PRELIMINARY PUBLIC HEALTH ASSESSMENT
TULALIP LANDFILL
MARYSVILLE, SNOHOMISH COUNTY, WASHINGTON
The Tulalip Landfill is in Snohomish County, Washington near the town of Marysville. Almost four million cubic yards of waste were deposited at this site between 1964 and 1979, when the landfill was closed. An estimated 10 to 90 million gallons of leachate are generated each year at this site. In February 1988, the U.S. Environmental Protection Agency (EPA) conducted a site inspection. Lead, copper, chromium, and cadmium were found in quantities above EPA's Maximum Contaminant Levels (MCL) in on-site ground and surface water. Samples of leachate and on-site surface water also contained numerous strains of opportunistic pathogens, or disease causing agents.
A potential ground water pathway to human exposure exists. Ground water movement at this site has not been fully characterized. Drinking water is obtained from ground water by area residents. The City of Marysville gets its water supply in part from area wells, one of which is located 2.5 miles east of the landfill. Marysville's drinking water was analyzed during April 1992 and no heavy metals were detected. People who enter the site may be exposed to the contaminants by incidental ingestion and inhalation.
Before the landfill was established in the mid 1960's many people in the area expressed concerns to the Snohomish County Health District. Some of the concerns expressed were: fear of health impacts, destruction of natural beauty, bad smells, public nuisance, spoiling a swim area, harm to fish and crabs, and the general contamination of waters and beaches.
This site is classified as an indeterminate public health hazard because the limited available data do not indicate that humans are being or have been exposed to levels of contamination that would be expected to cause adverse health effects. However, data are not available for all environmental media to which humans may be exposed. On-site samples of surface and ground water contained heavy metals and microbial organisms. Current samples of Marysville's drinking water have not shown contaminants. On-site exposure to heavy metals and microbial organisms may occur by incidental inhalation and/or ingestion during direct contact with the site.
The ground water affected by this site must be characterized to determine if a pathway exists to Marysville's or any other potable water supply. Access to this site by people may lead to direct exposure to on-site contaminants. The landfill should be secured to entry. Community health concerns need to be identified, if they exist.
The Health Activities Recommendation Panel (HARP) has determined that a community health education effort is indicated to assist the community in understanding their potential for exposure. As more information on this site becomes available, this site will be reevaluated for any indicated follow-up health activities.
The Washington State Department of Health (DOH) in cooperation with the Agency for Toxic Substances and Disease Registry (ATSDR) will as needed schedule follow up assessments and/or health consults as data becomes available during subsequent site investigations.
In cooperation with the Agency for Toxic Substances and Disease Registry (ATSDR), the Washington State Department of Health (DOH) will evaluate the public health significance of this site. DOH will determine whether health effects are possible and will recommend actions to reduce or prevent possible adverse health effects. ATSDR, located in Atlanta, Georgia, is a federal agency within the U. S. Department of Health and Human Services and is authorized by the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980 to conduct public health assessments at hazardous waste sites.
A. Site Description and History
The Tulalip Landfill is a National Priorities List (NPL) site located one-half mile southwest of Marysville, Washington, in Township 30N, Range 5E, Section 32, on the western part of Ebey Island, Snohomish County, Washington (Figure 1). The area has an oceanic climate, with mild winters, cool summers, and about 32 inches of precipitation annually. The landfill covers about 146 acres. Ebey island, which is uninhabited, is 3.75 miles long and lies between Ebey Slough on the north and Steamboat Slough to the south (Figure 3). The sloughs flow west into Possession Sound, a part of Puget Sound (Figure 2).
Prior to 1964, the site was part of a wetland which made up most of Ebey Island. The landfill area was cleared by bulldozer and dragline. Native soils were used to form cells into which wastes were placed. Reported depths of excavation varied from ten to thirty feet below mean sea level. Depth to ground water on the site varies from four to fifteen feet below mean sea level. Some of the wastes were placed directly into the shallow ground water.
Estimates are that 95 percent of the waste material was generated from commercial and industrial sources. Some types of waste source generation include: construction, paper/printing, utility companies, sanitary/refuse, laboratories/hospitals, and fertilizer plants.
The landfill has been filled and diked to a height of about 15 feet above the original land surface. An estimated four million cubic yards of waste were deposited in this landfill. Dikes have been installed along Ebey and Steamboat sloughs, but they are susceptible to a five-year flood event. The dikes have leaked and leachate has seeped from the site. The current surface cap ranges in depth from zero to five feet. Ponds of leachate occasionally collect on parts of the landfill surface.
Site inspections have been conducted on this site by several entities, including The Tulalip Indian Tribes, the Washington State Department of Ecology, and the U. S. Environmental Protection Agency. A brief outline of these efforts follows:
|
Date
|
Investigator
|
Significant Findings
|
| 6/71 | Ecology | Total coliform bacteria counts exceed Class B water standards in channel leading into landfill. |
| 10/74 | EPA | Discovered high levels of Clostridium perfringens, Staphylococcus aureus, and Pseudomonas aeruginosa, in water and sediment samples surrounding landfill. These bacteria are known to be health hazards and many were indicated as being antibiotic resistant hospital strains. |
| 1/75 | S T & R Inc. | Estimated leachate production at 50 to 100 million gallons per year from the landfill. |
| 6/76 | EPA | C. perfringens, S. aureus, and P. aeruginosa bacteria still present in soil and water samples. |
| 2/83 | Tulalip Fisheries | Elevated levels of iron, zinc, and manganese were found in leachate samples taken on site. |
| 9/84 | Ecology | Leachate was found to contain elevated levels of many metals including arsenic, chromium, lead, and zinc. |
| 6/85 | U.S. Fish & Wildlife | Found DDT in mussel samples and DDE Wildlife and PCBs in fish tissue samples taken in the sloughs. These levels were reported to not exceed probable background levels. |
| 9/86 | Tulalip Tribes Inc. | Concentrations of heavy metals in monitoring wells exceeded National Drinking Water Regulation levels. |
| 8/87 | EPA | C. perfringens, fecal coliform (including Klebsiella pneumoniae), and total coliform bacteria counts were exhibited in elevated levels in leachate samples and water samples taken on site. |
| 7/88 | EPA | Ground water, leachate, and sediments contaminated with a variety of metals and bacterial pathogens. On-site ground water, pools, and leachate contained several metals, and volatile and semi- volatile compounds. |
Jack Morris and Bob Poss of the Washington State Department of Health (DOH) made a site visit on January 13, 1992, but did not have access to the landfill area. It was noted at that time that the road to the landfill is blocked by two separate gates. Foot traffic could bypass the first gate, and a trail around this gate was apparent. Discarded food wrappers and empty shotgun shells were in the area. No person was observed on the landfill at this time. The landfill is also accessible by water from the adjacent sloughs or Sound. No warning signs were seen during this site visit.
A second site visit was made on July 16, 1992. On this occasion we had full access to the landfill. The first gate on the main road entrance was closed and locked and bore the sign, "NO DUMPING LANDFILL CLOSED". About fifty yards past this gate was a second gate with the sign, "WARNING WASTE DISPOSAL AREA NO TRESPASSING". Both gates block vehicular traffic, but foot traffic may by-pass the gates. At several points along the water side of the landfill, signs identical to the sign at the second gate are displayed toward the water.
During the second site visit shallow ponds of surface water were observed on the landfill. The last rain fall in this area had occurred about four days earlier. Leachate was seen flowing in roadside ditches. Empty shot gun shells were seen at several places on the landfill. Demolition debris, concrete and rebar, were piled throughout the site. Also, dikes intended to hold out sea water were broached.
C. Demographics, Land Use, and Natural Resource Use
Demographics
About 220 people live within one mile of the landfill. No person lives on Ebey Island. The estimated total cumulative population within two miles of the landfill is 2800, and within three miles, 55,000. More than 200 people live at Priest Point, a waterfront community 1.5 miles west of the landfill.
Land Use
Across the sloughs, which border the landfill, are industrial and commercial facilities, including a lumber mill, two marinas, and a boat repair yard. Also, along the north shore of Ebey Slough about two miles upstream from the site is the Marysville Sewage Treatment Plant, which discharges 1.7 million gallons per day of primary treated sewage. The Weyerhaeuser Everett pulp mill on the Snohomish River is about one mile south of the site. The mill discharges secondary treated pulp wastes to the river. Beyond these industrial areas are residential zones. To the east and north is the City of Marysville and the rural areas within the Tulalip Tribes Reservation. The City of Everett is across the Snohomish River, about one mile south of the landfill.
Natural Resource Use
Area ground water is used for potable water and agricultural irrigation. About 7,800 people obtain drinking water from over seventy private or municipal wells within four miles of the landfill. These wells range in depth from 10 to 190 feet (2). All of these wells are upgradient, of the general regional ground water flow, from the landfill. The aquifer which underlies the Marysville area extends from the north and is bounded by the Snohomish River, approximately 1/2 miles south of the landfill. Marysville takes water from the Kyle River reservoir and wells near the city. The Marysville well closest to the landfill is 2.5 miles to the east. The closest documented private water well is 0.9 mile from the landfill. There is an industrial use well on Smith Island, which is 0.2 miles south of the landfill.
The marine environment adjacent to the landfill provides excellent habitat for the production and growth of the Dungeness crab. Crabbing in the area is popular the year-round. Salmon and bottom fish in the adjacent waters are harvested by both sport and commercial fishermen.
The intensive recreational use of the area is exemplified by the five marinas, three public boat ramps, a river front park and nature trail system within a four-mile area around the landfill. The closest recreational access point is a public boat ramp across Ebey Slough from the landfill.
Washington's DOH maintains a Vital Statistics Department and an Office of Registries. The Cancer Surveillance System (CSS) for the state is maintained by the Division of Public Health Sciences of the Fred Hutchinson Cancer Research Center. The CSS works under contract to the Surveillance, Epidemiology and End Results (SEER) program of the National Cancer Institute.
The Vital Statistics Department gathers information on numbers of deaths, births, fetal deaths, marriages, and divorces for Washington State. Variables included in this date base are geographic location (city, county, town); age; sex; race; address; cause of death; birthweight; gestational age; and birth defects.
The CSS database is the central repository for all newly diagnosed malignancies (except non-melanotic skin cancers) occurring in residents of thirteen counties of northwest-Washington State. The population covered is almost one million and includes five Standard Metropolitan Statistical Areas (SMSA), 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. This information is available for Island County since 1974.
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 classifications and by demographic factors: county of residence, sex, race, address, and mother's occupation, smoking history, and age. Data for births occurring in military hospitals are not included due to uneven documentation from the facilities. As of August 1991, information was available for the entire state for 1986-1989. Health outcome data will be evaluated in the Public Health Implications section.
In the past, people expressed concern to the Snohomish County Health District about the establishment of the landfill. Some of the concerns they expressed were: fear of health impacts, destruction of natural beauty, bad smells, public nuisance, spoiling a swimming area, harm to fishing and crabbing, and contamination of waters and beaches. The letters were from people who lived in the local area communities of Marysville, Everett, Snohomish, Lake Stevens, and Arlington.
The Service Manager for The Tulalip Tribes was contacted for health concerns associated with the landfill. She responded by letter on February 14, 1992 and stated in part,
"The Tulalip Tribes and Tulalip Community Center are concerned over possible adverse health effects due to the landfill commonly referred to as 'Big Flats'. The primary concern expressed has been over possible contamination of food sources community members have relied on for many generations. These food sources are accessed by various means including hunting, fishing, digging (i.e., clams) and gathering (berries, etc)."
Personnel of the Indian Health Service in Seattle were asked if the Service had any reports of health impacts or health concerns which might be associated with the Tulalip Landfill. Indian Health Services stated there were none recorded.
The public was officially invited to review and comment on the Draft Preliminary Health Assessment during the period of November 10, 1992 to December 10, 1992. The document was made available at two repositories, The Tulalip Tribes Business Office and the Marysville Public Library. DOH issued a press release on November 10th which described the site and location of the health assessment for public review. No comments were received by DOH during or since the public comment period.
ENVIRONMENTAL CONTAMINATION AND OTHER HAZARDS
The tables in this section list the contaminants of concern. We evaluate these contaminants in the subsequent sections of the Public Health Assessment and determine whether exposure to them has public health significance. ATSDR and DOH select and discuss these contaminants based upon the following factors:
In the data tables that follow, under the On-site Contamination subsection and the Off-site Contamination subsection, the listed contaminant does not mean that it will cause adverse health effects from exposures. Instead, the list indicates which contaminants will be evaluated further in the Public Health Assessment.
Contaminants requiring further evaluation are selected by using medium-specific comparison values. These values include Environmental Media Evaluation Guides (EMEGs), Cancer Risk Evaluation Guides (CREGs), and other relevant health guidelines.
EMEGs are estimated contaminant concentrations at which daily exposure would be unlikely to result in noncancer health effects. EMEGs are calculated from ATSDR Minimal Risk Levels (MRLs). MRLs are estimates of daily exposure to contaminants below which noncancer, adverse health effects are unlikely to occur. If no MRLs exist for a contaminant, a comparison value is calculated from a U. S. Environmental Protection Agency (EPA) Reference Dose (RfD). A RfD is an estimate of the daily exposure to a contaminant that is unlikely to result in noncancer, adverse health effects. CREGs are estimated contaminant concentrations based on the probability that 1 additional cancer case may occur in excess of the number that will be expected to occur among 1 million people (assuming they have been exposed to the contaminant for a lifetime). CREGs are calculated from EPA's cancer slope factors. EPA Maximum Contaminant Levels (MCLs) represent contaminant concentrations that EPA deems protective of public health; however, in deriving these levels the EPA takes into consideration the technical feasibility and economics of water treatment. MCLs are regulatory concentrations.
To identify possible facilities that could contribute to the contamination near the Tulalip Landfill, DOH searched the Toxic Chemical Release Inventory (TRI) Database for all available years (1987, 1988, and 1989). TRI is developed by the EPA from information about chemical releases to air, water, or soil, as provided by industries according to law. TRI did not contain records of any releases in Marysville, Snohomish County, Washington that could contribute to the contamination near the landfill.
EPA collected the data presented in this subsection during its preliminary site inspections of December 1984 and a complete site inspection done during July 1988.
Samples analyzed from EPA's 1988 investigation indicated that the monitoring wells, on-site pools, and leachate seeps had detectable concentrations of several metals, and volatile and semi-volatile compounds. A total of 19 metals were present in levels considered significantly above background in the ground water samples, 16 of which were found in the on-site pooled water samples, and 13 in the leachate water samples. This is important since the aquifer underlying the site is believed to be the same as that underlying the Marysville area.
There were no sediment samples with concentrations significantly above background inorganic concentrations or detection limits. On-site pooled water and underlying sediments were sampled and analyzed for volatile organics. Volatile organics were not present in significant amounts. No pesticides or PCBs were detected above background in either the on-site water or sediment samples (2).
Ground Water
There are ten monitoring wells located on site, four of which are screened within the waste material. The remaining six wells are screened in the fine to medium sand aquifer underlying the site. Just above this sand layer is a dense, clay-silt layer approximately twenty feet thick. This same dense layer is also evident in most, but not all, off-site well logs in the Marysville area. Its sporadic nature suggests the shallow clay-silt layer may be discontinuous (2).
Comparison of water levels in wells on- and off-site indicates similar water table elevations. This data, in conjunction with lithology observed in well logs and hydrologic reports of the area suggest that Ebey Slough does not form a hydraulic barrier between the site and the Marysville aquifer. Consequently, the ground water underlying the site may be hydraulically connected to the aquifer in the Marysville area (2).
Table 1 lists the contaminants of concern, concentration ranges, and comparison values for the on-site ground water samples collected in February 1988.
TABLE 1. Range of Contaminant Concentrations in On-Site Ground water Samples
| Contaminant | Concentration Range - ug/L | Comparison Value | |
| ug/L | Source | ||
| Arsenic | 18 - 209 | 3 | * RfD |
| Barium | 96.6 - 1330 | 700 | * RfD |
| Cadmium | 8.8 - 37.7 | 2 | EMEG |
| Chromium | 2.7 - 1290 | 50 | * RfD |
| Lead | 11.9 - 4450 | 15 | AL |
Leachate
Leachate generation at the Tulalip Landfill is of prime concern because the landfill is unlined. It is estimated that between 50 and 100 million gallons of leachate are generated each year, most of which enters the adjacent sloughs via seeps along the perimeter dike or below the surface.
During the EPA's preliminary site inspection in 1984, several leachate samples were collected. Two of these samples were analyzed for the full range of EPA priority pollutants. One was a composite sample of two small seeps from the bank on the eastern corner of the old barge canal entrance, and another from a puddle along the entrance road to the landfill, just inside the gate (1).
Table 2 lists the contaminants of concern, concentration ranges, and comparison values for on-site leachate samples.
TABLE 2. Range of Contaminant Concentrations in On-Site Leachate
| Contaminant | Concentration Range - ug/L | Comparison Value | |
| ug/L | Source | ||
| Arsenic | 15,000 - 49,000 | 3 | * RfD |
| Chromium | 206,000 - 415,000 | 50 | * RfD |
| Lead | 48,000 - 289,000 | 15 | AL |
Surface Water
The following table is a range of inorganic analytical results for on-site pooled water samples collected during February 1988. Table 3 summarizes the contaminants of concern in on-site surface water samples.
TABLE 3. Range of Contaminant Concentrations in On-Site Surface Water
| Contaminant | Concentration Range - ug/L | Comparison Value | |
| ug/L | Source | ||
| Arsenic | 4.2 - 30 | 3 | * RfD |
| Barium | 5 - 365 | 700 | * RfD |
| Cadmium | 5 - 25 | 2 | EMEG |
| Chromium | 4 - 938 | 50 | * RfD |
| Lead | 3 - 486 | 15 | AL |
Soil
Soil samples were collected at five on-site locations. The samples were analyzed for semi-volatile organics, none were detected (2). No heavy metals analysis are reported. The site has been extensively capped with foreign soil. Therefore, it is doubtful that soil analysis will help characterize this site.
Microbial Contamination
Elevated populations of total coliform (TC), fecal coliform (FC), fecal streptococci (FS), Pseudomonas aeruginosa, Staphylococcus aureaus, Clostridium perfringens, Escherichia coli, and Klebsiella pneumoniae bacteria have been observed at the Tulalip Landfill. TC, FC, and FS are considered indicator organisms for the presence of other pathogenic bacteria. Therefore, populations of these organisms were quantified in each water sample submitted for bacterial analysis. The presence of other important bacterial organisms, including the Enterococci group and Clostridium perfringens, was also noted. C. perfringens is proliferating at the landfill and is recognized worldwide as an important cause of food poisoning. See table 4 for concentrations.
TABLE 4. Range of EPA Bacteria Sample Results Sampled August 3, 1987
| Sample Source | Bacterial Colonies/100ml (MPN) Colonies/ml | |||||
| TC | FC | EC | FS | CP | APC | |
| Seawater | 230-790 | 20-130 | <18-78 | 20 | 0-4 | 10-17 |
| Fresh Water | 170-220 | <18-110 | <18-45 | 40-2,200 | 7-60 | 21-210 |
| Leachate | 130-49,000 | 68-1,700 | 20-78 | 440-350,000 | 0-5,000 | 15-45,000 |
The presence of these organisms in many natural environments, as well as other landfills, is not uncommon. However, levels such as those seen in studies at this site are higher than background, and were evaluated with respect to the human food chain and on site exposure routes.
Past analyses have also indicated that the bacterial populations isolated from leachate samples exhibit an antibiotic sensitivity different from those typically found in landfill leachate. The antibiotic sensitivity displayed was reportedly influenced by bacterial populations originating from hospitals or similar health care facilities. Therefore, the antibiotic sensitivity was also measured in population isolates from water samples submitted for bacterial analysis.
Surface Water
A large volume of rain and tidal water pass through this landfill. During the 1988 EPA site inspection, leachate was observed flowing from the perimeter landfill dike into the adjacent wetlands. A total of three samples were collected in the areas where leachate was observed flowing directly into an off-site wetland. Table 5 lists the contaminants of concern, concentration ranges, and comparison values for surface water samples collected from the wetlands in February 1988.
TABLE 5. Range of Contaminant Concentrations in Off-Site Wetland Water
| Contaminant | Concentration Range - ug/L | Comparison Value | |
| ug/L | Source | ||
| Arsenic | 3 - 6.5 | 3 | * RfD |
| Barium | 7.1 - 62.1 | 700 | * RfD |
| Cadmium | 5.2 - 25 | 2 | EMEG |
| Chromium | 4 - 179 | 50 | * RfD |
| Lead | 8.5 - 122 | 15 | AL |
In February 1988, six water samples were collected from Ebey Slough, Steamboat Slough, and Possession Sound at Priest Point. The samples were taken at the surface and one foot above the bottom sediments. Table 6 lists the contaminants of concern, concentration ranges, and comparison values for off-site slough water samples.
TABLE 6. Range of Contaminant Concentrations in Off-Site Slough Water
| Contaminant | Concentration Range - ug/L | Comparison Value | |
| ug/L | Source | ||
| Arsenic | ND | 3 | * RfD |
| Barium | ND - 7.9 J | 700 | * RfD |
| Lead | ND - 13.3 J | 15 | AL |
Sediments
In February 1988, three wetland sediment samples were collected. The contaminants of concern, concentration ranges, and comparison values are summarized in Table 7.
TABLE 7. Range of Contaminant Concentrations in Off-site Wetland Sediment
| Contaminant | Concentration Range - ppm | Comparison Value | |
| ppm | Source | ||
| Arsenic | 49.9 - 75.5 | 15 | * RfD |
| Barium | 47.6 - 142 | 3500 | * RfD |
| Cadmium | 5240 - 32500 | 10 | EMEG |
| Chromium | 60.9 - 168 | 250 | * RfD |
| Lead | 16.9 - 137 | None | None |
Sediments were also collected from the Ebey Slough, Steamboat Slough, and Possession Sound at Priest Point . The contaminants of concern, concentration ranges, and comparison values for slough sediments are summarized in Table 8.
TABLE 8. Range of Contaminant Concentrations in Off-Site Slough Sediments
| Contaminant | Concentration Range - ppm | Comparison Value | |
| ppm | Source | ||
| Arsenic | 11.1 - 15.8 | 15 | * RfD |
| Barium | 23.8 - 34.7 | 3500 | * RfD |
| Chromium | 23.6 - 33.8 | 250 | * RfD |
| Lead | 3.2 - 5.5 | None | None |
Food Chain
Six Dungeness crab samples obtained from Ebey Slough and Possession Sound were analyzed for inorganic, pesticides, and polychlorinated biphenyl compounds. These samples did not exhibit a significant level of contaminants.
C. Quality Assurance and Quality Control
In preparing this Preliminary Health Assessment, The Washington State Department of Health relies on the information provided in the referenced documents and assumes that adequate quality assurance and quality control measures were followed with regard to appropriateness of testing procedures, chain-of-custody, laboratory procedures, and data reporting. The validity of the analyses and the conclusions drawn for this Preliminary Health Assessment is determined by the availability and reliability of the referenced information.
The concentration level for lead in on-site ground water is estimated because quality control criteria for the sample were not met.
The landfill is accessible to foot and water traffic. Signs are posted at the main gate and water accesses which state, "WARNING WASTE DISPOSAL AREA NO TRESPASSING". Piles of demolition debris, consisting of concrete and rebar, are piled throughout the site. These materials constitute a physical hazard.
To determine whether persons are exposed to contaminants migrating from the landfill, ATSDR evaluates the environmental and human components that lead to human exposure. This pathway analysis consists of five elements: a source of contamination, transport through an environmental medium, a point of exposure, a route of human exposure, and an exposed population.
ATSDR categorizes an exposure pathway as completed or potential, if the exposure pathway cannot be eliminated. Completed pathways require that the five elements exist and indicate that exposure to a contaminant has occurred in the past, could be occurring now, or could occur in the future. Potential pathways, however, have at least one of the five elements missing, but could exist. Potential pathways indicate that exposure to a contaminant could have occurred in the past, could be occurring now, or could occur in the future. An exposure pathway can be eliminated if at least one of the five elements is missing and will never be present.
A. Completed Exposure Pathways
To date, no completed exposure pathways have been determined for this site.
B. Potential Exposure Pathways
There are several potential exposure pathways that may have occurred, may be occurring, and may occur in the future associated with the contamination at Tulalip Landfill. A large volume of leachate is generated at the landfill, ground water, surface water, and sediments are contaminated. Because the landfill was capped, it is not known whether soils are also contaminated and a potential point of exposure.
Table 9 displays potential exposure pathways through private and public water supplies, by direct contact to contaminated wetland and slough sediments, and through direct contact with contamination in leachate ponds and soils on the landfill.
TABLE 9. POTENTIAL EXPOSURE PATHWAYS
| PATHWAY NAME | EXPOSURE PATHWAY ELEMENTS | TIME | ||||
| SOURCE | MEDIA | POINT OF EXPOSURE | ROUTE OF EXPOSURE | EXPOSED POPULATION | ||
| Public Water Supply | Tulalip Landfill | Ground water (Public Water Systems) | Residences (tap) | Ingestion and Dermal Contact | Residents | Past Present Future |
| Private Wells | Tulalip Landfill | Ground water (Private Wells) | Residences (tap) | Ingestion and Dermal Contact | Residents | Past Present Future |
| Surface Water | Tulalip Landfill | Surface Water | Leachate Ponds | Dermal Contact | Hunters | Past Present Future |
| Sediments | Tulalip Landfill | Wetland and Slough Sediments | Wetland and Slough Sediments | Dermal Contact | Hunters Boaters |
Past Present Future |
The pathway via ground water to a public water supply has the greatest potential to effect the city of Marysville (population 8,150 in 1989). The Marysville production well closest to the site is about 2.5 miles to the east. This well in the regional ground water pattern is generally recognized as being upgradient of the site. However, not until the remedial investigation is completed will the local ground water pattern be characterized. Marysville's drinking water was analyzed during April 1992 and no heavy metals were detected.
More than seventy private water wells are within four miles of the site. These wells range in depth below ground level of 10 to 190 feet. The closest documented private well is 0.9 miles from the landfill. Like the Marysville municipal well, these private wells are in a general upgradient location to the landfill. However, unlike the Marysville well these private wells have not been sampled and analyzed for hazardous substances. Therefore, because the private wells and both shallow and untested they present a greater potential to be an exposure pathway from the site.
Both surface water on site and sediments on and near the site present a pathway by direct exposure. The site has been posted, but remains accessible by foot and boat. Empty shotgun shells seen on site indicate that the site is used by hunters. The site is located in close proximity to marinas and small boat launching sites. Leachate continues to be generated on site and remains a potentially significant pathway to people who enter the site.
In this section we will discuss the health effects in persons exposed to contaminants at this site. To evaluate health effects, ATSDR has developed Minimal Risk Levels (MRL) for contaminants commonly found at hazardous waste sites. The MRL is an estimate of daily human exposure to a contaminant below which non-cancer, adverse health effects are unlikely to occur. MRLs are developed for each route of exposure and for acute (< 14 days), intermediate (14-365 days), and chronic (> 365 days) exposures.
When an MRL is not available, EPA's RfD is used. The RfD is an estimate of daily human exposure to a contaminant for a lifetime below which non-cancer health effects are unlikely to occur.
The calculated doses are estimations of the amount of chemical a person could be exposed to at the site. The computations are based on the assumptions that an adult weighs 70 kilograms (154 pounds) and a child weighs 10 kilograms (27 pounds). An adult ingests 2 liters of water per day, and a child ingests 1 liter of water per day. Adults typically ingest 50 to 100 milligrams of soil per day by inhalation of small soil particles carried in the air, and by placing soiled hands and other objects in the mouth. We assume that small children ingest a greater amount of soil, typically 200 mg/day, because they generally tend to place objects in their mouths more frequently. These assumptions and the respective exposure scenarios are used to determine the estimated doses for each chemical. The estimated doses are compared to heath guidelines (MRLs, RfDs) and the available scientific literature to determine if health effects are likely to occur.
The following discussions rely on the preceding assumptions combined with the information in the Pathways Analyses section. Because the Remedial Investigation of this site has not been performed, the available data are preliminary. The following discussion will therefore be brief and general in nature. This public health assessment will be updated as further and more complete data become available.
Based upon the available data, there are no indications that any pathway at this site is complete. The potential for exposure occurs if contaminated ground water effects private wells or public water systems near the site. Persons may be exposed to the contaminated ground water and ingest metals and pathogenic bacteria. Dermal contact and ingestion of those contaminants may occur while bathing. Persons who hunt and boat in wetlands and sloughs near the site may be exposed to heavy metals and pathogenic bacteria by dermal contact with contaminated sediments. Persons who trespass onto the landfill site may be exposed to heavy metals and pathogenic bacteria through dermal contact with contaminated water and sediment in leachate ponds.
Heavy Metals
People may be exposed to the heavy metals: arsenic, barium, cadmium, chromium, and lead through potential exposure scenarios described above. The ingestion of contaminated drinking water with these heavy metals at concentrations found in on-site ground water could result in adverse noncarcinogenic health effects. Health effects commonly associated with heavy metal exposures are stomach irritation, changes in the blood, hypertension, neurological problems, kidney and liver damage (3,4,5,6). Longterm exposures to arsenic, cadmium, chromium VI, and lead have been associated with causing cancer in laboratory animals (3,4,5,6). Health effects, both cancer and noncancer, would only occur from longterm ingestion of water containing contaminant levels found in on-site ground water. Exposures that would occur through inhalation of soil particles and/or placing soiled hands or objects in the mouth would not be likely to result in health effects due to the limited frequency and level of exposure.
Dermal contact to heavy metals could occur from showering and bathing with contaminated water, wading through contaminated leachate ponds, and walking through wetland and slough sediments. Though limited information is available on absorption of metals after dermal contact, it is presumed to be significantly less than absorption by inhalation or oral routes of exposure. It is unlikely that humans would experience any adverse health effects through occasional dermal contact to heavy metals. The exception is sensitive individuals who may experience mild to severe skin irritation or allergic reactions to arsenic and chromium (3,5).
Pathogenic Bacteria
Individuals may be exposed to the pathogenic bacteria: Clostridium perfringens, Staphylococcus aureus, Pseudomonas aeruginosa, Klebsiella pneumoniae, and Escherichia coli through exposure to bacterial contaminated leachate or surface water. If bacterial contamination should migrate into the ground water, nearby residents may be exposed to bacteria through ingesting contaminated water from private wells or public water systems. Ingestion of bacterial contaminated water, as well as food prepared with bacterial contaminated water can result in adverse health effects. Seafood, particularly shellfish such as clams and oysters, can become reservoirs for these pathogens. Health effects could result if individuals consume bacterial contaminated seafood.
The common health effects associated with Clostridium perfringens, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli are gastrointestinal disorder, such as vomiting, intestinal cramps, and diarrhea. Staphylococcus aureus and Klebsiella pneumoniae are also associated with bronchial and lung disease, such as pneumonia. Dermal contact with bacterial contaminated water, leachate ponds, or surface water could result in infection if people have open wounds (7).
B. Health Outcome Data Evaluation
Based upon the available data, completed human exposure pathways at this site have not been identified. It is not possible to identify any population which might have been impacted by the site. Thus, at this time, an evaluation of the available health outcome data would be unable to show whether or not the site has had an adverse impact on the health of the community. If information becomes available indicating that there is an exposed population, DOH will reconsider the need to evaluate health outcome data for this site.
C. Community Health Concern Evaluations
No current community health concerns have been found. Several attempts were made to elicit health concerns from the local health department, Indian Health Services, and the Tulalip Tribe. No information was available. Concerns will be addressed as they are raised by the community.
The data and information developed in the Tulalip Landfill Preliminary Public Health Assessment have been evaluated by the ATSDR Health Activities Recommendation Panel (HARP) for follow-up health activities. Although there have been no confirmed exposures to on-site contaminants, the site has not been secured and trespassing is occurring on the site. Trespassers entering the site may be exposed to the heavy metals and microbial organisms that contaminate the site. Also, human exposure to contaminated ground water may occur, although the nature and extent of the ground water contamination is not well defined. However, to date, no contaminants have been detected in the drinking water supply. To assist the community in understanding their potential for exposure, a community health education effort is indicated. As more information on this site becomes available, the Washington Department of Health and ATSDR will reevaluate this site for any indicated follow-up health activities.
The Public Health Action Plan (PHAP) for the Tulalip Landfill site contains a description of actions to be taken by ATSDR, DOH, and other governmental agencies subsequent to the completion of this assessment. The purpose of the PHAP is to ensure that this public health assessment not only identifies public health hazards, but provides a plan of action designed to mitigate and prevent adverse human health effects resulting from exposure to hazardous substances in the environment. Included is a commitment on the part of ATSDR and/or DOH to follow-up on this plan to ensure that it is implemented. The public health actions to be implemented by ATSDR and/or DOH are as follows:
DOH in cooperation with ATSDR will evaluate the feasibility and resources to pursue implementing the community health education effort as recommended by HARP, to assist the community in understanding their potential for exposure.
ATSDR and DOH will collaborate with appropriate federal, state, and local agencies to pursue the implementation of the recommendations outlined in this public health assessment.
ATSDR and DOH will reevaluate and may expand the PHAP when additional data becomes available. Future environmental and/or health outcome data may determine the need for additional actions at the Tulalip Landfill site. This PHAP will be evaluated annually unless information warrants more frequent evaluation.
The Tulalip Landfill public health assessment was prepared by the Washington State Department of Health under a cooperative agreement with the Agency for Toxic Substances and Disease Registry (ATSDR). It is in accordance with approved methodology and procedures existing at the time the public health assessment was begun.
Richard R. Kauffman
Technical Project Officer, SPS, RPB, DHAC
The Division of Health Assessment and Consultation, ATSDR, has reviewed this public health assessment, and concurs with its findings.
Robert C. Williams
Director, DHAC, ATSDR
Robert A. Poss
Public Health Advisor
Washington State Department of Health
Jack Morris, R.S.
Public Health Advisor
Washington State Department of Health
ATSDR Regional Representative:
Gregory D. Thomas
Senior Regional Representative
Office of Assistant Administrator
ATSDR Technical Project Officer:
Richard R. Kauffman
Environmental Health Scientist
Remedial Programs Branch, State Program Section
Division of Health Assessment and Consultation
Figure 3. Site Map With Location of Old Canals
