Category Archives: Air monitors

KQED: Coverage of Valero Benicia Refinery emergency releases

Repost from KQED California Report

Problems at Valero’s Benicia Refinery Increase, Prompt Health Advisory

By Ted Goldberg, Mar 24, 2019, updated at 10:05am
Problems began at the refinery on March 11 when a malfunction involving one of the refinery’s units led to the release of petroleum coke dust. (Sasha Khokha/KQED)

Benicia city officials are urging residents with respiratory issues to stay inside because a two week old problem at the Valero refinery has intensified.

“Go inside your home, workplace, or the nearest building that appears to be reasonably airtight and stay there,” reads an advisory sent out by the city of Benicia Sunday morning.

The problem began on March 11 when a malfunction involving one of the refinery’s units led to the release of petroleum coke dust.

A Valero representative said then that refinery’s flue gas scrubber was “experiencing operational issues.”

The releases prompted local air regulators to issue seven notices of violation against the refinery. 

Those problems eased after a few days but continued intermittently, air district officials said.

On Saturday several Benicia residents posted comments on the social media site, Nextdoor, expressing concerns about what appeared to be more black smoke coming from Valero’s stacks.

On Sunday that intensified.

“(The) City of Benicia has issued (an) advisory notice for all residents with respiratory issues due to particulate matter from an ongoing incident at the Valero Benicia Refinery,” the city’s statement reads.

City officials are telling local residents with weakened respiratory systems to close all doors, windows and fireplace dampers, urging them to put tape or damp towels around doors and windows to seal them.

The advisory also recommends that healthy people limit their outdoor activity.

“The concentration of particulate matter has become significantly higher over the past day. The emissions contain coke, a by-product of the refining process that is made up primarily of carbon particles,” the city’s statement says.

Benicia officials said testing of the coke dust released so far did not show heavy metals at harmful levels but warned that breathing in air from the releases could worsen underlying respiratory conditions like asthma.

In a statement, the Bay Area Air Quality Management District said inspectors are at the refinery investigating the cause of this heavy smoke. The Air District also deployed a monitoring van to drive throughout Benicia to “gather ground level emissions data.”

MUST SEE: All about particulate matter air pollution in the Bay Area

From James Leach of Lafayette, CA, on YouTube
[Editor: This is a really important, really helpful, informative and challenging video. I thought I knew all about air pollution, but I learned a lot here.  It’s 38 minutes, so get comfortable or bookmark and come back when you have a little time.  – R.S.]

Clearing the air

By James Leach, published on Aug 19, 2018
Solving the particulate matter air pollution problem in Lafayette, California and the San Francisco Bay Area Region.

Air monitoring in your neighborhood

Repost from League of Women Voters Bay Area Monitor
[Editor: Our small two-freeway/refinery town recently saw an increase in the number of residences with outdoor PurpleAir monitors – from 3 in December to 8 as of today.  For current air quality data in Benicia and how to buy your own PurpleAir monitor, see  – R.S.]

All Particulate is Local: New Tech Helps Map Community Air Quality

PurpleAir online mapping of the East Bay at the end of January shows real-time air quality data from sensors around the region. Image captured on 1/26/19 from

“If we can’t see or smell fine particulate matter in our air, it’s hard to be concerned about it, but it can still harm our health,” warned Jim Leach in an online presentation targeted at his neighbors in Lafayette. In his YouTube video posted last August, he urged them to install small monitoring devices outside their homes, schools, and offices to detect worrisome levels of fine particulate matter. Leach is part of a growing movement, sometimes referred to as “citizen science,” in which ordinary individuals use smaller, more affordable devices to monitor and assess their environment.

In his case, Leach relied on a device made by a grassroots group calling themselves PurpleAir, a reference to the “very unhealthy” category on the Environmental Protection Agency’s Air Quality Index scale. He first purchased the device to explore local movement of wildfire smoke, but once he started exploring the data mapped by PurpleAir’s network of devices, he became aware of the many ways in which air quality can vary within a community. Lafayette may be a leafy suburb, but it is bisected by a busy freeway and its quiet neighborhoods lie in valleys that can trap smoke. PurpleAir’s online mapping showed higher levels of pollution in areas near the freeway and in certain neighborhoods, levels that might concern a resident planning to jog or school athletes practicing outdoors.

Leach is participating in the simplest form of hyper-local air quality monitoring. Propelled by leaps in technology and data communication, there is now a plethora of monitoring devices available for a few hundred dollars, rather than tens of thousands, opening up both new ways to assess our environment and new challenges involving what to do with that data.

The California Air Resources Board webpages on community monitoring reveal that many factors must be considered, such as the number of pollutants a device can measure, how it communicates its data, and whether that data is compatible with other monitoring systems. The issue of compatibility is important in order for monitoring data to be compared with or integrated into regulatory programs.

Fern Uennatornwaranggoon, Bay Area Air Quality Policy Manager for the Environmental Defense Fund (EDF), said her organization recognized the need to better capture air pollution at a very localized level, and saw an opportunity presented by the proliferation of new environmental sensors making it possible to collect data at previously unachievable scales. But methodologies to manage and use the new data didn’t exist.

After using different instruments and techniques in a range of projects, EDF is developing and publishing data standards guidelines. “EDF started this program out of necessity,” she explained. “It was a completely new field; no one else was doing it.” They have addressed how to format data (i.e., adding a time stamp), but guidelines on how to calibrate instruments to ensure data reliability and consistency, how to maintain quality assurance and quality control, and how to adjust for changes in weather and over time are still in the pipeline, Uennatornwaranggoon said, adding, “We are catalyzing a space, trying to create infrastructure that can be used by others. Our goal is to make the data findable, accessible, and usable by people, but we’re still a ways off.”

How people will use the data is also still evolving. Like Leach, people can buy a monitor that measures one pollutant, or several at a time. They can use the data to guide their daily activities, or as members of a group that is pressuring regulators for greater pollution controls.

Or they may live in a community like West Oakland or Richmond, where there are a number of sources of pollution, but most residents can’t afford to purchase their own devices. These two communities are improving their monitoring by participating in the Bay Area Air Quality Management District’s Community Health Protection Program, created by 2017’s Assembly Bill 617 (C. Garcia).

It might seem tempting to simply blanket a community with small individual devices and utilize those reporting networks. However, laboratories for the South Coast Air Quality Management District, the largest air quality regulator in the state, report error rates as high as 30 to 50 percent for some sensors. And there’s another problem. Eric Stevenson, meteorology and measurement director at the Bay Area’s Air District, commented, “You can’t just put PurpleAir all over. That may be a starting point, but in order to fully characterize a small area, you’d need hundreds of sensors, which is expensive even though each sensor is relatively inexpensive.”

Where to place them matters, too. EDF’s Uennatornwaranggoon said these efforts face a complex question: “How do you determine the most representative location or area in a community?”

One option is mobile monitoring. Google, EDF, the University of Texas at Austin, and environmental tech company Aclima conducted an innovative one-year air quality streetmapping study in West Oakland ending in May 2016. New compact sensors measuring black carbon and nitrogen oxides were installed in Google Street View cars, which repeatedly drove a set pattern of routes throughout the community. The sensors collected extremely large amounts of data from the constant sampling, which were matched with Google mapping to pinpoint hyper-local variations in air quality within the community. By comparing results to existing Air District monitors in the same area, as well as to other information on pollution sources, researchers confirmed that the sensors were showing places, and points in time, when pollution was highest in certain locations.

Melissa Lunden, chief scientist at the San Francisco-based Aclima, is excited about the potential of using streetmapping for neighborhood monitoring. “It’s a way for a community to make sure that there are answers for the questions that are being asked, without needing to hire their own computing experts,” she observed, explaining that the vast amounts of data acquired by the sensors requires “meta data centers” to process the information. “It allows a community member to take the information and create their own story that they can then use for action.” In West Oakland, streetmapping verified a local pollution source, a metal recycler. “Community members are talking about moving the facility so that it’s not in a residential neighborhood, to where it can expand and use new control technology,” Lunden reported.

Aclima will continue to work with West Oakland representatives on their monitoring plan and is open to participating in Richmond. “We are talking about how to design a sampling program to give reliable standard results, and we would suggest options to the community,” Lunden said. “Our program is easily deployed to map an area of any size. It’s flexible and mutable.”

Stevenson noted that unlike West Oakland, Richmond is just getting started. Following an Air Quality summit scheduled for February 16, which will educate the community about the issues, a steering committee will guide the design of a monitoring plan. “The Air District will start with asking ‘What are your biggest concerns? Here’s what we can do to monitor for those concerns’,” said Stevenson. “We have a general idea of the air quality based on our current network,” he explained. “We need to devise a screening method with enough accuracy to ID sources.”

Stevenson emphasized that the focus is on the community rather than the source. “The message is that we want to monitor in your neighborhood, but we want to do it in an efficient and effective way,” he said, adding that “once you have sound data that people can agree on, people respond to it.”

Stevenson said he considers a mobile platform like Aclima’s to be the best solution for screening for local sources of pollution, but he noted that there is still a role for the “citizen scientist,” particularly for specific events like wildfire smoke. While Aclima’s mapping cars tracked the invasion of smoke from November’s fire in Paradise into the region, Lunden reported only a couple of cars on limited routes provided early data, and once smoke was more dispersed, results were not as clear. “PurpleAir monitors are great for seeing changes in air quality moving through the Bay Area. By comparing various locations against each other at a given point in time, they can help with forecasting and tracking movement [of pollutants] through the area,” Stevenson concluded.

Leslie Stewart covers air quality and energy for the Monitor.

Mayor Patterson: Air monitors and public health – Council agenda for Tuesday

From an E-Alert by Benicia Mayor Elizabeth Patterson

Much more than fence-line air monitors…

Monday, November 19, 2018

Elizabeth Patterson, Benicia Mayor 2007 - present
Elizabeth Patterson, Benicia Mayor 2007 – present

The regular council meeting will be at 7:00 and the agenda and staff reports and recommendations are online here.

The main item of interest is the “report” to Council about progress on installation of air monitors by Valero.  The report came about because of the request by the Industrial Safety Ordinance working group – a citizens’ steering committee which researched and developed a draft Industrial Safety Ordinance in response to the near catastrophic melt down of Valero Refinery in May of 2017 and subsequent plumes of black smoke.

The request to the city council was – and is – to have an outside subject matter expert with legal skills to review the proposed ISO and determine its legal sufficiency and report to the council.  For some reason staff does not make this clear but rather states that it is a vote up or down on the ordinance. This is incorrect.

The request to have an expert opinion report on the need, adequacy and value of the Industrial Safety Ordinance is meant to have a neutral party report to council.  I made a request for considering the ordinance in May of 2017 and soon realized that this would not be addressed quickly.  Therefore, I advised the Benicians for Safe and Healthy Community and thus they took the initiative to research, interview, have an expert panel discussion and draft the ordinance.  Naturally, this was done to expedite the process.  The small step of seeking outside advice on the draft Ordinance was voted down by the council majority.

A couple of common objections to the Industrial Safety Ordinance are:

  1. An ISO is not necessary now that the state has adopted many of the Contra Costa County ISO regulations.  It should be noted that none of the cities or county have rescinded their ordinance because they still find it meets specific needs and is subject to better reporting to local government.
  2. Now that the fence-line monitors are in place there is no need for the ISO because the county’s Program 4 suffices.  Actually this is a requirement of the state to coordinate state and local regulations and is incorporated by reference into the draft ISO.  The county does not have regulatory authority, but rather coordinates.  For instance, the county reports on inspections and status of required reports.  The coordination with local government to date has been a booth at the 2018 Peddlers’s Fair.  CalEPA requires a full public participation program for the community air monitor(s) to be implemented.  Neither the community air monitor nor the public participation program has been done.

In short the proposed Industrial Safety Ordinance is much more than fence-line monitors at the refinery or portable emergency air monitors.  It is providing a seat at the table participating with the county and state regulators and the regulated industries.  It is a guarantee to get reports and posting them on city website rather than chasing down reports at the county or state and often with broken links.  It is a fee structure to pay for continuous staff level of engagement rather than driven by budget constraints.  It is memorializing our affirmative duty to protect public health.  It establishes a collaborative relationship with regulators and the regulated refinery and not a co-dependent relationship.

For safe and healthy communities…