SUSTAINABILITY COMMITTEE
Meeting Date: March 9, 2026
Subject: RECEIVE REPORT on proposed updates to CalEnviroScreen, and PROVIDE DIRECTION
Submitted For: John Kopchik || Director | DCD
Department: DEPARTMENT OF CONSERVATION & DEVELOPMENT
Presenter: Jody London || Sustainability Coordinator | DCD
Contact: Jody London | (925) 655-2815
Referral History:
In 2012, the California Environmental Protection Agency (CalEPA) released the CalEnviroScreen mapping tool, which provides an analysis of the impact of both pollution and socioeconomic factors at the census tract level. One of the primary purposes of the data is to identify “disadvantaged communities” (DACs) that are disproportionately burdened by pollution and other hazards that can lead to negative health effects, exposure, or environmental degradation. The current Disadvantaged Community designation includes census tracts that meet one of the following four categories:
• Census tracts receiving the highest 25 percent of overall scores in CalEnviroScreen 4.0 (1,984 tracts).
• Census tracts lacking overall scores in CalEnviroScreen 4.0 due to data gaps but receiving the highest 5 percent of CalEnviroScreen 4.0 cumulative pollution burden scores (19 tracts).
• Census tracts identified in the 2017 DAC designation as disadvantaged, regardless of their scores in CalEnviroScreen 4.0 (307 tracts).
• Lands under the control of federally recognized Tribes.
Because Contra Costa County is home to four refineries, two power plants, and other large industrial facilities, many census tracts qualify as disadvantaged under CalEnviroScreen 4.0. The Contra Costa County General Plan and Climate Action and Adaptation Plan identify “Impacted Communities” using CalEnviroScreen 4.0 data with a cumulative CalEnviroScreen score of 72 or higher.
Since CalEnviroScreen was first adopted in 2012, it has been updated three times. In 2016, as CalEPA was considering CalEnviroScreen 3.0, the Board of Supervisors sent a letter to CalEPA raising concern that the proposed criteria would result in significantly fewer communities being identified as “disadvantaged.” See Attachment A. The County pointed out that projects critical to improving the quality of life for our residents would be more difficult for us to realize and recommended that the funding allocation methodology direct a portion of funds to communities located near large industrial sources.
Referral Update:
CalEPA has released CalEnviroScreen (CES) Draft 5.0 for public comment with comments due April 1, 2026. Staff analyzed the new data updates of how various factors have changed since CES 4.0, including an overview of the distribution of the changes at the state, region, and county level along with the factors that might impact specific census tract scores.
Overview of CES 5.0 Model
The CES model compares about 23 different environmental, health, and demographic criteria and assigns a Pollution Score, a Population Score, and a Cumulative Score for each census tract. The scores are then ranked statewide and given a percentile based on how the scores compare to other census tracts.
Those census tracts with a cumulative impact score in the highest 75%, roughly 1/4 of the state's Census Tracts/Population, are designated as 'Disadvantaged Communities' per Senate Bill 535. The Disadvantaged Community designation is used by various agencies and entities to identify where to direct resources to mitigate impacts of pollution and environmental hazards faced by the most vulnerable populations in the state.
Why Score Might Change between CES 4.0 and draft CES 5.0
Due to the evolving nature of the CES model, as well as its data sources, it can be complicated to discern if any given score change is attributable to on-the-ground mitigation of environmental hazards, refinements to the data that reveal a previously hidden hazard, or unintended side effects of methodology that are distorting the results. Furthermore, since the entire State is essentially 'graded on a curve', combinations of the first three factors in one part of the State may shift the percentages slightly in another.
• Variability in geographic attribution and data collection
The data sources used to create the CES model vary widely by geographic specificity. For example, a landfill is a precise location, a congested freeway is a specific corridor, and data on asthma rates are collected based on wide areas like Zip codes. CES combines these disparate data measures and ultimately assigns a score to an entire census tract.
Census tracts all by themselves vary in geographic scope. Some include a handful of square blocks of densely populated urban development and are relatively homogeneous in their environmental vulnerability. However, other census tracts are large sprawling expanses, containing the edges of several disparate communities. As such, CES may inadvertently combine areas with vastly different environmental factors onto a single census tract thus assigning them the same vulnerability score.
Additionally, criteria associated with the data collected through a major data source, such as the American Community Survey (ACS), often have wide margins of error. Data collected at the census tract level has increased uncertainty due to a smaller sample size. It should be noted that ACS data included in CES 5.0, such as linguistic isolation and unemployment rate, experience high variability for this reason.
• Geographic Updates
Census geography changes every decade to reflect population changes. In an effort to create geographies with an optimal target of 4,000 residents per census tract, the Census Bureau may combine or split census tracts, making comparisons to older census geography complex. The 2020 Census resulted in 34 more census tracts in Contra Costa County compared to 2010.
CES 4.0 uses 2010 census geography and CES 5.0 uses 2020 census geography. Therefore, comparing CES scores for two census tracts that split from one tract can be challenging. If the scores are very different, it may reflect an accurate refinement of the data. For example, if a 2010 tract had a high pollution score due to a pollution source was split, the new 2020 tract with the pollution source will get a higher score compared to the other 2020 tract without the pollution source.
The population score percentages also change due to the makeup of the residents within each of the new census tracts. Often census tracts are created due to new development, which can be different from the older community included in the original census tract.
• Evolving Methodology
The latest update to CES introduces several different levels of refinement to the CES model. The data refinements were developed by CalEPA in collaboration with community organizations focused on environmental justice issues. The model considers new measures, has updated methodology on how to synthesize other measures onto Census Tracts, and uses updated source data where available.
CES 5.0 includes two new indicators: Diabetes Prevalence and Small Air Toxics Site. These variables account for the percentage of adults with diabetes and proximity to Small Air Toxic Sites.
CES 5.0 has also refined existing criteria: Hazardous Waste, Drinking Water Contaminants, and Children’s Lead Risk from Housing. Specifically, these modifications are increasing the buffer around hazardous waste facilities from 1 km to 4 km, improving drinking water contaminant data and adding water quality data for additional Tribal areas, and incorporating children’s blood lead level data.
Given the evolving methodology is layered upon the inherent variability in data collection and attribution along with changing geography, it is difficult to pinpoint specific changes due to new and refined criteria.
Overview of Distribution
Census Tracts that have a cumulative impact score at or above the 75th percentile have shifted between CES 4.0 and Draft CES 5.0. It is not unusual for a portion of the population to swing in and out of CES Disadvantaged Community designation between CES versions.
Overall Draft CES 5.0 shows a 20% swing in the population in the top 75%. Of the roughly 10 million people statewide that were designated as impacted by CES 4.0, 2,000,000 are shown as not impacted in Draft CES 5.0, while another 2,000,000 people are now shown as impacted, though they were not in CES 4.0. Attachment B includes charts to demonstrate how the top 75% distribution has changed for California regions and how Bay Area counties have changed between CES 4.0 and Draft 5.0
Draft CES 5.0 in Impact on Contra Costa County Communities
In Contra Costa County, the changes to the census tracts in the top 75% include the following shifts, as shown on the map in Attachment B. The following provides a summary of how the unincorporated areas of Contra Costa County shift in Draft CES 5.0. Communities noted with an asterisk were subject to a census tract split.
• New Top 75% (Likely to be identified as Disadvantaged Community for funding)
Northern East Richmond Heights, Knightsen*, Byron
• No Longer Top 75%
Montalvin Manor & Bay View*, East Pacheco/Concord*, North Concord/Clyde/SW Bay Point, SE Bay Point (West of Bailey)*, NE Bay Point, NW Bay Point,
• No Change, still in top 75%
North Richmond (residential), Rodeo Old Town/West Crockett, SE Bay Point (East of Bailey)*
• No Change, was either Disadvantaged or Impacted Community by an alternate definition
Rollingwood, Tara Hills, Northern Vine Hill
Draft Comment Letter to CalEPA
Staff have prepared a draft letter for the Sustainability Committee to consider. The letter includes potential topics the Board may want to address in a comment letter to CalEPA. Comments are due by April 1, 2026, and anticipated to go to the Board of Supervisors with the Committee’s recommendations on March 24, 2026.
• Support Integrating Climate Change Indicators in CES 6.0
CalEPA will be developing a strategy for integrating climate data for use in CES 6.0. Contra Costa County supports this process as a collaborative effort to ensure Climate Action and Resiliency continue to be a priority for the State while reflecting local community impacts.
• Large Data Swings:
Some data points experience a swing of over 20% and often over 50% between CES versions due to small sample size, changes in methodology, or other factors. Specific criteria our analysis shows significant swings include cleanups, hazardous waste facilities, low birth weight, unemployment rate, and housing burden. For example, a census tract in Bay Point was in the top 76% for hazardous waste per CES 4.0 and in the Draft CES 5.0 it was in the bottom 7%. That is a substantial drop for a community that did not change significantly.
• New Designations do not match local knowledge on the ground
Some of the County’s most historically disadvantaged communities are no longer disadvantaged while others that are not especially disadvantaged in any way are now categorized within the top 75% of California cities. Communities such as Bay Point and the mobile home park in Pacheco are no longer in the top 75% while communities like East Richmond Heights and Knightsen have a Draft CES 5.0 in the top 75%.
There may be reasons within the underlying data for some of these inconsistencies. For example, there appears to be significant variation in the hazardous material points between CES 4.0 and Draft 5.0, with an increased number of hazardous materials identified in homes and removal of known facilities, including a landfill. A more in-depth analysis would be required to see if there are additional inconsistencies in the data.
• Balancing CES methodology updates with Local Planning Efforts.
CalEnviroScreen has evolved into a cornerstone for not only California policy and funding implementation, but also for local planning efforts.
The County’s General Plan and Climate Action and Adaptation Plan include policies focused on environmental justice, as required by Senate Bill 1000 and required by the County’s Board of Supervisors. Both documents rely on the CalEnviroScreen designation to identify Impacted Communities in Contra Costa County. Updating the General Plan to reflect updated designations is anticipated, however when the new designations conflict with local knowledge
Given the model attempts to quantify local impacts using a large scale, there are communities that continue to have the same impacts between CES versions, yet to move in and out of the Disadvantaged Community designation. Thus, local planning efforts and project funding anticipation diverge from State policy and funding opportunities.
Please consider integrating these transitionally disadvantaged communities into the analysis by either capitalizing on previous CES analysis or creating more than one designation.
• Consider updating Statewide Climate Funding Methodology:
As noted above, one of the ways the state uses the CES “disadvantaged” designation is to determine eligibility for funding. This leads to a situation where neighboring communities are often competing against each other for limited funds, and many communities are not eligible at all. The state could consider a different method of allocating funding that would increase participation and accelerate progress toward statewide climate goals by simplifying access to funding.
According to the California Climate Investments Programs web site, “Across California, 117 California Climate Investments programs administered by 27 State agencies are continuing to direct billions of dollars into our state’s transition to a low‑carbon and more equitable future.” It is a stretch for local government to track these grant opportunities, provide comments on draft guidelines, and then determine whether to apply for competitive grants. Before applying for a grant, the local government must weigh the time and resources needed to develop the grant application against the likelihood of receiving the grant award. This automatically censors the pool of participating applicants, often leaving out those who do not have the staff and/or resources to develop grant applications.
The State could consider using flexible block grants, rather than a competitive grant process, for local governments that demonstrate how funds will be used to meet State-identified criteria. The State could take the list of California Climate Investment programs and use it as a menu from which local governments could choose to spend their funds. The State could provide adders for communities that are considered disadvantaged. It could also provide adders for other criteria such as including community-based organizations in program design and delivery, designing implementation projects that create high-road jobs, or incorporating collaboration by neighboring jurisdictions to create projects with regional reach and significance. This would allow more communities across the state to benefit from the California Climate Investments Programs while still achieving State goals. And it would free up State agency staff to focus on program administration development and implementation, rather than writing grant guidelines and conducting bid processes.
This model has been successfully implemented in the past, including grants for Proposition 39 school energy efficiency projects and the Ocean Protection Council’s Senate Bill 1 Grant Program. Hallmarks of these programs include rolling quarterly submissions and intergovernmental collaboration, which enable jurisdictions to apply when they are ready and able to implement these priorities.
Recommendation(s)/Next Step(s):
RECEIVE REPORT on proposed updates to CalEnviroScreen and PROVIDE DIRECTION.
Fiscal Impact (if any):
Potential impact on future grant funding.