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Published on January 19, 2008

Author: Quintino

Source: authorstream.com

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Decisions/ questions and analysis – lack of linkage:  Decisions/ questions and analysis – lack of linkage Decisions to be made by the DTSC Upper TTLC – Are reduced management requirements acceptable? Lower TTLC – Is Class 2 disposal safe? Questions asked by the DTSC Upper TTLC – What level of management is required to ensure public and environmental protection? Lower TTLC – Is the material safe in a class 3 landfill? What level of management is required to ensure public and environmental protection? Risk assessments used to answer these question Upper TTLC – risk from Class 2 landfill disposal Lower TTLC – risk from off-site disposal Neither of these risk assessments answers the questions needed to make the decisions. Relationship between Risk Scenario Classification, and Disposal Options:  Relationship between Risk Scenario Classification, and Disposal Options INCORRECT Criteria Classification Risk Scenario Disposal Requirement Passes Fails Classification Hazardous Class 1 Upper TTLC1 Class 2 landfill Class 1 Class 1 Special Waste – (variance required) Class 2 Lower TTLC1 Off-site disposal Class 3 Class 1 Non Hazardous Class 3 1 acute toxicity standards for consideration of accidental releases and other short-term exposures also used for classification The TTLCs assess disposal risks, but they do NOT determine disposal requirements. If the risk assessment is not used in setting the standards, the process is NOT risk based Relationship between Risk Scenario Classification, and Disposal Options:  Relationship between Risk Scenario Classification, and Disposal Options CORRECT Criteria Classification Risk Scenario Disposal Requirement Passes Fails Classification Hazardous Class 1 Upper TTLC1 Class 2 landfill Class 2 Class 1 Special Waste – (variance required) Class 2 Lower TTLC1 Class 3 landfill Class 3 Class 2 Non Hazardous Class 3 1 acute toxicity standards for consideration of accidental releases and other short-term exposures also used for classification The TTLCs assess disposal risks, but they do NOT determine disposal requirements. If the risk assessment is not used in setting the standards, the process is NOT risk based Acute Toxicity Criteria Are Appropriate:  Acute Toxicity Criteria Are Appropriate Route Waste Type DTSC USEPA1 USEPA2 HCS3 Hodge & Sterner4 National Paint5 Dermal Non- >7400 mg/kg >5,000 mg/kg 2.82 - 22.59 mg/kg >5,000 mg/kg, ACT7 = 0 Hazardous Category IV6 practically non-toxic Special 5500-7400 mg/kg Hazardous <5500 <50 mg/kg <200 mg/kg 200 mg/kg <5 mg/kg 0 – 20 mg/kg, ACT = 4 Category I extremely toxic Oral Non-Hazardous >500 mg/kg >5,000 mg/kg 5 – 15 gm/kg >5,000 mg/kg, ACT = 0 Category IV Practically nontoxic Special 30 – 500 mg/kg Hazardous <30 mg/kg <25 mg/kg <50 mg/kg 50 mg/kg < 1 mg/kg Category I extremely toxic 0 – 1 mg/kg, ACT = 4 Inhalation Non- Based on >2.0 mg/l 10,000 - 100,000 >200mg/l Dust, mists, fumes Hazardous individual Category IV ppm >10,000 ppm gases, vapors compounds practically nontoxic ACT = 0 Hazardous Based on <0.5 mg/l <0.05 mg/ 200 ppm - < 10 ppm 0 – 0.2 mg/l ATR, ACT = 4 individual > per 8 hr. Category I gas or vapor extremely toxic >20 – 200 ppm , ACT = 3 compounds exposure 2 mg/l dust, mist or fume 1 Extremely Hazardous Substances-Technical Guidance for Hazards Analysis; Emergency Planning for Extremely Hazardous Substances; USEPA December 1987 2 Health Effects Test Guidelines OPPTS 870.100 Acute toxicity Testing Background: USEPA August 1998 3 Highly Toxic- Hazard Communication Standard 4 Hodge, H.C. and J.H. Sterner: Tabulation of toxicity classes. Am Ind. Hyg. Assoc. Q 10:93 (1949). 5 National Paint & Coating Association (Hazardous materials IdentificationR HMISR ; Label Master): Washington DC 6 Rating Category I to IV, with I being most toxic 7 Acute toxicity rating = ACT: 0 to 4, with 4 being most toxic DTSC Exposure Scenario: Resident Near Class 2 Landfill Containing Special Waste:  DTSC Exposure Scenario: Resident Near Class 2 Landfill Containing Special Waste Assumption DTSC Recommended Area and Distances Distance to Resident 100 meters 740 meters Landfill size included no 673x673 meters Farm size included no 400x400 meters Total modeled distance 100 meters 1300 meters Landfill Assumptions Landfill cover thickness (1) 1 cm 6 inches Landfill cover density 522 kg/m3 1600 kg/m3 Waste dilution monofill 4-10 waste streams Methane gas Duration of generation 70 years 2-4 years Area of generation whole landfill specific cells Release (1) un-captured captured Meteorology Windspeed 3 mph (volatiles) actual, annual average Windspeed high (dust) actual, annual average Stability high (volatiles) actual, annual average Stability low (dust) actual, annual average Data source generic worst case actual, annual average Direction always at residence actual, annual average Dust Level 50 ug/m3 actual average Re-entrainment no, 0% yes Modeled no yes Dust suppression (1) no yes Rain no yes Non-waste dust no yes Deposition 100% DTSC Exposure Scenario: Resident Near Class 2 Landfill Containing Special Waste:  DTSC Exposure Scenario: Resident Near Class 2 Landfill Containing Special Waste Assumption DTSC Recommended Food Pathway uncertainty evaluated no yes Full uncertainty evaluation no yes Typically evaluated by DTSC no no Normalized local information no yes Grain 88 lbs 0 lbs Fruit and Vegetable 234 lbs 2.3 lbs Milk 518 lbs 3 lbs Meat 263 lbs 2 lbs Eggs 37 lbs 0.2 lbs Fish 40 lbs 1.7 lbs Reasonably probable to occur yes no Reasonable exposure scenario yes n Adequate bioconcentration data yes n Adequate bioavailablity data yes no Documented transfer factors Air to plant no yes Air to soil no yes Soil to plant no yes Dust to soil no yes Dust to plant no yes Probable number of exposed individuals 0 770 (within 773 meters) With a farm as described 0 0 Pathway analysis conducted no yes Indoor/Outdoor protection no yes DTSC Exposure Scenario: Resident Living on Diluted Waste:  DTSC Exposure Scenario: Resident Living on Diluted Waste Assumption DTSC Recommended Area and Distances Farm size included no 400x400 meters Time from last waste application to Property transfer 1 day 2.5 years Residence built 1 day 3 years Pond created 1 day 3 years Pond ecosystem established 1 day 4 years Fish available 1 day 4 years Fruit trees mature 1 day 4 years Garden producing 1 day 3.5 years Feed for cattle, chickens 1 day 3.5 years Dairy, meat and eggs available 1 day 4 years Food Full uncertainty evaluation no yes Typically evaluated by DTSC no no Normalized local information no yes Grain 88 lbs 0 lbs Fruit and Vegetable 234 lbs 2.3 lbs Milk 518 lbs 3 lbs Meat 263 lbs 2 lbs Eggs 37 lbs 0.2 lbs Fish 40 lbs 1.7 lbs Reasonably probable to occur yes no Reasonable exposure scenario yes no Adequate bioconcentration data yes no Adequate bioavailablity data yes no Probable number of exposed individuals reasonable number 0 Actual “20 year” waste locations reasonable number 0 Pathway analysis conducted no yes Volatilization during application no yes Biodegradation during application no yes DTSC Exposure Scenario: Worker at Class 2 Landfill Containing Special Waste:  DTSC Exposure Scenario: Worker at Class 2 Landfill Containing Special Waste Assumption DTSC Recommended Area and Distances Landfill size included no 673x673 meters Modeling Height of box model 2 meters 50 met Landfill Assumptions Landfill cover thickness (1) 1 cm 6 inches Landfill cover density 522 kg/m3 1600 kg/m3 Waste dilution monofill 4-10 waste streams Methane gas Duration of generation 70 years 2-4 years Area of generation whole landfill specific cells Release (1) un-captured captured Meteorology Windspeed 3 mph (volatiles) actual, annual average Windspeed high (dust) actual, annual average Stability high (volatiles) actual, annual average Stability low (dust) actual, annual average Data source generic worst case actual, annual average Direction worst case actual, annual average Dust Level 50 ug/m3 actual average Non-waste dust no yes Modeled no yes Dust suppression (1) no yes Rain no yes Worker Protection (1) Clothing shorts and short sleeve shirt tivec suits Respiratory no yes Eating on site in cafeteria DTSC Exposure Scenario: Worker at Class 2 Landfill Containing Special Waste:  DTSC Exposure Scenario: Worker at Class 2 Landfill Containing Special Waste Assumption DTSC Recommended Hygiene no yes Probable number of exposed individuals 0 (exposure per DTSC) <10,000 (at all CA. Landfills) Pathway analysis conducted no yes Volatilization during application no yes Biodegradation during application no yes DTSC Exposure Scenario: Kingfisher Living on Diluted Waste:  DTSC Exposure Scenario: Kingfisher Living on Diluted Waste Assumption DTSC Recommended Area and Distances Pond size 640 acres 2 acres Adjustment for Kingfisher feeding area no 100-300 x Soil removed for pond creation no yes Soil tilled in ditch or stream bed yes no Waste dilution factor Monofill Area of pond receiving waste 100% Time from last waste application to Property transfer 1 day 2.5 years Pond created 1 day 3 years Pond ecosystem established 1 day 4 years Fish community established 1 day 4 years Benthic community established 1 day 4 years Foraging areas for fish included no yes Migratory feeding pattern included no yes Transfer factors Adequate bioconcentration data yes no Adequate bioavailablity data yes no Equilibrium established (sediment to biota) yes no Bioavailablity assumed 100% Actual Biodegradation during application no yes Biodegradation after application no yes Volatilization during application no yes Reasonably probable to occur yes no Reasonable exposure scenario yes no Actual “20 year” waste locations reasonable number 0 Pathway analysis conducted no yes Conclusions:  Conclusions Proposed waste classification scheme is seriously flawed. It does not achieve the intended objectives It is not risk based It does not follow sound risk assessment practices It does not apply the best science It is guided and driven by inappropriate policy decisions, not by sound science. The net result is drastically increased waste management costs with no health benefit The Landfill Worker fsoil Parameter:  The Landfill Worker fsoil Parameter The department has chosen a value of 0.3 for the fsoil parameter and references a 1992 USEPA document, Dermal Exposure Assessment: Principles and Applications, for this parameter value and other parameters pertaining to dermal exposure. This report states that one who "wears a long sleeve shirt, pants, and shoes" have a fsoil equivalent to 0.10 and one who "wears a short sleeve shirt, shorts, and shoes" will have a fsoil equivalent to 0.25. The authors consider the first case to be "typical" and the second to be a reasonable worst case" when estimating the dermal exposure for workers. The USEPA document further states: "Assessors may want to refine estimates of the skin surface area exposed on the basis of seasonal conditions. For example, in moderate climates, it may be reasonable to assume that 5% (0.05) of the skin is exposed during the winter, 10% (0.10) during the spring and fall, and 25% (0.25) during the summer." By this logic, the appropriate fsoil parameter value should be 12.5% or 0.125. DTSC Exposure Scenario: Phytotoxicity of Inorganic Lead:  DTSC Exposure Scenario: Phytotoxicity of Inorganic Lead DTSC utilizes an Oak Ridge National Laboratory screening number for phytotoxicity of 50 mg/kg for inorganic lead. DTSC then applies the 20-fold dilution from the land conversion scenario to arrive at the 1,000 mg/kg for lead. Toxicity data is based on a study from Holland where earthworms were placed in Pg+2 soil. However, Pb+2 soils are very rare in California found mainly around smelters and mine tailings. Other forms of lead are generally not bioavailable. U.S. EPA has determined that soils with lead concentrations below 2000 mg/kg pose no significant risk to children. Issues Inconsistent with SAB Review of HWIR:  Issues Inconsistent with SAB Review of HWIR Validation/Peer Review: “very concerned that there has been little grounding in reality of the overall methodology and of its individual elements.” “…the total construct has not been validated against actual data… …validation of the overall methodology and its components is essential to developing any degree of confidence…” “…seek the substantive participation, input and review of Agency scientists, and outside peer review groups… …to evaluate the specific elements of the proposed methodology…” Systematic Evaluation of Parameters: “…should conduct a systematic examination of parameters (and uncertainties) to ensure consistent and uniform application of the proposed approach to selecting high-end or central-tendency values.” “…Subcommittee concludes that this critical issue must be resolved before proceeding.” Alternate Approach: “…national-level set of criteria would be so overly protective at most sites as to be ineffective in addressing the original intent…” “..Agency could develop a consistent methodology for establishing .. ..exit criteria; i.e., a systematic approach that,… ..would yield site-specific exit criteria or exit criteria for groups of wastes or sites with similar characteristics.” “The spatial scale.. ...requires a series of worst-case assumptions for transport and exposure without accounting for differences among kinds of sites and wastes.” “A sequential approach (“iterative approach”) would be most effective in an adaptive approach to regulation. This approach.. .. also recommended by NRC in.. .. Science and Judgement in Risk Assessment.” Unrealistic Management Scenarios: “…the waste management scenarios are poorly developed and do not incorporate established engineering design and operation practices.” Transparency/Clarity: “Distributions developed on the basis of expert opinion or professional judgement should be clearly noted. If these parameters turn out to be the more sensitive, additional resources will be required to obtain valid estimates..” “should distinguish clearly between scientific judgement and policy decisions.” Inconsistencies with SB1082 RAAC Recommendations:  Inconsistencies with SB1082 RAAC Recommendations A1, Pg. 2-4. Incorporation of New Science: “…imperative that the public have confidence that Cal/EPA human health risk assessments reflect the best possible scientific judgements.” C6, Pg. 2-11. Stakeholder involvement: “…look for, and implement ways of involving risk managers and stakeholders in risk assessment… ..Particularly, strive for involvement as early as possible in the process.” E2, Pg. 2-27. Public input: “The public and interested stakeholders should be involved early in the risk assessment process and maintain involvement at key decision points…” A6, Pg. 5-6. Exposure Assessments: “Where Cal/EPA requires use of specific scenarios, it should provide justification as to why the specific scenario is appropriate or necessary.. ..should include a discussion of the land use and behavioral assumptions implicit in the scenario.” B2, Pg. 5-9. Exposure Assessments: “Cal/EPA should take greater advantage of the data from field studies of personal exposure.. ..should compare its exposure model predictions with the actual exposures measured…” B5, Pg. 5-11. Dietary Estimates: “Factors for proportion of home-grown vegetables and fruits or proportion of self-caught fish should be reexamined and alternative estimates derived or developed.” 1 & 3, Pg. 7-5. Uncertainty & Variability: “should consider whether the decision making processes are optimal.. ..also whether the way the risk assessments are optimal, given the information needs…” “Cal/EPA should review the effect of choices of assumptions, models, quantitative uncertainty analysis, etc., on decision outcomes, including a review of the impact of assumptions in the Cal/TOX program.” B1 & B3, Pg. 7-15. Models and Default Assumptions: “Cal/EPA should examine the impact of defaults or model choices on the outcomes of the risk assessment. This should include, in particular, the influence of assumptions in the CalTOX program.. .determine what may “drive” the assessment.” “Cal/EPA should more fully communicate the impacts of model and parameter choice in the risk assessment.” Federal Agencies Consider Cost & Population Burden (Not Individual Risk Alone):  Federal Agencies Consider Cost & Population Burden (Not Individual Risk Alone)

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