United States Environmental Protection Agency National Risk Management Research Laboratory Cincinnati, OH 45268 Research and Development EPA/600/SR-97/134 March 1998 Project Summary Evaluation of Emissions from the Open Burning of Household Waste in Barrels Paul M. Lemieux The report gives results of a detailed emissions characterization study to ex- amine, characterize, and quantify emis- sions from the simulated burning of household waste materials in barrels. The study evaluated two experimental conditions: that of an avid recycler, who removes most of the recyclable con- tent from the waste stream prior to combustion; and that of a non-recy- cler, who combusts the entire stream of household waste. Estimated emis- sions were developed in units of mass emitted per mass of waste burned. Con- tinuous gas samples were analyzed for oxygen (O2), carbon monoxide (CO), carbon dioxide (CO2), nitric oxide (NO), and total hydrocarbons (THCs). Gas- phase samples were collected using SUMMA® canisters and analyzed by gas chromatography/mass spectrom- etry (GC/MS) for volatile organic com- pounds (VOCs). Extractive samples from the combined particulate- and gas- phase were analyzed for semivolatile organic compounds (SVOCs), polycy- clic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), chlo- robenzenes (CBs), polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDDs/PCDFs), alde- hydes and ketones, hydrogen chloride (HCI), hydrogen cyanide (HCN), and metals. Emissions of particulate matter (PM) with aerodynamic diameters of 10 m or less (PM10) and of 2.5 urn or less (PM25) were also measured. Ash resi- due samples were analyzed for SVOCs, PCBs, PCDDs/PCDFs, and metals. For most of the non-chlorinated com- pounds, including VOCs, SVOCs, PAHs, and aldehydes and ketones, emissions from the non-recycler were higher, both on a per mass burned basis and on a per day basis (using waste generation estimates from New York State). How- ever, emissions of many of the chlori- nated organics, particularly CBs and PCDDs/PCDFs, were higher from the avid recycler, on a per mass burned basis. From estimates of waste gener- ated each day by New York households for the avid recycler and non-recycler scenarios, emissions per day of PCDDs/ PCDFs are significantly higher for the avid recycler. Emissions of PCBs were higher from the non-recycler: although its cause is not known for certain, this phenomenon is likely the result of sev- eral factors, including the higher mass fraction of PVC in the avid recycler's waste. It is also possible that some component of the non-recycler's waste may poison the metallic catalysts be- lieved to be responsible for enhancing formation rates of PCDDs/PCDFs. Re- sults from HCI sampling indicated much higher HCI emissions from the avid re- cycler, which is consistent with the higher emissions of chlorinated organ- ics, and ash residue analysis indicated that the avid recycler's residue had more copper, which could contribute to higher emissions of PCDDs/PCDFs. The temperature at the base of the burn- ing bed was significantly lower for the avid recycler than for the non-recycler. Gas-phase emissions of metals were ------- not a strong function of the test condi- tions. PM emissions were much higher from the non-recycler. Almost all of the PM emissions from both test condi- tions were < 2.5 ujnin diameter. This Project Summary was developed by the National Risk Management Re- search Laboratory's Air Pollution Pre- vention and Control Division, Research Triangle Park, NC, to announce key findings of the research project that is fully documented in a separate report of the same title (see Project Report ordering information at back). Introduction In many areas of the country, residen- tial solid waste disposal practices consist of open-burning using barrels or other simi- lar devices instead of, or in addition to, disposal to municipal landfills or municipal solid waste combustors. The motivations for households that open-burn their gar- bage may include convenience, habit, or landfill and cost avoidance. Some com- munities have regulations which ban the open burning of garbage. Emissions from backyard burning of residential solid waste are released at ground level resulting in decreased dilution by dispersion. Addition- ally, the low combustion temperature and oxygen-starved conditions associated with backyard burning may result in incom- plete combustion and increased pollutant emissions. In contrast, modern refuse com- bustors have tall stacks and specially de- signed combustion chambers, which pro- vide high combustion temperatures, longer residence times, and better waste agita- tion while introducing air for more com- plete combustion. The New York State Departments of Health (NYSDOH) and Environmental Con- servation (NYSDEC), as well as regula- tory agencies in other states, requested that the EPA's Control Technology Center (CTC) characterize emissions due to open burning of residential waste in burn bar- rels using techniques that would minimize the limitations of previous studies. The CTC, NYSDOH, and NYSDEC performed a cooperative study to: 1) characterize and fabricate the waste to be burned (in duplicate), 2) measure the emission rates of many pollutants of concern, 3) mea- sure these pollutant concentrations in the residual ash (except for the VOCs), 4) measure the volume of ambient air enter- ing the burn facility, and 5) be representa- tive of the combustion conditions typically found in a backyard burner. The study was conducted under the direction of the EPA's National Risk Management Re- search Laboratory, Air Pollution Preven- tion and Control Division (APPCD). The combustion tests were conducted by APPCD's on-site contractor, Acurex Envi- ronmental Corporation with the oversight of representatives from APPCD and NYSDOH. Analytical chemistry work was divided between Acurex and NYSDOH staffs. Experimental Approach The study qualitatively identified and quantitatively measured the emissions of hazardous air pollutants from the open burning of household residential refuse in barrels. A secondary objective was to evaluate the concentrations of hazardous compounds in the residual ash. The tar- get audience for this work is the scientific community at large as well as state and local regulatory agencies. The major in- tended end use of the data is to place the emissions from these processes in proper perspective with respect to other point and area sources and to provide estimated emissions values that can serve as inputs to a risk assessment for the barrel burn- ing process. This work is intended to pro- vide a sufficiently broad survey of the emis- sions from this process to allow evalua- tion of the need for further study of this practice. It should be noted that most risk assessment exercises currently include sources of uncertainty so great that the true risk can only be stated to be within a range of one or more orders of magni- tude. Thus, the formal data quality objec- tive for this study was stated as follows. Emissions from two categories of waste were analyzed in this study (Table 1): waste from avid recycling and non-recy- cling families of four. To reduce the amount of different types of material to be col- lected for the tests, percentages for like materials were combined (e.g., percent- ages for newspaper, books, and office paper have all been combined) and per- centages for "miscellaneous" items for each category were added to the items that make up the largest percent for that category. Household hazardous waste (e.g., household chemicals, paint, grease, oils, tires and other vehicle parts) were not included in the waste to be burned. For the recycling and non-recycling sce- narios, 6.4 - 13.6 kg (14 - 30 Ib) of waste were combusted (in duplicate) in a spe- cially designed vessel in the EPA's Open Burning Simulation Test Facility. The pol- lutants targeted in this study were VOCs, HCN, HCI, PM25, PM10, aldehydes, com- bined particulate- and vapor-phase SVOCs (including PAHs, PCBs, and PCDDs/ PCDFs), particulate-phase metals, and vapor-phase mercury. Additionally, SVOCs (including PAHs, PCBs, and PCDDs/ PCDFs), and metals were measured in the residual ash. Continuous emission monitors (CEMs) for O2, CO2, CO, THCs, and NO were also operated. Measured concentrations were related to dilution air volumes and measured net mass of de- bris combusted to derive emission rates. Emission rate data and ash sampling re- sults are intended to be useful in evaluat- ing the potential exposure due to pollutant emissions associated with the backyard burning of household refuse in barrels. Results For most of the non-chlorinated com- pounds, including VOCs, SVOCs, PAHs, and aldehydes and ketones, emissions from the non-recycler were higher, both on a per mass burned and on a per day basis (based on waste generation statis- tics provided by NYSDOH). However, emissions of many of the chlorinated or- ganics (on a per mass burned basis), par- ticularly chlorobenzenes and PCDDs/ PCDFs, were higher from the avid recy- cler. Emissions of PCBs were higher from the non-recycler, although the cause of this phenomenon is not known. On a per day basis, emissions of PCDDs/PCDFs are significantly higher for the avid recy- cler. This phenomenon is likely due to several factors, including the higher mass fraction of PVC in the avid recycler's waste. It is also possible that some component of the non-recycler's waste may poison the metallic catalysts believed to be respon- sible for enhancing formation rates of PCDDs/PCDFs. Results from HCI sam- pling indicated much higher HCI emissions from the avid recycler, which is consistent with the higher emissions of chlorinated organics; and ash residue analysis indi- cated that the avid recycler's residue had more copper, which could contribute to higher emissions of PCDDs/PCDFs. The temperature at the base of the burning bed was significantly lower for the avid recycler than for the non-recycler. Gas- phase emissions of metals were not a strong function of the test conditions. PM emissions were much higher from the non- recycler. Almost all of the PM emissions from both test conditions were < 2.5 |im in diameter. It may be useful to compare emissions from open burning of household waste to emissions from a full-scale municipal waste combustor (MWC) operating with good combustion and flue gas cleaning tech- nology. Based on data from a field test at a MWC, and averaging the "Normal Good" PT-08, PT-09, and PT-11 test conditions described in a detailed field test published in 1994, using the samples taken at the pollution control device outlet, the data in Table 2 were generated. For the results ------- Table 1. Composition of household wasted prepared by EPA. PAPER Newspaper, books and office paper Magazines and junk mail Corrugated cardboard and kraft paper Paperboard, milk cartons, and drink boxes PLASTIC RESIN3 PET#1 (bottle bill) HOPE: #2, LDPE #4, and PP #5 PVC: #3 PS: #6 MIXED #7 FOOD WASTE TEXTILE/LEATHER WOOD (treated/untreated) GLASS/CERAMICS Bottles/jars (bottle bill) Ceramics (broken plates and cups) METAL-FERROUS Iron - cans NON-FERROUS Aluminum - cans (bottle bill), foil, other Other non-iron (wire, copper pipe, batteries) TOTAL WEIGHT GENERATED PER HOUSEHOLD FOR DISPOSAL IN BURN BARRELS (kg/day) Non-Recycler (%) Avid Recycler (%) 32.8 11.1 7.6 10.3 0.6 6.6 0.2 0.1 0.1 5.7 3.7 1.1 9.7 0.4 7.3 1.7 1.1 4.9 3.3 61.9 10.4 4.5 0.3 0.3 3.7 6.9 4.0 1.0 3.7 1.5 aPET=POLYETHYLENE TEREPHTHALATE; HDPE=high-density polyethylene; LDPE=low density polyethylene; PP=polypropylene; PVC=polyvinyl chloride; and PS=polystyrene Table 2. Comparison between open burning of household waste and controlled combustion of municipal waste in a MWC; emissions are in |ig/kg waste burned. Avid Recycler Non-Recycler MWC PCDDs PCDFs CBs PAHs VOCs 46.7 222.9 1 ,007,450 23,974.7 2,052,500 38.25 6.05 424,150 66,035.65 4,277,500 0.0016 0.0019 1.16 16.58 1.17 from this study, concentrations of all tar- get VOCs were summed to give total VOC emissions (concentrations below detection limit were set at zero). A similar treatment was taken for PAHs, CBs, PCDDs/PCDFs, and PCBs. Figure 1 graphically depicts these results. It is readily apparent that even the sig- nificant differences between the avid re- cycler and non-recycler's emissions are minor in comparison to the difference be- tween open burning of household waste and the controlled combustion of munici- pal waste at a dedicated MWC facility. The emissions from open burning can be several orders of magnitude higher than controlled combustion. As an additional comparison of open burning versus controlled combustion in a properly designed combustion device, Table 3 was created by calculating the total air pollutants produced per day using the estimated emissions from Table 2, the waste generation rates described in Table 1, and comparing those values to a hypo- thetical 182,000 kg/day (200 ton/day) MWC facility emitting air pollutants at the rate described in Table 3. (NOTE: This size facility processes the equivalent waste from 37,000 non-recycling and 121,000 recycling households.) By dividing the daily estimated emissions from the MWC by the daily estimated emissions from open burning, it is possible to estimate how many open-burning households it would take to equal the air pollution produced by a moderately sized MWC facility. The num- ber is surprisingly low; in fact, for certain pollutants such as VOCs and CBs, a single household that burns their trash in barrels produces more pollutants than a full-scale MWC facility. Table 4 illustrates which test condition resulted in higher emissions. The first two columns are based on the mass/mass emissions, and the second two columns are based on mass/day emissions, using the waste generation rates reported by NYSDOH in Table 1. For the ash residue, estimates per person were based on both the waste generation rates reported by NYSDOH and the mass of material re- maining after combustion. Table 5 summarizes all the test data, showing the average results for the vari- ous pollutants that were measured, along with the ratio between the avid recycler and the non-recycler. Emissions from backyard burning of resi- dential solid waste are released at ground level, resulting in decreased dilution by dispersion. This could potentially exacer- bate potential impacts beyond what is ap- parent from the magnitude of the emis- sions alone. The large magnitude of the emissions, coupled with the concentration of these emissions in the local neighbor- hoods due to poor dispersions, will lead to increased direct inhalation exposure. Another issue related to this particular source is that it could potentially be a significant overall source of PCDDs/ PCDFs. A 1994 EPA document attempted to conduct a mass balance for dioxin emis- sions in the U.S. and identified a signifi- cant gap between current deposition esti- mates and emission estimates, with the former considerably higher than the latter. EPA speculated that this indicated that there were unknown dioxin emission sources. The dioxin emissions from burn barrels may be a missing link to help account for the gap between measured deposition rates and emission inventories. ------- Total VOCs Total PAHs Total chlorobenzenes Total PCDFs Total PCDDs c c c D MWC CH Non-recycler | | Avid recy^pr 1 1 1 i I I • I | I i i i i i i i i i ! 9 d 2 o 8 o 8 o c i - ° 8 8 8 g ° 8 8 T- O Estimated emissions (|ig/kg) Figure 1. Composition between open burning and controled combustion. Table 3. Number of open-burning households to equal the air pollution from a full-scale MWC facility3 Avid Recycler Non-Recycler PCDDs PCDFs CBs PAHs VOCs 4.15 1.03 0.14 83.8 0.07 1.55 11.65 0.10 9.31 0.01 aUsing refuse generation rate supplied by NYSDOH, shown in Table 1; MWC burns 182,000 kg/day (200 tons/day) Table 4. Which test condition resulted in higher emissions? Mass Emitted/Mass Burned Mass Emitted/Person3 Pollutant Gas-Phase VOCs SVOCs PAHs PCBs CBs PCDDs/PCDFs Aldehydes & ketones HCI HCN PM Metals Ash Residue SVOCs PCBs PCDDs/PCDFs Metals Recycler X X X - X X - Non-Recycler X X X X X X X - X - Recycler X X X - X - Non-Recycler X X X X X X X - X X - *Using refuse generation rate supplied by NYSDOH, shown in Table 1. ------- Tables. Summary of all test Parameter WASTE COMPOSITION total daily waste (kg) PVC in waste (kg) paper waste (kg) all plastics (kg) food (kg) textiles, leather (kg) wood (kg) glass/ceramics (kg) metals (kg) COMBUSTION RESULTS max. bed temp (°C) fractoin burned (%) unburned residue (kg) data Recycler 1.5 0.07 0.98 0.23 0 0 0.06 0.1 0.14 370 66.7 0.50 AIR CONTAMINANT EMISSIONS benzene acetone styrene total TICsa naphthalene13 phenol dichlorobenzenes trichlorobenzenes tetrachlorobenzenes pentachlorobenzene hexachlorobenzene acenaphthylene naphthalene0 phenanthrene aldehydes & ketones total PCDD total PCDF total PCB PM10 PM2.5 HCI HCN RESIDUALS IN ASH |im PCDD, ng/kg PCDF, ng/kg PCB, |ig/kg Cr Cu Pb Zn 725 190 310 4000 40 85 320 400 140 100 48 3.4 5.2 3.3 140 0.047 0.22 0.97 5800 5.3 2400 200 (or ng) per kg ash 14851 34040 220 300 4910 164 11500 Average, per mass lost Non-Recycler 4.9 0.01 3.02 0.36 0.28 0.18 0.05 0.5 0.49 740 49.1 2.49 (mg/kg burned) 1240 940 740 14400 48 140 160 110 74 53 22 11 18 7.3 2800 0.038 0.0061 2.86 19000 17.4 284 468 1556 5800 122 92 343 32 721 Ratio 0.31 7.00 0.32 0.64 0.00 0.00 1.20 0.20 0.29 0.50 1.36 0.20 0.58 0.20 0.42 0.28 0.83 0.61 2.00 3.64 1.89 1.89 2.18 0.31 0.29 0.45 0.05 1.24 36 0.34 0.31 0.30 8.47 0.43 9.54 5.87 1.80 3.26 14 5.13 16 Recycler 1.5 0.07 0.98 0.23 0 0 0.06 0.1 0.14 370 66.7 0.50 725 190 310 4002 40 85 320 400 140 100 48 3.4 5.2 3.3 140 0.047 0.220 0.97 5803 5.3 2401 200 Average, per household Non-Recycler 4.9 0.01 3.02 0.36 0.28 0.18 0.05 0.5 0.49 740 49.1 2.49 (mg/household-day) 2983 2262 1780 34645 115 337 385 265 178 128 53 26 43 18 6737 0.091 0.015 6.87 45712 42 682 1126 Ratio 0.31 7.00 0.32 0.64 0.00 0.00 1.20 0.20 0.29 0.50 1.36 0.20 0.24 0.08 0.17 0.12 0.35 0.25 0.83 1.51 0.79 0.78 0.91 0.13 0.12 0.19 0.02 0.51 15 0.14 0.13 0.13 3.52 0.18 tentatively identified (VOC) compounds. bSemi-volatile organics analysis. CPAH specific analysis. ------- Paul M. Lemieux is the EPA Project Officer (see below). The complete report consists of two volumes, entitled "Evaluation of Emissions from the Open Burning of Household Waste in Barrels:" Volume 1. Technical Report (Order No. PB98-127343; Cost: $25.00) Volume 2. Appendices (Order No. PB98127350-; Cost: $31.00) The above reports will be available only from: (cost subject to change) National Technical Information Service 5285 Port Royal Road Springfield, VA22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Air Pollution Prevention and Control Division National Risk Management Research Laboratory U.S. Environmental Protection Agency Research Triangle Park, NC 27711 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati, OH 45268 Official Business Penalty for Private Use $300 BULK RATE POSTAGE & FEES PAID EPA PERMIT No. G-35 EPA/600/SR-97/134 ------- |