Understanding the Sources and Formation Regimes of Present-day PM2.5 to Mitigate Particulate Pollution in California
Scope of Work
The objective of this study is to understand opportunities for additional emission control strategies on PM2.5 reduction, identify current sources and formation regimes of PM2.5, and optimize future mitigation strategies to jointly reduce PM2.5 and O3 levels in California.
Under the Federal Clean Air Act, the California Air Resources Board (CARB) is tasked with the development of State Implementation Plans (SIPs) to achieve the health-based air quality standards for particulate matter (PM). California has made substantial progress in reducing ambient PM over the past several decades.However, ambient fine PM (PM2.5) levels continue to exceed the 24-hour National Ambient Air Quality Standards (NAAQS) in many regions across the state. Achieving a concurrent reduction of PM2.5 along with other criteria pollutants such as ozone (O3) require a coordinated understanding of various emission control measures and their influences on atmospheric chemical composition. Recent plateauing of average ambient PM2.5 and O3 levels pose additional challenges for California’s air pollution reduction pathways that have been developed to reduce the design values of these criteria pollutants.
Photochemical modeling is the key tool used to design SIPs for PM2.5 and O3 mitigation. The models are sensitive to emission sources and chemical mechanisms among others. The source contributions to oxides of nitrogen (NOx)and volatile organic compounds (VOCs), the precursors for secondary PM2.5 and O3, have changed rapidly over the past 20 years. The chemical composition of atmospheric VOCs is also rapidly changing. Vehicular VOC emissions have decreased substantially due to implementation of various air pollutant emission controls. Further emission reductions will be driven by the Governor’s Executive Order with a goal of 100 percent Zero Emission Vehicle (ZEV) sales of new passenger cars and trucks by 2035. In contrast, the relative contributions of the off-road engine emissions, volatile chemical products (VCPs), industrial operations, cooking emissions, and other indoor sources to urban VOCs are growing. The changing abundance and composition of the precursors are expected to shift the atmospheric chemical regimes that lead to PM2.5 and O3 production, both of which vary non-linearly with respect to ambient NOx and VOC levels. Continued efforts are needed to track the influence of air pollutant sources on ambient PM2.5 and O3 under future atmospheric chemical formation regimes to refine California’s air pollution management strategies.
The project will improve our understanding of the current state of PM2.5 pollution in California in the context of recent PM2.5 trends. The formation regimes of PM2.5 will be examined and compared to those of ambient O3 to identify air pollution reduction pathways that lead to air quality co-benefits. The information will provide support to the refinement of air pollution management strategies for immediate and long-term PM2.5 and O3 reduction goals.
Scope of Work
The contractor should create a fully developed research plan and perform all tasks as described below.
Task 1. Evaluate the long-term trend of PM2.5 and O3 across California
The contractor will study the trends of ambient PM2.5, O3, and their precursors (e.g., NOx, VOCs) in California over the past 20 years based on comprehensive evaluation of existing peer-reviewed literature and historical ambient air quality data. Using statistical analysis, the contractor will compare the rate of change of PM2.5 to that of O3 and their precursors (e.g., VOCs and NOx). The contractor will summarize the changes in air pollutant sources and associate them to regions and time periods with the most frequent PM2.5 and O3 exceedances.
Task 2. Design and prepare for field campaigns to examine PM2.5 sources and formation regimes
Based on the results of Task 1 and with consultation from CARB staff, the contractor will design field campaigns in regions of interest to explore the present-day sources and mechanisms that lead to higher PM2.5 levels. The contractor will also design methods to estimate the formation regime of PM2.5 by examining how PM2.5 and its composition respond to the changes in its precursor gases.
The contractor will build and/or acquire instruments and tools (if applicable) that will be used during the field campaign. The contractor will also get the permit(s) for the access of the sampling site (if applicable) and perform site visits as necessary. The contractor will demonstrate the efficacy of both the instruments and the methods prior to the field campaign to optimize deployment and sampling strategies.
Task 3. Conduct field measurements
The contractor will conduct the field measurements in the Environmental Justice (EJ) communities that experience heavy PM pollution. When possible, additional measurements in non-EJ areas will be performed for comparison. The comparison of the EJ and non-EJ results will allow us to evaluate the fairness of the air quality control strategy. The measurements should be conducted during periods that typically exceed the NAAQS. The contractor will work with the communities of interest as appropriate. The contractor will work with the communities of interest for the experiment. The measurements will include sub-hourly PM2.5 speciation with any necessary supporting data. The sensitivity of PM2.5 to perturbations of the precursor gases will be measured and examined.
Task 4. Data analysis of PM2.5 and O3
The contractor will analyze the data collected in Task 4. After quality control of the data, the contractor will conduct source apportionment of PM2.5 to quantify the source contributions to the PM2.5 composition. The contractor will also explore the mechanisms that lead to PM2.5 formation, for example, the secondary organic aerosols (SOAs) and nitrate. The sensitivity of PM2.5 to precursors and the formation regime will be derived statistically from the sensitivity measurements. The sensitivity of PM2.5 will be compared to the sensitivity of ambient O3 to identify their similarities and differences under varying NOx and VOC control scenarios. The PM2.5 sensitivity data will be evaluated with respect to the results from Task 1. Recommendations of synergistic PM2.5 and O3 reduction pathways will be made, particularly addressing both immediate and long-term air quality projections.
Task 5. Final report
The contractor will submit a draft final report to the contract manager 6 months prior to the end date of the contract. The contractor will then modify the report according to the comments from CARB staff and the research screening committee (RSC). The contractor will provide the final report and finalized data collected during the study by the end date of the contract.
The results of this study will provide observational constraints on the present-day sources and production mechanisms of PM2.5, which will enable CARB to refine the modeling framework to refine SIPs for joint PM2.5 and O3 mitigation.
Beginning this fiscal year, 2021-2022, CARB’s Research Division (RD) will require its contracted research projects to embody racial equity components. The newly instituted initiative calls for all RD contracted projects to adopt racial equity components into their research. In light of this commitment to advance racial equity in research, RD will work closely with contractors to not only increase solicitation awareness, but also find opportunities to connect researchers with non-academic partners. Moving forward, RD staff will work with multiple interested stakeholders to develop additional well-established racial equity components that reflect the policies, programs, and interests of CARB to achieve equitable and healthy sustainable community strategies that meet California’s climate goals. The equity components that we hope to see included in the proposals that we receive through this solicitation include those listed in this section below.
- Quarterly Progress Reports and conference calls including public facing updates posted to CARB website (Template will be provided);
- Consultation calls with CARB and key stakeholders;
- Draft final report;
- Final Report and in-person or virtual seminar (pending health requirements);
- All data, analyses and analytical tools generated through the course of this project;
- In addition to the above deliverables, the project must incorporate equity components that could include but are not limited to the following:
- Equity implications section in the final report;
- Encourage academic partners new to CARB contracting and/or from smaller universities;
- All researchers must undergo a cultural competency training (examples include implicit bias training, racial equity training, etc.) and provide a cultural competency statement in the proposal;
- Peer reviewed publications should be publicly available (please budget for this expense);
- Work with CARB to create plain-language outreach deliverables for public (available in multiple languages and formats);
- Additional deliverables to be determined in consultation with CARB staff.
It is anticipated this project will be completed in 36 months from the start date. This allows 30 months for complete for completion of all work through the delivery of a draft final report. The last 6 months are for review of the draft final report by ARB staff and the RSC, medication of the report by the contractor in response to ARB staff and RSC comments, and delivery of a revised final report and data files to the ARB. The estimated budget for this project is $500,000.
In order to increase transparency of how winning pre-proposals are chosen, scoring criteria have been included for each project. Please note that scoring criteria is tailored to each project included in CARB's fiscal year 2021-2022 solicitation. If you are submitting pre-proposals for more than one project in the solicitation, please be sure to review the scoring criteria to get a better understanding of what components of the project are most valued for selection.
- Responsiveness to the Goals and Objectives Outlined in the Proposal Solicitation(15 points) Proposers should demonstrate a clear understanding of the policy objectives and research needs that CARB seeks to address with this project, and should convey their knowledge of the subject. The proposal should spell out, in adequate detail, exactly what the Proposer proposes to do to satisfy the requirements of the Solicitation. The draft proposal must propose work that would satisfy the objective(s) stated in the Research Solicitation: The objective of this study is to understand opportunities for additional emission control strategies on PM2.5 reduction, identify current sources and formation regimes of PM2.5, and optimize future mitigation strategies to jointly reduce PM2.5 and O3 levels in California.
- POLICY RELEVANCE/BENEFITS TO THE STATE(10 points) – Does the proposal describe how the project will provide data, information, and/or products to help CARB accomplish its mission? Under the Federal Clean Air Act, the California Air Resources Board (CARB) is tasked with the development of State Implementation Plans (SIPs) to achieve the health-based air quality standards for particulate matter (PM).
- PREVIOUS WORK (10 points) – Do the researchers have relevant experience in this area? Do they discuss how they will build upon previous relevant work that was funded by CARB, other state agencies, and the U.S. EPA, National Science Foundation, U.S. Department of Energy)?
- EXPANDING EXPERTISE (10 points) – Does the team bring in new talent that has not worked with CARB previously? Is the team composed of a multidisciplinary team of experts? Researchers new to CARB are encouraged to apply and partner with multidisciplinary teams.
- TECHNICAL MERIT (25 points) - Describe the submission's technical strengths and/or weaknesses. Proposers should demonstrate the logic and feasibility of the methodology and technical approach to the project, spell out the sequence and relationships of major tasks, and explain methods for performing the actual work. Please factor in how well the draft proposal describes these areas:
- Is this the correct measurement approach? Will the methodology provide novel data to achieve the objectives?
- Are the techniques used in the measurements comprehensive? Are the data analyses statistically sound?
- The review team will be selecting only one draft proposal for development into a full proposal. If this draft proposal has potential, what areas or topics should be prioritized or better explained in the full proposal?
- LEVEL AND QUALITY OF EFFORT TO BE PROVIDED(15 points) – Does the proposal allocate time and resources in such a way that the objectives of the study will be met? Is supervision and oversight adequate for ensuring that the project will remain on schedule? Is the distribution of workload appropriate for activities such as research, evaluation and analysis, data reduction, computer simulation, report preparation, meetings, and travel?
- COST EFFECTIVENESS (15 points) - Does the cost seem appropriate for the proposed work? Does the proposed work seem feasible within the requested budget? Projects that provide co-funding should be evaluated more favorably.