1 WILMINGTON AIR QUALITY STUDY Project Summary and Status Todd Sax Vlad Isakov Planning and Technical Support Division California Air Resources Board Presentation

  • Published on

  • View

  • Download

Embed Size (px)



    Project Summary and Status

    Todd SaxVlad Isakov

    Planning and Technical Support DivisionCalifornia Air Resources Board

    Presentation to Modeling Working Group

    March 16, 2004

  • OutlineIntroduction and OverviewObjectivesConceptual PlanPreliminary ResultsEmissions InventoryReviewStatus and Preliminary ResultsIndustrial-Commercial FacilitiesNon-Port Mobile Source InventoriesPort Inventories - StatusModel Status and EvaluationOngoing Work

  • Wilmington Air Quality StudyBarrio Logan project - first neighborhood assessment project. Neighborhood scale inventoryApplication of several local-scale and regional models

    Wilmington study - next step in neighborhood assessment. Improved local-scale emissions inventory and inventory evaluationLarger modeling domainExpanded model application and evaluation

  • Wilmington DomainWilmington modeling sub-domain

  • WAQS ObjectivesGoalsDevelop and evaluate inventory/modeling methods for assessing pollutant impacts at a fine resolutionConduct studies to assess inventory and modeling approaches for statewide assessmentKey QuestionsAre existing emissions inventories adequate for neighborhood assessment? What are the key data gaps?What are key pollutant, source impacts in Wilmington?Which models provide reliable results?How do we integrate model results?

  • Emissions

    Industrial and Commercial Facilities

    Industrial facilities Non-diesel emissions from marine terminals Gasoline stations Dry cleaners Autobody shops Metal fabricators Magnet Facilities like warehouses and distribution centers that attract diesel on-road sources Dedicated, on-site off-road equipment

    On-Road Sources

    Automobiles and Heavy duty trucks Freeways, and Ramps Major and Minor Arterials

    Other Off-Road Engines

    Marine, Harbor, and Dockside engines at marine terminals Railroad activity


    Local scale modeling - ISCST3, AERMOD, CALPUFF, CALINE4 Regional modeling - CALGRID, CMAQ, CAMx Combined results Limited time-activity based exposure modelingHealth Risk

    OEHHA Guidelines - Inhalation and multipathway risks - Cancer and chronic endpoints - Comparison to health based PM standards

    Model Evaluation

    Tracer Study

    Summer, 2003 Release from elevated stack

    Toxics Monitoring

    Long term (one year), one site - >50 pollutants Short term study(12-15 days) - Summer, 2003 - Multiple sites - Estimate diesel PM

    Uncertainty Assessment

    Gasoline service stations Stationary and Mobile Diesel IC enginesWilmington Neighborhood Assessment - Conceptual PlanInventory Analysis

    Expand quality assurance Assess contribution of neighborhood sources Evaluate uncertainty

  • OutlineIntroduction and OverviewObjectivesConceptual PlanPreliminary ResultsEmissions InventoryReviewStatus and Preliminary ResultsIndustrial-Commercial FacilitiesNon-Port Mobile Source InventoriesPort Inventories - StatusModel Status and EvaluationOngoing Work

  • Emissions: Industrial and Commercial Facilities405 facilities-toxics / 259 -criteria170 surveyed facilities(118 neighborhood / 52 CEIDARS)Compiled from multiple inventory databasesEnhanced QA/QCReview by SCAQMD and selected facilitiesOn-Road EmissionsLink-Based Inventory Use Travel Demand Models and EMFAC Marine Terminals and Related Off-RoadPorts of Los Angeles and Long Beach - develop inventories for marine terminals, on-road sources, and related locomotive emissions.Locomotives - develop link and throttle-notch specific inventoriesConstruction - not considered (included in regional modeling).

    Emissions Inventory Review

  • OutlineIntroduction and OverviewObjectivesConceptual PlanPreliminary ResultsEmissions InventoryReviewStatus and Preliminary ResultsIndustrial-Commercial FacilitiesNon-Port Mobile Source InventoriesPort Inventories - StatusModel Status and EvaluationOngoing Work

  • Industrial-Commercial FacilitiesDefinitionLarge and small point sources at non-port businessesMethodDevelop facility listMultiple data sources: HRA, AER, CEIDARS, TRI, etc. On-site surveys: verify and augment inventories118 neighborhood sources52 CEIDARS facilitiesChoose best emissions data from hierarchyIf surveyed, include on-site area and mobile emissions categoriesCompile inventory

  • Industrial-Commercial FacilitiesHierarchy

    Table 1Number of facilities in final inventories by data source.

    Number of Facilities

    Data Source

    Toxics Inventory

    Criteria Inventory

    CEIDARS Surveys

    Primary Data Source: Health Risk Assessment


    Primary Data Source: Annual Emissions Report



    Health Risk Assessments


    Air Toxic Inventory Reports (hardcopy files)


    Neighborhood Source Surveys

    with no additional data


    with limited CEIDARS data


    with limited AER data


    Limited Surveys (AQMD Annual Emission Reports)



    AQMD Annual Emission Reports









    LAUSD Surveys



    ARB Emissions Inventory Database (CEIDARS)

    Criteria Database


    Toxics Database




    Energy Commission List of Emergency Generators



    Toxics Release Inventory, Year 2000


    AQMD Permits - ARB Emission Estimates






  • Industrial-Commercial Facilities

    Table 2 Industrial-Commercial Facility Emission Inventory and Contribution to Potency Scores for Selected Pollutants in the Wilmington Modeling Domainxy.


    Emissions (lbs/yr)

    Percent of Total Cancer Score

    Percent of Total Chronic Score




  • Industrial-Commercial FacilitiesPreliminary Results: Inventory EvaluationDesigned to test inventory assumptionsWhy evaluate inventories?Existing databases designed for regional-scale analysisInventory update procedures designed and implemented with regional goal in mindBut NAP is local scale, not regional analysisAsking existing databases to do moreNeed to understand strengths and limitationsLearn how to improve and meet modeling needs

  • Industrial and Commercial FacilitiesDevelopment of a community-specific industrial-commercial facility inventory improved our ability to characterize emissions in WilmingtonWAQS inventory is more recently calculatedToxics Inventory Age65% of records identified by survey; year 2000 or laterCriteria Inventory Age55% or records in local-scale inventory updated by survey (>2000)WAQS is more comprehensive than CEIDARSContains small facilities that are area sources in CEIDARSContains improved stack data in toxics inventory64% of releases are actual data; 36% defaultsOnly 8% of CEIDARS records tied to stacksDuplicate, closed CEIDARS facilities corrected.

  • Industrial-Commercial FacilitiesTotal facility cancer scores differ substantially between inventories.

  • Industrial and Commercial FacilitiesOn a neighborhood scale, diesel PM and CrVI from area-wide sources at facilities are significant80% of diesel PM and 15% of CrVI generated by facilities which are not in CEIDARS as point sources. Other neighborhood sources have minimal impacts, but may be important near receptors.

  • Industrial and Commercial FacilitiesCurrent diesel exhaust particulate inventories representing industrial-commercial facilities need improvement for neighborhood assessmentsOnly ~20% of estimated diesel PM emissions at facilities generated by point sourcesRemaining ~80% generated primarily by off-road sources operating within facilities.Diesel PM from off-road sources is important at larger industrial facilities like petroleum refineriesOff-road diesel PM ~40% of total cancer potency-weighted emissions at refineries.

  • I-C Diesel Exhaust Particulate Inventory75% generated by inventory-reporting facilities in 90744 (Wilmington community)But 23 reporters, ~600 neighborhood sources not surveyed in 90744If extrapolate, inventory doubles

  • Implications of I-C DPMDPM is dominant cancer riskSignificant emissions generated by on-site off-road sourcesPoint source facilities generally do not report on-site mobile source inventoriesHowever, most on-site off-road emissions were generated by facilities subject to other inventory reporting requirementsStatewide inventory based on off-road modelTop-down approach4 km grid cell spatial resolution

  • Industrial and Commercial FacilitiesPetroleum Refinery Case StudyMethodEvaluate inventory reports from 6 refineries3 in Wilmington, +1 in SCAQMD, +2 in BAAQMDAnalysis requires process-level inventoriesObtained best toxics data representing each facilityMust be consistently calculated, SCC process codedResult: ability to compare facilities is limited Different process groupings/units between facilitiesWidespread inconsistencies in facility calculationsTop pollutant sources different at different facilitiesNeed to examine other facility categories; results may be consistent

  • Example: BenzeneFacility E: fugitive wastewaterFacilities B and C (AER): oil-water separators. B>C, due to activitySome totals different in AB2588, AERResults consistent for benzene, 1,3-B, H2S, CrVI, CHOH Case Study: Petroleum Refineries

    Table 4-4 Top Three Benzene Emissions Sources by Process Hot Spots Data. (#) = Emissions (lbs/yr) by Process.










    Fugitives, Not Classified (1000)

    Process Heaters, Process Gas


    Process Heaters, Process Gas


    Floating Roof Tanks (1100)

    Fugitive, Wastewater (6000)

    Fugitive Pipeline Valves, etc (1300)


    Gasoline Engines (300)

    Fixed Roof Tanks (300)

    Fugitives, Not Classified (200)

    Fugitives Wastewater (400)

    Fugitive, Pipeline Valves, etc. (3000)

    Process Gas External Combustion (160)


    Floating Roof Tanks (100)

    Floating Roof Tanks (300)

    Floating Roof Tanks (60)

    Fugitives, Not Classified (300)

    Fugitive, Not Classified (1400)

    Fugitives, Pump Seals (90)

    Table 4-5Top Three Benzene Emissions Sources by Process AER Data. (#) = Emissions (lbs/yr) by Process.







    Floating Roof Tanks (100)

    Fixed Roof Tanks (600)

    Process Heaters Process Gas



    Process Heater Process Gas


    Fugitive Oil/Water Separator (400)

    Fugitive Oil/Water Separator (60)


    Boilers Process Gas


    Boilers Process Gas


    Fugitive Valves


  • Case Study: Petroleum RefineriesSubstantial differences between identical facilities, different inventoriesMajor differences in facility-total emissions for high risk pollutants

  • Case Study: Petroleum RefineriesWhen emissions data reported using comparable methods, gain insights.Example: Hexavalent Chromium (CrVI) generated by process-gas fired process heatersOn paper, majority of emissions generated by a few units at few facilities

  • OutlineIntroduction and OverviewObjectivesConceptual PlanPreliminary ResultsEmissions InventoryReviewStatus and Preliminary ResultsIndustrial-Commercial FacilitiesNon-Port Mobile Source InventoriesPort Inventories - StatusModel Status and EvaluationOngoing Work

  • On-Road Emissions InventoryGoal: develop and evaluate link-specific inventoryDevelop and test approaches for link-specific inventory developmentAssess assumptions in developing a bottom-up inventoryCompare to proposed approach for statewide modelingAssess uncertainty and how to improve calculationsPreliminary ResultsEmissions models need better resolutionEmissions estimates are uncertain due to uncertain activity estimates and uncertain emission factors

  • Emission models were never intended to provide highly spatially resolved emissions estimates

    EMFAC and OFFROAD provide county-total emissions that can be allocated to 4 km grid cellsGreater inventory resolution is required for local-scale modelsAllocating emissions to roadways is uncertain due to county-level assumptionsFleet compositionTravel model limitations: link specific volumes and speedsOperating cycle / trip-based emission factors

    Mobile Emissions Inventories

  • Limited test data on diesel PM emissions complicates assessment of diesel PM impacts on a local level.

    Source test data are extremely limited~200 in-use heavy duty truck source testsNew data on-line with CRC E55-59

  • OutlineIntroduction and OverviewObjectivesConceptual PlanPreliminary ResultsEmissions InventoryReviewStatus and Preliminary ResultsIndustrial-Commercial FacilitiesNon-Port Mobile Source InventoriesPort Inventories - StatusModel Status and EvaluationOngoing Work

  • Emissions Inventory - PortsPort-wide inventoriesGoal: obtain spatially resolved port-specific inventoriesWork supports WAQS and SSD Port Regulatory ActivitiesWork conducted by Port consultantsContinuous consultation with SSD, PTSDImprove spatial allocation - berth/terminal/rail-link specific Improve inventory assumptions: load, stacks, etc.Improved traffic and idling activity estimates - terminal specificStatus: Draft reports are being reviewed.Commercial marine vessels (POLA)Harborcraft (POLA / SSD)Terminal on-road movement/idling (POLA and POLB) Dockside terminal (POLA and POLB)Locomotives (POLA and POLB)

  • OutlineIntroduction and OverviewObjectivesConceptual PlanPreliminary ResultsEmissions InventoryReviewStatus and Preliminary ResultsModel Status and EvaluationLocal-scale uncertainty analysisTracer study statusOngoing Work

  • Modeling StatusMicroscaleStatus: waiting on port inventoriesRegionalStatus: currently being planned, sensitivity studies in progressModel IntegrationGoal: combine regional and microscale models while minimizing double countingStatus: currently being planned.

  • Model Evaluation - Uncertainty AnalysisGoalUse uncertainty analysis as an objective evaluation procedure to determine the level of confidence we should have in modeling resultsTwo studiesDiesel PM Study in WilmingtonWilmington inventory sensitivity studiesWhat is uncertainty analysis?An analysis method that uses assumptions about the uncertainty in model inputs to assess uncertainty in model output.

  • Model Evaluation - Uncertainty AnalysisWhy Uncertainty AnalysisModels are not realityModel results are a function of assumptionsAssumptions are uncertainWe make best guess estimates to simulate realityThese estimates may be wrongThese estimates are uncertain - we pick a value from a rangeWhat do we hope to learn?How uncertain are our estimates?What are the most uncertain components?How can we reduce uncertainty?Given uncertainty, what are model strengths and limitations?

  • Wilmington Uncertainty Analysis (1)Diesel PM - ZIP 90744Industrial-Commercial facilitiesSurveyed and included in inventoriesExtrapolated, not in I-C inventory directlyOn-Road Major - Freeways, Ramps, Major ArterialsMinor - Minor arterials, Collectors, ConnectorsApproachAssess uncertainty in emissionsRun ISC for Base CaseAssess uncertainty in model results due to meteorology, inventory release characteristics.Develop Monte Carlo meta-model to estimate uncertainty in ISCST3 results

  • (IC, on-road)

  • Wilmington Uncertainty - EmissionsDiesel PM emissions: mobile sourcesMobile source DPM at 4 facilitiesTheoretical link Goal: assess precision, accuracy in emissions, apply to modeling analysisEmissions methodEstimate activity range by on-site surveyQuantify range of emission factors based upon source testsUse Monte Carlo to propagate uncertainty

  • Order of magnitude uncertainty in mobile source diesel emissions...


View more >