.

42. GADNR, EPD. Site Reconnaissance Inspection Trip Report, Armstrong World Industries, Inc., Macon, GA. July 19, 2007. 11 Pages.

43. GADNR. Guidelines for Eating Fish from Georgia Waters. 20 10 Update. 3 0 Pages. Accessed on

line at http://www.gaepd.org/Documents/fish_guide.html

.

44. Federal Emergency Management Agency. Flood Insurance Rate Map for Bibb County and

I ncorporated areas , Georgia. Excerpt of Panel 1 44 of 265 . Community

- Panel Number 130011 0 1 44

F

. Effective April 2, 2007 . 3 Pages.

45. Macon Water Authority. Operations: Water Reclamation Facilities. Accessed on September 7,

2011

. 4 Pages. Accessed on

- line at http://maconwater.org/water

- reclamation

- faci lities

.11 46. EPA. Enforcement and Compliance History Online (ECHO) with Attachment s . Macon Water Authority Rocky Creek Water Reclamation Facility. Report Generated November 1, 2011. 8 Pages.

Attachment s : ECHO Effluent Data and Google Earth Map Depicting NPDES Permit Outfall.

Accessed on

- line at http://www.epa

- echo.gov/cgi

bin/get1cReport.cgi?tool=echo&IDNumber=110007498412

.

47. Regulatio ns.gov. Docket Folder Summary. National Priorities List, Notice of Proposed Rulemaking

– Armstrong World Industries. Docket ID: EPA

- HQ

- SFUND

- 2010

- 0640. Accessed on January 3,

2012. 1 Page. Accessed on

- line at http://www.regulations.gov/#!docketDetail;dct=FR%252BPR%252BN%252BO%252BSR;rpp=10;p o=0;D=EPA- HQ

- SFUND

- 2010

- 0640

.12 Site Description 

### SITE DESCRIPTION

The f ormer Macon Naval Ordnance Plant (MNOP) propert y , currently the Allied Industrial Park (AIP),

covers about 433 acres in area and is located in an industrialized area in the southern portion of Macon, Bibb County, Georgia (Refs. 3; 7, p. 2 ; 8 ) (see Figure 1 of this Hazard Ranking System [ HRS ] documentation record)

. Specifically, the geographic coordinates for the MNOP property are latitude 32°

46 ′ 39

. 57 ′′ north and longitude 83° 38′ 22

. 83 ′′ west (as measured from the approximate location of surface

soil sample MNOP

- 04

- SF, collected during the EPA June 2011 Supplemental Sampling Event ) (Ref. 4)

. The U.S. Environmental Protection Agency (EPA) identification number for the MNOP propert y , as recorded in the Comprehensive Environmental Response, Compensation

, and Liability Information System (CERCLIS) database, is GA D003302676 (Ref. 5 ).

Land uses on the MNOP propert y are predominantly commercial and heavy industrial (Ref s . 6 , p p

. 2, 5, 12, 13, 15, 21, 24, 25, 26, 27, 28, 29, 32, 33, 36, 41, 45, 47, 49, 51, 54, 57, 59, 60 ; 15 ). The MNOP property is bordered to the north by Guy Paine Road ; to the east by Mead Road and the Norfolk Southern

railroad tracks ; to the southeast by Graphic Packaging; to the south by the Macon Water Authority ( MWA ) Rocky Creek Water Reclamation Facilit y and by the Armstrong World Industries (AWI) remote landfill, the former Macon Naval Ordnance Landfill ( FMNOL ), and Rocky Creek ; and to the west by the

AWI plant property (Refs. 3; 4, p. 2; 7 , p. 2

, Appendix A, p. A -2 ).

For HRS scoring, the site consists of one source and associated releases. Source No. 1 is contaminated

soil on the eastern section of the MNOP property. Source No. 1 contain s mercury (see Section 2.2 of this HRS documentation record). Mercury ha s also been detected at significant levels in sediment s collected

in wetlands that receive runoff from Source No. 1 via Drainage Ditch 4

, indicating that a release has occurred to the surface water migration pathway (see Section 4.0 of this HRS documentation record) (also see Figures 2 and 3 of this HRS documentation record)

.

OPERATIONAL AND REGULATORY HISTORY

MNOP was constructed and operated by the Reynolds Corporation before World War II for production of

ordnance (Ref s

. 12 , p. 1

- 1; 14, p. 2

- 9). The Navy assumed operations in 1941 and continued to

manufacture ordnance until 1965. Ordnance manufactured at the MNOP included flares, small primers, detonators, and other triggering mechanisms (Ref. 13 , p. 2 ; 14, p. 2 -9 ). The total area of the MNOP was

ap proximately 433 acres, which extended from Guy Paine Road to the north, Mead Road to the east, Rocky Creek to the south, and the Central of Georgia Railroad tracks to the west (Refs. 8; 12, p. 2

- 9; 14, p. 2 -9 ).

After it was declared surplus by the Navy, the property was sold in December 1965 to the Maxson Electronics Company (Maxson) of New York. Maxson continued to manufacture ordnance under contract with the Navy until it sold the property to Allied Chemical Corporation (Allied Chemical) in 1973. Allied Chemical manufactured automobile seat belts at the property and use d all or nearly all of the buildings, underground storage tanks (UST) and aboveground storage tanks (AST), and utilities. Allied

Chemical sold the property in 1980 to the Macon

- Bibb County Industrial Authority (MBCIA), which renamed the property the Allied Industrial Park. MBCIA currently leases or sells buildings as office and warehouse space to various industrial and commercial businesses on the AIP property (Ref s

. 7, Appendix A, p. A

- 3; 13 , pp. 1, 2, 3; 14, p. 2 -9 ; 15 ).

During ordnance manufacturing operations, structures at the MNOP included numerous buildings, several miles of paved roads, fueling facilities, ASTs and USTs, solvent storage buildings, explosives storage magazines , a bunker area, a metals plating facility, and a sewage treatment plant (also referred to as a wastewater treatment plant [ WWTP ] ), and the FMNOL (Refs. 8; 13, p. 2; 14, pp. 2- 9, 2- 10, 2

- 11, 2

- 12

, Appendix A, pp. A

- 3 through A -8 ).

The MNOP WWTP was located near the western boundary of the property, was constructed in the early 1940s, and operated until the early 1970s. The WWTP was designed to handle only sewage generated by13 Site Description the ordnance plant; however, chemicals used in the ordnance plant may have been disposed of in drains that connected to the WWTP (Ref. 13 , pp. 10, 52) (see Figure 2 of this HRS documentation record).

The primary metal plating facility at MNOP was located in Building 5. The metal plating operation began in the 1940s and continued through Maxson’s and Allied Chemical’s operation of the facility until 1980. The metal plating facility used cyanide, solvents, acid baths, caustic baths, and hydraulic oil.

Recor ds indicate that the plating operation generated chrome sludge during Allied Chemical’s use of the facility . It is not known how this sludge was managed or disposed of (Ref. 13 , pp. 11, 52)

. Metal shavings were centrifuged to remove excess oils in the oil recovery area. These oils were reportedly allowed to drain onto the ground surface (Ref. 13, pp. 11, 52) (see Figure 2 of this HRS documentation record).

Explosive compounds were either handled or stored at many areas throughout the MNOP property,
in cluding numerous small dryer buildings, ordnance magazines, and blending and weighing houses (Ref.

13 , pp. 11, 12, 54) (see Figure 2 of this HRS documentation record). According to a technical manual prepared by the Department of the Army, military explosives, such as those that were manufactured at the MNOP, contained mercury compounds as initiating agents, including mercury fulminate (Ref. 23, pp. 7

- 5,

7- 8). Building 109, located in the eastern portion of the MNOP, was a primary explosives production si te (Ref. 13, pp. 11, 12, 54) (see Figure 2 of this HRS documentation record). Soil samples collected from this area during the U.S. Army Corps of Engineers (USACE) 1996 site investigation contained mercury (Ref. 13, pp. 58, 83, 84).

FMNOL was reportedly used for disposal of solid wastes and ordnance throughout the operational history (1941 to 1974) of the MNOP facility, and intermittent dumping continued thereafter throughout the 1980s (Refs. 16 , p. 3 ; 17, pp. 42, 43, 46, 47 ; 18 , p. 2 ; 20, p. i ). The lan dfill was also used for disposal of used parts and construction debris (Refs. 14, p. 2

- 11; 18, p. 2 ). A fenced explosives demolition area, located near the toe of the landfill, was used for testing and demolishing explosives, primarily detonators, flares, and primers manufactured at the MNOP . Flammable materials were reportedly burned in this area as well (Ref. 1 4 , p p . 2

- 11 , 3 -9 ). The FMNOL is scored as part of the AWI site listed on the EPA NPL under

CERCLIS ID No. GAN000410033 at docket number EPA

- HQ

- SFUND

- 2010

- 0640

- 0002 (Ref. 47)

.

PREVIOUS INVESTIGATIONS

S everal investigations have been conducted at MNOP between 1989 and 2011 . Table 1 lists the previous investigations at MNOP, including the hazardous substances detected in the samples collected.

TABLE 1: Summary of Previous Investigations

Company/

Agency Investigation Date Samples

Collected Hazardous

Substances

Detected References

Beaver Engineering Environmental

Assessment 1989 Soil Metals 13 , p. 3

Environmental

Science and Engineering Confirmation Study of the

Former Macon

Naval Ordnance

Plant 1990 Soil , ground water, and

sediment Arsenic

Cadmium

Chromium

Lead

TCE 1 4 , pp. I, 2

- 1, 3

- 4, 3

- 6,

3- 9, 3

- 11, 4

- 2, 4

- 3, 4

- 11, 4

- 12

USACE,

Savannah District Site Investigation 1996 Soil

, ground water, surface

water, and

sediment Cadmium

Chromium

Lead Mercury 13, pp. vi, 1, 13, 20, 27, 28, 55 through 6 0, 63, 71 through 92, 94 through 104, 106, 10714 Site Description TABLE 1: Summary of Previous Investigations

Company/

Agency Investigation Date Samples

Collected Hazardous

Substances

Detected References
USACE,

Savannah District Hazardous Site Response Act (HSRA) Compliance Status Report 1998 to 2000 Soil, ground water, surface

water, and

sediment Arsenic

Cadmium

C hromium

Lead

Zinc

TCE

PCE Benzo(a)pyrene 12 , pp. i, ii, 1

- 1, 1

- 10

, 2- 9, 2

- 19, 2

- 33, Appendix O, pp. O15 through O53

USACE,

Savannah District Post

- Test

Groundwater Sampling 2004 Ground water DCE

TCE

PCE Vinyl Chloride 21, pp. 1, 2, 5 , 11

EPA Expanded Site Inspection May 2009 Soil, ground water, surface water, and

sediment Cadmium

Chromium Copper

Lead Manganese Mercury

Nickel

PCBs

Pesticides

SVOCs

VOCs 7, pp. 1, 6, 7

, Appendix B, pp. B-1 2 through B

- 69, B

- 71 through B -7 5, B

- 77 through B

- 113

EPA Supplemental Sampling Event June 2011 Soil and

sediment Mercury 9, pp. 1, 3 ; 11, pp. 5, 8, 19, 21

Notes:

DCE Dichloroethane

EPA U.S. Environmental Protection Agency

PCB Polychlorinated biphenyl

PCE Tetrachloroethylene

SVO C Semivolatile organic compound

TCE Trichloroethylene

USACE U.S. Army Corps of Engineers

VOC Volatile organic compound

In June 2011, EPA conducted a supplemen tal sampling event at the MNOP property. The purpose of the supplemental sampling was to further delineate mercury contamination previously found in Drainage

Ditch 4 that runs along the easte rn portion of the property (Ref s . 3 ; 7, Appendix A, p. A

- 4, Appendix B, p. B -95 (also see Figure 3 of this HRS documentation record)

. Six surface soil samples (0 to 6 inches below ground surface [ bgs ] ) were collected (including one background and one duplicate) from the eastern portion of the MNOP

, and 10 sediment samples (0 to 3 inches bgs) were collected (including one duplicate) from Drainage Ditch 4, which receive s runoff from the eastern portion of MNOP and flows south to Rocky Creek (Refs. 9; 10, pp. 3, 4, Appendix B, p. B

- 1) . All soil and sediment samples w ere analyzed for mercury (Refs. 9; 10, pp. 5, 10, Appendix B, p. B

- 3) . Mercury was detected in surface soil sample MNOP

- 04

- SF at a concentration of 0.40 milligrams per kilogram ( mg/kg ) , in Drainage Ditch 4 sediment sample MNOP

- D4

- 07

- SD at a concentration of 0.46 mg/kg, and in Drainage Ditch 4 wetland sediment sample MNOP

- D4 -W- 09

- SD at a concentration of 1.1 mg/kg (Ref. 11, pp. 8, 19, 21).Source No. 1

15 Site Description 2.2 SOURCE CHARACTERIZATION

2.2.1 SOURCE IDENTIFICATION

Number of source : 1

Name of source : Contaminated soil on the MNOP property

Source Type : Contaminated Soil

Description and Location of Source (with reference to a map of the site):

Source No. 1 consists of contaminated soil on the eastern portion of the MNOP property (Refs. 9 , p. 3 ; 11, p. 8) (see Figure 3 of this HRS documentation record). MNOP operated as an ordnance manufacturing facility from before World War II until 19 73 (Ref. 12 , p. 1 -1 , 1 -7 ). Ordnance manufactured at MNOP included flares, small primers, detonators, and other triggering mechanisms (Ref.

13 , p. 2)

.

According to a technical manual prepared by the Department of the Army, military explosives

, such as

those that were manufactured at the MNOP , contained mercury compounds as initiating ag ents , including mercury fulminate (Ref. 23 , pp. 7

- 5, 7

- 8). Explosive compounds were either handled or stored in many areas throughout the MNOP property, including numerous small dryer buildings, ordnance magazines, and blending and weighing houses. Specifically, B uilding 109, located in the eastern portion of the MNOP near Source No. 1, was a primary explosives pr oduction site (Ref. 13, pp. 11, 12, 54) (see Figure s 2 and 3 of this HRS documentation record)

. Soil samples collected from this area during the U.S. Army Corps of Engineers ( USACE ) 1996 site investigation and the EPA June 2011 supplemental sampling

event contained mercury (Ref s

. 9, p. 1; 11, p. 8; 13, pp. 58, 83, 84).Source No. 1

16 Site Description 2.2.2 HAZARDOUS SUBSTANCES ASSOCIATED WITH THE SOURCE

EPA June 2011 Supplemental Sampling

Background and Source Samples

The background and source soil samples listed in Table 2 were collected during the EPA June 2011

s upplemental s ampling event (Refs. 9 , pp. 1, 3, 7, 9 ; 11, p. 3 ). The background soil sample was collected

from the north

- central portion of the MNOP property where no site

- related activities have been known to occur (Refs. 8; 9, pp. 1, 3 ; 17, pp. 11, 17, 21, 25, 29, 33, 37, 41, 45)

. The source soil sample was collected from the eastern portion of the MNOP property where mercury has been previously detected

,

ne ar where facility operations were known to have occurred and where explosives were handled and

stored (Refs. 7, Appendix A, p. A

- 4; 9, p. 3 ; 13, pp. 11, 12, 54 ). The background and source surface soil sample s were collected at a depth of 0 to 6 inches bgs (Refs. 9 , p. 1 ; 10, Appendix B, p. B -1 ).

Background and Source No. 1 surface soil samples were collected during the same sampling event , from the same type of soil (sandy loam)

, and in accordance with the same sampling procedures (Refs. 9, pp. 1,

6 , 9; 10, p. 4 ; 30, pp. 1, 3 ). S urface soil sample s were collected in accordance with the EPA Region 4 SESD Field Branch Quality System and Technical Procedures for Soil Sampling, SESDPROC

- 300

- R1 (Refs. 9 , p. 6 ; 10, p. 4; 24 ) . The location s of the background and source soil sample s are depicted in

Reference 9 , page 3 and are listed in Reference 10, Appendix B, p age B

- 1 (see Figure 3 of this HRS documentation record) . Chain

- of

- custody records are provided in Reference 26 . Logbook notes are provided in Reference 9, Attachment 2

.

TABLE 2: Background and Source Soil Sample Descriptions

– June 2011

Sample ID Sample Location Depth (inches bgs) Date Sampled References

MNOP

- 01

- SF Background sample collected

from the north

- central portion of the MNOP property 0 to 6 06/29/2011 9, pp. 3

, 7 ; 26, p. 1

MNOP

- 04

- SF Source sample collected from the eastern portion of the MNOP property where explosives were handled and

stored 0 to 6 06/30/2011 9, pp. 3 , 9; 13, p. 54; 26, p. 1

Notes:

bgs Below ground surface

ID Identification number

MNOP Macon Naval Ordnance Plant

No. Number

SF Surface sampleSource No. 1

17 Site Description Background and Source Concentrations

Background and Source No. 1 samples listed in Table 3 were analyzed for mercury in accordance with EPA Method 245.5 and the EPA Region 4 Analytical Support Branch (ASB) Laboratory Operations and Quality Assurance Manual (LOQAM), January 2011 (Refs. 9, p. 1; 11, p. 1; 27)

. EPA Region 4 SESD reviewed all data according to the contract statement of work ( SOW ) and EPA guidelines (Refs. 28 ; 11 , p. 1 ). The minimum reporting limits ( MRL ) are listed on the analytical data sheets in Reference 11 . Each MRL is sample

- specific and corresponds to the lowest quantitative point on the calibration curve; it is adjusted for the amount of sample prepared and any dilutions performed, as well as for percent moisture. The MRLs are equivalent to sample quan titation limits ( SQL ) (Ref. 29 ).

TABLE 3: Analytical Results for Background and Source No. 1 Samples

– June 2011

Sample Designation Sample ID Hazardous

Substance Hazardous

Substance

Concentration MRL References

Background MNOP

- 01

- SF Mercury 0.073J (0.13) mg/kg 0.050 mg/kg 11, p p

. 4, 5; 31

Source No. 1 MNOP

- 04

- SF Mercury 0.40 mg/kg 0.050 mg/kg 11, p. 8

Notes:

( ) Concentrations shown in parentheses were adjusted in accordance with References 31 and 32

. ID Identification number

J The identification of the analyte is acceptable; the reported value is an estimate (Ref. 11, p. 4)

. mg/kg Milligram per kilogram

MNOP Macon Naval Ordnance Plant

MRL Minimum reporting limit

No. Number

SF Surface sampleSource No. 1

18 Site Description 2.2.3 HAZARDOUS SUBSTANCES AVAILABLE TO A PATHWAY

The s ample collected from Source No. 1 contain s mercury (Ref s

. 9, p. 3 ; 11, p. 8 ) (also see Table 3 of this HRS documentation record). Source No. 1 consists of contaminated soil on the eastern portion of the

MNOP property ( Refs. 9, p. 3 ; 11, p. 8)

. The MNOP operated as an ordnance manufacturing facility from before World War II until 1973 (Ref. 12 , p p . 1 -1 , 1 -7 ). Ordnance manufactured at the MNOP included flares, small primers, detonators, and other triggering mechanisms (Ref. 13 , p. 2 )

. Military explosives, such as those that were manufactured at the MNOP, contained mercury compounds (mercury fulminate) as initiating agents (Ref. 23, pp. 7

- 1, 7

- 5, 7

- 8). Building 109, located in the eastern portion of the MNOP near Source No. 1, was a pri mary explosives production site (Ref. 13, pp. 11, 12, 54) (see Figure 2 of this HRS documentation record). Soil samples collected from this area during the USACE 1996 site investigation contained mercury (Ref. 13, pp. 58, 83, 84). Analytical results for sediment samples collected from Drainage Ditch 4 indicate overland migration of mercury from Source No. 1 (see Additional Supporting Data in Section 4.1.2.1.1 of this HRS documentation record)

. Analytical results for sediment samples collected from wetlands contiguous with Rocky Creek and downstream of Source

No. 1 indicate that a release of hazardous substances has occurred to the surface water migration pathway,

as documented in Section 4.0 of this HRS documentation record. No run

- on or runoff con trol systems were observed during the EPA June 2011 s upplemental s ampling at MNOP , specifically in the area of

Source No. 1 (Ref. 33 ). Drainage Ditch 4 drains the eastern portion of MNOP and directs runoff to Rocky Creek and adjacent wetlands (Refs. 7, Ap pendix A, p. A

- 4; 9, p. 3) (see Figure 3 of this HRS documentation record)

. Therefore, a containment factor value of 10, as noted in Table 4 , was assigned for the surface water migration pathway (Ref. 1, Section 4.1.2.1.2.1.1).

TABLE 4 : Containment Fa ctors for Source No. 1

Containment Description Containment

Factor Value References

Gas release to air NS NA

Particulate release to air NS NA

Release to ground water NS NA

Release via overland migration or flood: no run

- on or runoff control system; runoff from Source No. 1 enters Rocky Creek via Drainage Ditch 4

. 10 1, Section 4.1.2.1.2.1.1; 9, p. 3 ; 33 ; see Figure 3 of this HRS

documentation record

Notes:

NA Not applicable

NS Not scoredSource No. 1

19 Site Description 2.4.2.1 SOURCE HAZARDOUS WASTE QUANTITY

2.4.2.1.1 Hazardous Constituent Quantity

The information available is not sufficient to evaluate Tier A, hazardous constituent quantity, as required by Reference 1, Section 2.4.2.1.1. Ava ilable S ource No. 1 data may not represent the extent of

contamination associated with the source and are insufficient to determine constituent quantity

.

Hazardous Constituent Quantity Assigned Value: NS

2.4.2.1.2 Hazardous Wastestream Quantity

The i nformation available is not sufficient to evaluate Tier B, hazardous wastestream quantity, as required by Reference 1, Section 2.4.2.1.2. Available S ource No. 1 data may not represent the extent of the

wastestream associated with the source

.

Hazardous Wastestream Quantity Assigned Value: NS

2.4.2.1.3 Volume

The information available is not sufficient to evaluate Tier C, volume, as required by Reference 1, Section

2.4.2.1.3.

Volume Assigned Value: 0

2.4.2.1.4 Area

One soil sample was collected from Source No. 1 during the EPA June 2011 supplemental sampling event (Ref. 9, pp. 3 , 9 ). As a result, it is not possible to determine a source area for Source No. 1 . Therefore,

the area of Source No. 1 is undetermined, but is greater than ze ro.

Sum (square feet [ft 2 ]): >0 Equation for Assigning Value (Table 2

- 5): Area (A)/34,000

Area Assigned Value: >0

2.4.2.1.5 Calculation of Source Hazardous Waste Quantity Value

Source No. 1 is assigned a source HWQ value of greater than zero, but un known (Ref. 1, Section 2.4.2.1.5).

Source HWQ Value: >020 Site Description SUMMARY OF SOURCE DESCRIPTIONS

TABLE 5 : Summary of Source Descriptions

Source

No. Source

Hazardous

Waste Quantity

Value Source

Hazardous

Constituent Quantity Complete? (Yes/No) Containment Factor Value by Pathway

Ground

Water (Ref. 1,

Table 3

- 2) Surface

Water

Overland/

Flood (Ref. 1,

Table 4

- 2) Air

Gas (Ref. 1,

Table 6

- 3) Particulate (Ref. 1,

Table 6

- 9)

1 >0 No NS 10 NS NS

Notes:

NS Not scored Total Source Hazard Waste Quantity Value: >0

Other Possible Source:

Contaminated Soil on Western Portion of MNOP

– During the EPA May 2009 expanded site inspection ( ESI ) conducted at the MNOP ( currently known as AIP), soil samples were collected on the western portion of the MNOP property (Ref. 7, p p . 1, 6 , Appendix A, p. A

- 4) . Soil samples AIP

- 124

- SB and AIP

134

- SF contained mercury at concentrations of 0.88 mg/kg and 1.3 mg/kg (Ref. 34, pp. 120, 166)

. Soil sample AIP

- 124

- SB was collected from the area where the Blending/Mixing Houses were located (Refs. 7, Appendix A, p. A

- 4; 13, p. 54) . The Blending/Mixing Houses were where MNOP mixed the explosives (Ref. 13, pp. 11, 12) . M ilitary explosives, such as those that were manufactured at MNOP,

contained mercury compounds (mercury fulminate) as initiating agents (Ref. 23, pp. 7- 1, 7- 5, 7

- 8). Soil sample AIP

- 134

- SF was collected from the northwestern portion of the MNOP, in the area where the MNOP WWTP was formerly located (Refs. 7, Appendix A, p. A

- 4; 13, p. 52) (see Figure 2 of this HRS documentation record)

. These areas drain into Drainage Ditch 2, which flows south and merges with the AWI drainage easement, then flows into Rocky Creek (Ref. 7, Appendix A, p. A

- 4)

. Contaminated soil on the western porti on of MNOP drains towards the AWI site to the west of MNOP and not towards the PPE and observed release scored in this HRS documentation record (see Figure 3) ; therefore, this other possible source is not scored in this HRS documentation record

.21 SW

- Overland/Flood Migration Component 4.0 SURFACE WATER MIGRATION PATHWAY

4.1 OVERLAND/FLOOD MIGRATION COMPONENT

– Drainage Ditch 4

4.1.1.1 Definition of Hazardous Substance Migration Path for Overland/Flood Component

The hazardous substance migration pathway includes both the overland segment and the in

- water segment that hazardous substances would take as they migrate away from sources. The overland segment begins at the source and proceeds downgradient to the probable point of entry (PPE) to surface water. The in

water segment at the PPE continues in the direction of flow (Ref. 1, Section 4.1.1.1).

Overland flow from Source No. 1 (contaminated soil in the eastern portion of the MNOP property) is directed to Drainage Ditch 4

. Drainage Ditch 4 is an intermittent drainage route located upgradient of the

PPE along the eastern boundary of the MNOP property (Ref. 9, pp. 1, 3)

. Surface water runoff from

Source No. 1 flows overland about 625 feet and enters Drainage Ditch 4. Drainage Ditch 4 flows south

for about 3,250 feet and enters HRS

- eligible palustrine forested wetlands adjacent to Rocky Creek. The point where Drainage Ditch 4 enters the palustrine forested wetlands is PPE 1. Drainage Ditch 4 continues south within palustrine forested wetlands for about 1,250 feet and enters Rocky Creek (Refs. 3;

36 , Map 1 ) (also see Figure 3 of this HRS documentation record).

Rocky Creek flows east

- southeast for about 1 mile before it converges with Tobesofkee Creek.

Tobesofkee Creek flows south

- southeast for about 4 miles before it converges with the Ocmulgee River,

which flows for more than 9. 5 miles, thus completing the 15

- mile surface water migration pathway target distance limit (TDL) east

- south east of Elbert a , Georgia (Ref. 3).

The flow rate for Rocky Creek is estimated to be between 10 and 15 cubic feet per second (cfs) (Ref. 3 7 ). Rocky Creek has several branches. Specific stream channels are difficult to discern because of the

extensive wetlands in the area (Refs. 3; 36 )

. According to the U.S. Geological Survey, the mean flow rate

for Tobesofkee Creek for water years 1937 to 2010 was 183 cfs, and the mean flow rate for the Ocmulgee

River for water years 1911 to 2010 was 2,657 cfs (Ref. 38, pp. 3, 10).

The southern portion of Drainage Ditch 4 is located wi thin wetlands and the 100

- year floodplain of Rocky

Creek. Th is area is prone to frequent flooding, resulting in the mixing of water in the surrounding area (Ref s

. 7, Appendix A, p. A

- 4; 36 , Map 1 ; 44).22 SW

- Observed Release 4.1.2.1 LIKELIHOOD OF RELEASE

4.1.2.1.1 OBSERVED RELEASE

– Chemical Analysis

EPA June 2011 Supplemental Sampling

Background and Contaminated Samples

During the EPA June 2011 supplemental sampling event

, one background sediment sample

, MNOP -W01

- SD, was collected from H RS

- eligible palustrine forested wetland s west of and upgradient from Drainage Ditch 4. Contaminated s ediment sample MNOP

- D4 -W- 09

- SD was collected from Drainage

Ditch 4 within H RS

- eligible palustrine forested wetland s down stream of the PPE

. Background and contaminated sediment samples were collected from HRS

- eligible palustrine forested wetlands at depths ranging from 0 to 3 inches bgs (Refs. 9, pp. 1, 3, 8, 9; 36 , Map 1 )

.

The sediment samples were collected in accordance with the EPA Region 4 SESD Field Branch es Quality System and Technical Procedures for Sediment Sampling, SESDPROC

- 200

- R2 (Refs. 9, pp. 1, 6; 10, p. 4; 25 ). The location of the background sediment sample is depicted on Figure 3 of this HRS

docum entation record . Chain

- of

- custody records are provided in Reference 26 . Logbook notes are provided in Reference 9 , pages 8 and 9

.

The background and contaminated sediment samples were collected during the same sampling event, in accordance with the same sampling procedures, and from the same type of HRS

- eligible wetland (palustrine forested) (Refs. 9, pp. 1, 3, 6; 36 ) (see Figure 3 of this HRS documentation record )

.

TABLE 6 : Background and Contaminated Sediment Samples

– June 2011

Sample ID Sample Location Distance

from PPE 1 Depth (bgs) Date Sampled References

MNOP -W- 01

- SD Background HRS

eligible palustrine

forested wetlands west and upgradient of Drainage Ditch 4

, upstream from site drainage NA 0 to 3

inches 06/29/2011 9, p. 8; 26, p. 2;

36 , Map 1 ; Figure 3 of this

HRS

documentation

record

MNOP

- D4 -W- 09

- SD Drainage Ditch 4,

HRS

- eligible palustrine forested

wetlands 700 feet

downstream 0 to 3

inches 06/30/2011 9, pp. 3, 9; 26, p. 2; 36 , Map 1

Notes:

bgs Below ground surface

D Ditch

HRS Hazard Ranking System

ID Identification number

MNOP Macon Naval Ordnance Plant

NA Not applicable

PPE Probable point of entry

SD Sediment sample

W Wetland23 SW

- Observed Release Background and Contaminated Concentrations

The sediment sample s listed in Table 7 were collected during the EPA June 2011 supplemental sampling

event (Ref. 9, pp. 3, 8, 9 ). Sediment s amples were analyzed for mercury in accordance with EPA Method

245.5 and the EPA Region 4 ASB LOQAM, January 2011 (Refs. 9, p. 1; 11, p. 1; 27). EPA Region 4 SESD reviewed all data according to the contract SOW and EPA guidelines (Refs. 28; 11, p. 1). The MRLs are listed on the analytical data sheets in Reference 11 , page s 21 and 22 . Each MRL is sample

specific and corresponds to the lowest quantitative point on the calibration curve; it is adjusted for the amount of sample prepared and any dilutions performed, as well as for percent moisture. The MRLs are equivalent to SQLs (Ref. 29).

TABLE 7: Analytical Results for Background and Contaminated Sediment Samples

– June 2011

Sample Description Sample ID Hazardous

Substance Concentration MRL References

Background MNOP -W- 01

- SD Mercury 0.16J (0.29) mg/kg 0.050 mg/kg 11, p p

. 4, 22 ; 31 ; 3 2

, pp. 8, 18

Release MNOP

- D4 -W- 09

- SD Mercury 1.1 mg/kg 0.050 mg/kg 11, p. 21

Notes:

( ) Concentrations shown in parentheses were adjusted in accordance with References 31 and 32.

D Ditch

ID Identification number

J The identification of the analyte is acceptable; the reported value is an estimate (Ref. 11, p. 4)

. mg/kg Milligram per kilogram

MNOP Macon Naval Ordnance Plant

MRL Minimum reporting limit

SD Sediment sample

W Wetland24 SW

- Observed Release Additional Supporting Data

The sediment samples listed in Table 8 below were collected from Drainage Ditch 4 during the June 2011 supplemental sampling event (Ref. 9, pp. 1, 3, 9). Sediment sample MNOP

- D4 -W- 08

- SD was collected at PPE 1. The samples presented below show the presence of mercury along the overland drainage route, Drainage Ditch 4

, from Source No. 1 to PPE 1. Because Drainage Ditch 4 is an intermittent water body upgradient of PPE 1

, these sediment samples were not included as part of the surface wate r pathway in

water segment discussion (Ref. 9, p p . 1, 3) (see Figure 3 of this HRS documentation record)

.

TABLE 8 : Drainage Ditch 4 Sediment Samples

– June 2011

Sample ID Hazardous

Substance Concentration MRL Reference

MNOP

- D4

- 02

- SD Mercury 0.051J mg/kg 0.050 mg/kg 11, p p. 4, 13

MNOP

- D4

- 04

- SD Mercury 0.083J mg/kg 0.050 mg/kg 11, p p

. 4, 16

MNOP

- D4

- 07

- SD Mercury 0.46 mg/kg 0.050 mg/kg 11, p . 19

MNOP

- D4 -W- 08

- SD Mercury 0.19J mg/kg 0.050 mg/kg 11, p p. 4, 20

Notes:

D4 Drainage Ditch 4

ID Identification

J The identification of the analyte is acceptable; the reported value is an estimate (Ref. 11, p. 4)

. mg/kg Milligrams per kilogram

MNOP Macon Naval Ordnance Plant

MRL Minimum reporting limit

SD Sediment

W Wetland25 SW

- Observed Release Attribution

Th e MNOP was constructed before World War II a nd was operated as an ordnance manufacturing facility

until 1973 (Ref s

. 12 , p. 1 -1 ; 13 , p. 2 ). Ordnance manufactured at the MNOP included flares, small primers, detonators, and other triggering mechanisms (Ref. 13 , p. 2) . The total area of the MNOP was approximately 433 acres, which extended from Guy Paine Road in the north to Rocky Creek in the south and Mead Road to the east and the Central of Georgia Railroad tracks to the west (Refs. 8; 18, p. 2; 22

, pp. 1, 2).

Explosive compounds were either handled or stored in many areas throughout the MNOP property, including numerous small dryer buildings, ordnance magazines, and blending and mixing houses (Ref.

13 , pp. 11, 12, 54). According to a technical manual prepared by the Department of the Army, military explosives, such as those that were manufactured at the MNOP , contained mercury compounds as initiating agents , including mercury fulminate (Ref. 23 , pp. 7- 1, 7- 5, 7

- 8). Building 109, located in the
eastern p ortion of the MNOP near Source No. 1, was a primary explosives production site (Ref. 13, pp. 11, 12, 54) (see Figure s 2 and 3 of this HRS documentation record). Soil samples collected from this area during the USACE 1996 site investigation and EPA June 2011 supplemental sampling event contained mercury (Refs. 9, p. 3; 13, pp. 58, 83, 84).

Other facilities in the area include t he MBCIA, which renamed the MNOP property the Allied Industrial

Park and currently leases or sells buildings as office and warehouse space to various industrial and commercial businesses on the AIP property (Refs. 7, Appendix A, p. A

- 3; 13, pp. 1, 2, 3; 14, p. 2

- 9; 15). Politex U S Inc. (Politex) is the only manufacturing business that is currently located at the AIP. Politex

is a textile manufacturing firm that produces roofing membranes, clothing and furniture padding, and building materials (Ref. 15)

. Politex is located on the western portion of the MNOP property (Refs. 6, pp.

42 through 49 ; 7, Appendix A, p. A

- 3). Runoff and drainage originating from Politex does not enter Drainage Ditch 4 (Ref. 7, Appendix A, pp. A

- 2, A

- 3) (see Figure 3 of this HRS documentation record)

. The property where Source No. 1 soil sample MNOP

- 04

- SF was collected is owned by the City of Macon

and is operated as a recreational park that includes baseball fields (Refs. 6, pp. 7, 8; 7, Appendix A, pp.

A- 2, A

- 3; 9, p. 3)

.

P ossible off

- site sources also include the FMNOL, AWI, and the Rocky Creek water reclamation facility (RC WRF) . AWI and FMNOL ar e currently listed on the EPA NPL under CERCLIS ID No.

GAN000410033 at docket number EPA

- HQ

- SFUND

- 2010

- 0640

- 0002 (Ref. 47) . Runoff from FMNOL and AWI flows into Rocky Creek via a drainage easement. The drainage easement enters Rocky Creek west and upstream of Source No. 1 soil sample MNOP

- 04

- SF and Drainage Ditch 4. Drainage Ditch 4 is located just west of the RC WRF (Ref. 7, Appendix A, p. A

- 2).

The FMNOL was reportedly used for disposal of solid wastes and ordnance throughout the operational history (1941 to 1974) of the MNOP (Refs. 8; 17, pp. 42, 43, 46, 47; 18, p. 2). The landfill was also used for disposal of used parts and construction debris (Refs. 14, p. 2

- 11; 18, p. 2). During the EPA May 2009 ESI, mercury was detected in soil samples collected from the FMNOL at concentrations ranging from 0.47 mg/kg (FML

- 303

- SF) to 4.7 mg/kg (FML

- 304

- SB) (Ref . 35, pp. 130, 132 ).

Since 1948, AWI has operated an acoustic ceiling tile manufacturing plant on 130 acres of land west of the MNOP property (Ref. 19, p. 3). In 1980, AWI notified the Georgia Environmental Protection Division (GAEPD) that it was a generator of hazardous waste and AWI was classified as a conditionally exempt small quantity generator under the Resource Conservation and Recovery Act (RCRA). PCBs are

the primary hazardous substance of concern for this facility, not metals (Ref. 19, pp. 5, 6).

The RC WRF

, located south east of and downstream from MNOP , provides waste water treatment for the southern and western portions of the City of Macon. T reated wastewater from this facility is discharged into the Ocmulgee River ; however, RC WRF maintains a National Pol lutant Discharge Elimination System (NPDES)

- permitted discharge point at the southern property boundary (Refs. 9, p. 3; 45, p p . 2, 3; 46, pp. 1, 8)

. The NPDES permit requires RC WRF to monitor outfall discharges for biochemical oxygen26 SW

- Observed Release demand, total suspended solids, pH, chlorine, fecal coliform, nitrogen, dissolved oxygen, PCBs, and phosphorus (Ref. 46, pp. 6, 7)

. There are currently no documented releases of mercury at this location (Refs. 9, p. 3; 46, pp. 6, 7)

.

The source sample collected from Source No. 1 (contaminated soil on the eastern portion of MNOP) during the EPA June 2011 supplemental sampling event contained mercury (Refs. 9, p. 3; 11, p. 8) (see Table 3 in Section 2.2.2 for Source No. 1 of this HRS documentation record) . Sediment sa mples collected from Drainage Ditch 4, which receives runoff from Source No. 1, also contained mercury. The presence of mercury in Drainage Ditch 4 documents the migration of releases from Source No. 1 at the

MNOP (Refs. 9, p. 3; 11, pp. 13, 16, 19, 20, 2 1) (also see Tables 6 and 7 in Section 4.1.2.1.1, Observed Release, of this HRS documentation record)

. Furthermore , an observed release of mercury has been

documented in HRS

- eligible wetlands along Drainage Ditch 4 (Refs. 9, p. 3; 11, p. 21; 36 ).

Mercur y has been documented in Source No. 1

, in Drainage Ditch 4 and in palustrine forested wetlands indicating migration of hazardous substances from the MNOP propert y (see Table 3 in Section 2.2.2 for Source No. 1, and Table 7 in Section 4.1.2.1.1, Observed Release, of this HRS documentation record).

Hazardous Substance in the Release

Mercury

Surface Water Observed Release Factor Value: 550.0027 SW

- Drinking Water Threat 4.1.2 DRINKING WATER THREAT

The drinking water threat was not scored because it is not expected to contribute significantly to the

overall score.28 SW

- Human Food Chain Threat 4.1.3.2 HUMAN FOOD CHAIN THREAT WASTE CHARACTERISTICS

4.1.3.2.1 Toxicity/Persistence/Bioaccumulation

The toxicity, persistence, and bioaccumulation factor value for mercury detected in Source No. 1 with containment factor values of greater than 0 is summarized in Table 9 . The combined toxicity, persistence,

and bioac cumulation factor value is assigned in accordance with Reference 1, Section 4.1.3.2.1.

TABLE 9 : Toxicity/Persistence/Bioaccumulation

Hazardous

Substance Source

No. Toxicity

Factor

Value Persistence

Factor

Value 1 Bioaccu mulation

Value 2 Toxicity/

Persistence/

Bioaccumulation Factor Value ( Ref. 1, Table 4

- 16) Reference
Mercury 1 10,000 1 50,000 5 × 10 8 2, p. BI -8

Notes:

1 Persistence factor value for rivers

2 Bioaccumulation factor value for fresh water

Toxicity/Persistence/Bioaccumulation Factor Value: 500,000,000.00 (Ref. 1, Section 4.1.3.2.1.4)29 SW

- Human Food Chain Threat 4.1.3.2.2 HAZARDOUS WASTE QUANTITY

TABLE 10 : Hazardous Waste Quantity

Source No. Source Type Source Hazardous Waste Quantity

1 Contaminated soil >0

Total Source Hazardous Waste Quantity: >0

One soil sample , MNOP

- 04

- SF, was collected to represent Source No. 1 (Ref. 9, pp. 3, 9 ; see Table 3 in

Section 2.2.2 for Source No. 1 of this HRS documentation record ) . As a result, it is not possible to

calculate an area measurement for Source No. 1. Therefore, the area of Source No. 1 is undetermined, but is greater than zero. In addition

, the hazardous waste quantity receives a minimum factor value of 100 for the surface water migration pathway because actual contamination at Level II concentrations is present in

HRS

- eligible palustrine forested wetlands and hazardous constituent quantity is not adequately

determined (Ref. 1, Section 2.4.2.2).

Hazardous Waste Quantity Factor Value: 10 0 (Ref. 1, Table 2

- 6)

4.1.3.2.3 CALCULATION OF HUMAN FOOD CHAIN THREAT

WASTE CHARACTERISTICS FACTOR CATEGORY VALUE

The waste characteristics factor category was obtained by multiplying the toxicity, persistence, and hazardous waste quantity ( HWQ ) factor values, subject to a maximum product of 1 x 10 8 . Then, this product was multiplied by the bioaccumulation potential factor value, subject to a maximum product of 1

x 10 12 . Based on this product, a value was assigned in accordance with Reference 1, Table 2

- 7.

Toxicity/Persistence Factor Value: 10,000.00 Hazardous Waste Quantity Factor Value: 10 0

Toxicity/Persistence Factor Value × Hazardous Waste Quantity Factor Value: 1 x 10 6

Toxicity/Persistence Factor Value × Hazardous Waste Quantity Factor Value × Bioaccumulation Factor Value (50,000): 5 x 10 10

Waste Characteristics Factor Category Value: 320 (Ref. 1, Table 2

- 7)30 SW

- Human Food Chain Threat 4.1.3.3 HUMAN FOOD CHAIN THREAT TARGETS

4.1.3.3.1 Food Chain Individual

An observed release of a hazardous substance having a bioaccumulation factor value of 500 or greater is documented in perennial surface water with a fishery downstream

— specifically, an observed release to Drainage Ditch 4 within HRS

- eligible palustrine forested wetlands (Refs. 9, p. 3; 11, pp. 21, 22 ; 36, Map

1 ) (see Figure 3 of this HRS documentation record). Drainage Ditch 4 flows south for about 1,2 5 0 feet within palustrine forested wetlands and joins Rocky Creek (Ref. 9, p. 3 ). Rocky Creek, Tobesofkee Creek, and the Ocmulgee River are designated as fisheries by the State of Georgia’s Ocmulgee River Watershed Management Plan (Refs. 39, p. 2; 40, Appendix A, pp. A

- 89 , A

- 91 ; 41, p. 4

- 14). Rocky Creek is fished between Broadway and its confluence with Tobesofkee Creek within the site TDL where it is accessible to the public; fish are also harvested for consumption (Refs. 3; 37; 42, pp. 3, 10, 11). In 2007, GAEPD personnel observed people fishing in Rocky Creek east of Hig hway 41 . The fishermen indicated to GAEPD personnel that they clean and eat the fish that they catch (Refs. 19, p. 9; 42, pp. 3, 10, 11). In addition, Tetra Tech observed fishing gear, including a fishing line and weight, along Rocky Creek during

the EPA 2009 ESI sampling event (Ref. 7, Appendix D, p. D

- 14). F ish species caught for consumption in Rocky Creek include br ea m, blackfish, bass, redear sunfish, redbreast sunfish, bluegill, and brown bullhead catfish (Ref s

. 19, p. 9; 37 ; 42, p. 3 ). T he State of Georgia has issued fish consumption guidelines for the Ocmulgee River as a result of mercury contamination (Refs. 9, p. 9; 43, p. 41 ).

Food Chain Individual Factor Value: 20 (Ref. 1, Section 4.1.3.3.1)

4.1.3.3.2 Population

4.1.3.3.2.1 Level I Concentrations

No Level I samples were collected.

4.1.3.3.2.2 Level II Concentrations

No Level II samples were collected.

4.1.3.3.2.3 Potential Human Food Chain Contamination

Drainage Ditch 4 flows south for about 1,2 5 0 feet within HRS

- eligibl e palustrine forested wetlands and joins Rocky Creek (Ref. 9, p. 3 ). Rocky Creek is fished between Broadway and its confluence with

Tobesofkee Creek within the site TDL where it is accessible to the public; fish are also harvested for consumption (Refs. 3; 37; 42, pp. 3, 10, 11). Information is not available on the annual production of fish caught in Rocky Creek; therefore, the annual production is undetermined but great er than 0.

TABLE 11 : Potential Population Targets

Identity of Fishery Annual

Production

(pounds) Type of

Surface

Water Body Average

Annual Flow (cfs) Population Value (P i )

(Ref. 1,

Table 4

- 18) Dilution Weight (D i ) (Ref. 1, Table

4

- 13) P i × D i References

Rocky

Creek >0 Small to

Moderate

Stream 10 to 15 0.03 0. 1 0.0 03 37; 39, p. 2; 40, Appendix A, p. A

- 91 ; 41, p. 4

- 14

Notes:

cfs Cubic feet per second31 SW

- Human Food Chain Threat For the potential human food chain contamination factor value

, the sum of P i × D i is divided by 10.

Potential Human Food Chain Factor Value: 0. 0 003 (Ref. 1, Section 4.1.3.3.2.3)32 SW

- Environmental Threat 4.1.4.2 ENVIRONMENTAL THREAT WASTE CHARACTERISTICS

4.1.4.2.1 Ecosystem Toxicity/Persistence/Bioaccumulation

The ecosystem toxicity, persistence, and bioaccumulation fa ctor value for mercury detected in Source No. 1, with a containment factor value of greater than 0

, is summarized in Table 12 . The combined ecosystem toxicity, persistence, and bioaccumulation factor value is assigned in accordance with Reference 1,

Secti on 4.1.4.2.1.

TABLE 12 : Ecosystem Toxicity/Persistence/Bioaccumulation

Hazardous

Substances Source

No. Ecosystem Toxicity

Factor

Value 1 Persistence

Factor

Value 2 Bioaccu mulation

Value 3 Ecosystem/ Toxicity/

Bioaccumulation

Factor Value (Ref. 1, Table

4

- 21) Reference
Mercury 1 10,000 1 50,000 5 × 10 8 2, p. BI -8

Notes:

1 Ecotoxicity for fresh water

2 Persistence value for rivers

3 Bioaccumulation factor value for fresh water, environmental threat

Ecosystem Toxicity/Persistence/Bioaccumulation Factor Value: 5 × 10 8

(Reference 1, Section 4.1.4.2.1 .4 )33 SW

- Environmental Threat 4.1.4.2.2 HAZARDOUS WASTE QUANTITY

TABLE 13 : Hazardous Waste Quantity

Source No. Source Type Source Hazardous Waste Quantity

1 Contaminated soil >0

Total Source Hazardous Waste Quantity: >0

One soil sample , MNOP

- 04

- SF, was collected to represent Source No. 1 (Ref. 9, pp. 3, 9 ; see Table 3 in

Section 2.2.2 for Source No. 1 of this HRS documentation record ) (Ref. 9, pp. 3, 9). As a result, it is not possible to calculate an area measurement for Source No. 1. Therefore, the area of Source No. 1 is undetermined but is greater than zero. In addition , the hazardous waste quantity receives a minimum factor value of 100 for the surface water migration pathway because actual contamination at Level II concentrations is present in HRS

- eligible palustrine forested wetlands, and hazardous constituent quantity is not adequately determined (Ref. 1, Section 2.4.2.2).

Hazardous Waste Quantity Factor Valu e: 100 (Ref. 1, Table 2

- 6)

4.1.4.2.3 CALCULATION OF ENVIRONMENTAL CHAIN THREAT

WASTE CHARACTERISTICS FACTOR CATEGORY VALUE

The waste characteristics factor category was obtained by multiplying the ecosystem toxicity, persistence, and HWQ factor values, subject to a maximum product of 1 x 10 8 . Then, this product was multiplied by the bioaccumulation potential factor value, subject to a maximum product of 1 x 10 12 . Based on this product, a value was assigned in accordance with Reference 1, Table 2

- 7.

Ecosystem Toxicity/Persistence Factor Value: 10,000.00 Hazardous Waste Quantity Factor Value: 100

Ecosystem Toxicity/Persistence Factor Value × Hazardous Waste Quantity Factor Value: 1 x 10 6

Ecosystem Toxicity/Persistence Factor Value ×

Hazardous Waste Quantity Factor Value × Bioaccumulation Factor Value (50,000): 5 x 10 10

Waste Characteristics Factor Category Value: 320 (Ref. 1, Table 2

- 7)34 SW

- Environmental Threat 4.1.4.3 Environmental Threat Targets

Level I Concentrations

No Level I concentrations have been documented.

L evel II Concentrations

Actual contamination has been documented in wetland areas along Drainage Ditch 4 in Section 4.1.2.1.1 of this HRS documentation record. The sampling locations are shown in Reference 9 , page 3. Wetland

areas were identified from Reference 36 , Wetlands Inventory Map s . The wetland areas evaluated are palustrine forested (Refs. 3; 9, p. 3; 36 ).

Most Distant Level II Sample

Investigation: June 2011 Supplemental Sampling Sample ID: MNOP

- D4 -W- 09

- SD Sample Medium: Sediment

Hazardous Substance: M ercury Location: Drainage Ditch 4 , about 700 feet downstream from PPE 1

References: 3; 9, p. 3; 11, p. 21; 36 (also see Table 7 of this HRS documentation

record )

4.1.4.3.1 Sensitive Environments

4.1.4.3.1.1 Level I Concentrations

Sensitive Environments

Sensitive environments other than wetlands have not been identified within the 15

- mile surface water migration pathway TDL.

Wetlands

No Level I wetlands were scored.

4.1.4.3.1.2 Level II Concentrations

Sensitive Environments

Sensitive environments other than wetlands have not been identified within the 15

- mile surface water migration pathway TDL.

Wetlands

The wetland s were identified from Reference 36, Wetlands Inventory Map s . The wetland s evaluated are palustrine forested (Refs. 3; 9, p. 3; 36 ). The southern portion of Drainage Ditch 4 is located within HRS

eligible wetlands (Refs. 3; 9, p. 3; 36 ). The sediment sample evaluated at a Level II concentration is located in palustrine forested wetlands along Drainage Ditch 4 (Refs. 3; 9 , p. 3; 36 ). The total wetland frontage from PPE 1 to the most downstream sample that contained Level II concentrations ( MNOP

- D4

- W- 090SD ) is about 1,400 feet , or 0.26 mile (Refs. 3; 9, p. 3 ; 36 ). Both sides of Drainage Ditch 4 within this segment contain HRS eligible wetlands, so both sides of Drainage Ditch 4 were included in the

calculation of the wetland frontage (Refs. 3; 9, p. 3; 36 ).35 SW

- Environmental Threat TABLE 14: Level II Wetland Frontage

Wetland Water Body Wetland Frontage References

Palustrine forested Drainage Ditch 4 1,400 feet or 0.26 mile 3; 9, p. 3; 36

Total Wetland Frontage 1,400 feet or 0.26 mile 3; 9, p. 3; 36

Total Wetland Frontage: 1,400 feet

The wetland ratings value for 0.26 mile is obtained from Reference 1, Table 4

- 24 and is 25

.

Wetland Value: 25 (Ref. 1, Table 4

- 24)

For wetlands subject to Level II concentrations, the wetland value ( 25 ) is multiplied by 1 (Ref. 1, Section 4.1.4.3.1.1).

Wetland Value: 25 × 1

Level II Concentrations Factor Value: 25 (Ref. 1, Section 4.1.4.3.1.1)

4.1.4.3.1.3 Potential Contamination

Sensitive Environments

Potential sensitive environments were not evaluated because the presence of sensitive environments other

than wetlands has not been identified.

Wetlands

The wetlands were identified from Reference 36

, Wetlands Inventory Map s . The wetland s evaluated for potential contamination are palustrine forested (Refs. 3; 9, p. 3; 36 ). Wetlands were measured from the farthest downstream sediment sample ( MNOP

- D4 -W- 09

- SD ) collected on Drainage Ditch 4 to the complet ion of the 15

- mile surface water migration pathway TDL. Wetland frontage from both sides of Drainage Ditch 4, Rocky Creek, Tobesofkee Creek, and the Ocmulgee River were measured (Ref s

. 3; 36 ).

Wetlands that were evaluated as Level II were not included in the potential contamination wetland frontage. The flow rate for Rocky Creek is estimated to be between 10 and 15 cfs (Ref. 37 ). According to the U.S. Geological Survey, the mean flow rate for Tobesofkee Creek water years 1937 to 2010 was

183 cfs, and the mean flow rate for the Ocmulgee River water years 1911 to 2010 was 2,657 cfs (Ref. 38

, pp. 3, 10 ).36 SW

- Environmental Threat TABLE 15 : Wetland Frontage

Surface Water Body Type of Surface Water Body Wetland Frontage Wetlands

Value Based

on Wetland

Frontage References

Rocky Creek Smal l to Moderate

S tream About 2.5 miles 75 1, Tables 4

- 13, 4

- 24; 3; 36;

3 7

Tobesofkee Creek Moderate to L arge S tream About 7.75

miles 150 1, Tables 4

- 13, 4

- 24; 3; 36;

38 , p. 3

Ocmulgee River Large S tream to

R iver About 7 miles 150 1, Tables 4

- 13, 4

- 24; 3; 36;

38 , p. 10

Total Wetlands Value 3 75 1, Tables 4

- 13, 4

- 24; 3; 36

TABLE 16 : Potential Contamination

Surface Water Body Sum of

Sensitive

Environments

Values (S i ) Wetlands Value (W i ) (Ref. 1, Table

4

- 24) Dilution Weight (D i ) (Ref. 1,

Table 4

- 13) D i (W i + S i ) (Ref. 1,

Section 4.1.4.3.3.3) References

Rocky Creek 0 75 0. 1 7.5 3; 36; 37

Tobesofkee Creek 0 150 0.01 1.5 3; 36; 38 , p. 3

Ocmulgee River 0 150 0.001 0. 15 3; 36; 38 , p. 10

Total Potential Contamination Factor Value: 9. 15

For wetlands subject to potential contamination, the wetland value ( 9. 15 ) is multiplied by 0.1 (Ref. 1, Section 4.1.4.3.1.3).

Wetland Value: 9. 15 × 0.1

Potential Contamination Factor Value: 0. 915 (Ref. 1, Section 4.1.4.3.1.3)