Standard Operating Procedures
West Berkeley Community Air Monitoring Project


Standard Operating Procedures
West Berkeley Community Air Monitoring Project
Global Community Monitor BAAQMD Grant September 2007


minivol air monitor Pacific Steel Casting (Pacific Steel) is a large steel foundry in West Berkeley.  According to publicly available data from the California Air Resources Board, its toxic air emissions have increased up to 160% over the period 2002-5.  According to the UC Berkeley School of Public Health, these toxic air contaminants consist of substances that have been targeted in the U.S. and California for tracking and emission reductions because they are know to be toxic to humans at even low levels of exposure.  Pacific Steel’s toxic air emissions include benzene, formaldehyde, phenols and a number of highly toxic heavy metals (including lead) that persist in the environment, accumulate in human tissues, and are especially hazardous to children.

Prior community testing found alarmingly high levels of lead at two locations.  An earlier test also found high levels of formaldehyde at one location.  In both cases, EPA health standards were exceeded.  The community requested funds from the Bay Area Air Quality Management District (BAAQMD) to conduct additional air monitoring focusing on toxic metal particulates.  BAAQMD agreed to provide a grant to Global Community Monitor for the community to do this follow-up monitoring. 

BAAQMD recommended that a Mini Vol Portable Air Sampler be used because it provides accurate and precise results, is easy to use, and can be moved from location to location allowing for a broader assessment of how toxic air contaminants might be distributed in West Berkeley.  This monitoring represents the first time there has been any systematic monitoring of the air in West Berkeley despite decades of complaints and health concerns about Pacific Steel’s emissions.

The Monitor

The MiniVol Portable Air Sampler samples ambient air for particulate matter  (PM10, PM2.5 or TSP) and/or non-reactive gases (CO, NOx). Airmetrics and the US Environmental Protection Agency jointly developed the patented low-flow technology used in the MiniVol.  While not a US EPA Federal Reference Method (FRM) sampler, the MiniVol provides results that closely approximate reference method data. Affordable and portable, the MiniVol is ideal for saturation studies, emergency response situations,  fugitive emission and prescribed burning sampling, and urban air quality studies.   

The MiniVol is basically a pump unit that pulls air through a filter holder assembly, where particle size separation occurs by impaction.  The flow of air can be adjusted and, in this case, has been set at 6 liters/minute.  The particulate matter is collected on a 47mm filter. The filters are weighed pre- and post-exposure by a microbalance accurate to one microgram to determine the particulate concentration. The MiniVol does not provide any real-time readout.  Samples are sent to an EPA-approved lab for analysis.

The MiniVol features include a 7-day/6-run programmable timer, an elapsed time totalizer, low flow and low battery shut-offs, and operation from rechargeable battery packs. The MiniVol can sample for only one size of particulate at a time and can sample for PM10, PM 2.5 or TSP depending on the nozzle attachment used. 

At the end of a particulate sampling period, the filter holder and battery pack are replaced by a second filter holder and a second battery pack (two of each come standard with a new MiniVol). Once a sample is collected, the exposed filter is sent to the lab for post-exposure weighing and analysis and a fresh, pre-weighed 47mm filter is placed into the filter holder for the next sample collection. Recharge of the spent battery is accomplished in about 16 hours using a universal transformer connected to a wall circuit. At certain sampling locations electrical power is available and the Mini Vol is simply plugged in during sampling periods.

Prior to leaving the vendor’s shop, each MiniVol sampler is calibrated using a Laminar Flow Element and a calibration curve traceable to NIST is included with each new sampler (attached). 

Using the Monitor

A training video has been prepared for each person using the monitor.  In addition, on-site training is provided.  This training is intended to ensure uniformity and consistency.  Specifically it covers:

  • An introduction to the monitor and its features.
  • How to assemble the monitor, including how to attach the battery pack.
  • How to assemble the intake nozzle assembly, how to distinguish the pm 2.5 from the pm 10 assemblies, and what particle diameter assembly (pm 10) to use for this project.
  • How to load the filter into the assembly without contaminating it.  Plastic gloves are used and filters are loaded indoors to prevent contamination prior to testing.
  • How to fit the nozzle on pump.
  • How to make sure the monitor is properly calibrated to ensure a 6-liter/minute airflow.
  • How to program the monitor to ensure it runs for a complete 24-hour cycle, including waiting and listening to ensure the pump starts up as programmed.
  • How to remove the filter when the monitoring period is over—again using plastic gloves and conducting this operation indoors—and immediately placing the filter in the clean plastic holder it was shipped from the lab in.
  • How to ensure proper custody by entering key information on the laboratory control sheet, including:  sample location, date and run times, relevant observations about wind direction, strength, etc., and signing and retaining a copy of the control sheet.
  • Samples are then packaged in a Federal Express envelope, delivered to a Federal Express employee who signs the control sheet ensuring and unbroken chain-of-custody, and then mailed to an EPA-approved lab, Columbia
  • Analytical Laboratory in Kelso, Washington, for analysis using EPA-approved methods.

In addition, trained volunteers have been instructed in how to document key monitoring variables, such as wind speed and direction, whether odors are present, etc. and how to enter this information into a log for use in analyzing the laboratory data. 

Selecting Monitoring Locations

Locations will be identified in West Berkeley and Albany that are directly downwind of Pacific Steel and within a specified radius of the plant.  Volunteers have been instructed in how to determine when wind conditions are right and how to make an assessment, at the end of the monitoring period, about the consistency of the winds during the previous 24-hour period.  BAAQMD meteorological data will be used to make these assessments. 

Generally, while it is typical for wind direction to shift during a normal 24 hour period so that some of the time the wind may not be coming from the direction of the plant, ideal samples involve monitoring when the monitor is located downwind for most of the monitoring period.  Additionally, lower wind speeds are preferred to ensure monitoring is conducted when maximum particulate fallout can be expected.

Locations within a quarter mile of the plant will be over-sampled but samples will also be taken at increasing distances from the plant to see how pollutants are dispersed.  Since Pacific Steel is not cooperating in this effort, volunteers will determine if the plant is operating by conducting a visual inspection of the plant and by noting any odors.  In addition, all potential locations will be visited prior to actual sampling to ensure they are not obstructed, that the monitor can be placed in a secure location, and that they meet the location criteria just described.

In addition to the downwind monitoring, samples will also be taken upwind of Pacific Steel for comparative purposes.   At least one of these upwind locations will include a site adjacent to the I-80 freeway to assess the relative contribution, if any, of mobile sources.

BAAQMD Involvement

BAAQMD staff participated in the first use of the monitor and observed volunteers using the equipment consistent with the above operating procedures.  BAAQMD staff also assessed the use of selection criteria for the choice of the monitoring location.

Discarded Samples

Any samples that do not meet the above standard operating procedures will be discarded.  For example, at one location the battery unit failed and the data was collected for a period of less than 24-hours.  This sample was not sent to the laboratory for analysis.

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