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., 11th Floor

 Atlanta, Georgia 30303

 (404) 562-8637

 Donna Seadler, Remedial Project Manager

 U.S. Environmental Protection Agency, Region 4

61 Forsyth Street, S.W., 11th 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) documentation 

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

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, 1985 

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 the 

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 evaluate 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 about 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 48.97
2 

WORKSHEET FOR COMPUTING HRS SITE SCORE

S Pathway S2 Pathway

Ground Water Migration Pathway Score (Sgw) Not Scored Not Scored

Surface Water Migration Pathway Score (Ssw) 97.94 9,592.2436

Soil Exposure Pathway Score (Ss) Not Scored Not Scored

Air Migration Pathway Score (Sa) Not Scored Not Scored

S2

gw + S2sw + S2s + S2a 9,592.2436

(S2

gw + S2sw + S2s + S2a) / 4 2,398.0609

√ (S2

gw + S2sw + S2s + S2a) / 4 48.97 
3 

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) 100

17. Waste Characteristics 1,000 320

Targets:

18. Food Chain Individual 50 20
4 

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) 0.0003

19d. Population (lines 19a + 19b + 19c) (b) 0.0003

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 42.66

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) 0.915 

26d. Sensitive Environments (lines 26a + 26b + 

26c) (b) 25.915

27. Targets (value from line 26d) (b) 25.915

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 Scorec (lines 13+21+28, subject to a 

maximum of 100) 100 97.94 

Surface Water Overland/Flood Migration Component Score

30. Component Score (Sof)

c (highest score from line 

29 for all watersheds evaluated, subject to a maximum 

of 100) 100 97.94 

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 Naval 

Ordnance Plant 

/ 

BI

Un

T

P
Wg

Guy Paine Road 

Mead

Road 

Allied Industrial Road Ennis Boulevard 

MIXING/BLENDING 

HOUSES 

BUILDING 109 

WWTP DISCHARGE 

WASTE WATER 

TREATMENT PLANT 

BUILDING 105 - ASSEMBLY 

BUILDING 5 METAL PLATING FACILITY 

RAILCAR UNLOADING 
")")

Guy Paine Road 

MNOP-01-SF 

MNOP-04-SF 

") 

"Former" Macon Naval 

Ordnance Plant 

#*#*

PEM

PFO/PSS

Rocky Creek 

Drainage Ditch 1 

Rocky Creek 

MNOP-W-01-SD 

PFO/PSS

Dra

in

age 

D

itch 2 

Dr

i a

#*

#*

#*

#*

#*

Drainage Ditch 4 

PEM

PFO/PSS

PFO/PSS

PFO/PSS

nage Ditch 3 

Rock Creek 

Rocky Creek 

MNOP-D4-07-SD 

MNOP-D4-04-SD 

MNOP-D4-02-SD 

MNOP-D4-W-09-SD 

MNOP-D4-W-08-SD 

(PPE 1) 

Rocky Creek 

Water Reclamation 

Facility 
8 

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 with NWI Wetlands. 

U.S. Geological Survey (USGS) 7.5 Minute Series Topographic Maps of Georgia Quadrangles: 

Macon West (1985), Macon East (1985), 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. Query: 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/cerclisquery.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 Plant, 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 Ordnance 

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, Armstrong 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. Operating Procedure for Soil Sampling, Number SESDPROC-300-R1. 

November 1, 2007. 22 Pages. Accessed on-line at http://www.epa.gov/region4/sesd/fbqstp/SoilSampling.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-Sampling.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 Quinn 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, 2011. 3 Pages.

40. GADNR, Environmental Protection Division. Water Quality in Georgia 2008-2009. Approved 

November 10, 2010. 505 Pages. Accessed on-line at http://www.gaepd.org/Documents/305b.html. 

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

Assessment. 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. 2010 Update. 30 Pages. Accessed online at http://www.gaepd.org/Documents/fish_guide.html. 

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

Incorporated areas, Georgia. Excerpt of Panel 144 of 265. Community-Panel Number 130011 0144 

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-facilities. 
11 

46. EPA. Enforcement and Compliance History Online (ECHO) with Attachments. Macon Water 

Authority Rocky Creek Water Reclamation Facility. Report Generated November 1, 2011. 8 Pages. 

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

Accessed on-line at http://www.epa-echo.gov/cgibin/get1cReport.cgi?tool=echo&IDNumber=110007498412. 

47. Regulations.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 former Macon Naval Ordnance Plant (MNOP) property, 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 property, as 

recorded in the Comprehensive Environmental Response, Compensation, and Liability Information 

System (CERCLIS) database, is GAD003302676 (Ref. 5). 

Land uses on the MNOP property are predominantly commercial and heavy industrial (Refs. 6, pp. 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 Facility 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 contains mercury (see Section 2.2 of this 

HRS documentation record). Mercury has also been detected at significant levels in sediments 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 (Refs. 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 

approximately 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 used 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 (Refs. 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 by 
13 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. 

Records 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, 

including 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 site 

(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 landfill 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. 14, pp. 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

Several 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

14, 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 60, 

63, 71 through 92, 94 

through 104, 106, 107
14 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

Chromium

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-12 

through B-69, B-71 

through B-75, 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

SVOC Semivolatile organic compound

TCE Trichloroethylene

USACE U.S. Army Corps of Engineers

VOC Volatile organic compound

In June 2011, EPA conducted a supplemental 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 eastern portion of the property (Refs. 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 receives 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 were 

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 1973 (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 agents, 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, Building 109, located in the eastern portion of the 

MNOP near Source No. 1, was a primary explosives production site (Ref. 13, pp. 11, 12, 54) (see Figures 

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 (Refs. 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 

supplemental sampling 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, 

near 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 

samples 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). Surface soil samples 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 locations of the background and source soil samples are depicted in 

Reference 9, page 3 and are listed in Reference 10, Appendix B, page 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 sample
Source 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 quantitation 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, pp. 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 sample
Source No. 1

18 Site Description

2.2.3 HAZARDOUS SUBSTANCES AVAILABLE TO A PATHWAY

The sample collected from Source No. 1 contains mercury (Refs. 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, pp. 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 primary 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 control systems 

were observed during the EPA June 2011 supplemental sampling 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, Appendix 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 Factors 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 scored
Source 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. Available Source 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 information available is not sufficient to evaluate Tier B, hazardous wastestream quantity, as required 

by Reference 1, Section 2.4.2.1.2. Available Source 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 zero.

Sum (square feet [ft2

]): >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 unknown (Ref. 1, Section 

2.4.2.1.5).

Source HWQ Value: >0
20 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, pp. 1, 6, Appendix A, p. A-4). Soil samples AIP-124-SB and AIP134-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). Military 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 portion 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 inwater 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-southeast of Elberta, Georgia (Ref. 3). 

The flow rate for Rocky Creek is estimated to be between 10 and 15 cubic feet per second (cfs) (Ref. 37). 

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 within wetlands and the 100-year floodplain of Rocky 

Creek. This area is prone to frequent flooding, resulting in the mixing of water in the surrounding area 

(Refs. 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 HRS-eligible palustrine forested wetlands west of and upgradient from 

Drainage Ditch 4. Contaminated sediment sample MNOP-D4-W-09-SD was collected from Drainage 

Ditch 4 within HRS-eligible palustrine forested wetlands downstream 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 Branches 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 

documentation 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 HRSeligible 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 Wetland
23 SW-Observed Release

Background and Contaminated Concentrations

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

event (Ref. 9, pp. 3, 8, 9). Sediment samples 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, pages 21 and 22. Each MRL is samplespecific 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, pp. 4, 22; 31; 32, 

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 Wetland
24 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 water pathway inwater segment discussion (Ref. 9, pp. 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, pp. 4, 13

MNOP-D4-04-SD Mercury 0.083J mg/kg 0.050 mg/kg 11, pp. 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, pp. 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 Wetland 
25 SW-Observed Release

Attribution

The MNOP was constructed before World War II and was operated as an ordnance manufacturing facility 

until 1973 (Refs. 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 portion of the MNOP near Source No. 1, was a primary explosives production site (Ref. 13, pp. 

11, 12, 54) (see Figures 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 the 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). 

Possible off-site sources also include the FMNOL, AWI, and the Rocky Creek water reclamation facility

(RC WRF). AWI and FMNOL are 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 southeast of and downstream from MNOP, provides wastewater treatment for the 

southern and western portions of the City of Macon. Treated wastewater from this facility is discharged 

into the Ocmulgee River; however, RC WRF maintains a National Pollutant Discharge Elimination 

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

46, pp. 1, 8). The NPDES permit requires RC WRF to monitor outfall discharges for biochemical oxygen 
26 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 samples 

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, 21) (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).

 

Mercury has been documented in Source No. 1, in Drainage Ditch 4 and in palustrine forested wetlands 

indicating migration of hazardous substances from the MNOP property (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: 550.00
27 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 bioaccumulation 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 

Value1

Bioaccumulation 

Value2

Toxicity/

Persistence/

Bioaccumulation 

Factor Value (Ref. 

1, Table 4-16) Reference

Mercury 1 10,000 1 50,000 5 × 108 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: 100 

(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 108

. Then, this 

product was multiplied by the bioaccumulation potential factor value, subject to a maximum product of 1 

x 1012. 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: 100 

Toxicity/Persistence Factor Value × 

Hazardous Waste Quantity Factor Value: 1 x 106 

Toxicity/Persistence Factor Value × 

Hazardous Waste Quantity Factor Value × Bioaccumulation Factor Value (50,000): 5 x 1010

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 1,250 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 Highway 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). Fish species caught for consumption in 

Rocky Creek include bream, blackfish, bass, redear sunfish, redbreast sunfish, bluegill, and brown 

bullhead catfish (Refs. 19, p. 9; 37; 42, p. 3). The 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 1,250 feet within HRS-eligible 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 greater than 0.

TABLE 11: Potential Population Targets

Identity 

of Fishery

Annual 

Production 

(pounds)

Type of 

Surface 

Water 

Body

Average 

Annual 

Flow (cfs)

Population 

Value (Pi) 

(Ref. 1, 

Table 4-

18)

Dilution 

Weight 

(Di) (Ref. 

1, Table 

4-13) Pi × Di References

Rocky 

Creek >0 

Small to 

Moderate

Stream

10 to 15 0.03 0.1 0.003 

37; 39, p. 2; 

40, Appendix 

A, p. A-91; 

41, p. 4-14

Notes:

cfs Cubic feet per second
31 SW-Human Food Chain Threat

For the potential human food chain contamination factor value, the sum of Pi × Di is divided by 10.

Potential Human Food Chain Factor Value: 0.0003

(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 factor 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, 

Section 4.1.4.2.1. 

TABLE 12: Ecosystem Toxicity/Persistence/Bioaccumulation

Hazardous 

Substances

Source 

No.

Ecosystem 

Toxicity 

Factor 

Value1

Persistence 

Factor 

Value2

Bioaccumulation 

Value3

Ecosystem/

Toxicity/

Bioaccumulation

Factor Value

(Ref. 1, Table 

4-21) Reference

Mercury 1 10,000 1 50,000 5 × 108 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 × 108

(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 Value: 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 108

. Then, this product was multiplied by 

the bioaccumulation potential factor value, subject to a maximum product of 1 x 1012. 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 106 

Ecosystem Toxicity/Persistence Factor Value × 

Hazardous Waste Quantity Factor Value × Bioaccumulation Factor Value (50,000): 5 x 1010 

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.

Level 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 Maps. 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: Mercury

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 wetlands were identified from Reference 36, Wetlands Inventory Maps. The wetlands evaluated are 

palustrine forested (Refs. 3; 9, p. 3; 36). The southern portion of Drainage Ditch 4 is located within HRSeligible 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 Maps. The wetlands 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 

completion 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 (Refs. 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

Small to Moderate

Stream About 2.5 miles 75 1, Tables 4-13, 4-24; 3; 36; 37

Tobesofkee Creek

Moderate to Large 

Stream

About 7.75

miles 150 1, Tables 4-13, 4-24; 3; 36; 38, p. 3

Ocmulgee River

Large Stream to 

River About 7 miles 150 1, Tables 4-13, 4-24; 3; 36; 38, p. 10

Total Wetlands Value 375 1, Tables 4-13, 4-24; 3; 36

TABLE 16: Potential Contamination

Surface Water 

Body

Sum of 

Sensitive 

Environments 

Values (Si)

Wetlands 

Value (Wi) 

(Ref. 1, Table 

4-24)

Dilution 

Weight (Di) 

(Ref. 1, 

Table 4-13)

Di (Wi + Si) 

(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)