PUBLIC HEALTH ASSESSMENT
SAVANNA ARMY DEPOT ACTIVITY
Savanna Army Depot Activity (SVADA) is a military installation in northwestern Illinois, approximately 150 miles west of Chicago. Established in 1918 as the Savanna Proving Ground, the installation has had various munitions-related missions, including manufacture, testing, and storage of various types of ammunition and weapons. In 1995, SVADA was placed on the Base Realignment and Closure list. Military use of the site is being phased out and closure is scheduled for March 2000.
Past operations at SVADA, including munitions manufacture, renovations, testing, and disposal, fire-fighting training, landfilling, and use and disposal of solvents, fuels, and pesticides, have resulted in the release of hazardous materials to the environment. Principal site contaminants are munitions-related contaminants (explosives and metals), polycyclic aromatic hydrocarbons, solvents, and unexploded ordnance (UXO).
The Agency for Toxic Substances and Disease Registry (ATSDR) released a preliminary public health assessment for SVADA in 1989. At that time, the site was considered a possible public health concern, but limited data were available. Since then, environmental data have been collected during remedial investigations of various contaminated sites at SVADA. ATSDR evaluated these data in this public health assessment. However, many known or suspected areas of contamination on the installation have not yet been evaluated. This public health assessment only evaluated sites for which sampling data were available.
ATSDR evaluated the following potential exposure pathways: consumption of groundwater; contact with soil, surface water, and sediment; consumption of livestock, game, and fish; contact with UXO; and contact with radiologic contamination. ATSDR found that known groundwater contamination is currently limited to on-post shallow aquifers, which are not used for drinking water. Sporadic contact with contaminated soil, surface water, and sediment is unlikely to pose or have posed a public health hazard. Cattle grazed at SVADA are unlikely to take up significant amounts of site contaminants and are not judged to represent a potential health threat; the available data and information indicate that the consumption of wild game hunted at SVADA is not likely to result in adverse health effects; but additional data are required to evaluate if the consumption of fish caught locally may be a health hazard. UXO poses a potential physical hazard. No radiation hazards have been identified.
ATSDR assumes that appropriate assessment and remediation will be completed before any
changes in land or groundwater use, and that adequate monitoring will take place until
remediation is concluded. Based on these assumptions, the soil, groundwater, surface water,
sediment, radiologic contamination, and consumption of livestock and game pathways pose no
apparent public health hazard. Because adequate fish tissue data are not available, consumption
of fish is an indeterminate public health hazard. Possible UXO at various locations at SVADA
poses a potential physical hazard that should be dealt with appropriately. ATSDR will evaluate
the potential public health impacts of additional environmental and biota data as they become available and will also evaluate remedial and reuse plans when they are finalized.
Savanna Army Depot Activity (SVADA) is an active military installation in northwestern Illinois, approximately 150 miles west of Chicago; the nearest large cities are Dubuque and Davenport, Iowa, to the northwest and southwest (Figure 1). SVADA covers just over 13,000 acres in Jo Daviess and Carroll Counties. It is a long, narrow piece of land lying between the Mississippi River and a line of hills and bluffs. The installation is surrounded primarily by agricultural land; the neighboring communities are Hanover and Savanna, Illinois, and Bellevue, Iowa (Dames and Moore, 1994c; OEES, 1996).
SVADA was established in 1918 as the Savanna Proving Ground, a proof and test facility for artillery weapons and ammunition. In 1919 and 1920, many new buildings were constructed at the site and, in 1921, its name was changed to Savanna Ordnance Depot. A shell-loading facility was built in 1931 to load and renovate 155-millimeter shells and 300-pound bombs. During World War II, additional facilities were constructed and Savanna Ordnance Depot was given the task of studying and developing methods to stabilize ammunition for shipping. From 1947 to 1962, various types of mustard-filled projectiles were shipped to Savanna for renovation; the fuses were removed and reused and the mustard-filled projectiles were either shipped to Rocky Mountain Arsenal or destroyed (by burning) at Savanna (Dames and Moore, 1994c).
The U.S. Army Ordnance Ammunition, Surveillance, and Maintenance School (currently known as the Defense Ammunition Center and School, or DACS) was activated at the post in 1950. The installation was designated as a U.S. Army Ordnance Depot in 1959 and was assigned a special weapons storage and maintenance mission from 1961 to 1974. In 1962, the installation's name changed to Savanna Army Depot when it was placed under the jurisdiction of the U.S. Army Supply and Maintenance Command (Dames and Moore, 1994c). The installation finally became known as the Savanna Army Depot Activity in 1976 and was put under the command of Letterkenny Army Depot in Pennsylvania. From that time on, SVADA's mission was the receipt, storage, issue, and demilitarization of conventional ammunition and general supplies, as well as the manufacture, procurement, and maintenance of ammunition-peculiar equipment and repair parts for worldwide Department of Defense (DOD) support. In 1995, SVADA was placed on the Base Realignment and Closure (BRAC) list. Military use of the site is being phased out and closure is scheduled for March 2000 (Clarke, 1999b).
The SVADA property includes 923 buildings, many of which are ammunition storage igloos or other storage facilities. Buildings are designated by numbers and areas are designated by letters. The four major plant areas at SVADA are the CN Plant (originally developed as an ammonium nitrate plant, but never used for that purpose), the CL Plant (first used to load bombs with explosives, and later used to demilitarize, renovate, and modify equipment), the CF Plant (first used to load fixed round ammunition with explosives, and later used for various other purposes), and the Ammunition Washout Facility (constructed to wash explosives from bombs). Storage buildings are grouped into the "A" through "H" and "J" Areas (SAIC, 1996a).
- munitions manufacture and renovation,
- munitions testing,
- munitions disposal (including burning),
- fire-fighting training,
- landfilling, and
- use and disposal of solvents, fuels, and pesticides.
As a result of these past operations and waste disposal practices, hazardous materials have been
released to the environment. Principal site contaminants are munitions-related compounds
(trinitrotoluene [TNT], dinitrotoluene [DNT], trinitrobenzene [TNB], Royal Demolition
Explosive [RDX], and metals), polycyclic aromatic hydrocarbons (PAHs), solvents, and
unexploded ordnance (UXO).
In 1979, the U.S. Army Toxic and Hazardous Materials Agency (USATHAMA) conducted an initial installation assessment at SVADA. The investigation identified 59 potential areas of concern, including industrial areas, burning grounds, demolition grounds, and burial sites (OEES, 1996). Subsequent investigations identified additional sites. These investigations included an environmental survey in 1982, an evaluation of solid waste management units completed in 1988, and a groundwater and surface water evaluation in 1989 (SAIC, 1997a). SVADA was proposed for listing on the U.S. Environmental Protection Agency's (EPA's) National Priorities List (NPL) in October 1984, and was listed final in March 1989 (SAIC, 1996a). In September 1989, EPA, the Illinois Environmental Protection Agency (IEPA), and SVADA signed an Interagency Agreement (also known as a Federal Facilities Agreement) outlining a cooperative approach to site investigation and remediation (OEES, 1996).
In 1994, a preliminary draft remedial investigation (RI) report addressing 30 SVADA sites was completed (Dames and Moore, 1994c). More specific investigations of 12 other sites were completed in 1993, 1994, 1995, and 1996 (SAIC, 1997b). As a result of SVADA's selection for closure by the BRAC Commission, an environmental baseline survey (EBS) was conducted, with a technical report issued in 1996 (SAIC, 1996a). The purpose of the EBS was to identify areas on the installation where storage, disposal, or release of hazardous substances occurred, as well as any other related environmental, hazard, or safety issues that would limit or preclude the transfer of property for unrestricted use (SAIC, 1996a). As a result of all investigations that have occurred at SVADA, there currently are 176 sites of possible, known, or remediated contamination in the installation's environmental restoration program (Clarke, 1998b). (These are known as Installation Restoration Program [IRP] Sites. See Figure 2 for locations of many of these sites.) In 1997, an RI field sampling plan was submitted to evaluate additional sites identified during the EBS and fill data gaps remaining from previous investigations (SAIC, 1997b).
A Record of Decision (ROD) for the Washout Lagoon Area Soils Operable Unit (Sites 21 and 22) was signed by the U.S. Army, EPA, and IEPA on March 31, 1992. Engineering Evaluation and Cost Analyses (EECAs) were developed for the Fire Fighting Training Facility (Site 67), the Open Burning Ground (Sites 13 and 14), the CF and CL Areas, and Sites 15 and 33 (the SAA Burn Area and the Artillery Ballistic Test Site) in October 1993, February 1994, April 1995, and July 1995 respectively (SAIC, 1996a). Contaminated soils at the Washout Lagoon Area and the Fire Training Area have been remediated (SAIC, 1997a).
In addition to Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, also known as Superfund) activities, SVADA is performing or has completed other remediation-related actions including: investigation and removal of underground storage tanks (USTs); identification, inspection, and removal of PCB (polychlorinated biphenyl)-containing transformers; and an archives search concerning UXO (SAIC, 1997a). Closure of a Deactivation Furnace (APE 1236) under the Resource Conservation and Recovery Act (RCRA) was completed in 1996 (SAIC, 1996a).
Many known or suspected areas of contamination on the installation have not yet been fully evaluated. This public health assessment will only evaluate the sites for which sampling data are available.
The Agency for Toxic Substances and Disease Registry (ATSDR) released a preliminary public
health assessment for SVADA on January 19, 1989. The site was considered a potential public
health concern because of possible human exposure to contaminants in groundwater, surface soil,
soil, sediment, and air. On June 5, 1991, ATSDR conducted an initial site visit and met with
representatives from the Army, EPA, and the Illinois Department of Public Health. At this time,
ATSDR identified soil, groundwater, and food-chain contamination as potential exposure
pathways. In May 1998, ATSDR conducted another site visit, during which ATSDR met with
representatives from the Army. ATSDR did not identify any community concerns related to contamination at SVADA.
At the time of the 1990 U.S. Census, the population within one mile of the site was 2,729; 99% were white. There were 252 children aged 6 and younger, 540 adults aged 65 and older, and 512 females of reproductive age (15-44 years) (numbers calculated by ATSDR from 1990 U.S. Census data using an area-proportion spatial analysis technique; see Figure 3). The population in Jo Daviess and Carroll Counties was 37,906 (SAIC, 1997b).
As of January 1996, approximately 165 SVADA employees, 209 DACS employees, 29 interns,
10 other employees, and 35 on-site contractors worked on SVADA. Four employees and 10
dependents resided in the family housing area at the southern end of the installation. The troop
housing area, also in the southern end of the installation, sometimes houses Reserve Component
and National Guard personnel when they are stationed at SVADA (SAIC, 1997b).
Generally, geology at SVADA and in the immediate surrounding area is characterized by layers of different types of bedrock overlain by an unconsolidated overburden of clay, silt, sand and/or gravel. The uppermost overburden layer is either Parkland sand or Cahokia alluvium (clay, silt, and sand) near the Mississippi River. The bottom layer of the overburden is the Henry formation, made up of unconsolidated gravel. At SVADA, the overburden is generally from 132 to 190 feet deep, except in the bluff areas where bedrock is more highly elevated and the overburden is much thinner. Below the overburden, the uppermost bedrock layer in most of the area is the Galena formation, composed of dolomite and limestone (Dames and Moore, 1994c).
The shallow aquifer at SVADA occurs in the sandy overburden in the central and southern areas of SVADA, and is mostly unconfined. The top of the water table generally occurs between 0 and 60 feet below ground surface (bgs) (Dames and Moore, 1994c). The direction of groundwater flow in this aquifer at SVADA is generally west toward the Mississippi River. On the southern portion of the installation, a groundwater divide exists in the aquifer, with some groundwater flowing east to the Apple River and some flowing west to the Mississippi River. Groundwater flow may temporarily reverse when the Mississippi River is flooded (Dames and Moore, 1990).
There are at least three bedrock aquifers in the vicinity of SVADA (Dames and Moore, 1994c).
- The first is within the Galena formation, which underlies the unconsolidated overburden (i.e., generally beginning at 132 to 190 feet bgs, but much nearer the surface in the upland part of the installation) and is approximately 120 to 215 feet thick at SVADA. This aquifer is unconfined and is in hydraulic communication in places with the overlying sand and shallow aquifer. At SVADA, the Galena aquifer is recharged by vertical seepage through this sand; in northern Jo Daviess County, it is exposed at the surface and is recharged directly by rainfall. This aquifer has a groundwater ridge in northern Jo Daviess County, from which groundwater flows southwest toward the Mississippi River and southeast toward the Apple River Valley. The majority of private water wells within 1 mile of SVADA pump from this aquifer, yielding moderate quantities of water for household use.
- Below the Galena aquifer is the Cambrian-Ordovician aquifer, at a depth of approximately 340 to 1,400 feet bgs. In this aquifer, composed of dolomite and sandstone, groundwater is confined under pressure, but there is some leakage to the surrounding formations. From 1971 to 1980, an average of 103 million gallons of water per day were pumped from the Cambrian-Ordovician aquifer in northwest Illinois. The main water supply for SVADA is derived from this aquifer.
- The Mount Simon aquifer is an even deeper aquifer, present at approximately 1,200 to 1,300 feet bgs. This aquifer is not used for water supply due to high levels of total dissolved solids.
Surface water hydrology at SVADA includes rivers and streams, the east-central swamp area, and Mississippi River backwater areas (See Figure 4). SVADA is bordered on the west by the Mississippi River and on the east by the Apple River, which flows into the Mississippi River at the southeastern corner of the installation. Beaty Hollow, the principal perennial stream on the SVADA property, drains into Prairie Lake, a component of the Crooked Slough backwater complex. There are also a handful of intermittent streams. The east-central swamp area, a poorly drained area comprising several hundred acres, is located along the northeastern-central SVADA boundary. There are two Mississippi River backwater areas at SVADA; these areas consist of numerous braided sloughs and ponds. One backwater area is the Crooked Slough complex, which consists of Crooked Slough, Straight Slough, and Prairie Lake. The other backwater area is smaller and is located near the mouth of the Apple River (Dames and Moore, 1994c; SAIC, 1997b).
Generally, the western two-thirds of the installation drains either directly or indirectly into the Mississippi River backwater area. Some central region drainage flows into the Apple River, which is located at the southeastern boundary of SVADA. The southern portion of SVADA drains north into a shallow, broad depression (SAIC, 1997b).
Topographically, SVADA is composed of a mixture of bottomland and upland. The northwest section of SVADA consists of relatively flat bottomland, large areas of which are subject to flooding during high water. The remainder of the installation is composed of gently rolling hills and flat areas (Dames and Moore, 1990).
An inventory of land use at SVADA in 1975 found that of the total 13,062 acres, 300 acres consisted of improved grounds (e.g., lawns, ballfields, parade and drill grounds, and landscape plantings), 1,005 acres consisted of semi-improved grounds (e.g., production facilities, isolated mission activities, firebreaks, road and utility borders, and a heliport facility), 5,329 acres consisted of unimproved grounds (e.g., roads, buildings and structures, and agricultural leases), and 6,470 acres consisted of woodlands (Dames and Moore, 1990; Clarke, 1999b).
Recreational fishing takes place in Crooked Slough, the Apple River, and the Mississippi River. Although Crooked Slough lies entirely within SVADA boundaries and fishing access is legally restricted to SVADA personnel and other approved users, in practice the public does access the area for fishing. Commercial fishing is permitted in the portion of the Mississippi River bordering SVADA (SAIC, 1996a). A variety of wildlife species are found on the installation and hunting is allowed by permitted hunters (Dames and Moore, 1990).
The area surrounding SVADA is rural and not heavily populated. Towns in the vicinity are Bellevue, Iowa, across the Mississippi River to the north of the installation, and Hanover and Savanna, Illinois, approximately 2 miles east and 7 miles southeast of the installation, respectively. Southeast of Bellevue along the Mississippi River are areas of conservation land such as Bellevue State Park, the Upper Mississippi River Wildlife and Fish Refuge, and the Green Island State Wildlife Management Area. Land use northeast of SVADA is primarily agricultural (mainly cropland) or undeveloped (Dames and Moore, 1994c).
In January 1997, the "Savanna Army Depot Reuse Plan and Implementation Strategy" was
prepared for the Savanna Army Depot Local Redevelopment Authority (LRA). At that time, the
plan for land transfer of SVADA property was as follows: 9,445 acres, including 6,000 acres of
bottomlands, to the U.S. Fish and Wildlife Service (USFWS); 3,157 acres to the LRA; and 460
acres to the Army Corps of Engineers (Economics Research Associates, 1997).
In preparing this public health assessment, ATSDR relied on the information provided in the referenced documents. ATSDR assumes that adequate quality assurance and control measures were followed with chain-of-custody, laboratory procedures, and data reporting. The validity of the analyses and conclusions drawn in this document are dependent upon the availability and reliability of the referenced information. The environmental data presented in this public health assessment are from reports produced by the Army and its contractors.