Smoking Polluters: Visible Emissions and Citizen Science in the Valley

Guest Blogger: Rodrigo Alatriste-Diaz (Tulare County) – PHD Grad-Student at Cornell Univ.

This blog post describes an ongoing project between CCEJN and U.S. EPA to engage San Joaquin Valley (the Valley) community members in citizen science.  As part of this project, a cohort of seven community members was convened to participate in CA-EPA Air Resource Board’s (ARB) 100 Series Course–Visible Emissions Evaluation (VEE). This course is typically limited to regulatory agencies and industry personnel. Our participation in this training and in citizen science is part of an ongoing process to increase community involvement. Below we explain citizen science, its importance, and share our recent experience in completing VEE training and certification. Observations and recommendations are made to make the certification process more accessible and ultimately democratize environmental protection.

Citizen Science for Who?

Citizen science is a method to increase public input in environmental protection and management by way of education, data collection, and dialogue. This goal is achieved by community learning and public involvement in the environmental protection process.

Citizen science, as an EPA initiative, has been found to lead to the following: input into the environmental protection process, involvement in the outdoors, advocate and researcher collaboration, environmental science education, and the local creation of data and experts.

However, citizen science is also a limited form of civic engagement. Volunteering is a luxury that some people can’t afford; citizen science volunteers must find the disposable time and resource to participate[1].  Another major obstacle is the scientific literacy required to engage in citizen science. Again, volunteers must donate their time to educate themselves and become literate and understand bureaucratic processes and their respective agencies. In the end, volunteers must unquestionably accept science as a language to engage and influence technical decisions and processes.

Making Citizen Science in the San Joaquin Valley:

Despite the challenges noted above, citizen science has the potential to make environmental protection more democratic in the Valley.  Among other environmental health concerns in the valley, air quality is very low and contributes to high rates of asthma and cardiovascular disease. Sources of pollution in the Valley vary from mobile emissions like cars and trucks to stationary sources like agriculture, dairy, and oil processing.  According to the American Lung Association, four Valley metropolitan areas are ranked as the most polluted cities across three types of pollution in the United States (see chart below). Of the nine California Air Districts, the San Joaquin district is the largest by land size. Thus, an important place for a citizen science project.

With this goal in mind, the CCEJN cohort completed the VEE course during the month of October. To become a certified visible emissions evaluator three steps are required: 1) complete an online course that takes 10-14 hours to complete, 2) a half-day classroom lecture, 3) and a field exam.

The online course-is well organized and includes visualizations and some interactive learning. In order to complete the online course reliable internet access is needed for long periods of time. The course is divide into seven sub-sections; each section is followed by a short exam.  The entire online module is well structured and very helpful to an air quality novice. However, at times the online course can be overtly detailed and highly technical. For example, learning equations used to read a psychrometer table or learning a specific volatile organic compounds (VOC) substance like formaldehyde.

At the end of each section a PDF version of all on-line material is made available for printing. If printed material is made available before online instruction, students will be able to read and review materials off-line and at their leisure.  Supplemental learning materials like flash cards or visual materials like the Visible Emissions Evaluations Handbook (see picture below) are good teaching materials.  Materials like these can help a variety of learners such as visual learners and limited English language learners.

After completing the online course, our cohort drove to Monterey to participated in a half-day course. The instructor for this course was very knowledgeable and engaging. He shared that the certification rate has steadily increased to its current rate of 80% and in-class instruction was reduced from five days to one.  The course was very relaxed, and focused primarily on the logistics and strategies for passing the field exam.

The field exam is the highpoint and the final part of the certification. Students meet at a park or public location to observe stationary emissions released from an ARB trailer and determine opacity of emissions (see picture above). During the exam, students are required to visually determine opacity on a twenty point-scale of twenty-five white and twenty-five black plumes. In order to certify your total answers can deviate no more than 7.4 points.  The visual exam is challenging and requires a lot of concentration. From our cohort 3 out of 5 people certified (60% passed).

Final Remarks and Recommendations

VEE is a powerful tool.  A visual emission observation with proper documentation from a VEE certified community member can result in a violation against a polluting facility. In fact, a VEE can trump air monitoring data from instruments generated within that polluting facility.

However, to make use of VEE and democratize environmental protection the fundamentals of this course and certification need to be shifted away from industry and compliance agency expertise to a wider community. Below, are some recommendations to make VEE training more accessible to community members. The urgent need for environmental protection and regulation of air pollution in the Valley are compelling reasons why individuals and organizations are, and will continue to be, committed to citizen science in the Valley.


  • Train local community experts to increase general knowledge of environmental regulations and compliance standards.
  • Increase access to technical education for volunteer monitoring programs to provide specialized knowledge of specific mediums (air, water, etc.) to increase accuracy of reporting and more dialogue with compliance agencies.
  • Tailor learning materials to various kinds of learners (visual learners, English language learners, etc.) and use of informal education models or popular education to increase accessibility to material.
  • Use a train the trainer model, such as the use of health promotoras, to disseminate regulation and compliance information to the general public and to help with transcription of technical information.
  • Determine demand and need for VEE training and examination in counties with the lowest air quality–Fresno and Tulare County (VEE training and VEE exam are currently not available in these counties).
  • Supplement community monitoring projects with training and access to publicly available information (i.e. location of violation, location of facility, and incidence of violations). For example, according to ARB’s 2016 case settlement data the majority of violations appear to come from mobile sources. Thus, monitoring projects can use data to focus on a specific sector or super polluters[2].

[1] Pfeffer, M. J. and L. P. Wagenet (2007). Volunteer Environmental Monitoring, Knowledge Creation and Citizen-Scientist Interaction. Sage Handbook of Environment and Society Los Angeles ; London, SAGE.

[2] Mary, B. C., et al. (2016). “Linking ‘toxic outliers’ to environmental justice communities.” Environmental Research Letters 11(1): 015004.