Clean_School_bus_eval_methods.docx

www.pca.state.mn.us

School Bus Replacement Grant Minnesota Diesel Replacement Program Volkswagen NOX Mitigation Settlement Phase 3 Evaluation Methods

This document outlines the methods used to develop criteria for project selection for the Minnesota Pollution Control Agency’s (MPCA) School Bus Replacement Grant round in FY 2025. All the available funding for this grant round comes from the Volkswagen (VW) settlement. As part of Minnesota's plan for its VW settlement funds, the MPCA established overarching goals for the program. Those goals are:

Achieve significant emissions reductions of nitrogen oxides (NOX), fine particles (PM2.5), and greenhouse gases (GHGs) Benefit all parts of the state Help people and places disproportionately affected by air pollution Reduce exposures to harmful air pollutants and maximize health benefits Balance cost effectiveness with other goals As part of the MPCA’s efforts to achieve these goals, we have developed methods to help select projects that advance these priorities. We have worked with the Minnesota Department of Health (MDH) and the MPCA’s Environmental Justice Advisory Group on these methods. We will review and improve these methods as necessary in future ground rounds. The methods that will be used to evaluate and score projects submitted to the School Bus Replacement Grant Request for Proposal (RFP) are outlined here. Only applications meeting the eligibility criteria outlined in the RFP will be considered for scoring.

Scoring Criteria A 100-point scale per project will be used to evaluate eligible applications. Scores will be used to develop final recommendations. Projects will be evaluated and ranked in their respective categories (Twin Cities 7-county Metro area versus Greater Minnesota) according to the following criteria:

Applications will be evaluated and ranked according to the following criteria:

· Emissions reductions cost effectiveness (45 points max)

· Environmental justice benefits (30 points max in Greater Minnesota, 20 points max in the Twin Cities Metro area)

· Vulnerable population benefits (5 points max) Comment by Josephson, Tracey (MPCA): Need to match with any changes to the RFP

· Health benefits (5 points max)

· Air pollution benefits (5 points max)

· Other (10 points max) Emissions reductions For each diesel school bus submitted to be replaced, MPCA estimates the potential reductions of three air pollutants: nitrogen oxides (NOX), fine particles (PM2.5), and greenhouse gases (GHGs). We consider emissions of NOX and PM2.5 because they are the primary pollutants associated with diesel pollution and are harmful to human health. We consider GHG emissions due to their contribution to climate change. We calculate operation (tailpipe) emissions reductions of NOX and PM2.5 and well-to-wheel reductions of GHGs. This means that the upstream GHG emissions impacts from electricity generation and fossil fuel production are included in our calculations.

To calculate emissions, MPCA uses data from Argonne National Laboratory’s Alternative Fuel Life-Cycle Environmental and Economic Transportation (AFLEET) tool. AFLEET is a publicly available tool that uses Argonne’s Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET) fuel-cycle model to generate wheel-to-wheel greenhouse gas emission coefficients for different fuel types of on and off-road equipment, and Environmental Protection Agency's (EPA) Motor Vehicle Emission Simulator (MOVES) and certification data to estimate tailpipe air pollutant emissions.

Estimated emissions reductions are largely based on the old bus’s age, usage, and performance, and the new bus’s fuel efficiency and fuel type. Applicants supply information about the usage of their old bus in the application (bus type, annual mileage/hours and fuel usage, etc.) that MPCA uses to model the bus’s annual emissions. For school bus emissions evaluations, the model year of the old bus will be obtained from the vehicle’s VIN check. If an applicant submits a bus for replacement that is known to have an engine model year that is different than the model year returned by a VIN check as a result of an engine replacement (example: a 2008 engine in a 1991 school bus chassis), the applicant must submit verification that an engine replacement took place. The applicant should also supply the accurate engine model year that should be used for eligibility verification and emissions evaluations. All new busses and pieces of busses will be evaluated as 2023 models. If any inputs required for emissions evaluations are missing from an application, the project will automatically receive zero points for emissions reductions, as MPCA will be unable to evaluate it.

MPCA will calculate emissions from the old and new bus using whichever reported annual mileage or hourly usage is less, since that would be the actual mile-to-mile or hour-to-hour replacement taking place between the old and new bus. For example, if an old bus went 10,000 miles over the last 12 months, and the new bus is expected to travel 12,000 miles annually, we will evaluate the annual emissions from both buses using 10,000 miles.

Emissions reductions are calculated over the estimated remaining lifetime of the old bus and consider the deterioration of both the old and new bus over time. MPCA assumes diesel on-road vehicles to have a useful life of 32 years, so remaining years of life will be determined by subtracting the bus’s age in 2023 from 32.

To account for Minnesota’s biodiesel requirement of a 20% blend of biodiesel (“B20”) in diesel fuel sold during the warm-weather months of April-September and a 5% blend (“B5”) from October through March, we will use a weighted average of 12.5% biodiesel when evaluating GHG emissions associated with diesel fuel consumption. MPCA will use the most recently available US Energy Information Administration’s (EIA) average Minnesota mix of coal, natural gas, residual oil, biomass, nuclear, and renewables for calculating the upstream GHG emissions from electricity generation.

Emissions reductions points will be available as outlined in Table 1.

Table 1. Points available for emissions reductions

Emissions reductions cost effectiveness Once the emissions reductions for nitrogen oxides (NOX), fine particles (PM2.5), and greenhouse gases (GHGs) are calculated for all busses in the project proposal, MPCA then calculates the cost effectiveness per pollutant. Cost effectiveness is calculated by dividing the emissions reduction amounts for each pollutant by the total dollar request for the application. For each pollutant, the project that achieves the greatest emissions reductions per dollar receives the maximum number of points possible (see below for points per pollutant). All other projects are scored based on the ratio of their cost effectiveness compared to the most cost-effective project. For example, if the project with the best cost effectiveness for NOX achieves a reduction of 1 pound per dollar, that project will receive 20 points for ranking as the most cost-effective project. If another project achieves a NOX reduction of 0.5 pounds per dollar, that project will receive 10 points. This is calculated by taking the ratio of cost effectiveness (0.5 ÷ 1 = 0.5) and multiplying by the maximum number of points (0.5 x 20 = 10).

Environmental justice benefits MPCA modeling shows that low-income people and people of color are at greater risk from air pollution. Environmental Justice means that pollution does not harm one group of people more than another, that all Minnesotans benefit from the same level of environmental protection, and that everyone has equal opportunity to participate in decisions that may affect their environmental health. The MPCA is committed to investing at least 20% of the Volkswagen Settlement funds in areas disproportionately affected by air pollution in the Twin Cities Metro region, and another 20% of funds in those areas in Greater Minnesota.

The MPCA considers areas disproportionately affected by air pollution to be environmental justice areas. These areas are:

Census tracts where more than 50% of residents are people of color or Native Americans Census tracts where more than 40% of the households have an income of less than 185% of the federal poverty level Tribal lands A map of areas of concern for environmental justice in Minnesota can be found online here. This map is subject to change. MPCA will use the most current map available at the time of evaluation.

The MPCA’s environmental justice mapping tool identifies environmental justice areas at the census tract-level. However, because busses move around, census tracts are too small a geography to reasonably identify as a primary place that the bus operates. Instead, MPCA uses ZIP codes. For each ZIP code in Minnesota, MPCA has calculated the percentage of its area that is made up of areas of concern for environmental justice and considers higher population in proportion to environmental justice areas in Greater Minnesota. Points are assigned to ZIP codes based on the percentage of their area that is made up of environmental justice areas. For 75 zip codes that fall in the 0-50% environmental justice areas in Greater Minnesota, zip codes that contain the 25% highest populations in Minnesota AND contain some areas of concern for environmental justice will also receive the maximum points.

For each ZIP code in Minnesota, MPCA has also calculated the primary county in which it is located. MPCA will determine whether a project is in Greater Minnesota, or the Twin Cities Metro area based on the primary county associated with the primary ZIP code.

Vulnerable population benefits Comment by Josephson, Tracey (MPCA): Is this applicable?

Up to 5 points will be awarded to each replacement project based on responses to the two vulnerable population questions. Applicants should answer both questions for each requested bus replacement on the application.

Health benefits To consider the potential health benefits of reduced diesel pollution in a community from a project, an inter-disciplinary team at MDH worked to develop a science-based method for identifying areas of the state overburdened with air quality-related health concerns. MDH relied on multiple MDH data sources, covering representative health conditions that can either be worsened by air pollution exposure or make individuals more vulnerable to air pollution exposure.

MDH considered a variety of health indicator data and among these selected indicators that best and most uniquely represent health vulnerability to air pollution exposure. The four health indicators they selected – respiratory and cardiovascular diseases, adverse birth outcomes, and obesity – are summarized in Table 2. For data privacy reasons, health data is available at the ZIP code level for the Twin Cities Metropolitan Area, but only at the county level in Greater Minnesota.

Table 2. Indicators included in health burden index

*Note that data sources for the obese/overweight indicator are different for Metro zip codes versus Greater MN counties, due to data availability and resolution.

MDH staff determined that a health burden index was the best way to combine multiple important conditions in a single health metric for scoring project applications. They calculated the index using standard public health methods. They calculated quartiles for each indicator, and assigned a 1, 2, 3, or 4 depending on the quartile, with 4 being the highest health burden category.

For example, if the rate of asthma emergency department visits in each county fell above the overall statewide 75th percentile, or in the top quartile, then that county would be assigned a score of 4 for the asthma indicator. The quartiles were calculated separately for Greater Minnesota counties and Twin Cities Metro ZIP codes. The scores assigned for each of the four indicators were then summed for each geographic area. The index range is 4 to 16, with higher scores indicating higher health vulnerability to air pollution. For simplicity, they created three score categories – 0, 2.5, and 5 – each containing the same number of counties or zip codes. Each Greater Minnesota ZIP code was analyzed to determine its primary county (the county making up the majority of its area) and was assigned the same score as its primary county.

Detailed information about each of the health data sources can be found on the MN Public Health Data Access Portal.

Air pollution benefits Reducing emissions anywhere is beneficial for the environment and human health, but reducing emissions in areas that tend to have more air pollution than others has the additional benefit of decreasing the level of exposure to pollution in those areas. To consider the locational benefits of reduced NOX and PM2.5 emissions in different parts of the state, the MPCA developed a method to score projects based on modeled air pollution concentrations in areas where a new bus will operate and reduce emissions.

Because it is not feasible to monitor air quality on every block in the state, the MPCA uses its MNRISKS model to understand potential air pollution concentrations at a fine scale. The MNRISKS model uses reported and estimated air pollution emissions from all kinds of sources, including traffic, along with meteorological and topographic conditions and modeled understanding of chemical reactions in the atmosphere to estimate air pollution levels across the state.

Using MNRISKS, MPCA produced two modeled air pollution concentration maps for the state: one for NO2 and one for PM2.5. Each ZIP code in Minnesota was then analyzed to determine the maximum pollution concentration of each pollutant within its area. Using federal Air Quality Index (AQI) breakpoints, MPCA classified each ZIP code’s maximum concentration value into the six AQI categories: “good”, “moderate”, “unhealthy for sensitive groups”, “unhealthy”, “very unhealthy”, and “hazardous”. The AQI breakpoints are pollutant-specific and are established by the US EPA through the National Ambient Air Quality Standards (NAAQS). ZIP codes were assigned 0 to 2.5 points (at half-point increments) for each pollutant depending on the AQI category of the maximum pollution level within the ZIP code’s area. AQI categories corresponding to higher modeled concentrations were assigned more points. The points each ZIP received for each pollutant was summed for a maximum possible total of 5 points for air pollution benefits.

Table 3: ZIP code points for modeled air pollution concentrations

Other scoring criteria Five (5) points will be awarded to projects purchasing a new propane or natural gas-fueled bus.

Three (3) points will be awarded to projects that are equipped with technology designed to assist passengers with disabilities.

Two (2) points will be awarded to busses equipped with idle reduction technology image1.png