COMMENCEMENT BAY, SOUTH TACOMA FIELD
(a/k/a COMMENCEMENT BAY, SOUTH TACOMA CHANNEL)
TACOMA, PIERCE COUNTY, WASHINGTON
The Commencement Bay, South Tacoma Field site occupies 260 acres of land located in the southwestern section of the city of Tacoma in Pierce County, Washington. Situated in a heavy industrial district, the site consists of a few industrial and commercial facilities surrounded largely by undeveloped grasslands. During the past 100 years the site had been used for a variety of industrial and disposal activities. Historical industrial activities involved the manufacture and repair of railroad cars and equipment, the operation of a brass and iron wheel foundry, the maintenance of an airport runway, refueling depot and repair facility, and the construction and operation of an electric and water utility company. Large parts of the airport were used as dump sites for industrial and construction materials. Swamp and lakebed areas of the site were filled with refuse and dirt, including slag and sand from the foundry operations and dirt from the utility building foundation. Early investigations of the site suggested that past industrial and disposal activities have contributed to the contamination of soil, groundwater, surface water, and sediments at the site.
In 1981, the U.S. Environmental Protection Agency included the South Tacoma Field site on the National Priorities List as part of the Commencement Bay Superfund site. The remedial investigations to characterize the site contamination were conducted from February 1991 through August 1992. Based on the Remedial Investigation and Feasibility Study reports, the U.S. Environmental Protection Agency approved the Record of Decision in September 1994.
The South Tacoma Field site poses a public health hazard to trespassers who repeatedly ingest contaminated surface soils, surface water, and sediments during recreational activities at the site. Exposure to the contaminants arsenic, copper, lead, manganese, as well as polychorinated biphenyl and polycyclic aromatic hydrocarbon compounds may have occurred in the past, may be presently occurring, and may occur in the future, which could result in noncarcinogenic and carcinogenic health effects.
Of these contaminants, elevated concentrations of lead appear to be widespread in surface soils, surface water, and sediments at the site. Because young children tend to be more susceptible to lead absorption and toxicity than adults, exposure to even low concentrations of lead over an extended period of time may result in long-term health effects, such as learning disabilities, decreased growth, hyperactivity, and impaired hearing. Lead exposure in adults may cause health effects, such as increased blood pressure, and impairment of hearing, vision, and muscle coordination. Frequent exposure of recreationalists/trespassers to highly contaminated media for long periods of time may result in these noncarcinogenic effects, particularly for individuals who have blood lead levels already elevated by exposure from other sources of lead. Due to the lack of toxicity data, the lifetime cancer risk for lead exposure cannot be predicted. However long-term exposure of recreationalists/trespassers to highly contaminated media may potentially cause an increased risk of developing cancer over a lifetime.
Potentially, the site can pose a public health hazard through exposure to groundwater and subsurface soil contaminants that could cause adverse health effects. Industrial development of the site may result in future exposure by workers to groundwater contaminants, should private supply wells access the shallow aquifer in areas of contamination. Additionally, should construction/excavation activities uncover contaminated subsurface soils, workers as well as recreationalists/trespassers may be exposed.
During the remedial investigation, groundwater contamination was detected in off-site background and upgradient wells; however, the actual extent of contamination is not known. Should new public and private (residential and industrial) supply wells be installed accessing the contaminated aquifer, workers and residents could be exposed to groundwater contaminants. Exposure of workers and residents could also occur should migration of groundwater contamination impact existing public and private supply wells.
In the effort to protect public health, the Washington State Department of Health and the Agency for Toxic Substances and Disease Registry recommend 1) restricting public access and maintaining site security at the Burlington Northern Railroad Dismantling Yard, Burlington Northern Railroad Railyard, Tacoma Industrial Properties, and Amsted sampling units within the site; 2) maintaining present groundcover, vegetation, and asphalt to reduce exposure to contaminated surface soils and soil dust; 3) restricting public access to surface water and sediments; 4) implementing institutional controls to eliminate future exposure to contaminated groundwater and subsurface soils on the site; 5) informing owners of public and private supply wells in the vicinity of off-site groundwater contamination of potential exposure to contaminated groundwater; and 6) analyzing groundwater from public and private supply wells that may be installed in the future within the vicinity of off-site groundwater contamination prior to use.
A. Site Description and History
The Commencement Bay, South Tacoma Field Superfund site occupies 260 acres of land located in the southwestern section of the city of Tacoma in Pierce County, Washington (Appendix - A, Figure 1). During the past 100 years, the site has been used for a variety of industrial and disposal activities. Historical industrial activities involved the manufacture and repair of railroad cars and equipment, the operation of a brass and iron wheel foundry, the maintenance of an airport runway, refueling depot and repair facility, and the construction and operation of an electric and water utility company. Large parts of the airport were used as dump sites for industrial and construction materials. Swamp and lakebed areas of the site were filled with refuse and dirt, including slag and sand from the foundry operations and dirt from the utility building foundation. Early investigations of the site suggested that past industrial and disposal activities have contributed to the contamination of soil, groundwater, surface water, and sediments at the site.
In November 1981, the U.S. Environmental Protection Agency (EPA) initially included the South Tacoma Field site on the National Priorities List as a portion of the Commencement Bay site. Later, the Commencement Bay site was divided into two separate sites, Commencement Bay Nearshore/Tideflats and South Tacoma Channel. In September 1983, the South Tacoma Channel site was further divided into three separate sites, Tacoma Well 12-A, Tacoma Landfill, and South Tacoma Field. Under an Administrative Order on Consent with EPA, Burlington Northern Railroad conducted an initial remedial investigation on their property in 1986 through 1987. Later, a remedial investigation on entire South Tacoma Field site was conducted from February 1991 through August 1992, which comprised of eleven separate investigations characterizing contamination of surface and subsurface soils, groundwater, surface water, sediments, blackberries, soil-gas, and air at the site.
For the South Tacoma Field Remedial Investigation, the site was divided into seven sampling units based on previous investigations and historic uses of the site (Appendix - A, Figure 2).
Currently two businesses, General Plastics and Pioneer Builders Supply, operate within the BNR Railyard area. In 1981, General Plastics opened a manufacturing plant to produce high-density rigid and flexible polyurethane foams and high-density rigid polyisocyanurate foams for aviation, construction, marine, nuclear, architectural, and sports equipment industries. General Plastics uses and stores several chemical products on the site. In 1990, one underground storage tank which had been available for spill containment purposes was removed.
In 1988 Pioneer Builders Supply constructed a warehouse and office building on a portion of the former Northern Pacific Car Shops site. Pioneer Builders Supply is a commercial distribution center for asphalt and cedar roofing material. No products are manufactured at the site. Three underground storage tanks were discovered on the property and removed in 1990. Pioneer Builders Supply had two underground storage tanks used to store gasoline and diesel fuel. During the excavation of these tanks in 1991, the surrounding soils were discovered to be contaminated with petroleum. Currently, most of the businesses' property is paved and fenced.
In April 1987, EPA jointly with Washington Department of Ecology and Tacoma-Pierce County Health Department released their first quarterly update on the investigations of the Commencement Bay Superfund sites. Today, EPA continues to provide the community with information regarding these hazardous waste cleanup projects which include the South Tacoma Field Superfund site. Principal characterization of the nature and extent of contamination at the South Tacoma Field site began in February 1991 and extended to August 1992. Warning signs were posted on the site and the public were notified to avoid using the site for recreational purposes due to contaminants identified and the unknown nature of much of the site. In addition, EPA interviewed members of the community to learn about community interest and concerns related to the site.
In 1991 and 1992, Washington Department of Health (WDOH) under cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR) assisted EPA in determining whether contaminants detected in soils and groundwater at the South Tacoma Field site were of health concern. Based on the conclusions, EPA requested WDOH to provide recommendations regarding site security for the South Tacoma Field site. Working closely with EPA to ensure that appropriate data was evaluated and site conditions understood, WDOH made the following recommendations:
In November of 1992, EPA again notified the community to avoid recreational use of the South Tacoma Field site and informed them of WDOH recommendations concerning the restriction of public access, particularly children, to several areas within the site. EPA then requested that the potentially responsible parties restrict access to all areas identified by WDOH which have not already been secured, and to ensure that the security measures are properly maintained.
The Remedial Investigation report outlining the investigation findings at the South Tacoma Field site was finalized in April 1993. Based on the Remedial Investigation and Feasibility Study reports, the Record of Decision for the South Tacoma Field site was developed and later approved in September of 1994. This document summarizes the decision for remediation of soil and groundwater contamination at the site.
B. Site Visit
On July 15, 1991, WDOH and ATSDR representatives visited the South Tacoma Field site along with representatives from EPA and the consulting firm responsible for performing the site remedial investigations. The main entrance to the South Tacoma Field site is at the south end on Burlington Way from South 56th Street. Along Burlington Way, workers have access to the business currently operating on site: Pioneer Builders Supply, Northwest Welding and Fabrication, Savage Industries, KML Corporation, and General Plastics. The groundcover in the area immediately surrounding these business is mostly paved. These businesses are located within the designated sampling units, TIP and BNR Railyard units. The TIP unit is enclosed by a 6-foot, chain-linked fence with locking gate at South Proctor Street. In addition, Pioneer Builders Supply and General Plastic properties are fenced.
Directly south of the Savage Industries and Northwest Welding and Fabrication is the Amsted unit. This unit is completely enclosed by a 6-foot, chain-linked fence with a locking gate. Within the fenced area is the remains of the old foundation of the former Griffin Wheel Brass Foundry. The ground is mostly vegetated with grasses and brush with little exposed surface soil.
Located north of the Amsted unit is the former Griffin Wheel Iron Foundry building. Presently, the KML Corporation uses this building for their operations. A dirt road, once part of Madison Street, runs north-south between the Amsted and TIP units and the Airport and Swamp/Lakebed units. A gate now separates the dirt road from the main Madison Street. Along the eastside of the dirt road is a bank created from foundry slag, sand, and dirt. Vegetation, primarily blackberry bushes and grasses, covers areas along both sides of the road.
The Swamp/Lakebed and Airport units are open land mostly covered with vegetation, small deciduous trees, shrubs, and grasses. A surface water drainage channel transverses the western portion of these units from two storm drain outlets at the northwest boundary, south to a storm drain outlet off-site along Madison Street. Surface water from this channel supports a perennial wetland in the northwest corner of the site, and swamp remnant in southern portion of site. Seasonal wetlands exist in the Swamp/Lakebed unit; however during the site visit this area appeared dry.
The western edge of the South Tacoma Field site is bordered by a 150-foot bluff. Coniferous trees cover this bluff as well as the northwest edge of the site. Fencing extends along most of the western boundary; however the Airport and Swamp/Lakebed units are not completely enclosed, and in places the fence is damaged. There are dirt trails leading from the residential area on the bluff to the fence along the Airport unit. Though warning signs are posted along the fence, trespassers have been accessing the site by these trails and entering through damaged areas in the fence.
At the north end, the Tacoma City Light unit is completely enclosed by fencing and is only accessible by workers. The unit consist of office, maintenance, and storage buildings, and the surrounding ground is paved. The BNR Dismantling Yard and BNR Railyard units are basically open or undeveloped land and appear well-vegetated with grasses and shrubs. A railroad track extends the length of the eastern edge of the two units. Outside the tracks, the eastern boundary is fenced. Though the majority of the South Tacoma Field site is posted and fenced, EPA has observed people generally using the site as a recreational park. Adults and children have been seen picking blackberries, walking and biking through the site, and workers from nearby businesses taking breaks and eating their lunches in the grassy areas. During the site visit, no trespassers were observed, but signs of trespassing were apparent.
In the surrounding areas directly north, east, and south of the South Tacoma Field site, a combination of industrial and commercial businesses line the main streets. Residential areas, mainly single and multi-family dwellings, exist west along the bluff on Tyler Street and further northwest near Snake Lake, southwest along Tyler Street, and southeast along Cakes Street. According to the EPA site manager, the South Tacoma Field site has not undergone any significant changes since July 1991 that would warrant another visit of the site at this time.
C. Demographics, Land Use, and Natural Resources Use
The land use surrounding the South Tacoma Field site within one mile is a combination of residential, commercial, and industrial. Over 21,000 residents live within the immediate vicinity of the site based on the 1990 Census of Population and Housing. The primary residential areas are west of Tyler Street and east of South Tacoma Way and consist mainly of single family and multi-family dwellings within about one-half to one mile of the site (26).
Located within one mile of the site are 4 kindergartens and 13 other schools. Two of these schools are within one to three blocks of the site boundaries. Mt. Tacoma High School, south of the site, is the nearest school. There are also a number of parks and playgrounds in the vicinity. The South End Recreational Area, mainly baseball fields and open space, is near Mt. Tacoma High School. Less that one mile north of the site is the Snake Lake Park which is another open space recreational area. There are six nursing homes within one mile of the site with the nearest nursing home situated two blocks to the west of the site. In addition, two hospitals are located one mile north of the site.
Over 19,000 workers are employed at 1,430 companies within the postal zip code (98409) area of the South Tacoma Field site. The boundaries of this zip code area lie within about one-half to one mile of the site. The majority of these companies are in the retail trade and service industries. Also located in this area are finance, insurance, and real estate industries and a significant number of companies in construction. Approximately half of these companies employ between 1 and 5 employees and only 3 companies employ more than 500 employees.
Several of these companies are situated within the South Tacoma Field site. At the General Plastics plant about 100 people are employed, of which 80 are production workers and 20 are administrative and management workers. Tacoma Public Utilities employs about 600 people; 300 individuals work in the offices and the remaining work in the service shops or with the field crew. There are about 5 employees working at KML Corporation and 10 employees at Savage Industries (26). The number of employees was not reported for Pioneer Builders and Northwest Welding and Fabrication companies.
Described below is the current zoning designated for the South Tacoma Field site, as well as the surrounding area.
The natural resource use associated with the South Tacoma Field site is groundwater production primarily for the city of Tacoma. Within the local and regional area of the site, groundwater is encountered in two stratigraphic layers designated as Layer A and Layer C in the upper 200 feet of subsurface material. Layer A is separated into Upper Layer A and Lower Layer A by a semi-confined to confined stratigraphic layer about 40 feet thick. This layer appears to effectively limit the hydraulic communication between the Upper and Lower Layer A at the site. Locally, the saturated thickness of Upper Layer A is about 62 to 101 feet, while Lower Layer A is 59 to 68 feet thick.
Lower Layer A is separated from Layer C by a stratigraphic layer typically ranging in thickness from 50 to 150 feet. However in the site vicinity, the thickness of this layer is from approximately 2 feet in the south to 15 feet in the north. Studies indicated that hydraulic communication between Lower Layer A and Layer C exists through this stratigraphic layer. Though the saturated thickness of Layer C is about 100 feet thick, this layer was penetrated at about 25 feet during the groundwater investigation. Regionally, Layer C ranges in thickness from 50 to 180 feet.
Groundwater from the Upper Layer A and Layer C aquifers is used as a municipal water supply for the city of Tacoma and nearby towns. North-northeast of the site approximately 3,000 to 7,000 feet is the nearest municipal well field which consist of 13 production wells and is owned by Tacoma Public Utilities. Of these production wells, TAC-4A, TAC-6A, and TAC-11A are located within 1,000 feet of the eastern site boundary. Some of the wells in this field are high capacity with the potential of producing flows in excess of 3,000 gallons per minute. To the northwest, the towns of Fircrest and University Place have six production wells within 8,000 to 10,000 feet of the site. These production wells are considered upgradient of the site. Within one mile of the South Tacoma Field site, 41 residential wells also access local groundwater for domestic purposes. The nearest residential well is about 2,500 feet west of the site on South Mullen Street.
In general, the direction in groundwater flow of Layer A is toward the northwest. However, groundwater flow in several areas of the site trend to the east, west, or southwest during certain times of the year. These variations of direction in groundwater flow are the result of groundwater extraction from municipal production wells, seasonal variation in groundwater recharge, and lithologic and structural influences of the aquifer. Although few monitoring wells access Layer C to establish flow direction at the site, available information suggests that groundwater flow is also toward the northwest.
The operation of the municipal production wells significantly impacts the direction and the magnitude of the groundwater flow at the site. During the months of May through September the municipal production wells pump groundwater to meet seasonal water demands. When seasonal groundwater pumping is conducted in the Upper Layer A, a large cone of depression develops around municipal production wells, TAC-4A, TAC-6A, and TAC-11A. As a result, groundwater flow may change direction or be completely reversed. The strongest effect of seasonal pumping is apparent in the eastern-central portion of the site. During non-pumping months, November through May, the principal direction of groundwater flow is from the south-southwest to the north-northwest. The flow direction is generally consistent throughout the site, except in the southwest portion where the flow is toward the west-southwest.
In addition, Tacoma Public Utilities has five heat pump wells located on the northwest portion of the site. These heat pump wells are used for heating and cooling the Tacoma Public Utilities buildings. The operation of these heat pump wells can cause short-term fluctuation in water levels of both the Layer A and Layer C aquifers.
D. Health Outcome Data
Health outcome data are health data contained in databases such as cancer, birth defects, and vital statistic records. Using health outcome databases, it may be possible to determine whether the occurrence of certain health outcomes are greater than expected in Pierce County, Washington. Following are the health outcome databases available for the State of Washington.
WDOH has a Vital Statistics Department and an Office of Registries. The Vital Statistics Department collects information on the number of deaths, births, fetal deaths, marriages, and divorces for Washington State. Variables included in this database are geographic location (city, county, town), age, sex, race, cause of death, birth weight, gestational age, and birth defects.
The Washington Birth Defects Registry is a registry of children with serious birth defects diagnosed before their first birthdays. The database contains information by major birth defect classification and by demographic factors: county of residence, sex, race, address, and mother's occupation, smoking history, and age. Information is available for the entire state for the years 1986 through 1989.
The Cancer Surveillance System (CSS) for Washington State is kept by the Division of Public Health Sciences of the Fred Hutchinson Cancer Research Center in Seattle. The CSS works under contract to the Surveillance, Epidemiology, and End Results program of the National Cancer Institute. This database is the central repository for all newly diagnosed malignancies (with the exception of nonmelanotic skin cancers) which occur in residents of 13 counties of northwest Washington State. The population covered is almost one million and includes five standard metropolitan statistical areas: the Seattle-Everett area (King and Snohomish counties), Tacoma (Pierce County), Kitsap, Thurston, and Whatcom counties. The population-based cancer surveillance system monitors the incidence and mortality of specific cancers over time. The variables collected in this database are designed to permit the detection of differential risks of cancer by geographic region, age, race, sex, marital status, social security number, occupation, type of cancer, extent of disease, treatment, hospital identification, and other demographic data.
The health outcome data from relevant databases will be evaluated in the Health Outcome Data Evaluation section of this public health assessment.
In recent years, no community health concerns regarding the South Tacoma Field site have been expressed. Though the community has been kept informed about site activities through EPA, no community health concerns have been received. The lack of community interest may be because the site is located within a heavy industrial district rather than a residential district.
The public was officially invited to comment on the draft Public Health Assessment for South
Tacoma Field Superfund site, April 17 through July 7, 1995. During the public comment period,
written comments were submitted from one party. Response to these comments can be found in
Appendix - D.
