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PUBLIC HEALTH ASSESSMENT

VOLUNTEER ARMY AMMUNITION PLANT
CHATTANOOGA, HAMILTON COUNTY, TENNESSEE


FACILITY NO. TN6210020933

September 7, 2004


Table 7: Contaminants Detected above Comparison Values (CVs) in Surface Water
Contaminant Maximum Detected (ppb) Year of Maximum Detection Comparison Value (ppb) Source
Drainage Basin A and B
Organics
Bromodichloromethane 1.2 1999 0.6 CREG
Toluene 300 1999 200 child intermediate EMEG
Explosives
1,3-Dinitrobenzene 2.81 1999 1 child RMEG
2,4-Dinitrotoluene 2370 1984 20 child EMEG
2,6-Dinitrotoluene 230 1999 40 child intermediate EMEG
RDX 6.51 1999 0.3 CREG
2,4,6-Trinitrotoluene 740 1984 1 CREG
Pesticides
Delta-BHC 0.0062 1999 0.006 CREG (alpha-BHC)
Heptachlor 0.0224 1999 0.008 CREG
Inorganics
Arsenic 10 1984 0.02 CREG
Chlorine 1,600 1984 1,000 child RMEG
Total Chromium 53.5 1999 30 child RMEG (chromium VI)
Cobalt 138 1999 100 child intermediate EMEG
Lead 290 1999 15 MCL action level
Manganese 16,000 1999 500 child RMEG
Sulfate 413,000 1984 250,000 Secondary MCL
Ammonia Nitrogen 34,000 1999 3,000 child intermediate EMEG (ammonia)
Drainage Basin C
Inorganics
Manganese 603 1994 500 child RMEG
Drainage Basin F
Inorganics
Arsenic 3.12 1994 0.02 CREG
Manganese 792 1994 500 child RMEG
Source: Army 2003c

Notes:
CREG Cancer Risk Evaluation Guideline for drinking water
EMEG Exposure Media Evaluation Guideline for drinking water
MCL EPA maximum contaminant level for drinking water
ppb parts per billion
RMEG Reference Media Evaluation Guideline for drinking water


Table 8: Contaminants Detected above Comparison Values (CVs) in Sediment
Contaminant Maximum Detected (ppm) Year of Maximum Detection Comparison Value (ppm) Source
Drainage Basins A and B
Organics
Acenaphthylene 0.55 1999 N/A N/A
Benzo(a)anthracene 3.9 1999 0.87 RBC-C
Benzo(a)pyrene 4 1999 0.1 CREG
Benzo(b)fluoranthene 3.6 1999 0.87 RBC-C
Benzo(g,h,i)perylene 2.5 1999 N/A N/A
Bis(2-ethylhexyl)phthalate 80 1999 50 CREG
Dibenz(a,h)anthracene 0.7 1999 0.087 RBC-C
Phenanthrene 4.1 1999 N/A N/A
Polychlorinated Biphenyls
Aroclor 1260 5.1 1999 0.32 RBC-C
Total PCBs 5.1 1999 0.4 CREG
Inorganics
Aluminum 102,000 1999 100,000 child intermediate EMEG
Antimony 57 1999 20 child RMEG
Arsenic 100 1984 0.5 CREG
Total Chromium 12,000 1999 200 child RMEG (chromium VI)
Iron 220,000 1999 23,000 RBC-N
Lead 8,400 1999 400 SSL
Manganese 7,000 1999 3,000 child RMEG
Thallium 254 1999 5.5 RBC-N
Vanadium 293 1999 200 child intermediate EMEG
Drainage Basin C
Organics
Acenaphthylene 1.5 1994 N/A N/A
Benzo(a)anthracene 6 1994 0.87 RBC-C
Benzo(a)pyrene 6 1994 0.1 CREG
Benzo(b)fluoranthene 6.8 1994 0.87 RBC-C
Benzo(g,h,i)perylene 3.9 1994 N/A N/A
Dibenz(a,h)anthracene 0.78 1994 0.087 RBC-C
Phenanthrene 1.6 1994 N/A N/A
Inorganics
Arsenic 30.1 1994 0.5 CREG
Iron 49,100 1994 23,000 RBC-N
Drainage Basin E
Organics
Acenaphthylene 0.7 1999 N/A N/A
Benzo(a)anthracene 3.1 1999 0.87 RBC-C
Benzo(b)fluoranthene 2.9 1999 0.87 RBC-C
Benzo(g,h,i)perylene 1.5 1999 N/A N/A
Phenanthrene 9.2 1999 N/A N/A
Inorganics
Arsenic 28.4 1999 0.5 CREG
Iron 78,200 1999 23,000 RBC-N
Thallium 106 1999 5.5 RBC-N
Drainage Basin F
Organics
Acenaphthylene 2.9 1994 N/A N/A
Benzo(a)anthracene 8.5 1994 0.87 RBC-C
Benzo(a)pyrene 12 1994 0.1 CREG
Benzo(b)fluoranthene 11 1994 0.87 RBC-C
Benzo(g,h,i)perylene 8.5 1994 N/A N/A
Benzo(k)fluoranthene 12 1994 8.7 RBC-C
Dibenz(a,h)anthracene 1.5 1994 0.087 RBC-C
Phenanthrene 4.6 1994 N/A N/A
Inorganics
Iron 43,800 1994 23,000 RBC-N
Off-Site (Waconda Bay)
Organics
Phenanthrene 0.34 1999 N/A N/A
Inorganics
Arsenic 23.9 1999 0.5 CREG
Iron 96,000 1999 23,000 RBC-N
Source: Army 2003c

Notes:
CREG Cancer Risk Evaluation Guideline for surface soil
EMEG Exposure Media Evaluation Guideline for surface soil
N/A not available
ppm parts per million
RBC-N EPA Region III Risk Based Concentration, non-carcinogenic effects for residential soil
RBC-C EPA Region III Risk Based Concentration, carcinogenic effects for residential soil
RMEG Reference Media Evaluation Guideline for surface soil
SSL EPA Soil Screening Level


Figures

Figure 1: Area MapFigure 1: Area Map

Figure 2: Volunteer Army Ammunition Plant (VAAP) SitesFigure 2: Volunteer Army Ammunition Plant (VAAP) Sites

Figure 3: ATSDR's Exposure Evaluation ProgramFigure 3: ATSDR's Exposure Evaluation Program

Figure 4: Drainage BasinsFigure 4: Drainage Basins

Figure 5: Demographics MapFigure 5: Demographics Map

Appendix A: History

The Volunteer Army Ammunition Plant (VAAP) operated as a trinitrotoluene (TNT) manufacturing facility from 1942 to 1977 and supported a fertilizer production facility from 1962 to 1982. The following provides a detailed history or operations occurring at VAAP from it's creation in 1942 to present.

Appendix B: The TNT Production Process

2,4,6-Trinitrotoluene (commonly referred to as TNT) is an explosive used in military shells, bombs, and grenades (ATSDR 1995). Volunteer Army Ammunition Plant (VAAP) was constructed for the sole purpose of manufacturing TNT to support U.S. war activities. VAAP was active from 1942 to 1945, 1952 to 1957, and 1965 to 1977 to support World War II, the Korean War, and the Vietnam War, respectively. In total, VAAP produced approximately 2.9 billion pounds (lbs) of TNT (IT Corp 1994).

Background
TNT production involves the chemical nitration (adding a nitrogen dioxide [NO2] group to an organic compound) of toluene (C7H8) to create TNT (C7H5N3O6). Nitric acid (HNO3) is used as the source of nitrogen dioxide for each of the three nitration steps required. Sulfuric acid (H2SO4) is used to absorb water formed during the nitrogen reactions. Maintaining the correct nitric acid concentration in the reactors is essential to successful nitration, and sulfuric acid does this by acting as dehydrator. The addition of nitrogen dioxide groups to toluene becomes increasingly difficult as more nitrogen dioxide groups become attached. In fact, for the third group to attach, strong nitric acid (98 percent), oleum (108 percent, concentrated sulfuric acid to which sulfur trioxide [SO3] is added), and increased temperatures are needed (USAEHA 1985).

The following information briefly describes the TNT manufacturing processes used at VAAP and identifies the types of chemical by-products that could be expected from the production process. Two TNT manufacturing methods, both located in VAAP-32-TNT Manufacturing Valley, were used: the batch process was used in 16 lines and the Canadian Industries Limited (CIL) process was used in continuous process lines. The chemical nitration of toluene to create TNT is the same for both processes.

In addition, nitric acids, sulfuric acids, and oleum were also produced at VAAP to support TNT production. These production processes are also briefly described to identify the types of potential chemical by-products expected. This information is based primarily on material provided by VAAP, and the US Environmental Protection Agency (EPA) AP-42 (Chapter 6.3, Explosives; Chapter 8.8, Nitric Acid; and Chapter 8.10, Sulfuric Acid).

TNT Production
Combining nitric acid with toluene in the presence of sulfuric acid ultimately forms TNT and water containing sulfuric acid. The sulfuric acid is not consumed in the process. Figure B-1 schematically shows the production process and the compounds emitted to the air or present in the waste products (EPA 1983).

After the nitration process is complete, the crude TNT is washed to remove the remaining acid. The acidic rinsate containing sulfuric acid with un-reacted nitric acid and TNT production products (yellow water) may be recycled back into the nitration process. The washed TNT is neutralized with soda ash (sodium carbonate [Na2CO3]) and purified with Sellite (a water based mixture of sodium sulfite [Na2O3S] and sodium hydrogen sulfite [HNaO3S]) to remove impurities. Effective removal is a function of pH, temperature and Sellite concentration. Soda ash and sulfur dioxide (SO2) are added to the Sellite mixture to maintain an optimum pH range. Anecdotal information indicates that at VAAP, the purified TNT was washed with hot water, melted, dried, and either flaked (Public Comment 2004b).



TNT Production By-Products
The following table identifies the by-product categories resulting from TNT production.

Table B-1: By-Products from TNT Production
Aqueous By-Products Gaseous By-Products Solid By-Products
Waste sulfuric acid
Waste nitric acid
Yellow water*
Redwater*
Pink water*
Nitrogen oxides (NO and NO2)
Sulfur oxides (SO2 and SO3)
Nitric acid mist
Sulfuric acid mist
No solid by products were identified in the literature review.
* Each of these solutions is likely to contain various combinations of sulfuric acid, nitric acid and TNT production products (isomers of TNT, DNT and nitro-toluene)


Liquid waste streams primarily consisted of redwater, pink water, and waste acids generated during the TNT nitration or purification processes. Yellow water is generated during the nitration process and is highly acidic. The used Sellite solution is named 'redwater' because it reacts with sunlight and turns a deep red color. Redwater is generated from the purification process. The water used to clean TNT contaminated areas generally turns a pink color, and is therefore called 'pink water'. While these solutions contained various combinations of acidic compounds, TNT isomers, isomers of dintritrotoluene (DNT) and other chemical compounds; each solution is chemically different than the others (EPA 1983; USAEHA 1985, Public Comment 2004b).

Direct discharge as a liquid waste, collection and resale, and concentration and incineration are three options for disposing of the redwater (EPA 1983). Some portion of the VAAP redwater was incinerated; the ash from the incineration process, identified as 'redwater ash,' was buried onsite. Records also indicate that the yellow and pink waters, after settling, were combined with wastewater and neutralized. These wastes were then added to the redwater at the redwater treatment plant. The redwater was then evaporated to 35% solids and sold to the paper industry (USAEHA 1985).

Redwater treatment facilities were located at considerable distances, at times over 1 mile, from the TNT production lines for safety reasons (USAEHA 1985). Anecdotal information indicates that initially, when TNT was produced using the batch process, the redwater was transported in open top flumes to the redwater treatment facility. After the continuous TNT production lines were constructed, the redwater was transported in a 'pipeline' system. Transport lines were steam-traced (warmed by steam) to prevent the redwater from solidifying within the line (Public Comment 2004).

The primary air emissions from the TNT nitrification process were nitrogen oxides (NOx; primarily nitrogen oxide and nitrogen dioxide) and sulfur oxides (SOx; primarily sulfur dioxide and sulfur trioxide). Nitric acid mist and sulfuric acid mist were also emitted during some of the production steps. For all of these compounds, the actual amount emitted varies greatly; partly due to the kind of production process used (batch vs. continuous) and the quality of air pollution control equipment used (EPA 1983).

Acid Production
The acids necessary for the TNT nitration process were produced in VAAP-1-East Acid Area (constructed in the early 1940s and operated until 1970), VAAP-33-New Acid Area (constructed in the early 1970s), and the CFI lease area (Public Comment 2004). The main products of this area were: nitric acid, sulfuric acid, oleum, and a mixture of strong nitric acid and oleum. However, it is possible that much of the oleum was produced off-base during the late 1960's (Chattanooga Times, April 18, 1969).

Documents reviewed by ATSDR suggest that VAAP may have used the direct strong nitric (DSR) process to produce nitric acid. This entails first burning ammonia to form nitric oxide (NO) and steam. The nitric oxide is then condensed and converted with strong nitric acid to nitrogen dioxide, which subsequently forms dinitrogen tetraoxide (N2O4). The oxidation of dinitrogen tetraoxide results in 100% nitric acid (USAEHA 1985). Anecdotal information indicates VAAP actually used the ammonia oxidation process (AOP) during most of the TNT production years and only used the DSR process during the late 1970's. The AOP process only produces 60% nitric acid by absorbing the nitrogen oxides in water or weak nitric acid (Public Comment 2004b).

Concentrated sulfuric acid production starts with molten elemental sulfur, which is burned in clean air to produce sulfur dioxide. The gaseous sulfur dioxide is passed over a vanadium pentoxide catalyst to produce sulfur trioxide. The sulfur trioxide gas enters the bottom of an absorption tower and migrates up through a downward flowing solution of sulfuric acid and water. The water combines with the sulfur trioxide to produce more sulfuric acid. The solution at the bottom of the tower is concentrated sulfuric acid (EPA 1998b; USAEHA 1985, Public Comment 2004b).

Oleum is a mixture of concentrated sulfuric acid with dissolved sulfur trioxide. The VAAP sulfuric acid regeneration (SAR) plant produced oleum by a process similar to that used for sulfuric acid. However, the sulfur trioxide was sent to an absorption tower where it flowed through a solution of concentrated sulfuric acid. In this case the resulting solution (oleum) consists essentially of only sulfuric acid and sulfur trioxide (EPA 1998b, USAEHA 1985). The oleum was used to produce mixed acid and in the nitration process.

Mixed acid was produced by combining strong nitric acid with oleum; the final product was approximately one-half strong nitric acid and one-half sulfuric acid.

Acid Production By-Products
The following table identifies the by-product categories resulting from acid production.

Table B-2: By-Products from Acid Production
Aqueous By-Products Gaseous By-Products Solid By-Products
Nitric Acid
Sulfuric Acid
Nitrogen oxide (NO)
Nitrogen dioxide (NO2)
Sulfur dioxide (SO2)
Nitric acid mist
Sulfuric acid mist
Vanadium pentoxide


The primary emissions from nitric acid production are nitrogen oxide and nitrogen dioxide, which are the visible emissions. Nitric acid mist emissions from properly operating plants are minimal and were not quantified in EPA AP-42. Nitrogen oxide and nitrogen dioxide emissions occur during production and storage. The actual emissions are highly variable and depend on the type of pollution control technology used (EPA 1998a, EPA 2003c).

Small quantities of hydrogen sulfide and sulfur dioxide (approximately 1% or less each) are present in molten sulfur (Montana Sulphur 1977). Small amounts of hydrogen sulfide gas may be liberated from the molten sulfur. In an open environment the hydrogen sulfide concentration will be extremely low-below levels of health concern. Typically hydrogen sulfide concentrations in air are only a concern when the molten sulfur is stored in an enclosed space; allowing the hydrogen sulfide to accumulate (Amerada Hess 2000). Based on this information ATSDR concluded that hydrogen sulfide gas concentrations in open air, outside of the occupational environment, would be below levels of health concern for the general public and were not considered further.

Sulfur dioxide and sulfuric acid mist are the primary sulfur compounds released to the air during production of oleum and sulfuric acid. Sulfur trioxide is also formed and released during the production process; however in the environment, sulfur trioxide rapidly reacts with the water vapor to form sulfuric acid (ATSDR 1998).

Acid sewer lines routed waste from the production and storage areas in VAAP-1-East Acid Area to the Neutralization Plant. Wastes from VAAP-33-New Acid Area were routed to a diverter station located adjacent to Pond 10 before being discharged for eventual release to Waconda Bay to the north via the Surface Water Discharge Area (IT Corp 1994).



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