Attachment A Scope of Work

Transcription

1 Attachment A Scope of Work Introduction The WRAP Dust Emissions Joint Forum (DEJF) is interested in gathering and improving data pertaining to the PM 2.5 and PM 10 components of fugitive dust emissions. Most of the PM 2.5 emission factors in the US EPA s AP-42 guidance for fugitive dust sources were determined by using high-volume samplers fitted with a cyclone precollector and cascade impactor. Under the same conditions, the PM 2.5 mass measured using these cyclone/cascade impactors should be nearly identical to the mass collected using an ambient PM 2.5 sampler that meets US EPA ambient air monitoring requirements. The MRI cyclone/impactor system (see Figure 1) has been recognized as the standard method to characterize fugitive dust emissions for the USEPA and to develop predictive emission factor equations for AP-42. A sample of particles is drawn at a flow rate of 34 m 3 /hr (20 acfm) into an isokinetic probe tip with an inlet velocity of 2.2 m/s (5 mph) and then through a cyclonic preseparator to remove particles larger than 15 µm in diameter. The PM 15 in the exit airflow from the cyclone is channeled through multiple impactor stages before being collected on a back-up filter, from which time-integrated PM 10 and PM 2.5 concentrations can be calculated. Historically, data from the MRI high-volume cyclone/impactor system have provided the basis for PM 2.5 /PM 10 ratios that have been published by USEPA in AP-42 for various categories of fugitive dust sources. The advantage of the high volume cyclone/impactor systems relates to its isokinetic sampling capability and higher analytical sensitivity for particle size measurement. However, particle bounce from the cascade impactor stages to the backup filter may have resulted in higher PM 2.5 measurements for the original AP-42 tests than the actual PM 2.5 concentrations. This possible measurement error may help to explain why the AP-42-based PM 2.5 emission estimates seem to show about 20 percent of the fugitive dust mass is in the fine fraction, while ambient air monitor data suggest that it may be less than 10 percent. Through this project, PM 2.5 measurements using the high-volume cascade impactors that were used to generate the original AP-42 emission factors will be compared to simultaneous measurements obtained using US EPA reference method samplers for PM 2.5. These tests will be conducted in a flow-through exposure chamber, where concentration level and uniformity can be controlled. The results of the tests should quantify any sampling bias that likely occurred during the original AP-42 emission factor tests. With the same test set-up, additional tests will be performed to measure the PM 2.5 to PM 10 ratio for fugitive dust from different geologic sources to provide more information on the variability of this ratio. 1

2 Figure 1. Cyclone/Impactor 2

3 As stated in the Request for Proposal, the results of this project are needed to ensure the most accurate PM 2.5 and PM 10 fugitive dust emissions inventory that is possible for regional haze regulatory purposes, given the available resources and the significant contribution of fugitive dust to visibility impairment. In particular, the results of this project may affect the quantity of dust apportioned to the fine versus coarse size modes, which have significantly different effects on visibility and long-range transport potentials. The results will also be helpful in developing accurate emission inventories for PM nonattainment, maintenance, and action plan areas in the WRAP region. Finally, if appropriate, results may be used to seek modifications to the EPA s AP-42 emission factors to ensure widespread availability of the most recent and accurate scientific information. Even though steps were taken by MRI to minimize particle bounce, when using the high-volume cyclone/impactor system, some comparative data collected in dust plumes downwind of paved and unpaved roads in the late 1990s indicate that PM 2.5 /PM 10 ratios determined with other particle sizing systems produced consistently lower ratios than with the cyclone/impactor system. This comparative particle sizing work was performed by MRI under contract to USEPA. As a result, modifications to reduce the ratios have been made by USEPA to the appropriate sections of AP-42. 3

4 Task Completion Requirements This section addresses the six work tasks defined in the RFP. It describes the level of effort required and the approach to be taken to each task. This section also describes the equipment and facilities required for each task. The first phase of the testing will establish that uniform PM 10 and PM 2.5 concentrations can be achieved in the dust exposure chamber. These concentrations may either be held at fixed values (as might represent a developed dust storm), or they can be varied to simulate the passage of a road dust plume. This phase will be used to determine any biases in PM 2.5 concentrations measured with the high-volume cyclone/impactor system. The second phase of the testing will be directed to quantifying PM 2.5 /PM 10 ratios for dust generated from a range of geologic source materials. All of the other tasks relate to planning for and reporting on the two test components. MRI will develop the experimental design, perform the testing, and analyze the performance data collected during the study. MRI will also provide the high-volume cyclone/impactors for the study and the associated impactor substrates and filter media. Gravimetric analysis of exposed impactor and filter media will be performed by MRI in the special laboratory normally used for this purpose at its headquarters facility in Kansas City. In addition, MRI will provide reference-method R&P Partisol PM 10 and PM 2.5 monitors, with 47-mm diameter filters. MRI will prepare the test plan (with its quality assurance component) and compile the SOPs for the sampling and analysis methods. MRI will perform the pilot study at the start of the testing program, for purposes of validating the operating performance of the wind tunnel and dust exposure chamber and setting the final test parameter values. MRI will provide the primary test facility (including the DustTRAK monitors to establish PM 10 dust concentration uniformity). MRI will also take the day-to day responsibility for operating and documenting the performance of the exposure dust chamber, in accordance with the test plan, during the main portion of the testing program. Task 1 Project Work Plan MRI will submit a draft project work plan, including a final schedule, to accomplish Tasks 2 through 6. The schedule will provide time for the DEJF to adequately review draft work products for each task. The work plan will also include a cost and time estimate to analyze additional soil samples per Task 4 under an addendum to the contract. A final work plan will be submitted after review and approval by the DEJF. Task 2 Test Protocol and Quality Assurance Project Plan MRI will submit a draft test protocol, including design of the dust generation system and exposure chamber, specification of monitoring equipment, procedures for sampling, 4

5 testing, and data analysis, and other procedures or design information essential to the completion of the project. A final test protocol will be submitted after review and approval by the DEJF. MRI will submit a draft quality assurance project plan (QAPP) according to EPA standards. Because the results of this project may be considered in revisions to EPApublished emission factors, adherence to EPA quality assurance documentation procedures will be an important part of this project. MRI has already prepared several EPA-approved QAPPs, and these will be used as models for this specific test program. A final QAPP will be submitted after review and approval by the DEJF. The test protocol and quality assurance plans will comply with EPA standards and will specify all procedures to be followed in collecting, recovering, transferring, and analyzing samples. As stated above, the quality assurance project plan (QAPP) will be patterned against QAPPs that MRI has prepared for EPA-sponsored test programs that involved both cascade impactors and reference samplers. These plans were prepared to be in compliance with EPA document QA/R-5 (EPA Requirements for QA Project Plans) as well as the guidance document QA/G-5 (Guidance for Quality Assurance Project Plans). The plans were thoroughly reviewed and approved by Office of Research and Development prior to the start of test activities. To aid the EPA in review of the plans, the documents were structured to mimic the required groups and elements of QA/G-5. As a practical matter, MRI recommends that DEJF consider whether a combined test protocol/qapp may be preferable. MRI has prepared both separate and combined plans and finds that the combined versions are usually more useful. A sample outline for a combined plan is given as Table 1. Note that the labels in parentheses (such as A3 ) after each section refer to the group/element labels in QA/G-5 and are included to facilitate review. 5

6 Table 1. Example Annotated Outline for Combined Test Protocol/QAPP Preface Distribution of QAPP (A3) includes list of persons who have received the QAPP, signature approval page, and revision history of the document Figures includes Test Facility Schematic, Sampler Locations, Amendment Record for QAPP, Corrective Action Report Form Tables includes Data Quality Objectives, Test Design, Test Schedule, Critical and Non- Critical Measurements, and Quality Control Procedures for Sampling Media, Quality Control Procedures for Sampling Equipment, Quality Assurance for Miscellaneous Equipment 1. Project Management (A) 1.1 Project Organization (A4) 1.2 Introduction/Background (A5) 1.3 Project Task Description (A6) 1.4 Quality Objectives (A7) 1.5 Project Narrative 1.6 Special Training Requirements/Certification (A8) 1.7 Documentation and Records (A9) 2. Measurement/Data Acquisition (B) 2.1 Sampling Process Design (Experimental Design) (B1) 2.2 Sampling Methods Requirements (B2) 2.3 Sampling Handling and Custody Requirements (B3) 2.4 Analytical Methods Requirements (B4) 2.5 Quality Control Requirements (B5) 2.6 Instrument/Equipment Testing, Inspection, and Maintenance Requirements (B6) 2.7 Instrument Calibration and Frequency (B7) 2.8 Inspection/Acceptance Requirements for Supplies and Consumables (B8) 2.9 Data Acquisition Requirements (B9) 2.10 Data Management (B10) 3. Assessment/Oversight (C) 3.1 Assessments and Response Actions (C1) 3.2 Corrective Action 3.3 Reports to Management (C2) 4. Data Validation and Usability (D) 4.1 Data Review, Validation, and Verification Requirements (D1) 4.2 Validation and Verification Methods (D2) 4.3 Reconciliation with User Requirements (D3) 5. References 6

7 Task 3 Sample Collection and Handling Soil and road surface material samples for the proposed testing may be collected from a variety of locations. Existing samples may be available from prior studies, such as those involving unpaved Arizona road dust and surface materials from Owens Lake. However, some or all of the samples analyzed under Tasks 4 and 5 should or may have to come from other sources. MRI will work with the DEJF to determine the most appropriate types of samples to be used in this study. Samples that are not available from other studies must be collected specifically for this study. Again, MRI will work with the DEJF to determine the best locations and surfaces from which to collect such samples. It is assumed that members of the WRAP (e.g., state, local, and tribal air quality professionals) will be available to collect and ship the samples to MRI. Materials and procedures will be provided by MRI as specified in the test protocol and QAPP. An example procedure is supplied in Figure 2. In the event that targeted portions of the soil textural triangle are not represented in the samples provided by WRAP members, MRI has arranged to acquire from USDA a limited number of selected standard soils from western locations. USDA is unaware of any prior efforts to characterize the PM 2.5 and PM 10 dustiness of standard soil samples. Because of USDA s research interest in this project, they have expressed willingness to provide the required soil samples at no charge to the proposed project. Tasks 4 and 5 Testing and Analysis The proposed experiments will be conducted in the Aerosol Test Facility in Building 2 at MRI s Deramus Field Station. The system for generation and control of dust concentrations in the exposure chamber will use equipment similar to that used in the recent performance evaluation of the MetOne GT-641 aerosol monitor for use at Owens Lake. The MRI test facility consists of an existing push-through flow system (3 ft by 3 ft cross section) with an exposure chamber at the downstream end of the flow tunnel, as shown in Figure 3. The flow system can be operated at low air speeds (as low as 0.5 m/s) that match the isokinetic intake velocity of the cyclone/impactor system. A fluidized bed will inject dust into the blower inlet that feeds the flow tunnel (Figure 4). The fluidized bed will aerosolize fine dust from samples of loose, dry soil. The fluidization rate will be controlled by the upward airflow through the bed. The dust concentration in the exposure chamber will be continuously monitored with DustTRAK monitors, which will be calibrated against a reference method time-integrating PM 10 sampler. An air return loop will connect the outlet of the exposure chamber with the inlet to the blower. The tunnel flow rate will monitored by a pitot tube in the return loop, where the mean air velocity will be higher because of a smaller cross-sectional area. 7

8 The Dust Emissions Joint Forum of the Western Regional Air Partnership is supporting a study of the particle size distribution of dust emissions generated from soils and road surface materials. In particular, experiments are to be performed that will determine whether biases exist in the particle size data generated by the MRI high-volume cyclone/impactor system used to support the PM 2.5 /PM 10 ratios published by USEPA s Compilation of Air Pollutant Emission Factors (AP-42). Besides Owens Dry Lake surface material and Arizona Road Dust, there will be an opportunity for testing other soils/road surface materials submitted by DEJF members. Described below are the procedures for collecting and submitting candidate soils for testing. Of particular interest are soils and unpaved road surface materials of high dustiness potential. It should be noted that soils with high dustiness potential tend to be subject to frequent mechanical disturbed by agricultural operations, construction operations, or other operations involving vehicle travel across exposed areas. Therefore, only samples of unconsolidated (uncrusted and uncompacted) soils or road aggregate materials are likely to have high dustiness potential. Two 5-gal containers of a dusty soil or aggregate material are needed to sustain a series of tests to determine PM 2.5 /PM 10 ratios under a variety of test conditions. Only loose, dry (less than 1% moisture) soils should be collected. For soils, the depth of sampling should not exceed 2 in (5 cm). All particles greater than 4-mesh (0.47 cm) are considered nonerodible and should be removed from the sample by dry sieving prior to shipment of the sample to MRI. MRI will provide a special screen for this purpose. Collection of Surface Soil Samples The following steps outline the procedure to collect a two 5-gal soil samples of pulverized soil from an open area: 1. Define and document the area of interest: a. Size of sampled field b. Lat/long or UTM coordinates of approximate field centroid c. Land use and recent disturbance history d. Recent and current weather e. Observed field surface texture/appearance f. USDA surface soil classification 2. Collect surface soil sample a. Collect two 5-gal containers of soil by compositing approximately equal amounts from a minimum of 10 locations in the same agricultural field i. Use a straight-edge shovel to collect each incremental sample ii. Sample to a loose soil depth not exceeding 2 in (5 cm) iii. Empty each incremental sample from the shovel into the screen that covers a 5-gal plastic bucket iv. Measure the approximate volume of coarse material that is screened from the total composite sample b. Seal the bucket lid using tape and label the bucket with a permanent marker i. Field name ii. Date/time of collection iii. Sample number corresponding to the data sheet iv. Name of person collecting the sample c. Document the sample collection on a data sheet i. Location of sampled areas (e.g., GPS coordinates, sketch of field locations) ii. Approximate area (sq ft) from which each incremental sample is taken Figure 2. Proposed Sampling Procedure for Collecting Test Soil or Road Surface Material 8

9 Collection of Surface Samples of Unpaved Road Aggregate The following steps outline the procedure to collect two 5-gal samples of surface aggregate from an unpaved road. 3. Define and document the area of interest: a. Length and width of sampled road segment b. Lat/long or UTM coordinates of approximate road segment centroid c. Road use and recent maintenance history d. Recent and current weather e. Observed road surface texture/appearance f. Road aggregate type and origin 4. Collect surface soil sample a. Collect 5 gal of loose surface material by compositing equal amounts of uncrusted soil from a minimum of 10 edge-to-edge steps across in the traveled area of the road i. Use a whisk broom and dust pan ii. Sample to a 1 cm depth or to the hardpan iii. Empty each incremental sample from the dust pan into the screen that covers a 5-gal plastic bucket b. Seal the bucket lid using tape and label the bucket with a permanent marker i. Road name ii. Date/time of collection iii. Sample number corresponding to the data sheet iv. Name of person collecting the sample c. Document the sample collection on a data sheet i. Location of sampled areas (e.g., GPS coordinates, sketch of field locations) ii. Approximate area (sq ft) from which each incremental sample is taken Prior to testing for particle size distribution of the suspended dust, sub-samples of loose (unconsolidated) soil/road aggregate samples will be dried to determine the moisture content. In addition, the samples will be dry-sieved to determine the texture (i.e., dry silt content). Figure 2. Proposed Sampling Procedure for Collecting Test Soil or Road Surface Material (Concluded) 9

10 Figure 3. MRI Flow Tunnel Test Chamber Figure 4. Inlet to Test Chamber Blower for Push-Through Operation 10

11 Table 2 lists the air sampling equipment that will be used in the two testing phases. The EPA reference method samplers that will be utilized include Partisols for PM 2.5 and PM 10 measurements. The approximately 3 ft by 3 ft working cross section (Figure 5) can easily provide space for the inlets of two cyclone/impactors, two Partisol samplers, and two DustTRAKs, depending on the requirements of the test being performed. The bodies of the air samplers will be placed underneath the exposure chamber. Figure 5. Test Chamber Interior With Flow Straightener (viewed from downstream exit) 11

12 Task Table 2. Air Samplers for Proposed Testing No. in use Sampler Manufacturer/model Flow rate Comments 4 2 Cyclone preseparators 2 Multistage impactor Sierra Model 230 CP 20 acfm Third stage has D 50 cut of 2.1 µma, which MRI has used surrogate for PM 2.5. Sierra Model 230 First three stages used. 2 Partisol R&P Model alpm Device uses WINS impactor to provide PM 2.5 cut point. 2 DustTRAK TSI Model alpm Used to continuously tract concentration level and uniformity within exposure chamber 5 1 Partisol R&P Model alpm Reference sampler uses WINS impactor to provide PM 2.5 cut point. 1 Partisol R&P Model alpm Reference sampler uses dichot inlet, which has D 50 cut point of 10 µma. Sampler will be fitted with R&P part to bypass WINS impactor. 2 DustTRAK TSI Model alpm Used to continuously track concentration level and uniformity within exposure chamber. Required filter and substrate media will be prepared for air sampling. A temperature- and humidity-controlled gravimetrics laboratory will be used for obtaining tare and final weights of filters and greased impactor substrates. The MRI cyclone/impactor system, shown earlier in Figure 1, traditionally used to determine PM 2.5 /PM 10 ratios for fugitive dust, consists of a cyclone with a directional intake and a three-stage slotted-type cascade impactor. When operated at 20 acfm, the cyclone has an aerodynamic cut point of 15 microns, and the cascade impactor stages have cut points of 10.2, 4.2, and 2.1 microns, respectively. The slotted glass fiber substrates are coated with a thin film of grease before tare weighing, to mitigate against particle bounce problems. For the same reason, care is taken not to overload the substrates with collected dust. Projection of the dust loading on the impactor stages must take into account that the PM 10 sample is distributed over three separate impactor stages plus the back-up filter when the cyclone is operated at 20 acfm. Typically, the cyclone/impactor system has been utilized to generate PM 2.5 /PM 10 ratios that can be used 12

13 in combination with PM 10 plume profiles to generate PM 2.5 emission factors. MRI has an inventory of cyclone/impactor systems available for the proposed program. EPA reference-method R&P Partisol analyzers will be used to measure the concentrations of PM 10 and PM 2.5 in the dust chamber. The dust chamber will be large enough to accommodate two Partisol units and two cyclone/impactor inlets. MRI has available three R&P Partisol monitors for either PM 10 or PM 2.5. An additional Partisol monitor is available as a spare unit in the event that problems are encountered with one of the primary units. It should be noted that because all of the sampling systems involve collection of PM on filters (and impactor substrates), the measured concentrations represent averages over each test period expected to span 30 to 60 minutes. With regard to the filter medium, it is recommended that a fibrous rather than a membrane type filter be used for better retention of dust particles (i.e., inhibit flaking of collected particles). Table 3 shows the proposed test matrix for Tasks 4 and 5. Ten percent field blanks are included for all particle collection media, as is customary to meet quality control requirements. Task 4 AP-42 PM 2.5 Emission Factor Evaluation As indicated in Table 3, three dust source materials will be tested under this task. It is anticipated that Owens Dry Lake surface soil will be used to provide one dust source material for the testing under Task 4. Another likely dust source material is Arizona road dust, which is available as a reference test material. The third material will likely be one provided by a WRAP member. Task Source materials 4 3 (Arizona road dust, Owens Lake surface material, selected soil) Table 3. Preliminary Test Matrix Concentration levels 3 (Low fixed, high fixed, full range variable) Replication 3 (triplicates) Total No. of tests Sampling media used x10 filters x 5 substrates mm plus > 10% field blanks Representative soils or road surface materials (low fixed, high fixed, full range variable) (triplicates) mm filters plus > 10% field blanks 13

14 It is proposed that three separate PM 10 concentration levels (each with its naturally occurring PM 2.5 level) will be tested. Fixed PM 10 concentration levels of 1,000 and 5,000 micrograms per cubic meter will be tested. The PM 10 concentration level during each 30- to 60-min test will be maintained as closely as possible to a predetermined target value. In addition, a variable concentration level representative of a road dust plume will be tested. Tests at each concentration level will be performed in triplicate. It is expected that a total of about 27 individual tests will be performed, as shown in Table 3. Because filter-based reference-method PM 2.5 monitors with relatively low sampling rates will be used in the study, the test periods may have to be extended so that minimum quantifiable mass is collected on the PM 2.5 (47-mm) filters. In addition, certain test soils may not have sufficient dust emission potential to achieve the higher concentrations using the dust aerosolization system. In accordance with the test protocol and QAPP, MRI will compare the accuracy of the AP-42 cyclone/impactor PM 2.5 measurements to the reference method monitor for PM 2.5. Task 5 PM 2.5 to PM 10 Ratios for Different Soil Samples Based on the outcome of Task 4, the sampling configuration for Task 5 will be determined. It is anticipated that reference-method Partisols will measure both PM 10 and PM 2.5 concentrations. Once again, fixed and variable PM 10 concentration (each with its naturally occurring PM 2.5 level) will be tested. In accordance with the test protocol and QAPP, MRI will measure the ratio of PM 2.5 to PM 10 for fugitive dust from up to five (5) different geologic soil types. Data will include the calculation of the average PM 2.5 concentration and the collocated PM 10 concentration. Any variation in PM 2.5 /PM 10 ratio will be evaluated as a function of the test soil properties (for example, wind erodibility group). As stated under Task 3, MRI will work with the DEJF in selecting the five soil types to be tested. These soils may come from three sources: 1. One or more of the soil samples tested under Task 4 2. Soil samples provided by WRAP members 3. Soil samples provided by USDA (with coordination by MRI) With regard to the last source, MRI will coordinate with the USDA National Soil Survey Center in Lincoln, Nebraska. Based on previous communications with USDA, they are willing to provide soil texture analysis of all samples tested in this study as an alternative to providing actual soil samples for testing. 14

15 Task 5A Particle Size Ratios for Additional Samples As an option, Task 5 can be extended to apply to one or more additional soil samples. If this option is selected, the methodology used in Task 5 will be repeated to characterize the PM 2.5 /PM 10 ratios for these samples. The budget amounts for this work (per sample) assume that the samples are available for testing at MRI within two weeks after the laboratory work on Task 5 is complete. Task 6 Project Report MRI will submit a draft report to include an Executive Summary, a description of data collected, data sources, methods and techniques employed, as well as findings, results, and recommendations. If the DEJF decides that the results support changes to AP-42, MRI will also provide draft and final version of any AP-42 sections to be revised along with background documents and appendices associated with such revisions. Such documents will include all experimental procedures, equipment used, and findings. Differences between the existing and proposed AP-42 emission factors will be thoroughly documented and explained. A final report will be submitted after review and approval by the DEJF. 15

16 Attachment B Schedule The project Gantt chart is shown in Figure 6. The chart assumes that the contract will be finalized during the week of December 15, However, there will be a 1-week shift because MRI is closed during the week of December 27, MRI will submit project deliverables per the specifications of the RFP: Within 10 days of the start date, submit a draft work plan for review and approval. Within 30 days of the start date, submit a draft test protocol and QAPP for review and approval. Within 120 days of approval of the test protocol and QAPP, complete testing for at least five (5) soil types. Within 30 days of completing the testing, submit a draft report for review and approval describing the general test procedures and results of the project. Within 60 days of submitting a draft report, respond to comments and submit a final report. It is proposed that the test program be conducted over a period of approximately 10 months from December 2004 to September

17 Figure 6. Proposed Project Schedule 17