United States Environmental Protection Agency Office of Water Regulations and Standards Washington, DC 20460 Water June. 198? ------- PREFACE This document is one of a series of preliminary assessments dealing with chemicals of potential concern in municipal sewage sludge. The purpose of these documents is to: (a) summarize the available data for the constituents of potential concern, (b) 'identify the key environ- mental pathways for each constituent related to a reuse and disposal option (based on hazard indices), and (c) evaluate the conditions under which such a pollutant may pose a hazard. Each document provides a sci- entific basis for making an initial determination of whether a pollu- tant, at levels currently observed in sludges, poses a likely hazard to human health or the environment when sludge is disposed of by any of several methods. These methods include landspreading on food chain or nonfood chain crops, distribution and marketing programs, landfilling, incineration and ocean disposal. These documents are intended to serve as a rapid screening tool to narrow an initial list of pollutants to those of concern. If a signifi- cant hazard is indicated by this preliminary analysis, a more detailed assessment will be undertaken to better quantify the risk from this chemical and to derive criteria if warranted. If a hazard is shown to be unlikely, no further assessment will be conducted at this time; how- ever, a reassessment will be conducted after initial regulations are finalized. In no case, however, will criteria be derived solely on the basis of information presented in this document. ------- TABLE OP CONTENTS Page PREFACE i 1. INTRODUCTION . 1-1 2. PRELIMINARY CONCLUSIONS FOR VINYL CHLORIDE IN MUNICIPAL SEWAGE SLUDGE 2-1 Landspreading and Distribution-and-Marketing 2-1 Landfilling 2-1 Incineration 2-1 Ocean Disposal 2-1 3. PRELIMINARY HAZARD INDICES FOR VINYL CHLORIDE IN MUNICIPAL SEWAGE SLUDGE 3-1 Landspreading and Distribution-and-Marketing 3-1 Landf illing 3-1 Incineration 3-1 Index of air concentration increment resulting from incinerator emissions (Index 1) 3-1 Index of human cancer risk resulting from inhalation of incinerator emissions (Index 2) 3-4 Ocean Disposal 3-6 4. PRELIMINARY DATA PROFILE FOR VINYL CHLORIDE IN MUNICIPAL SEWAGE SLUDGE 4-1 Occurrence 4-1 Sludge 4-1 Soil - Unpolluted 4-1 Water - Unpolluted 4-1 Air 4-1 Food 4-2 Human Effects 4-2 Ingestion 4-2 Inhalation 4-3 Plant Effects 4-4 11 ------- TABLE OF CONTENTS (Continued) Page Domestic Animal and Wildlife Effects 4-4 Aquatic Life Effects 4-4 Soil Biota Effects 4-4 Physicochemical Data for Estimating Fate and Transport 4-4 5. REFERENCES 5-1 APPENDIX. PRELIMINARY HAZARD INDEX CALCULATIONS FOR VINYL CHLORIDE IN MUNICIPAL SEWAGE SLUDGE A-l ------- SECTION 1 INTRODUCTION This preliminary data profile is one of a series of profiles dealing with chemical pollutants potentially of concern in municipal sewage sludges. Vinyl chloride was initially identified as being of potential concern when sludge is incinerated.* This profile is a compi- lation of information that may be useful in determining whether vinyl chloride poses an actual hazard to human health or the environment when sludge is disposed of by this method. The focus of this document is the calculation of "preliminary hazard indices" for selected potential exposure pathways, as shown in Section 3. Each index illustrates the hazard that could result from movement of a" pollutant by a given pathway to cause a given effect (e.g., sludge •* air -*• human toxicity). The values and assumptions employed in these calculations tend to represent a reasonable "worst case"; analysis of error or uncertainty has been conducted to a limited degree. The resulting value in most cases is indexed to unity; i.e., values >1 may indicate a potential hazard, depending upon the assumptions of the calculation. The data used for index calculation have been selected or estimated based on information presented in the "preliminary data profile", Section 4. Information in the profile is based on a compilation of the recent literature. An attempt has been made to fill out the profile outline to the greatest extent possible. However, since this is a pre- liminary analysis, the literature has not been exhaustively perused. The "preliminary conclusions" drawn from each index in Section 3 are summarized in Section 2. The preliminary hazard indices will be used as a screening tool to determine which pollutants and pathways may pose a hazard. Where a potential hazard is indicated by interpretation of these indices, further analysis will include a more detailed exami- nation of potential risk.s as well as an examination of site-specific factors. These more rigorous evaluations may change the preliminary conclusions presented in Section 2, which are based on a reasonable "worst case" analysis. The preliminary hazard indices for selected exposure routes pertinent to incineration practices are included in this profile. The calculation formulae for these indices are shown in the Appendix. The indices are rounded to two significant figures. * Listings were determined by a series of expert workshops convened during March-May, 1984 by the Office of Water Regulations and Standards (OWRS) to discuss landspreading, landfilling, incineration, and ocean disposal, respectively, of municipal sewage sludge. 1-1 ------- SECTION 2 PRELIMINARY CONCLUSIONS FOR VINYL CHLORIDE IN MUNICIPAL SEWAGE SLUDGE The following preliminary conclusions have been derived from the calculation of "preliminary hazard indices", which represent conserva- tive or "worst case" analyses of hazard. The indices and their basis and interpretation are explained in Section 3. Their calculation formulae are shown in the Appendix. I. LANDSPREADING AND DISTRIBUTION-AND-MARKETING Based on the recommendations of the experts at the OWRS meetings (April-May, 1984), and assessment of this reuse/disposal option is not being, conducted at this time. The U.S. EPA reserves the right to conduct such an assessment for this option in the future. II. LANDFILLING Based on the recommendations of the experts at the OWRS meetings (April-May, 1984), and assessment of this reuse/disposal option is not being conducted at this time. The U.S. EPA reserves the right to conduct such an assessment for this option in the future. III. INCINERATION The concentration of vinyl chloride in air is not expected to increase above the background concentration when most vinyl chloride-contaminated sludges are incinerated. A slight increase above the background concentration is expected only when worst-case conditions prevail (see Index 1). The incineration of vinyl chloride-contaminated sludges will not, in most cases, increase the risk of cancer above the pre-existing risk attributable to background concentration. A potential increase in the risk of cancer (of about 1 per 100,000) is indicated only when worst-case conditions are assumed for all parameters (see Index 2). IV. OCEAN DISPOSAL Based on the recommendations of the experts at the OWRS meetings (April-May, 1984), and assessment of this reuse/disposal option is not being conducted at this time. The U.S. EPA reserves the right to conduct such an assessment for this option in the future. 2-1 ------- SECTION 3 PRELIMINARY HAZARD INDICES FOR VINYL CHLORIDE IN MUNICIPAL SEWAGE SLUDGE I. LANDSPREADING AND DISTRIBUTION-AND-MARKETING Based on the recommendations of the experts at the OWRS meetings (April-May, 1984), an assessment of this reuse/disposal option is not being conducted at this time. The U.S. EPA reserves the right to conduct such an assessment for this option in the future. II. LANDPILLlNG Based on- the recommendations of the experts at the OWRS meetings (April-flay, 1984), an assessment of this reuse/disposal option is not being conducted at this time. The U.S; EPA reserves the right to conduct such an assessment for this option in the future. III. INCINERATION A. Index of Air Concentration Increment Resulting from Incinerator Emissions (Index 1) 1. Explanation - Shows the degree of elevation of the pollutant concentration in the air due to the incinera- tion of sludge. An input sludge with thermal properties defined by the energy parameter (EP) was analyzed using the BURN model (Camp Dresser and McKee, Inc. (CDM), 1984). This model uses the thermodynamic and mass balance relationships appropriate for multiple hearth incinerators to relate the input sludge characteristics to the stack, gas parameters. Dilution and dispersion of these stack gas releases were described by the U.S. EPA's Industrial Source Complex Long-Term (ISCLT) dispersion model from which normalized annual ground level concen- trations were predicted (U.S. EPA, 1979).' The predicted pollutant concentration can then be compared to a ground level concentration used to assess risk. • 2. Assumptions/Limitations - The fluidized bed incinerator was not chosen due to a paucity of available data. Gradual plume rise, stack tip downwash, and building wake effects are appropriate for describing plume behavior. Maximum hourly impact values can be translated into annual average values. 3. Data Used and Rationale a. Coefficient to correct for mass and time units (C) = 2.78 x 10~7 hr/sec x g/mg 3-1 ------- b. Sludge feed rate (DS) i. Typical = 2660 kg/hr (dry solids input) A feed rate of 2660 kg/hr DW represents an average dewatered sludge feed rate into the furnace. This feed rate would serve a commun- ity of approximately 400,000 people. This rate was incorporated into the U.S. EPA-ISCLT model based on the following input data: EP = 360 Ib H20/mm BTU Combustion zone temperature - 1400°F Solids content - 28% Stack height - 20 m Exit gas velocity - 20 m/s Exit gas temperature - 356.9°K (183°F) Stack diameter - 0.60 m ii. Worst = 10,000 kg/hr (dry solids input) A feed rate of 10,000 kg/hr DW represents a higher feed rate and would serve a major U.S. city. This rate was incorporated into the U.S. EPA-ISCLT model based on the following input data: EP = 392 Ib H20/mm BTU Combustion zone temperature - 1400°F Solids content - 26.6% Stack height - 10 m Exit gas velocity - 10 m/s Exit gas temperature - 313.8°K (105°F) Stack diameter - 0.80 m c. Sludge concentration of pollutant (SC) Typical 0.43 mg/kg DW Worst 311.94 mg/kg DW The typical and worst case concentrations are the geometric mean and 95th percentile, respectively, statistically derived from sludge concentration data from a survey of 40 publicly owned treatment works (POTWs) (U.S. EPA, 1982). (See Section 4, p. 4-1.) d. Fraction of pollutant emitted through stack (FM) Typical 0.05 (unitless) Worst 0.20 (unitless) These values were chosen as best approximations of the fraction of pollutant emitted through stacks (Farrell, 1984). No data was available to validate 3-2 ------- these values; however, U.S. EPA is currently testing incinerators for organic emissions. Dispersion parameter for estimating maximum annual ground Level concentration (DP) Typical 3.4 Worst 16.0 ug/m3 The dispersion parameter is derived from the U.S. EPA-ISCLT short-stack model. f. Background concentration of pollutant in urban air (BA) = 43.316 Ug/m3 The average concentration of vinyl chloride in air within a 5 mile radius of a polyvinyl chloride or vinyl chloride plant was calculated to be 17 ppb (U.S. EPA, 1980). This value was used to calculate the concentration given above because it represents the expected air concentration where vinyl chloride is used in industry and would, thus, be a possible pollutant in sludge. This value was the only data immediately available. The value, 17 ppb, was converted to Ug/m3 of air by multiplying by the vapor density of vinyl chloride relative to air (Sax, 1984) and the appropriate unit conversions. (See Section 4, pp. 4-1 to 4-2.) 4. Index 1 Values Sludge Feed Fraction of - Rate (kg/hr DW)a Pollutant Emitted Sludge Through Stack Concentration 0 2660 10,000 Typical Typical Worst 1.0 1.0 1.0 1.0 1.0 1.0 Worst Typical 1.0 1.0 1.0 Worst 1.0 1.0 1.1 a The typical (3.4 ug/m^) and worst (16.0 ug/m3) disper- sion parameters will always correspond, respectively, to the typical (2660 kg/hr DW) and worst (10,000 kg/hr DW) sludge feed rates. 5. Value Interpretation - Value equals factor by which expected air concentration exceeds background levels due to incinerator emissions. 3-3 ------- 6. Preliminary Conclusion - The concentration of vinyl chloride in air is not expected to increase above the background concentration when most vinyl chloride- contaminated sludges are incinerated. A slight increase above the background concentration is expected only when worst-case conditions prevail. B. Index of Human Cancer Risk Resulting from Inhalation of Incinerator Emissions (Index 2) 1. Explanation - Shows the increase in human intake expected to result from the incineration of sludge. Ground level concentrations for carcinogens typically were developed based upon assessments published by the U.S. EPA Carcino- gen Assessment Group (CAG). These ambient concentrations - reflect a dose level which, for a lifetime exposure, increases the risk of cancer by 10~^. For non- carcinogens, levels typically were derived from the Amer- ican Conference of Government Industrial Hygienists (ACGIH) threshold limit values (TLVs) for the workplace. 2. Assumptions/Limitations - The exposed population is assumed to reside within the impacted area for 24 hours/day. A respiratory volume of 20 m-Vday is assumed over a 70-year lifetime. 3. Data Used and Rationale a. Index of air concentration increment resulting from incinerator emissions (Index 1) See Section 3, p. 3-3. b. Background concentration of pollutant in urban air (BA) = 43.316 Ug/m3 See Section 3, p. 3-3. c. Cancer potency = 1.74 x 10"^ (mg/kg/day)"^- The cancer potency value was derived from studies in which rats were exposed to a range of vinyl chloride levels in air. The effect of concern in these studies was hepatic angiosarcoma (U.S. EPA, 1980). (See Section 4, p. 4-2.) d. Exposure criterion (EC) = 0.20 ug/m^ A lifetime exposure level which would result in a 10~6 cancer risk was selected as ground level concentration against which incinerator emissions are compared. The risk estimates developed by CAG are defined as the lifetime incremental cancer risk in a hypothetical population exposed continuously 3-4 ------- throughout their lifetime to the stated concentration of the carcinogenic agent. The exposure criterion is calculated using the following formula: • _ 10"6 x 103 ug/mg x 70 kg t.C - — ^ Cancer potency x 20 mj/day 4. Index 2 Values Sludge Feed Fraction of Rate (kg/hr DW)a Pollutant Emitted Sludge Through Stack Concentration 0 2660 10,000 Typical Typical 220 220 220 Worst 220 220 220 Worst Typical 220 220 220 Worst 220 220 230 a The typical (3.4 ug/nr*) and worst (16.0 Ug/m3) disper- sion parameters will always correspond, respectively, to the typical (2660 kg/hr DW) and worst (10,000 kg/hr DW) sludge feed rates. 5. Value Interpretation - Value > 1 indicates a potential increase in cancer risk of > 10~6 (1 per 1,000,000). Comparison with the null index value at 0 kg/hr DW indicates the degree to which any hazard is due to sludge incineration, as opposed to background urban air concentration.' 6. Preliminary Conclusion - The incineration of vinyl chloride-contaminated sludges will not, in most cases, increase the risk of cancer above the pre-existing risk attributable to the background concentration. A poten- tial increase in the risk of cancer (of about 1 per 100,000) is indicated only when worst-case conditions are assumed for all parameters. IV. OCEAN DISPOSAL Based on the recommendations of the experts at the OWES meetings (April-May, 1984), an assessment of this reuse/disposal option is not being conducted at this time. The U.S. EPA reserves the right to conduct such an assessment for this option in the future. 3-5 ------- SECTION 4 PRELIMINARY DATA PROFILE FOR VINYL CHLORIDE IN MUNICIPAL SEWAGE SLUDGE I. OCCURRENCE A. Sludge B. 1. Frequency of Detection 33 of 477 samples (7%) from 50 POTWs contained detectable levels of vinyl chloride 2. -Concentration For 13 POTWs reporting analyses for vinyl chloride, the following results were found: Minimum: not detected not detected 0.43 mg/kg DW 69.82 mg/kg DW 311.94 mg/kg DW 686.54 mg/kg DW Median: Geometric mean: Arithmetic mean: 95th percentile: Maximum: Soil - Unpolluted Vinyl chloride does not occur in nature. U.S. EPA, 1982 (pp. 42, 50) Values statistically- derived from U.S. EPA, 1982 C. Hater - Unpolluted No evidence of vinyl chloride in unpolluted environments D. Air 1. Frequency of Detection • Data not immediately available. 2. Concentration a. Urban The average concentration within a 5-mile radius of a polyvinyl chloride or vinyl chloride plant was calculated to be 17 ppb. NAS, 1977 (p. 783) U.S. EPA, 1980 (p. C-2) U.S. EPA, 1980 (p. C-54) 4-1 ------- 17 ppb was converted to 43.316 by using the vapor density of 2.15 for vinyl chloride relative to Sax» 1984 air and appropriate unit conversions. b. Rural Data not immediately available. E. Food 1. Total average intake Data not immediately available. 2. - Concentration Vinyl chloride has been found in foods U.S. EPA, 1980 packaged in polyvinyl chloride wraps (p. C-7) and containers, especially alcoholic beverages, oils, and cider or vinegar. Product Type Range (ug/mL) Alcoholic beverages 0.025 to 1.60 Vegetable oil 0.3 to 3.29 Cider or vinegar ND to 8.40 II. HUMAN EFFECTS A. Ingestion 1. Carcinogenicity a. Qualitative Assessment Data for humans are not immediately U.S. EPA, 1980 available, but at least one study (p. C-36) using rats indicates that vinyl chloride is carcinogenic when ingested. b. Potency Cancer Potency = 1.4 x 10"1 U.S. EPA, 1984 (mg/kg/day)'1 (p. 35) c. Effects In the study using rats, U.S. EPA, 1980 angiosarcomas of the liver and (p. C-36) thymus gland were noted. 4-2 ------- 2. Chronic Toxicity Data not presented because cancer potency will be used to assess hazard. 3. Absorption Factor Data not immediately available. 4. Existing Regulations Interim U.S. EPA target risk levels and U.S. EPA, 1980 the corresponding water quality criteria (p. C-61) (assuming average daily consumption of 2 L drinking water and 6.5 g of fish and shellfish) Risk Level Criteria (yg/L) 10~7 0.2 10~6 2.0 ID'5 20 B. Inhalation 1. Carcinogenicity a. Qualitative Assessment Viny chloride has been shown to be U.S. EPA, 1984 carcinogenic when inhaled. b. Potency Cancer potency = 1.74 x 10~2 U.S. EPA, 1980 (mg/kg/day)"1 (p. C-82) c. Effects Vinyl chloride has caused significant U.S. EPA, 1984 increases in the incidence of hepatic (p. 12) angiosarcomas, and has been implicated as a causal factor in increased incidences of lung, brain, breast, pancreatic, and other tumors among polyvinyl chloride and vinyl chloride workers. 4-3 ------- 2. Chronic Toxicity a. Inhalation Threshold or MPIH 10 mg/m3 time weighted average (TWA) b. Effects Angioneurosis, dermatitis, acro- osteolysis, hepatomegaly, spleno- megaly, liver fibrosis, thrombocyto- penia, and others 3. Absorption Factor In rats, vinyl chloride has been reported to be absorbed rapidly from the lungs into the bloodstream. 4. Existing Regulations 10 mg/m3 TWA 2.6 mg/m3 8-hour TWA 13 mg/m3 average over any period <15 minutes III. PLANT EFFECTS Data not immediately available. IV. DOMESTIC ANIMAL AND WILDLIFE EFFECTS Data not immediately available. V. AQUATIC LIFE EFFECTS Data not immediately available. VI. SOIL BIOTA EFFECTS Data not immediately available. American Conference of Governmental Industrial Uygienists (ACGIH), 1983 U.S. EPA, 1984 (p. 7) U.S. EPA, 1984 (p. 2) ACGIH, 1983 Occupational Safety and Health Admini- stration (Code of Fed. Reg., 1981) as cited by U.S. EPA, 1984 (p. 30) 4-4 ------- VII. PHYSICOCHEMICAL DATA FOR ESTIMATING FATE AND TRANSPORT Chemical composition: Molecular weight: Vapor density relative to air: Water solubility: CH2CHC1 62.5 2.15 2760 mg/L at 25°C 1100 mg/kg at 28°C Octonol/water partition coefficient: 24 (estimated) Bioconcentration factor: Half-life Air: - Water: 2.97 (estimated) 1.2 days 1 to 5 days (estimated) Sax, 1984 U.S. EPA, 1984 U.S. EPA, 1984 U.S. EPA, 1984 U.S. EPA, 1984 4-5 ------- SECTION 5 REFERENCES American Conference of Governmental Industrial Hygienists. 1983. Threshold Limit Values for Chemical Substances and Physical Agents in the Work Environment with Intended Changes for 1983-84. Second Printing. ACGIH, Cincinnati, OH. 93 pp. Camp Dresser and McKee, Inc. 1984. Development of Methodologies for Evaluating Permissible Contaminant Levels in Municipal Wastewater Sludges. Draft. Office of Water Regulations and Standards, U.S. Environmental Protection Agency, Washington, D.C. Farrell, J. B." 1984. Personal Communication. Water Engineering Research Laboratory, U.S. Environmental Protection Agency, Cincinnati, OH. December. National Academy of Sciences. 1977. Drinking Water and Health. National Academy of Sciences, Washington, D.C. 939 pp. Sax, N. I. 1984. Dangerous Properties of Industrial Materials. Sixth Edition. Van Nostrand Reinhold Co., Inc., New York, NY. U.S. Environmental Protection Agency. 1.979. Industrial Source Complex (ISC) Dispersion Model User Guide. EPA 450/4-79-30. Vol. 1. Office of Air Quality Planning and Standards, Research Triangle Park, NC. December. U.S. Environmental Protection Agency. 1980. Ambient Water Quality Cri- teria for Vinyl Chloride. EPA 440/5-80-078. Office of Water Regulations and Standards, Criteria and Standards Division, Washington, D.C. October. U.S. Environmental Protection Agency. 1982. Fate of Priority Pollu- tants in Publicly-Owned Treatment Works. Final Report. Volume 1. EPA 440/1-82-303. Effluent Guidelines Division, Washington, D.C. September. U.S. Environmental Protection Agency. 1984. Health Effects Assessment for Vinyl Chloride. ECAO-CIN-H036. Environmental Criteria and Assessment Office, Cincinnati, OH. November. 5-1 ------- APPENDIX PRELIMINARY HAZARD INDEX CALCULATIONS FOR VINYL CHLORIDE IN MUNICIPAL SEWAGE SLUDGE I. LANDSPREADING AND DISTRIBUTION-AMD-MARKETING Based on the recommendations of the experts at the OWRS meetings (April-May, 198A), an assessment of this reuse/disposal option is not being conducted at this time. The U.S. EPA reserves the right to conduct such an assessment for this option in the future. II. LANDPILLING Based on' the recommendations of the experts at the OWRS meetings (April-May, 198A), an assessment of this reuse/disposal option is not being conducted at this time. The U.S. EPA reserves the right to conduct such an assessment for this option in the future. III. INCINERATION A. Index of Air Concentration Increment Resulting from Incinerator Emissions (Index 1) 1. Formula T ., 1 (C x PS x SC x FM x DP) + BA Index 1 = — where: C = Coefficient to correct for mass and time units (hr/sec x g/mg) DS = Sludge feed rate (kg/hr DW) SC = Sludge concentration of pollutant (mg/kg DW) FM = Fraction of pollutant emitted through stack (unitless) DP = Dispersion parameter for estimating maximum annual ground level concentration (pg/m3) BA = Background concentration of pollutant in urban air (ug/m3) 2. Sample Calculation 1.0 = [(2.78 x 10"7 hr/sec x g/mg x 2660 kg/hr DW x 0.43 mg/kg DW x 0.05 x 3.4 wg/m3) + 43.316 yg/m3] * 43.316 ug/m3 A-l ------- B. Index of Human Cancer Risk Resulting from Inhalation of Incinerator Emissions (Index 2) 1. Formula ! - 1.) x BA] + BA Index 2 = EC where: II = Index 1 = Index of air concentration increment resulting from incinerator emissions (unitless) BA = Background concentration of pollutant in urban air (ug/m3) EC = Exposure criterion (yg/m3) 2. Sample Calculation 216 58 _ f(1.0 - 1) x A3. 316 Ug/m3] * 43.316 ug/m3 0.20 IV. OCEAN DISPOSAL Based on the recommendations of the experts at the OWRS meetings (April-May, 1984), an assessment of this reuse/disposal option is not being conducted at this time. The U.S. EPA reserves the right to conduct such an assessment for this option in the future. A-2 ------- |