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CIB 006 1592

DATE:

IBJECT:

FROM:

MAY 14 1907

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION II

R4«* Asseaaimaot Policy Group Meeting*.

illiam J. Tin _ n 1 \jf?jft**C puty Regional Administrator

Addressees * SPECIAL

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The next meeting of the Risk Assessment Policy Group i s scheduled for Monday. May 18 at 1:30 P.M. in Room 900A. The agenda f o r the meeting i s attached.

Please contact A l i c e Jenik a t Ext. 4296 i f you have any questions concerning the meeting or the agenda.

Attachment

Addressees

H. Barrack K. Bricke

V/S. L u f t i g J. Marshall B. Metzger W. Nelson C. Simon

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QrON II FORM 1320-1 (9/85) CIB 006 1593

Risk Assessment Policy Group Meeting

Agenda

Monday May 18, 1987 Room 90OA

I . Peer Review of the Ciba-Geigy Risk Assessment

A) Presentation by the Science Subgroup (Attachment I )

B) Discussion of the Peer Review Process and Recommendations (Attachment I I )

I I . Risk Assessment Training A c t i v i t i e s

A) Risk Assessment Guidelines Training (Attachment I I I )

B) IRIS Training

I I I . Proposed date f o r next meeting: June 29

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DRAFT

Report on the ENVIRON and NUS Corporations

Risk Assessment of the Ciba-Geigy Plant Located In

Toms River, New Jersey

Prepared by

Region i i ' s Risk Assessment Science Subgroup

May, 1987

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Table of Contents

Page

I . Executive Summary 1

I I . I n t r o d u c t i o n 2

I I I . Summary of NUS and ENVIRON Findings 2

IV. Background and Si t e Information 4

V. NUS and Environ Assumptions 6

V I . Hazard I d e n t i f i c a t i o n and T o x i c i t y 7

V I I . Exposure Assessment and Risk Characterization 10

V I I I . Recommendations 19

IX. Conclusions 21

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ATTACHMENTS

I . Topography and Hydrogeology of Site

I I . Waste Generation and Storage

I I I . P o t e n t i a l l y Exposed Populations

IV. Routes of Contamination and I d e n t i f i e d Contaminants

V. Assumptions

LIST OF FIGURES AND TABLES

Figure 1. Map of Ciba-Geigy Site and Surrounding Area

Figure 2. Migration of Contaminants O f f - S i t e .

Table l a . Total No Action Carcinogenic Risks f o r Completed A g r i c u l t u r a l Pathways.

Table l b . Total No Action Carcinogenic Risks f o r Completed Recreational Pathways.

Table 2a. Total No Action Chronic Hazards f o r Completed A g r i c u l t u r a l Pathways.

Table 2b. Total No Action Chronic Hazards f o r Completed A g r i c u l t u r a l Pathways.

Table 3. Total Carcinogenic Risk and Total Chronic Hazard.

Table 4. L i s t of Chemicals Found O f f - S i t e .

Table 5. Selected Inventory of Chemicals Used by Ciba-Geigy or Disposed of As Waste By-Products (CAI, 1983).

Table 6. Exposure Scenarios.

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I . EXECUTIVE SUMMARY

On March 30, 1987, Region I I ' s Emergency and Remedial Response Division submitted two risk assessments of the Ciba-Geigy Plant located in Toms River, New Jersey for review by the regional Science Subgroup. The NUS Corporation's Public Health Evaluation was prepared to be part of the Superfund Feasibility Study for this site, and the other risk assessment was prepared by Environ for the Potentially Responsible Party.

Results of the NUS evaluation identified a r"ig>f ^ f additional cancers per one million people exposed for the next 70 years to contaminants migrating from the plant. Tne principal contaminants included volatile organics and metals. The Environ evaluation identified a risk in the range of less than 1 excess cancer per ten million to one hUndrea million people exposed to contaminants from the plant during the next" /u years^ Both assessments were based on a no action alternative.

The principal differences between the assessments that explain this variance are:

° Selection of indicator chemicals used to calculate risks,

° Selection of potential routes of exposure, and

° Assumptions used in identifying potential routesi of exp^ure_ over the population*^ lifetime.

The Subgroup also identified differences in the Quality Control/Quality Assurance procedures used in each assessment, the format for presentation of the assessment, and the "risk numbers" used. These differences contributed to differences in the conclusions drawn by each assessment.

Based on this analysis, the Subgroup determined that the NUS report was more representative of potential risks from the Ciba-Geigy plant. The various deficiencies identified in the Environ assessment raise questions about whether the Environ analysis adequately reflects potential exposures from contaminants migrating from the plant. The last section of this report identifies areas requiring further clarification.

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I I . INTROLXJCTION

On March 30, 1987 Region I I ' s Emergency and Remedial Response Division (ERRD) submitted the NUS Corporation's Quantitative Public Health Evaluation for the No Action Remedial Alternative at the Ciba-Geigy Site to the Region I I Risk Assessment Science Subgroup for peer review. ERRD also provided the Potentially Responsible Party's (Ciba-Geigy's) assessment of the same site for comparison. The second report prepared by Environ is t i t l e d An Assessment of the Risk Associated with the Ground Water Contamination at the Toms River Plant. Each report includes the four parts of a risk assessment: hazard identification, dose-response, exposure assessment and risk characterization.

The Superfund Public Health Evaluation Manual (SPHEM) (EPA/540/186/060) and the Draft Superfund Exposure Assessment Manual OSWFR Directive 9285.5-1 were used as source documents for the review.

Since two assessments of the same site were available, the Subgroup decided to review and compare the methodologies and conclusions of both reports. The results of this analysis are provided in the following report.

I I I . SUMMARY OF NUS AND ENVIRON FINDINGS

Although each consultant based i t s assessment on monitoring data and general information gathered by AWARE Incorporated, JTC Environmental Consultants, SR Analytical Incorporated, Radian Corporation and the NUS Corporation, Clement Associates, Inc., substantially different conclusions regarding the risks associated with the Ciba-Geigy site were reached by NUS and by Environ.

NUS Findings

NUS concluded that the population in the v i c i n i t y of the Ciba-Geigy site is exposed to an unacceptable risk from foreseeable exposure to contaminants migrating from the Ciba-Geigy Plant, and that feasible alternatives to lower the contaminant concentrations need to be addressed.

NUS modeled potential exposure pathways associated with the recreational use of Toms River and the marshland area of Winding River Park, along with the exposure pathways associated with the use of private agricultural wells. Tables la and lb show the total carcinogenic risks for each completed exposure pathway.

The total risk estimate calculated by NUS for carcinogenic effects is 2800 additional cases of cancer per one million people exposed over a 70 year lifetime. Although this risk is due largely to the ingestion of agricultural water, the risk calculated by NUS for the other agricultural pathways and the recreational pathways was not insignificant.

The to t a l risk estimate calculated by NUS for the agricultural pathways associated with inhalation exposure from sprayed agricultural water, volatizing wet s o i l and volatizing pool water is 250 x 10~6. The total carcinogenic risk estimate calculated for the recreational pathways is 280

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additional cases of cancer per one million people exposed over a 70 year lifetime.

This risk is almost entirely due to inhalation exposure of contaminated air from the marshland. Therefore, even i f the exposure pathway for the ingestion of agricultural water is discounted, the remaining agricultural and recreational exposure pathways s t i l l produce carcinogenic risk levels that are excessive and unacceptable.

NUS also performed a chronic hazard assessment, which presents a ratio of the predicted daily dose and the acceptable daily intake. I f the value is greater than one, then chronic effects are possible. Tables 2a and 2b show the t o t a l chronic hazard index for each completed exposure pathway and Table 3 shows the total chronic hazard. NUS calculated a chronic hazard index of 15, which indicates that there is a 15 times greater chance of demonstrating a chronic effect from these contaminants.

Although this risk is also due largely to the ingestion of agricultural water, the chronic hazard index calculated by NUS for the other agricultural pathways and the recreational pathways was not insignificant.

The chronic hazard index calculated by NUS for inhalation exposure from volatizing wet s o i l is 3.6. The chronic hazard index calculated by NUS for the recreational pathways is 5.8. Again, this is almost entirely due to the inhalation exposure of contaminated air from the marshland. Therefore, even i f the exposure pathway for the ingestion of agricultural water is discounted, the remaining agricultural and recreational exposure pathways s t i l l produce a chronic hazard index that is excessive and unacceptable.

Environ Findings

Environ concluded that there is no evidence that suggests the presence of a significant risk to public health from foreseeable exposure to contaminants migrating from the Ciba-Geigy Toms River Plant, even i f no remedial action were to be instituted.

Environ modeled potential exposure pathways that i t considered to be the most significant for specific populations and for the population in general. These exposure pathways were associated with the recreational use of Toms River and the marshland area of Winding River Park. Environ did_not consider rhp exposure pathways associated with the use of the aqriculturaTwells that NUS considered. The risk estimates calculated by Environ for the exposure pathways examined for the carcinogenic effects are in the range of 10""' to 10~ 1 2 . This translates to a range of one additional case of cancer per ten million people exposed to one additional case of cancer per one hundred million people exposed.

Environ also conducted a chronic hazard assessment. Environ concluded that noncarcinogenic health effects are not expected to occur for any of the exposure pathways since the predicted average daily dose of the identified contaminants was less than the acceptable daily intake. This assumption results in a chronic hazard index of less than one, which indicates that chronic effects are not l i k e l y .

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Environ also considered the possibility of adverse impacts on aquatic organisms. When Environ compared predicted river concentrations to the lowest concentration at which adverse effects have been reported for aquatic organisms, the predicted river concentrations were several orders of magnitude lower than the lowest concentration at which adverse effects have been reported for aquatic organisms. Environ concluded that adverse health effects on aquatic organisms are not expected to occur.

IV. BACKGROUND AND SITE INFORMATION

Site. The Ciba-Geigy Corporation owns and operates an organic chemical and dye manufacturing plant on approximately 1,255 acres in Dover Township, Ocean County, New Jersey. Approximately 320 acres of the site are developed and including 7 production buildings, administration and laboratory f a c i l i t i e s , an on-site wastewater treatment plant, and land disposal operations. The remainder of the site is undeveloped. The site is bounded by the Toms River to the east and northeast and by residential and commercial developments to the south and west. Figure 1 shows the site and the surrounding area. Attachment I summarizes the topography and hydrogeology of the area.

Manufacturing Processes. The Ciba-Geigy plant, formerly known as the Toms River Plant (TRP), has been in operation since 1952, i n i t i a l l y producing organic dyes and intermediates. Since 1959, the plant produced epoxy resins and specialty chemicals. Ciba-Geigy has reported that i t s future plans for this site include the phasing out of the current operations and a shi f t towards pharmaceutical production.

Attachment I I provides a summary of the wastes produced by the current manufacturing processes. In addition, a selected inventory of chemicals used or disposed of as waste by-products at the site is included in this Attachment.

Contaminants. In general, the sources of contamination considered in the risk assessments arise from waste disposal practices which had been followed at the s i t e . These sources include: backfilled lagoons, drum disposal areas, lime sludge disposal areas, f i l t e r cake disposal areas, wastewater treatment plant, active l a n d f i l l , and former calcium sulfate disposal area.

Figure 2 shows the off-site migration of these contaminants and Table 4 provides a l i s t of chemicals identified as a result of this contamination. The primary contaminants are volatile organics and heavy metals.

Exposure. Attachment I I I summarizes the 1980 census data on Dover Township and provides background information on the community. Detailed demographic information on the community was not included in either assessment.

In addition to the residential and commercial developments, the site is surrounded by a recreational area which provides public access to playground and picnic f a c i l i t i e s , concerts, hunting, extensive hiking and bicycling paths, fishing and crabbing, and canoeing in the Toms River.

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The community's drinking water supplies are provided by the Toms River Water Company. The Toms River Water Company draws i t s water from wells in Farrington, Kirkwood, and Cohansey Aquifers located 1.1 miles from the site. These aquifers service Dover Township, a portion of South Toms River and Berkeley Townships, and is also being considered as a public water supply for island catmunities in the area experiencing salt water intrusion problems. The risk assessments excluded these areas as possible sources of exposure.

The risk assessments also excluded routine plant emissions that are in compliance with New Jersey State and Federal guidelines as possible routes of exposure since they are not part of the Superfund remedial investigation.

The risk assessments considered the following exposed populations:

0 Residents in the Cardinal Drive area using agricultural wells for watering lawns, f i l l i n g swimming pools, etc. and

° Residents and visitors using the Toms River and surrounding marshlands where seepage of contaminants from the site has occurred for recreation.

The principal routes of exposure reviewed by both analyses included:

Agricultural Use

° Ingestion of agricultural water and/or soil 0 Dermal absorption of pool water ° Dermal absorption of contaminants from agricultural soil ° Inhalation of contaminated air from sprayed water ° Inhalation of contaminated air from s o i l ° Inhalation of contaminated air from pool water

Recreational Uses

° Ingestion of surface water from Toms River ° Ingestion of sediment in marshland ° Ingestion of fish from Toms River ° Dermal absorption of surface water from Toms River ° Dermal absorption of contaminants from sediments in the marshland ° Inhalation of contaminated air from Toms River

Attachment IV summarizes the routes of contamination and the contaminants found in each media.

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V. NUS AND ENVIRON ASSUMPTIONS

Attachment V summarizes the assumptions used in each assessment. The following major differences in assumptions made account for the different in conclusions reached by NUS and Environ.

° Environ assumed that since a purge well was already being used at the site and since Ciba-Geigy planned to cap the agricultural wells in the Cardinal Drive area that the residents in this area would not be exposed to contaminants through an agricultural pathway.

NUS assumed that since the wells are located on private property and residents are not obligated to cap the wells, agricultural exposure is a significant source of exposure. Specifically, as long as the well is not capped, i t is a potential source of exposure.

This difference accounts for a risk of 2500 additional cancers per one million people exposed over a 70 year lifetime by NUS.

° NUS calculated total risk based on adding contributions from each chemical for every pathway. Environ, on the other hand, calculated total risk based on individual chemicals in each pathway.

° Environ also selected different indicator chemicals than NUS. I t appears from the document that Environ concentrated on the volatile organics and discounted the potential effects from the inorganic metals.

This variance in selection of indicator chemicals can affect f i n a l risk calculations since the inorganics have a higher chronic risk than many of the organics. For example, lead has an Acceptable Intake Concentration 1.4xl0E-03 and inhalation of surface water from the Toms River containing this contaminant would result in a risk of one excess chronic health effect per one hundred thousand people per 70 years of exposure.

Environ also excluded arsenic with a Carcinogenic Potency Factor of 1.5xl0El as an indicator chemical. Exclusion of this chemical significantly reduced the potential risk to the exposed population. For example, i f one calculates the potential risk from ingesting surface water contaminated with arsenic from the Toms River, the risk is 9.9 excess cancers one thousand people per 70 years of exposure.

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VI. HAZARD IDENTIFICATION AND TOXICITY

As outlined in SPHEM, the f i r s t step in conducting a public health evaluation is to identify the hazards at the site. This process involves the selection of indicator chemicals that identify the "highest risk" chemicals at the site that pose the greatest potential public health risk. Such indicators must be chosen carefully so that they represent the most toxic, mobile and persistent chemicals at the site, as well as those present in the largest amounts.

Two important factors for ranking chemicals in this process are their measured concentration at the site and their toxicity. Additional factors to be considered include physical and chemical parameters related to environmental mobility and persistence. However, i t should be emphasized that professional judgment should also be used in deciding which chemicals should be selected. I f after ranking the chemicals, a certain chemical considered potentially significant was not selected, i t should be included anyway.

A review of the quality assurance of data and sampling procedures used by each contractor, the determination of representative concentrations from site data, and a calculation of the f i n a l indicator chemical selection is provided in the following section.

NUS followed the format listed in the SPHEM while ENVIRON did not. An attempt was made to analyze the data presented in ENVIRON using the SPHEM however i t was not always possible since the format and presentation of data were not clear.

Quality Assurance of Data

Fundamental to the development of a risk assessment is the identification of chemical contaminants. This determination is based on f i e l d sampling and quantitative laboratory analysis of samples taken at the site.

To determine the quality of the data presented in the two reports, the Subgroup identified the contractors and sub-contractors involved in sampling and analyzing chemical contaminants on the site. Review of the data sources i n each report identified the following contractors and sub-contractors involved in the data sampling and analysis: NUS, Inc., ENVIRON, AWARE, Inc., JTC Environmental Consultants, Northeastern Analytical Corporation, Radian, and Clement Associates.

Next, available Quality Assurance Project Plans and data sources for each of the contractors were reviewed. NUS used site monitoring data from two sources to identify the chemicals at the site. One source was samples collected during 24 sampling events conducted by NUS during 1985 and 1986. These included groundwater, residential well, s o i l , sediment and surface water samples. The second source of data used by NUS was from 14 selected sanpling events conducted by Ciba-Geigy during 1985 and 1986. These included groundwater, sediment, surface water, marsh water and air samples.

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A Ouality Assurance Project Plan was submitted to EPA by NUS for review of Ouality Assurance/Quality Control {QA/QC) practices for d r i l l i n g the wells, sampling the different matrices, and for laboratory analysis and data validation. This plan, with some revisions, was approved by the Monitoring Management Branch (MMB). NUS collected the samples, and the analyses were conducted by a participant of EPA's Contract Laboratory Program (CLP). The data was validated by MMB.

I t appears Environ only used data collected by the responsible party during 1985 and 1986. These included groundwater, s o i l , surface water, residential well and a i r samples. I t is not clear whether this data was properly QA/QC'd or i f i t was done to what degree. Without this assurance, i t is not possible to determine the validity of the data.

Based on this analysis the Subgroup determined that NUS had followed proper QA/QC procedures for data and i t is not clear that Environ did. Since Environ did not provide evidence of a proper QA/QC practices, the Subgroup raised serious questions concerning the validity of the data and conclusions drawn from this data.

Calculation of Indicator Scores

The indicator score is a ratio between a measured concentration and a toxicity-based concentration benchmark that is used to rank the site chemicals.

To calculate the indicator score, i t is f i r s t necessary to rate the compounds based on their potential carcinogenic and/or noncarcinogenic effects. NUS did this for several volatile, semi-volatile, pesticide and inorganic compounds. This selection appears to be based on concentrations at the site and potential carcinogenic and noncarcinogenic effects. These compounds were listed in two tables that also included toxicity constants, EPA weight-of-evidence categories for carcinogens and severity of effect values for noncarcinogens.

Toxicity constants are derived for each environmental medium and for carcino­genic and noncarcinogenic effects. The SPHEM has a l i s t of the toxicity constants, the weight-of-evidence categories for carcinogens, and severity of effect rate values for noncarcinogens. NUS used the SPHEM values.

NUS calculated the indicator scores by f i r s t multiplying the carcinogenic and noncarcinogenic toxictiy constants by their maximum and mean concentrations within each media. This value is referred to as a contaminant toxicity (CT) value. The indicator score is the sum of a l l the CT values for each chemical for a l l media keeping maximum and mean values separate.

The chemicals were then ranked by the value of the indicator score, highest to lowest value, keeping the carcinogens and noncarcinogens separate.

ENVIRON did not calculate indicator scores and rank the chemicals as out­lined in the SPHEM. They calculated input values and mass loadings into the Toms River from several groundwater sources. The mass loadings were products of the contaminant concentrations, permeability, hydraulic gradients and cross-sectional areas. Dilution factors were calculated based on flows into the river. This whole section was extremely confusing.

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Final Indicator Chemical Selection

Based on the indicator score ranking of the compounds, NUS selected seven potential carcinogens and nine noncarcinogens as the indicator chemicals. Other factors, such as, water solubility, vapor pressure, Henry's Law constant, KQC values and persistence in various media were also taken into account.

NUS' f i n a l indicator chemicals are as follows:

Carcinogens

arsenic benzo(a)pyrene 1,2-dichloroethane trichloroethene benzene chloroform tetrachloroethene

Noncarc i nogens

barium 1,2-dichorobenzene trichloroethene chlorobenzene lead selenium copper nickel zinc

As stated above, ENVIRON did not rank their chemicals. They looked at several organic compounds and estimated the input and mass loadings of these compounds into the Toms River from several sources including the groundwater.

I t appears their assessment was then conducted on the effects of these compounds on the public from various exposure routes taking into account dilution factors. I t was not explained how these compounds were selected as a basis for assessing risk.

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V I I . EXPOSURE ASSESSMENT AND RISK CHARACTERIZATION

Exposure assessment describes mechanisms by which a population or an individual is exposed to contaminants originating from a site. Each exposure pathway must contain the following four elements to be complete: (1) a source and mechanism of chemical release to the environment; (2) an environmental transport medium (e.g., air, ground water) for the released chemical; (3) a point of potential human contact with the contaminated medium; and (4) a human exposure route (e.g., drinking water ingestion) at the contact point. Exposure pathways which are incomplete require no further analysis. Wherever possible, exposure pathways that are complete should be evaluated quantitatively to charac­terize the extent of human exposure and the extent of any associated health risks. The overall risks posed by a site are a composite of the individual pathway risks. The following is a discussion of the exposure pathways analyzed by NUS and Environ in their respective risk assessments for the Ciba-Geigy Toms River Plant site.

Contaminant Transport And Fate Analysis

The DSEAM identifies a f u l l range of possible contaminant transport mechanisms that should be evaluate as part of any superfund exposure assessment. The groundwater, surface water, s o i l , and air transport mechanisms considered by NUS and Environ are identified in Table 6, and are discussed in the following sections.

Groundwater

Region I I ' s Office of Ground Water Coordination reviewed the RI for Ciba-Geigy and the U. S. Geological Survey's in-depth review of the hydrogeological study. OGWC's comments on both reports are as follows:

° Contaminant Release: There are several contaminant sources identified at the Toms River site. Figure 1 indicates portions of the production area and the entire drum disposal area to be major sources of contamination. I t appears that the lime sludge disposal area, the active l a n d f i l l , and the f i l t e r cake disposal area are a l l contributing to the southern (Cardinal Drive) contaminant plume. However, the focal point of the plume was not determined, due to insufficient data.

° Contaminant Transport and Fate: Ground water transport is generally in the direction of Toms River. The northern contaminant plume, originating in the production area has reached, the river and migrated beneath the river a short distance eastward. The southern contaminant plume has also reached the river, but there is no evidence of i t s migrating further. The piezometric contour map of the 200 foot sand indicates a component of ground water flow to the southeast that may not intercept the river. I t is d i f f i c u l t to predict fate of the contaminants due to missing data and a lack of confidence in existing data.

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° Exposed Population Analysis: The material provided (hydrogeol-ogical investigation) afforded l i t t l e information on exposed populations. I t is understood that groundwater discharge to wetlands is the greatest route of exposure. Concern was raised that no information about the Toms River Water Company wellfield, located 1.1 miles from the Ciba-Geigy site and pumping more than 2500 million gallons per year, was included in the hydrogeological investigation. No contaminants have yet been detected at these wells, according to NJDEP, but such a large withdrawal w i l l impact groundwater flow patterns and should be addressed as a possible route of exposure.

° Summary of Assumptions: I t was assumed that terrain conductivity correlated with inorganic groundwater contamination, and also indicated organic contamination in the subsurface. A sta t i s t i c a l regression of ground water quality data with terrain conductivity data should have been performed to substantiate this assumption. Additional traverses are desirable to establish and confirm contamination plumes.

The report refers to the Kirkwood fonnation as an aquitard. There is substantial evidence that the Kirkwood is capable of yielding large quantities of potable water locally. I t is more accurate to refer to the ground water underneath the site as the Kirkwood-Cohansey Aquifer System and to recognize the interconnection.

° Assessment of Adequacy: The report adequately presents the areal distribution of ground water contaminants. However, the vertical migration of contaminants is not adequately presented.

The conceptual model of hydrogeology may lead to underestimates of the risks to potentially exposed populations. Specific problems with the conceptual model include:

- The designation of the 200 foot sand as part of the Manasquan For­mation, and the subsequent assignment of aquifer parameters indicative of the Manasquan. Previous studies have identified this 200 foot sand as part of the Kirkwood-Cohansey System.

- When defining Toms River as a "hydraulic barrier", or more precisely, a ground water drain, the river was sampled at high stage which would yield results that are not indicative of normal flow patterns.

Concentration should be on hydrogeological systems, not geological forma­tions. Groundwater flow and contaminant transport do not necessarily follow neat geological formation lines.

In addition, there were QA/QC problems during sample preservation, ana­lysis and in presentation of the water quality data. In one instance, an isoconcentration map was drawn using data from the wrong contaminant.

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° Data Gaps; There are three main data gaps in the report:

- L i t t l e attention was given to formerly conducted studies of the geology-hydrogeology of the site area. There are extensive reports available.

- There were no monitoring wells installed in the Kirkwood formation. This would greatly improve the analysis of potential for vertical migration of contaminants.

- The effect of the Toms River Water Company withdrawals 1.1 miles from the site needs to be evaluated. During 1983 the conpany pumped 2,558 million gallons from the Cohansey, Kirkwood and Farrington formations. Local ground water flow patterns w i l l be altered by this amount of pumpage. Protection of this wellfield from Ciba-Geigy contaminants should be addressed.

Surface Water

Off-site transport of contaminants via surface runoff was not considered significant in either study. NUS indicated, however, that runoff from the filtercake area could eventually become significant and should be considered in any remedial action plans.

Both NUS and Environ considered the transport of contaminants from groundwater seeps to the Toms River, and to the marshes on the western side of the river.

Soil

NUS indicated that monitoring data showed no apparent current transport of contaminated s o i l from the filtercake area either by fugitive dust or surface runoff. Environ did not assess these transport mechanisms.

Air

The reports used emissions and dispersion modeling to predict ambient air concentrations of hazardous chemicals at various sites around the plant. These chemicals are released into the air through various volatilization processes, and then are inhaled by the exposed population. The predicted concentrations were used to assess carcinogenic and noncarcinogenic risks caused by inhalation.

The Environ Report - The report does not include risk factors due to watering the grass, f i l l i n g pools, or inhalation of chemicals at a local marsh. Downwind transport from contaminated off-plant locations are not considered.

° Contaminant Emission Models: A valid emissions model was used to characterize the volatilization process from water and s o i l surfaces. However, this model contains a few errors, according to EPA's Office of Research and Development, which may cause an overestimate of volatile emissions by a factor of approximately two.

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° Air Dispersion Models: The air dispersion model used to predict ambient air concentrations is a simple standard model. However, there are some deficiencies in the modeling which need to be clarified.

First, the time period corresponding to the calculated concentrations is unclear. Do the concentrations represent a worst hourly condition, a long term average, or perhaps some intermediate condition? What are the air concentrations that have actually been used to assess risk? Answers to these questions would allow determination whether the risk assessment is unrealistically conservative, conservative or realistic.

0 Completeness: The Environ report is incomplete. Volatilization from agricultural processes is not considered. Volatilization from the Toms River is considered to be negligible based on a few small measured values. Volatilization from a local marsh is considered, but i t does not consider enough of the population who may occasionally be in the area.

Air transport and dispersion of hazardous chemicals from off-plant locations are not considered. Instead calculations of concentration are made only at the off-plant site. There may be significant risk to portions of the population downwind of the marsh as well.

Local topography which may be significant has not been considered in the air analysis. I f there are pronounced local wind patterns which seems li k e l y , these w i l l affect the locations containing exposed members of the population. Local wind patterns need to be discussed, described and included in the calculations i f they are judged to be important.

The NUS Report - The NUS report includes risk factors due to volatilization from contaminated water and s o i l . The risks are due to watering lawns, swimming in residential pools, and exposure due to recreation at the nearby marsh and the Toms River. Downwind transport from contaminated off-plant locations (like the marsh) was not included in the report, but i t does need to be considered.

0 Contaminant Emission and Dispersion Models: Appropriate emission and dispersion models have generally been used. However the approach used to estimate emissions due to watering of lawn with contaminated water is questionable.

The concentrations of some chemical contaminants in contaminated water are considerably greater than the corresponding values in the Environ report. I t is suggested that these values be checked to be certain that the order of magnitude is correct.

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The time period corresponding to the modeled air concentrations needs to be clarified. The magnitude of the exposure and the risk is determined by the modeled air concentration during the specified time. The corresponding lifetime risk factors should probably be calculated based on average daily exposures over a lifetime. I t is not clear i f they are.

0 Contaminant Transport and Exposed Population: Contaminant transport in the air from sites like the marsh and the Toms River are not considered. Since calculated risks at these sites are so high, i t is possible that sections of the population could be exposed to significant downwind concentrations.

° Exposure Analysis and Assessment of Risk: Lifetime exposures depend on calculated concentrations and corresponding time periods. I t is not clear i f the exposures in this report were calculated in this manner.

° Completeness: The report should address downwind transport frcm hazardous off-plant locations, local topography and meteorological conditions.

Human Exposure Routes And Risk Characterization

Environ - The community surrounding the plant was divided into subgroups for the purpose of identifying specific exposure pathways and performing risk assessment calculations. The subgroups consisted of an adult male, adult female, small children (using a 4-year old as an average of children ages 2-6), older children (using a 9-year old as an average of children ages 6-12), and teens (using a 15-year old as an average of children ages 12-18). Specific exposure pathways were identified for each of these populations.

The marshland area of Winding River Park was identified as a possible exposure point due to a plume of contaminated ground water that is migrating from the the plant towards the Toms River and seeping into the marshland area on the western bank of the Toms River. Winding River Park is a recreational complex. Environ identified the inhalation of contaminated air , dermal absorption of contaminated so i l and water, and ingestion of contaminated s o i l and water as potential exposure routes for children playing at the park. Environ addressed these routes of potential exposure for a 9-year old child (average of ages 6 -12).

Toms River is also extensively used for recreational purposes. Environ identified the inhalation of contaminated air , and dermal contact and ingestion of contaminated so i l and water as potential a exposure route for children playing along the river and for recreational fishermen. Environ addressed these routes of exposure for a 9-year old child and an adult male. Environ also identified the ingestion of fish from Toms River as a potential route of exposure for a member of each subgroup.

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Three miles downstream from the plant, several communities were identified as having beach f a c i l i t i e s . Boating and fishing are also extensive. Environ determined that exposures to contaminants from the plant at this location were not reasonable and therefore did not consider the associated exposure pathways.

Environ did not conduct a risk assessment associated with the use of the private residential agricultural wells. Ciba-Geigy conducted a survey in the area of known groundwater contamination and located 14 irrigation wells. Of the 11 wells sampled, three wells were reported to exceed standards or proposed standards developed under the EPA Safe Drinking Water Act. Since Environ determined that only one of the three contaminated wells is presently used, and only for lawn watering, Environ concluded i t was not necessary to conduct a risk assessment associated with the use of these wells.

NUS - NUS divided the exposure pathways into two types, recreational and agricultural.

For the completed human recreational pathways, NUS identified the marshland area of Winding River Park and Toms River as potential exposure sites due to the groundwater plume that flows to Toms River and the nearby marshlands. The ingestion exposure route was addressed for the surface water from the Toms River, sediment from the marshland and fish from Toms River. The human dermal exposure routes identified were the dermal absorption of surface water from Toms River and the dermal absorption of contaminated sediment in the marshland.

Inhalation exposure to contaminated air from the Toms River and the marshland area was also considered. NUS calculated risk estimates for these exposure routes assuming lifetime exposure. Where exposure was anticipated to be greater for children, the lifetime daily dose (LDD) was taken as the sum of the calculated LDD for a child and the calculated LDD of an adult.

NUS considered the exposure pathways associated with the use of the agricultural wells to be relevant completed human pathways of exposure. NUS identified the agricultural wells as sources of water for watering lawns and gardens, f i l l i n g swimming pools and possible ingestion. Although the residential area is serviced by the Toms River Water Company, NUS considered the ingestion of the agricultural well water to be a relevant completed human exposure route. NUS, for the purpose of this assessment, assumed that a l l of these uses do occur and w i l l continue to occur in the future.

NUS identified the completed human ingestion routes from the agricultural pathways to be the ingestion of agricultural water and contaminated s o i l . Since no restrictions are placed on the use of the wells, NUS assumed that the agricultural water might be ingested by the residents of the community. The so i l contamination is a result of the use of the well water to water lawns and gardens.

Since the well water is used for watering lawns and f i l l i n g swimming pools, NUS considered the dermal absorption of contaminated so i l and the dermal absorption of water from pools as completed exposure pathways for organic chemicals.

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NUS also considered the inhalation route of exposure for volatilizing organic contaminants due to contaminated air from sprayed water, volatilizing soil or volatilizing pool water. Organic compounds w i l l volatilize while watering a lawn, after contact with the s o i l , and during and after f i l l i n g a swimming pool.

NUS addressed a l l of these exposure pathways assuming lifetime exposure for individual being 70 years.

Evaluation of Exposure Pathways Assessed by NUS and Environ

NUS and Environ considered different exposure pathways in their respective risk assessments. While Environ considered the recreational pathways associated with Toms River and Winding River Park as the only relevant completed human exposure pathways, NUS also addressed the agricultural pathways and concluded that the agricultural pathways were the most important human exposure pathways.

Environ decided not to address the agricultural pathways because out of the fourteen private wells identified, only three out of the eleven wells sampled were shown to violate the standards or proposed standards developed under the EPA Safe Drinking Water Act. Of the three wells identified as containing violations, only one well was identified as being presently in use. Environ, therefore, concluded that the human exposure pathways associated with the agricultural wells were incomplete. Environ neglected to consider the potential future contamination of the agricultural wells from the plume migrating from the plant. Wells with the potential for contamination are being used for watering lawns and gardens, f i l l i n g swimming pools and washing cars. Environ should have considered the ingestion, dermal and inhalation exposure due to these uses, as they have the potential to be completed human exposure pathways.

NUS considered the human exposure pathways associated with the use of the agricultural wells for watering lawns and gardens and for f i l l i n g swimming pools. NUS also considered the possible ingestion of the well water. Although no restrictions are placed on the use of the water from the agricultural wells, i t seems unlikely that the wells would be used significantly as a source of drinking water since domestic water is supplied by the Toms River Water Company.

Both NUS and Environ considered the human exposure pathways associated with the recreational uses of Toms River and the marshland area of Winding River Park. NUS however did not consider the pathways associated with the dermal absorption and ingestion of surface water from the marshland area, or dermal absorption and ingestion of contaminated sediment from Toms River. NUS only considered dermal absorption and ingestion of surface water from Toms River and dermal absorption and ingestion of contaminated sediment from the marshland area. In light of the risk estimates calculated by NUS for the ingestion and dermal absorption of sediment from the marshland area, on the order of 10~6, the ingestion and dermal absorption of sediment from Toms River may be an important exposure pathway to examine.

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NUS calculated risk estimates for each individual chemical, and summed the result to give a total risk estimate for each exposure pathway. NUS then summed the total risk estimate for each exposure pathway to give the total risk estimate for a l l pathways, both agricultural and recreational. The end result was a total carcinogenic risk estimate for a l l pathways and a total chronic hazard index for a l l pathways. By summing the risk estimates for each chemical for each exposure pathway, NUS followed EPA "Guidelines for the Health Risk Assessment of Chemical Mixtures" (1986), which states that i f sufficient data are not available on the effects of chemical mixtures of concern or a reasonably similar mixture, the proposed approach is assumed additivity.

Environ, however, states that "the fact that the risk assessment process for each chemical tends to overestimate the risks for any one chemical is likely to compensate for any additive (or synergistic) effects among chemical mixtures." Environ decided not to follow EPA guidance and sum the risks of each chemical, but treated each exposure pathway for each chemical independently. Therefore, Environ did not arrive at a total carcinogenic risk estimate or a tota l chronic hazard index for a l l exposure pathways.

Other Potential Expsoure Pathways

There are potential completed human pathways of exposure which were not addressed by either NUS or Environ, which should be considered. In a door to door survey conducted by Ciba-Geigy in August 1986, residents identified one of the uses of the water from the agricultural wells as the watering of lawns and gardens. Persons who grow their own f r u i t or vegetables at home may experience additional exposure from the ingestion of food grown in contaminated soils with contaminated water. Chemicals that tend to bioaccumulate in plants may cause exposure to contaminant concentrations that are many times greater than those present in the s o i l or water. Due to this bioaccumulation, the ingestion of contaminated f r u i t s and vegeatables has the potential to be an important exposure pathway. Another use of the agricultural well water identified by the residents is the washing of cars. Persons who wash their cars with the well water are exposed via dermal absorption of the water and inhalation of volatilizing organics from the water. Since NUS calculated a carcinogenic risk estimate of 34 x 10~6 for the inhalation of contaminants from sprayed agricultural water, i t is conceivable that the inhalation of volatizing organics from washing a car could be an important exposure pathway.

Athough both NUS and Environ addressed the potential exposure due to the inhalation of contaminated air from the marshland area and Toms River, the potential migration of the contaminated air to the residential communities was not considered. NUS calculated the carcinogenic risk estimates for the inhalation of contaminated air from the marshland and from the Toms River to be 240 x 10~6 and 2.8 x 10~6, respectively. These risk estimates were calculated assuming exposure to the air for 8 hours a day, two days a week for 30 weeks a year for 70 years. Although the air concentration of the volatile chemicals decreases as the air migrates from the marshland area and Toms

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River, the exposure time would potentially increase to 24 hours a day, 365 days a year over a 70 year lifetime as the contaminated air moved into the residential areas. Although the dispersion w i l l decrease the air concentra­tions, the increase in the duration and area of exposure could result in a significant risk to the population. The possible migration of the contaminated air from the marshland and Toms River to the surrounding residential areas should be examined more closely to determine i f i t w i l l result in a significant completed human exposure pathway.

Neither NUS nor Environ addressed the potential for airborne particulates to migrate from the contaminated plant to the adjacent residential and recreational areas. Data should be presented on the wind speeds and directions in the vici n i t y of the site along with the possibility of airborn migration. The potential for inhalation of the contaminated airborn particulates should be analyzed to determine i f i t is a completed human exposure pathway.

Although the risk assessments conducted by NUS and Environ deal with the population of the community in general, susceptible subgroups of the population or those potentially subject to greater exposure were not considered. The vic i n i t y of the plant is known to contain several retirement communities. NUS and Environ should have addressed the potential for the elderly to be more susceptible to the effects caused by the exposure to contaminants migrating from the plant site. The elderly are known to have deterioration of the immune system which could lead to increased chronic effects and possibly shorter latency periods for the development of cancer. NUS and Environ did not consider other high risk groups such as women of childbearing age, the chronically i l l and infants.

Both NUS and Environ failed to address the potential exposure to the employees at the plant who may reside in the affected communities. Data on employees at the plant who reside in the area is not presented. Employees who reside in communities that may be at risk, may be at a much greater risk due to their increased exposure. Workers at the site (remedial workers are not included) may have direct dermal contact with contaminated soils, accidental ingestion of contaminated soils, and inhalation of contaminated air.

Although NUS and Environ addressed the potential for accidental s o i l ingestion, neither NUS nor Environ considered the potential exposure pathway of soil consumption by a very young child. Very young children may eat contaminated so i l from yards watered with the agricultural well water. Since the accidental ingestion of so i l from the marshland area was calculated by NUS to have a risk of 3.2 x 10~6, i t is conceivable that the risk to very young children from the consumption of contaminated s o i l may be significant.

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RECOMMENDATIONS

Demographic information on the populations living in Toms River and especially those living near the site are missing in both reports. This information is especially needed to determine the populations at highest risk of exposure from the contaminants. Although the reports provide general background information i.e., census data for the area, the demographic information is needed to characterize the community actually affected.

The reports should be expanded to provide background information on the sections of Dover Township not affected by this particular site. For example, i t is not clear where other manufacturing sites, communities, the ocean, etc. are located in Dover Township. This information would be necessary to understand other possible sources of exposure.

The maps provided in both assessments were of poor quality in many cases. The Subgroup suggests providing better maps of the Winding River Park, Dover Township i t s e l f , and the surrounding communities. These maps would be useful to better understand the area.

The reports should be expanded to characterize the Toms River in terms of velocity, depth, etc. Without this information i t is d i f f i c u l t to visualize the potential uses of the river by residents. In addition, i t is d i f f i c u l t to understand the interactions between the river and the aquifers and potential sources of contamination.

Both reports need to address the concerns raised by the U. S. Geological Survey in the mapping of the aquifers and aquitards. In addition, the reports should also provide more detailed information on the Toms River Water Company wells and the potential impact of the Ciba-Geigy contaminants on this water supply.

Since this is a Superfund site the analysis concentrated specifically on the exposures from this site. However, numerous other sources of exposure are possible including: air pollution from other plants in the area, occupational exposures, etc. These possible exposures should be considered in analyzing contaminants from the site since they might make the population more sensitive.

The report was vague in describing the fishing in the river. Specifically, the reports indicated that trout (fresh water) were stocked in the river and that crabs (? salt water) were also caught. Since fish are considered as a potential source of contaminants, the fish population and numbers of each species should be better characterized.

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The NUS report considered spray from the hose and volatilization from the soil as possible routes of exposure. The routes of exposure should be expanded to consider growing and consumption of vegetables grown in that s o i l . This is especially important since many contaminants bioaccumulate and biomagnify in plants and vegetables.

Both reports consider the primary exposure w i l l occur during the months of June, July and August. Since the park has a wide variety of activities, i.e., equestrian t r a i l s , etc. the number of months assumed that the park is used should be expanded.

The exposure routes for children assumes that the child playing w i l l be 9 years old (i.e., the average of a 6 and 12 year old child). Since many of the children playing in the park might take younger brothers and sisters with them and also families with younger children w i l l be using the park, the younger child ( i . e . , 1 to 5 years old) should be considered as an exposed population.

The months the individual is exposed while gardening should be expanded to include April, May and September since many people plant seedlings early in the Spring and also since many people prepare the s o i l for future plantings in the Fall.

The reports indicate that children w i l l play in the park three days/week during the summer months. This should be expanded since many children w i l l spend more time ( i . e . , 5 to 7 days/week) in the park during the summer. In addition, the park also offers a number of other activities during the winter where children might be exposed.

The Cardinal Drive Area may be an adult community ( i . e . , members must be 55 years or older). A recent report by Baker and Roull indicates that senior citizens are a sensitive population since aging can affect a number of systems including the immune response, kidney function, etc. Although the Agency has not yet developed specific guidance on the consideration of this population i t is important that in this particular risk assessment special consideration should be given to this group.

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IX. CONCLUSIONS

Based on the analysis of both risk assessment the Subgroup has reached the following conclusions:

0 The level of Quality Assurance of the data used in the Environ risk assessment is undefined. In addition, the assessment was poorly constructed making i t d i f f i c u l t y for the reviewers to understand how the fi n a l risk numbers were determined. On this basis the Subgroup did not accept the conclusions drawn from this report.

° The NUS risk assessment provided a much better presentation of the data used to develop their assessment. However, the risk calculations were extremely high. As indicated in the Recommendations section a number of the estimates could be modified which might impact specific risk calculations. However, the Subgroup does not anticipate that total risk number would be significantly affected.

The Subgroup raised concerns that many of the people affected in the Cardinal Drive Area are senior citizens and therefore more sensitive. In addition, some of these residents might have occupational exposure from other chemical plants in the area. Considering these other routes of exposure and the sensitivity of the populations the Subgroup considers the high risk number w i l l be protective of health.

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Attachment I : Topography and Hydrogeology of Site

TOPOGRAPHY. The topography of the site is f l a t but drops off sharply toward the Toms River in the northeastern sector of the property. The Toms River forms the northeastern boundary of the site. Winding River Park, an outdoor recreational area situated on the floodplain of the Toms River, adjoins the site on the east and southeast. The site is bounded on the west by an industrial park, and on the south by residential and commercial properties. Major residential developments, including two planned retirement communities, are located one mile south of the site. The business d i s t r i c t of the town of Toms River lies three miles southeastward of the site (CAI, 1983)

HYDROGEOLOGY. Studies performed by a subcontractor AWARE, Inc. (Aware, 1986) have defined the southern portion of the contaminated groundwater plume to be migrating from the site beyond the property boundaries in the Cardinal Drive area of the Oak Ridge Subdivision. The northern portion of the plume, comprised largely of volatile organic contaminants, is migrating towards the Toms River. This plume passes beneath the active channel of the Toms River and discharges to the flood plain on the east bank of the River (Aware, 1986).

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Attachment I I . Waste Generation and Storage.

Manufacturing processes at Ciba-Geigy generate both liquid and solid wastes. Table V provides a selected inventory of chemicals used by Ciba-Geigy or disposed of as waste by-products (CAI, 1983). Liquid wastes are treated prior to discharge to the Atlantic Ocean. Solid wastes, consisting of residues from manufacturing processes and sludges from on-site wastewater treatment are disposed of either in bulk or in drums in on-site l a n d f i l l s . Since 1977, the Active Landfill has been relied upon as the only State-permitted on-site repository for solid wastes.

In the past, known disposal areas for chemical wastes at Ciba-Geigy included: backfilled lagoons, drum disposal area, lime sludge disposal area, filtercake disposal area, wastewater treatment plant, active l a n d f i l l , and former calcium sulfate disposal area. As known disposal areas these represent known or suspected sources of contaminant release from Ciba-Geigy into the groundwater.

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Attachment I I I . Description of Population.

Dover Township had a 1980 Census population of 64,455 residents, with a majority of the population residing east of the Garden State Parkway. Single-family residential neighborhoods to the south and east of the site have populations of 900 and 1,800 people, respectively. A retirement community is located three miles north of the site and a residential development of 180 units is located less than one half mile north of the site across the Toms River. Manchester Township to the west of the Ciba-Geigy site had a population of 27,927 in 1980. A large single-family residential development of 4,500 people, Pine Lake Park, lies within one mile of the northwest of the site. In 1980, the census population of Berkeley Township, south of the Ciba-Geigy site was 23,151, with a majority of the population residing in developments west of the Garden State Parkway and one mile south of the site. Two retirement communities, Silver Ridge and Holiday City, located within these residential areas have populations totalling 9,000. Residential areas of Dover Township are supplied with municipal water from the Toms River Water Company which maintains 20 supply wells to the northeast of Ciba-Geigy.

Winding River Park, a Green Acres site maintained by Dover Township, is a recreational complex providing public access to playground and picnic f a c i l i t i e s , extensive hiking and bicycling paths and canoeing in the Toms River. Recreational uses of the Toms River including bathing, boat and bank fishing and crabbing, canoeing, sailing and power boating, water skiing and additional bank uses such as concerts, picnicking and hunting. Recreational uses of the river are broadly divided according to the upper and lower section of the river.

Potential sources of contamination for Toms River residents include contaminated wells and seepage of contaminants into the Toms River and adjacent marshlands.

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Attachment IV. Routes of Contamination and Identified Contaminants.

The routes of contamination and identified contaminants listed in the Remedial Investigation are listed below by media.

Groundwater was found to be the medium primarily affected by contamination at the site. The RI identified two major contaminant plumes, both extending from on-site areas to the Toms River which acts as an effective discharge zone. The northern plume extends northeastward to the river and discharges to the river and adjacent marsh areas located within the floodplain. Table I summarizes the contaminants detected by sampling analysis.

A southern plume extends eastward from the site through the northern portion of the Cardinal Drive community before being intercepted by the Toms River. Although this community receives its drinking water from the Toms River Water Company a number of residents utilize irrigation wells in the area which might serve as a potential source of exposure. Table I I summarizes the contaminants detected by sampling analysis.

Soil analyses indicated the presence of several organic compounds and also heavy metals including mercury in the vicinity of the filter cake disposal area. No evidence was found to indicate that contaminants have migrated off-site through surface runoff and air-borne dust.

Surface Water and Sediment Sampling was conducted in the Toms River and also in the marsh area located between the river and the northeastern section of the Cardinal Drive community. Analysis of surface water samples indicated only trace quantities of trichloroethene in downstream samples. Sediment samples indicated trace quantities of chlorobenzene and benzene in downstream samples. Analyses of marsh surface water and sediment samples indicated the presence of organic volatiles which are believed to be from the groundwater discharging to the area.

Air sampling was not performed either on or off site with the exception of health and safety monitoring of NUS personnel during field activities. Air sampling was conducted in the marsh area and indicated an increased concentration of volatile organic compounds in the marsh area on the days sampled.

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Attachment V. Assumptions Used in Risk Assessments.

To project the possible routes of exposure over a 70 year lifetime, both NUS and Environ developed a number of exposure assumptions. Use of these assumptions allows the risk assessor to more closely approximate the actual risk from specific chemicals or routes of exposure.

A catalogue of the assumptions developed by each contractor is provided below. The assumptions are grouped according to the general and specific categories.

NUS.

General Assumptions

° The carcinogenic risks and noncarcinogenic effects for projected future site conditions assumes no remedial activities occur at the site.

° Two major contaminant plumes were identified from on-site source areas to the Toms River where the river channel acts as an effective discharge zone. The Northern plume extends northeastward to the river. The Southern plum extends eastward from the Drum Disposal area passing through the Filter Cake Area and the Northern Portion of the Cardinal Drive community before intercepting the Toms River.

° The indicator chemicals represent the highest ranked chemicals in both plumes.

° Mean concentration is the arithematic mean of a l l samples within a media.

° Compounds for which carcinogenic and/or noncarcinogenic effects are not classified cannot be quantitatively scored or ranked and therefore are not considered.

0 The pathways are projected to be completed at some time in the future assuming no remedial activities occur at the site and the exposure will continue for a person's lifetime (i.e., 70 years).

° The risk estimates for each specific chemical should be added together to develop a total risk calculation.

0 Quantitative health evaluation does not evaluate or quantitate any emissions that were not covered by the remedial investigation i.e., routine plant emissions in compliance with N. J. State and Federal guidelines.

° If agricultural wells are capped then the carcinogenic risk to 280 x 10E-6 and the chronic risk would be reduced to 5.8

Sources of Contamination.

° Sources of past contaminant release include the backfilled lagoons, drum disposal area, lime sludge disposal area, filtercake disposal area, waste water treatment plant, active landfill, and former calcium sulfate disposal area.

0 Current potential sources of release include: the production area, compactor area, former fire prevention training area, and waste­water treatment plant pipline.

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Exposure

° Primary pathways of concern for human exposure is the Cardinal Drive Plume/Plume 1 and the upwelling at the marshland.

° Secondary pathways, the Northern Plume/Plume 3 identified flows to the Toms River shoreline along the northeastern plant boundary.

0 A zero value was used to calculate the mean for each compound reported either below the analytical laboratory's quantitative limit or below the instrument detection limit.

° Wells in the Cardinal Drive Area were used for agricultural purposes, i.e., watering lawns and gardens, filling of swimming pools and possible ingestion. All uses do occur and will continue to occur in the future.

° The wells are located on private property and therefore i t is not possible to force owners to cap these wells. Therefore, the wells will remain as a potential source of contamination.

° Exposure routes for agricultural use include:

- Ingestion of agricultural water and/or soil - Dermal absorption of pool water - Dermal absorption of contaminants from agricultural soil - Inhalation of contaminated air from sprayed water - Inhalation of contaminated air from soil

- Inhalation of contaminated air from pool water

° Exposure routes for recreational use include:

- Ingestion of surface water from Toms River - Ingestion of sediment in marshland - Ingestion of fish from Toms River - Dermal absorption of surface water from Toms River - Dermal absorption of contaminants from sediments in the marshland - Inhalation of contaminated air from Toms River - Inhalation of contaminated air from marshland

° Water usage assumed for a sprinkler system operating at a flow rate of 2.0 gallons/minute for 8 hrs/day, three days a week for 17.5 weeks. Total volume of water sprayed on a 7.5 meter radium, 5xlOE-02 meter deep soil would be 190,784.75 liters. Assuming average soil bulk density for sandy soil with low organics is 1.50 gm/cubic centimeters. The mass soil over which the water is sprayed is 13,254 kg.

° All indicator chemicals are carried into the sprinkler system and are retained in the soil.

° A box model was used to calculate an individual's exposure from water used to irrigate lawns or an individual is exposed to volatiles released from the saturated surface.

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° Groundwater is continually saturated during the time of exposure and as a result of the amount of contaminants present is constant.

° Contaminated well water from the Cardinal Drive Plume is used to f i l l - u p swimming pools in residential areas.

° Ingestion of agricultural water assumes drinking 1 l i t e r of water/day for 8 months a year for a lifetime of 70 years for a 70 kg person.

° Inhalation exposure from sprayed and volatilizing wet s o i l for a 70 kg individual would occur for 1 hr/day, 3 days/week for 30 weeks/year over a 70 year lifetime. Lifetime exposure would result in 100% absorption.

° I n i t i a l contaminant concentrations in pool were assumed to be those from Plume 1.

° Contaminants were i n i t i a l l y found only in pool water. No contaminants in the air or gas phase.

° Contaminant concentrations in the pool are the same as the contaminant concentrations in the Cardinal Drive groundwater plume.

° Dermal absorption of pool water assumes exposure to the water for 3 hrs/day 3 days/week for the months of June, July and August for 70 years. The body w i l l be immersed 80% and 12% of organic compounds w i l l be absorbed through the skin.

° Toms River model assumes the turbulent effects generated from the movement of the water was minimal.

° A l l contaminants exist in the river water with more found in the air or gas phase.

° Contaminants were i n i t i a l l y found only in the marsh waters, no contaminants existed in the air or gas phase.

° Over a lifetime an individual would be exosed to the s o i l 1,180 times which includes 660 times, 2 days/week for 30 weeks a year for 11 years (i . e . , age from 6 to 17 years). As an adult the persons would be exposed 10 times a year for 52 years totaling 520 exposures at the marsh over this time period.

° In the marshland, 100% of ingested contaminants would be absorbed. The child would ingest 5xlOE-05 kg/day and the adult 4.8xlOE-0-4 kg/day on any day of exposure.

° A l l f i s h coming from the Toms River are contaminated. A child would ingest 3.25 grams of fish per day, 365 days/year for 14.5 years while the adult would ingest 6.5 grams of fish per day, 365 days/year, for 52 years.

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ENVIRON.

General Considerations

0 Current exposure would continue indefinately. Remedial action at the site was not assessed as part of the risk assessment.

0 The risk assessment is based on those chemicals both identified and quantified using currently accepted procedures.

° Cohansey Sand Formation serves as a significant aquifer in the Toms River region.

° Purge well system already in place w i l l capture contaminants migrating from the area of the l a n d f i l l . I t takes 7 years for contaminants to downgradient from the purge well system to the marshland where they are naturally flushed.

° Drinking water is provided by the Toms River Water Company. The Toms River Water Company wells are not contaminated.

Well Contamination

° Three of the fourteen wells in a four block radius from the old storage area are contaminated. Only 13 wells were sampled since one property owner would not allow sampling.

° The wells are used primarily for agriculture including watering lawns, vegetable gardens, f i l l i n g swimming pools, etc. The wells are not used for drinking water since residents rely on the Toms River Water Company for drinking water.

° Of the three contaminated wells: one is sealed, one has not been used since 1985, and one is used only for watering lawns.

° Ciba-Geigy plans to identify and seek closure of potentially affected wells thereby preventing future routes of exposure.

° Therefore, water from the contaminated wells are discounted as a potential route of exposure.

Recreational Exposure

° Contaminants discharge to the:

- marshland area of Winding River Park and - Toms River along the reach that borders the plant site.

° Pine Lake Park is upgradient and therefore unaffected by existing contaminants.

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° Other sources of contamination include seeps into the Toms River and the marshland on the flood plains in the Winding River Park Area.

° Principal routes of exposure at the recreational area include ingestion of contaminated soil, ingestion of contaminated surface water from the river and marshland, ingestion of fish from the Toms River, and inhalation of volitilized contaminants from the Toms River and the marshland.

° Primary exposures will occur during recreational use of the river and surrounding marshlands.

° No priority pollutants at concentrations above the method of detection limit were identified. River sediments are far below toxic levels for aquatic organisms. Therefore, there will be no adverse impact on aquatic organisms.

Populations Exposed

° Exposure was calculated for a 9 year old child (average of a 6 to 12 year old) playing in the marshland area of Winding River Park. The child is expected to play 210 times over a 7 year period and the child will ingest 100 mg of contaminated soil each time he plays in the marsh. All contaminants will be absorbed.

° This child will also expose 1/2 of his body surface to soil and sediment in the playing area and also ingest 5 ml of surface water while playing and absorb 100% of contaminants. The child will also inspire contaminants for 2 hrs/day and 100% of inspired contaminants will be absorbed into the blood stream.

° Fisherpersons (i.e., 18 to 70 years old) will expose 1/2 of their body surface to soil and sediment and ingest 10 mg of soil each time they fish. The fisherpersons will fish 30 times/year for 52 years.

° Fish consumption was calculated for a family of five including 1 male, 1 female, 1 9 year old child, 1 1 to 4 year old child, and 1 15 year old child. Fish from the Toms River will be consumed at a rate of 6.5 grams/day for 365 days/year over a 70 year lifetime.

° Potential exposure from accidental ingestion of soil contaminants or dermal absorption of contaminants from soil is not expected to result in adverse effects.

° Toms River is not appreciably contaminated.

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° Other sources of contamination include seeps into the Toms River and the marshland on the flood plains in the Winding River Park Area.

0 Principal routes of exposure at the recreational area include ingestion of contaminated soil, ingestion of contaminated surface water from the river and marshland, ingestion of fish from the Toms River, and inhalation of volatilized contaminants from the Toms River and the marshland.

° Primary exposures will occur during recreational use of the river and surrounding marshlands.

° No priority pollutants at concentrations above the method of detection limit were identified. River sediments are far below toxic levels for aquatic organisms. Therefore, there will be no adverse impact on aquatic organisms.

Populations Exposed

° Exposure was calculated for a 9 year old child (average of a 6 to 12 year old) playing in the marshland area of Winding River Park. The child is expected to play 210 times over a 7 year period and the child will ingest 100 mg of contaminated soil each time he plays in the marsh. All contaminants will be absorbed.

° This child will also expose 1/2 of his body surface to soil and sediment in the playing area and also ingest 5 ml of surface water while playing and absorb 100% of contaminants. The child will also inspire contaminants for 2 hrs/day and 100% of inspired contaminants will be absorbed into the blood stream.

° Fisherpersons (i.e., 18 to 70 years old) will expose 1/2 of their body surface to soil and sediment and ingest 10 mg of soil each time they fish. The fisherpersons will fish 30 times/year for 52 years.

° Fish consumption was calculated for a family of five including 1 male, 1 female, 1 9 year old child, 1 1 to 4 year old child, and 1 15 year old child. Fish from the Toms River will be consumed at a rate of 6.5 grams/day for 365 days/year over a 70 year lifetime.

° Potential exposure from accidental ingestion of soil contaminants or dermal absorption of contaminants from soil is not expected to result in adverse effects.

° Toms River is not appreciably contaminated.

° Table 6 summarizes potential exposure scenarios.

CIB ©06 1629

Table la. Total No Action Carcinogenic Risks for Completed Agricultural Pathways.

^ r Carcinogenic Route of Exposure Risk x 10E-6

Ingestion of Agricultural Water 2300

Dermal Absorption of Pool Water 0.020

Inhalation Exposure from Sprayed Agricultural Water 34

Inhalation Exposure for Volatilizing Wet Soil 130

Inhalation Exposure from Pool Water 8.9

TOTAL RISK (PER MILLION POPULATION) 2500xlOE-06

Table lb. Total No Action Carcinogenic Risks For Completed Recreational Pathways.

Carcinogenic

Exposure Routes Risk x 10E-06

Ingestion of Surface Water from the Toms River 0.02

Ingestion of Marshland Sediment 3.2

Ingestion of Fish Which Inhabit the Toms River 33

Dermal Absorption of Surface Water from the Toms River 0.0029

Dermal Absorption of Marshland Sediment 1.2

Inhalation Exposure from Contaminated Air from the Toms River 2.8

Inhalation Exposure from Contaminated Air from the Marshland 240

TOTAL RISK (PER MILLION POPULATION) 280X10E-06

CIB 006 1631

Table 2a. Total No Action Chronic Hazards for Completed Agricultural Pathways

Route of Exposure Total Chronic Hazard

Ingestion of Agricultural Water

Dermal Absorption of Pool Water

Inhalation Exposure from Sprayed Agricultural Water

Inhalation Exposure from Volatilizing Wet Soil

Inhalation Exposure from Pool Water

4.2

6.2xlOE-05

0.81

3.6

0.21

TOTAL CHRONIC HAZARD (CDI) (AIC)

8.8

Table 2b. Total No Action Chronic Hazard for Completed Recreational Pathways

Exposure Pathways Chronic Hazard

Ingestion of Surface Water from the Toms River

Ingestion of Marshland Sediment

Ingestion of Fish Which Inhabit the Toms River

Dermal Absorption of Surface Water from the Toms River

Dermal Absorption of Marshland Sediment

Inhalation Exposure from Contaminated Air from the Toms River

Inhalation Exposure from Contaminated Air from the Marshland

2.5xlOE-5

4.2xlOE-3

5.0xlOE-2

2.2xlOE-6

4.0xlOE-4

3.9xlOE-3

5.7

TOTAL CHRONIC HAZARD (CDI) (AIC)

5.8

C I B 006 1632

Table 3. Total Carcinogenic Risk and Total Chronic Hazard

Exposure Carcinogenic Chronic Pathways Risk Hazard

Agricultural 2500 8.8

Recreational 280 5.8

TOTAL RISK 2800 (PER MILLION POPULATION)

TOTAL CHRONIC HAZARD (CDI) 15 (AIC)

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Table 4. List of Chemicals Found Off-Site

Volatiles Semi-Volatiles Pesticides Inorganics

Benzene Aniline 4,4-DDE Aluminum Chlorobenzene Benzoic Acid Endosulfan I I Antimony Chloroform Benzyl Alcohol Dieldrin Arsenic 1,2-Dichloroethane Di-N-Butylphthalate Chlordane Barium 1,1-Dichloroethene Bis(2-Chloroethyl)Ether Aroclor 1016 Beryllium Ethylbenzene 4-Chloroaniline Ar color 1221 Cadmium Toluene 4-Chloronapthalene Aroclor 1232 Calcium Trans-1,2-Dichloroethene 2-Chlorophenol Aroclor 1242 Chromium 1,1,1-Trichloroethane 1,2-Dichlorobenzene Aroclor 1248 Cobalt 1,1,2,2-Tetrachloroethane 1,3-Dichlorobenzene Aroclor 1254 Copper Tetrachloroethene 1,4-Dichlorobenzene Aroclor 1260 Iron Trichloroethene Bis(2-Ethylhexyl) Lead Vinyl Chloride 4-Chloroani1ine Lithium Total Xylenes 2-Chloronapthalene Magnesium Acetone 2-Chlorophenol Maganese 2-Butanone 1,2-Dichlorobenzene Mercury Carbon Disulfide 1,3-Dichlorobenzene Nickel Chloromethane 1,4-Dichlorobenzene Potassium 2-Hexanone Bis(2-Ethylhexy1)Phthalate Sodium Methylene Chloride Napthalene Tin 4-Methyl-2-Pentanone 4-Methylphenol Silver Styrene Nitrobenzene ' Vanadium

Di-N-Octyl Phthalate Phenol 1,2,4-Trichlorobenzene 2-Methylphenol Anthracene Butyl Benzyl Phthalate Fluoroanthene Phenanthrene Chrysene Benzo(b)Fluoroanthene Benzo(k)Fluoroanthene

CIB ©06 1634

Table 5. Selected Inventory of Chemicals Used by Ciba-Geigy or Disposed of As Waste By-Products (CAI, 1983).

Closed Inactive Raw Active Chemical Filtercake Stack Ground

Chemical Material Landfill Landfill Disposal Area Emissions water Aldehydes and Ketones formaldehyde x X methyl isobutyl ketone *

paraformaldehyde X x(a)

Aliphatic Amines dimethylamine X monoethylamine X

monome thylamine X ethanolamine x(a)

Aromatic Amines aniline x * X dimethylani1ine *

4,4'-methylenedianiline * toluidines * x(a) diphenylamine *

1,4-phenylene diamine *

aniline hydrochloride *

3-chloroaniline * 4-chloroaniline *

2,5-dichloroaniline *

xylidine *

Benzene Derivatives benzene X * X ethylbenzene X * X X

toluene X * X X resorcinol X

Chlorinated Benzenes chlorobenzene X * X X X

1,2-dichlorobenzene * X X X

1,3-dichlorobenzene X

1,4-dichlorobenzene X

1,2,3-trichlorobenzene x(a) X

1,2,4-trichlorobenzene * X X chlorotoluene x(a)

Chlorinated Aliphatics 1,2-dichloroethane X X 1,1,1-trichloroethane *

chloroform X

trichloroethylene X

tetrachloroethylene X

1,2-transdichloroethylene X

Ethers and Epoxides anisole * epichlorohydrin X

C I B 006 1635

Table 5 Continued

Chemical Nitrobenzenes nitrobenzene 2-chlorobenzene 4-chloronitrobenzene

Closed Inactive Raw Active Chemical Filtercake Stack Ground

Material Landfill Landfill Disposal Area Emissions water

* * *

Phenolics 2-chlorophenol 2-nitrophenol phenol(phenols) cresol

trichlorophenol

x x X

* *

x(a)

x X (a)

Phthalate Esters di-n-butylphthalate diethylphthalate

Polycyclic Aromatics anthracene napthalene

Miscellaneous Organics phosgene

* *

x x

X X

Inorganics arsenic barium cadmium chromium copper cyanide iron lead manganese mercury nickel selenium silver zinc

x *

X *

X X

X X X *

X

X X X

X X X X

X X

X X

X X

Footnotes x » present * = present, but below the test limit of detectability. (a) = These air emissions data were taken from NJDEP, Bureau of Air Pollution Control,

Air Pollution Enforcement Data System Emissions Report.

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Table 6. Exposure Scenarios

Adult Adult Male Female 15 Yr Old 9 Yr Old 4 Yr Old

TOTAL LIFESPAN IN DAYS BODY WEIGHT (KG) AVERAGE BREATHING RATE (m3/hr)

25550 70

0.958

28105 58

0.875

25550 55

0.875

25550 31

0.625

25550 17

0.333

SOIL-INGESTION Amount Ingested (kg) 0.00001 Total time of ingestion (days) 1560 Fraction of time soil contaminated 1

0.0001 210

1

SOIL-DERMAL CONTACT Total Time of Contact (days) 0.000005 Total Time of Ingestion (days) 1560 Fraction of Time Water Contaminated 1

0.000005 210

1

WATER-DERMAL CONTACT Total Time of Contact (days) 1560 Amount of Water per Surface Area 0.000002

of Contact (kg/cm2) Surface Are of Contact (cm2) 9000

210 0.000002

4500

VAPORS-INHALATION * Presently available data are insufficient to model the concentrations of contaminants

in the air , thus the risk from inhalation of these vapors cannot be estimated.

FISH-INGESTION Amount ingested - Average (kg) 0.0065 0.065 0.0065 0.0065 0.0065 Total Time of Ingestion (days) 18980 20805 2555 2555 1460 Fraction of Time Fish Contaminated 1 1 1 1 1

CIB 006 1637

Attachment I I

REPORT QN REVIEW OF RISK ASSESSMENTS

The following hours were spent by Subgroup members on the review of the two risk assessments:

NAMFJ DIVISION NUMBER OF HOURS

Anne Marie Higham WMD 40 Steve Sambol AWM 35 Harvey Simon OPM 60 Marian Olsen OPM 60 Linda Comerci ERRD 60 Barbara Finazzo ESD 45 Larraine Koehler AWM 16 Stoyell Robbins WMD 20 Vinh Cam ERRD 10 Lisa Voyce WMD 8 Drew Barris WMD 6

TOTAL 360

These hours include time spent reviewing supporting documentation in preparation for the review of the risk assessment. We anticipate in the future that review of risk assessments from other divisions would require a similar investment of time since the Subgroup members would need to spend time becoming familiar with the source literature for the specific programs.

Science Subgroup Recommendations

Based on our experience reviewing the two risk assessments we offer the following recommendations with respect to the preparation and presentation of future risk assessments.

1« The Region should consider developing guidance or issuing a policy on how risk assessments should be conducted and presented by EPA contractors and responsible parties: Since NUS and Environ did not follow the same format for conducting the assessments, i t was not possible to compare the results of their hazard identification. I t is suggested that contractors submit a workplan ahead of time for EPA approval, similar to the OA project plan requirement that is currently i n effect in the Region. Contractors and responsible parties are required to submit a OA project plan to EPA for approval before sampling can occur. Most times this is included in their workplan and site operation plans. The same can be done for the risk assessments.

CIB 006 1638

-2-

2* A generic format for the presentation of data and conclusions in a risk assessment needs to be developed; In reviewira the WTC risk assessment, we found i t d i f f i c u l t to quickly locate many parts of the assessment i.e., assumptions, models used, methodologies, etc. I t was not possible to easily locate this material in the Environ report since the majority of the information needed was buried in the Appendices. Therefore, the Subgroup suggests the need for developing a specific document that w i l l provide guidance to contractors in presenting the data of a risk assessment.

3* Data used in making a risk assessment or public health evaluation needs to be Quality Assured/Quality Controlled; I f this data is not subject to OA/OC, there is no assurance that the numbers are in fact valid. Due to the uncertainty in many of the cancer numbers that are used in the risk assessment process, an additional source of uncertainty that can be prevented is unwarranted. Sound decisions cannot be made i f the data i t s e l f i s questionable.

4* The Subgroup also needs to develop a protocol for reviewing risk assessments; Based on our experience with these risk assessments, we plan to develop a checklist system to identify specific areas that should be covered in the assessment. This, along with the foregoing reccmmendations concerning the manner of presenting the risk assessment, should make i t easier to review future risk assessments.

5* One of the delays encountered in the current review was time needed to identify additional materials required in the review; The Subgroup w i l l also be developing a l i s t of materials that should be provided with each risk assessment submitted for review.

6* The Subgroup needs to develop better expertise in computer modeling of the air and water exposure; We suggest as a first- step o*t- ai giving ^ f ^ R t i ? n

on the various models used and identifying the assumptions and uses of these models.

Beyond these specific recommendations, there are basic issues related to the region's capability and capacity for peer review of risk assessments. These include:

A) The risk assessment review represented a substantial effort on the part of the Science Subgroup; and was found to be very time consuming. Many of the hours devoted to the review represented overtime and weekend work.

B) There is a need to develop mechanisms for including risk assessment activities in an individual's performance standards.

C) There is a need to identify a means by which those who participate in the reviews can receive credit for work completed during performance evaluations.

D) There is a need to supplement regional expertise for review of risk assessments in many areas (for example, fate and exposure modelling, groundwater modelling, ai r modelling, etc.).

CIB 006 1639