Preliminary Assessment of Air Quality for the Proposed Site of the Ursula Sherman Village
Environ, February 14, 2002
BOSS (Building Opportunities for Self-Sufficiency) is proposing to develop the Ursula Sherman Village, a planned community designed to provide emergency and transitional housing, and social services for community residents. This development would include the reconfiguration of the Harrison House, an existing homeless shelter on Harrison Street in West Berkeley, as well as the construction of new residential, commercial, and administrative buildings.
Due to the history of concerns about elevated particulate concentrations in the area of the Harrison Street site, BOSS has contracted with ENVIRON International Corporation to perform an air quality assessment of this area. An assessment of air quality is not required by any federal, state, or local regulations for this type of project, since the Ursula Sherman Village would not be a source of new air pollution. Instead, this assessment has been undertaken voluntarily by BOSS to ensure that the existing air quality at this site would not adversely impact the health of any new residents of the Ursula Sherman Village. In order to ensure this, the concentration of measured particulate at the Harrison Street site is being compared with the air quality monitored at other urban locations, primarily those in the San Francisco Bay Area.
This report is a preliminary assessment of the air quality at the Harrison Street site based on the air monitoring data available at this time. A more-detailed report will be prepared once the results of some of the ongoing work (described below) are known.
In 1997, the City of Berkeley created a children's soccer field on a previously empty lot in West Berkeley, located immediately adjacent to the Harrison Street site. Before deciding to build the soccer field at this location, the City commissioned a report on the potential health risks children playing at this location might incur due to exposure to air pollution. Regarding these exposures, this report concluded that:
"These risk levels are typical of urban exposures. Furthermore, CAPCOA-1 and ARB-2 guidelines consider these levels to be acceptable. Based on these results, the site can be used as a playing field. "3
Since this time, a limited amount of additional air monitoring has been performed at the soccer field and at other locations around Berkeley. A second, two-week study of air pollutant concentrations was compiled in 2000 at the request of the City of Berkeley. This study concluded that further monitoring was warranted before any conclusions could be drawn about the health effects of air pollution on West Berkeley residents. Regarding possible sources of air pollutant concentrations, this study concluded that "(t)he West Berkeley area appears to be impacted from the effects of the 1-80 corridor, although these effects are mitigated by the strong input of clean air from the bay into the area."4
A report of PM10 monitoring conducted in St. Louis, Missouri in 1999, however, suggests that PM10 impacts on West Berkeley due to the freeway are probably limited. According to this report, downwind PM10 concentrations measured at several locations near freeways showed linear decreases with increasing distance from the freeway. At each location, PM10 concentrations measured downwind of the freeway dropped off to match upwind levels at a distance of 70 meters (230 feet) from the freeway. 5
A third, ongoing study has been commissioned by the City of Berkeley to monitor airborne concentrations of hexavalent chromium and particulate matter at the Harrison Street soccer field. Concentrations measured at this site between July and December 2001 are available and are discussed below, but a final report for this study has not yet been produced.
3. Available Air Monitoring Data
3.1. Soccer Field Monitor - Hexavalent Chromium
In the 1997 and 2000 air monitoring studies described above, the air pollutants considered the greatest potential health risk in West Berkeley were hexavalent chromium and particulate matter. At the beginning of the current study, between June and August 2001, air concentrations of hexavalent chromium monitored at the Harrison Street soccer field were all found to be below the instrument detection limit.
As a result, the conservative assumption made by the 1997 study that all of the airborne chromium was hexavalent chromium appears to have been incorrect. Since hexavalent chromium exposure was a major portion of the health risks assessed by the 1997 study, these risks (although within acceptable levels) were overestimated.
3.2. Soccer Field Monitor - Particulate Matter
In July 2001, a monitor was also placed at the Harrison Street soccer field to measure concentrations of two sizes of particulate matter: particulates less than ten micrometers in diameter (PM10) and particulates less than 2.5 micrometers in diameter (PM2.5). Due to mechanical problems with the PM2.5 monitor , PM2.5 data are only available for ten days in January 2002 from this site. The Bay Area Air Quality Management District (BAAQMD) only monitors PM2.5 data in a few locations around the Bay Area, and data from these sites are currently only available up through November 2001. Comparing this limited data, hourly and 24-hour average PM2.5 readings from the soccer field monitor in January 2002 are generally the same or lower than readings monitored at other Bay Area locations in the fall of 2001. Additional data will be required to draw more definitive conclusions.
PM10 data are available for the Harrison Street site for the period July through December 2001. To date, data for other Bay Area locations monitored by BAAQMD are only available up through September 2001. Thus, a preliminary comparison can only be performed for a three-month period (July to September 2001). During this period, 24-hour average PM10 concentrations at the Harrison Street site appear to be higher than those monitored at other Bay Area locations. These concentrations, though, are not atypical of those monitored in other urban areas. PM10 monitoring data are collected at 14 monitoring sites around the Bay Area, once every six days. Since these monitors are sited in order to determine regional average pollution levels, and since data are collected infrequently, additional data will be necessary to compare with the data currently being collected near the Harrison Street site.
A review of the monitoring data shows that, for six days a week, (Monday through Saturday) the PM10 concentrations begin each day at relatively low levels, then steadily increase until about noon, and then slowly decrease. On Sunday, the levels are approximately the same throughout the day.
The West Berkeley Waste Transfer Station is located approximately 200 feet upwind of the current PM10 monitoring station. The transfer station operates six days per week (Monday through Saturday) and has peak waste-moving operations from 8 a.m. to 12 p.m. Because the pattern of increasing PM10 concentrations during the six days that the transfer station operates corresponds to the peak operations of the transfer station, and not the freeway, this suggests that the transfer station is impacting PM10 concentrations at the site.
Were concentrations at Harrison Street impacted mainly by Highway 1-80 (located immediately west of the Transfer Station, about 1,000 feet from the Harrison Street site), weekday air pollution concentrations would be expected to peak during the periods of heaviest traffic (i.e., morning and evening rush hours). Also, Saturday and Sunday patterns would be expected to be different from weekday patterns. Instead, weekday PM10 concentrations rise steadily during the day, peak just after noon, and steadily drop again. In addition, the pattern is consistent, Monday through Saturday, and is different on Sunday. On Sundays, when the Transfer Station is closed, PM10 levels do not show the same rise-and-fall pattern as other days; noontime concentrations on Sundays are nearly identical to those measured at midnight. In addition, the concentrations on Sunday are similar to Sunday values measured at other locations in the Bay Area.
3.3. Transfer Station Monitor - Particulate Matter
In order to test the hypothesis that the Transfer Station was impacting particulate matter concentrations at the Harrison Street site, a two-day sampling study was performed using a portable monitor. As part of this study, concentrations of various sizes of particulate matter were sampled at eight locations immediately upwind and downwind of the Transfer Station. Instantaneous readings were taken at a different location every ten minutes between 9 a.m. and 3:30 p.m. on January 28, 2002, and between 7:00 a.m. and 2:00 p.m. on February 4, 2002.
The results of this study were not conclusive, but some trends did appear. On January 28, the data showed a great deal of variability, with greater disparity between downwind and upwind concentrations, but no clear trend that one was consistently higher than the other. Samples taken on this day are of questionable value due to rainy weather on this day. The portable monitor used in this study is sensitive to precipitation and very high levels of humidity, so that mist in the air can be misread by the monitor as particulate matter. Concentrations measured on this day were generally lower than those typically measured in this area, with spikes corresponding to periods of rain.
On February 4, downwind concentrations were consistently higher than those measured upwind, but the difference was relatively small. For most of the day, downwind concentrations were approximately 10% higher than upwind concentrations. During one hour, the average downwind concentration was more than five times the corresponding upwind value, but this may have been an anomalous reading, or it may reflect the scatter that exists in the soccer field monitoring data.
In general, the samples taken as part of this study had a much larger range of values than the data monitored at the soccer field on the same days. However, the data is consistent with the hypothesis that the Transfer Station is the source of elevated dust at the Site.
4. Ongoing and Future Activities
By contacting the West Berkeley Waste Transfer Station, we have learned that the City of Berkeley is in the process of implementing substantial measures to control PM10 emissions from this facility. Within the past few months, the Transfer Station has converted the fuel used in its diesel trucks to a mix of biodiesel and regular diesel fuel. The use of biodiesel should result in reductions in air pollution from these trucks, including PM10 emissions. More significantly, the City of Berkeley has designed and purchased a dust (including PM10) control system for the trash movement operations at the Transfer Station. This system is similar to systems that have significantly reduced emissions from other Bay Area Transfer Stations, and is expected to be operational at the West Berkeley facility by April 2002.
Since concentrations of PM10 are seasonal, additional data collected over a longer period of time may provide a better basis of comparison with data for other locations. Data collection for PM10 and PM2.5 at the soccer fields is ongoing, and monitoring diesel particulate matter (DPM) is expected to begin soon. This additional data may further add to our knowledge base about air quality at the site.
5. Recommendations! Conclusions
• In the limited monitoring data available for the Harrison Street Site, PM2.5 concentrations were generally the same or lower than those measured at other Bay Area locations. (Note: PM2.5 data was extremely limited...incomplete. )
• PM10 concentrations from this site were generally higher than those measured at other Bay Area locations. These concentrations are not atypical, though, of concentrations measured in other urban areas.
• A preliminary evaluation of available soccer field monitoring data indicates that the West Berkeley Waste Transfer Station is the cause of elevated PM10 concentrations at the Harrison Street site. It is therefore reasonable to assume that the dust control system planned for this facility will result in air quality improvements for this area.
• Based on the available long-term sampling data, it appears that, without the emissions from the Transfer Station, owned and operated by the City of Berkeley, the air quality at the site would be similar to air quality at other locations in the Bay Area. The City has proposed measures to mitigate emissions from the Transfer Station within the next few months. The monitoring system currently operating at the site can be used to determine whether the controls at the Transfer Station are effective, or whether additional controls at the Transfer Station are needed. As such, a permit should be granted for the construction of the Ursula Sherman Village.
Acurex Environmental Corporation, 1997. "Ambient Air Pollution and Health Risks at the Harrison Street Site - Berkeley, California," December 10.
Applied Measurement Science, 2000. "West Berkeley Air Monitoring, July 13-24, 2000." September 6.
Lamoree, David P. and Turner, Jay R., 1999. "PM Emissions Emanating From Limited-Access Highways." Journal of the Air and Waste Management Association Volume 49: PM-85-94. September.
1 CAPOA = California Air Pollution Control Officers Association
2 ARB = California Air Resources Board