PM 10/PM 2.5 Monitoring, Harrison Park Part 2
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Berkeley, California July, 2001 to January, 2003

33.2 Example Monthly Pattern

Figure 19 shows the detailed plot of the month of April, 2002. As with the daily detail, the peaks and valleys in concentration can be seen, with a few even higher peaks in PM10 concentration from time to time than was seen in the first three days examined above. High concentration peaks above 100 ug/m3 were not uncommon.

The data from a monthly data compilation were also compiled into bar charts showing the concentrations of daily PM10 and PM2.5 concentrations relative to the California and Federal air quality standards.

333 PM10 Diurnal Patterns

3.3.3.1 Average Daily Pattern

The daily pattern of PM10 concentrations shows a similar pattern as shown for the short three day period above. Figure 21 shows the average over the 24 hours for the entire study period. This includes all days of the week. The increase in concentration for the period from approximately 8 AM to 5 PM is evident. The larger errors bars (which are the 95% confidence limit to the average concentrations) for the daytime hours reflects the much greater variation in concentration due to the high and low concentrations registered on typical days.

A comparison of this plot to the data from the Berkeley Recycling Center (BRC) in Figure 22 shows that a local source appears to cause the increase during the day, as there is no similar "hump" during the daytime hours. The heading BRC-UP indicates the upwind location at the corner of Gilman and 2nd and the heading BRC-DN indicates the downwind location at the north end of the lot.

The non-work hours for the BRC show a higher concentration than at Harrison (significant because of the lack of influence by the Transfer Station), mostly likely due to their proximity to Gilman and 1-80. This difference is on the order of 6 ug/m3. In addition, the BRC data show the effect of a periodic nearby emission at around 8 PM. That emission does not appear to affect Harrison Park, as there is no corresponding sharp concentration spike at that time, just a slight increase that is too slight to be conclusively linked to the BRC event.

3.3.3.2 Day of Week Pattern

The day of the week pattern shows that Sunday has the lowest concentration-37 ug/m3, which is similar to the background level. The Sunday concentration level is significant in that there is no activity at the Transfer Station on that day and traffic on 1-80 and Gilman is lower, thus this represents the generally lowest level that might be expected to be found consistently at the Park.

The day of week dependence is further elucidated by examining the diurnal pattern of Saturday vs. Sunday. Figure 24 shows how the concentrations of PM10 on Sunday only slight increase during the day, while the Saturday concentrations display the same large hump during work hours.

33.4 PM2.5 Diurnal Patterns

The PM2.5 concentration data are useful to compare against what was seen for PM 10, as the processes for formation of each size fraction are different. A simplistic view is that PM10 is generally formed by physical processes such as abrasion and erosion, while PM2.5 is formed by chemical processes such as atmospheric chemical reactions and combustion. Therefore, the two fractions may not correlate completely at all times. While PM2.5 is a subset of PM10, the "coarse" fraction (between PM2.5 and PM10) may dominate and any distinction between the two subsets will likely be blurred or lost.

For Harrison Park, the PM2.5 processes that may be of interest are exhaust from the nearby highway sources and the nearly truck sources at the Transfer Station. The examination of daily and weekly patterns assists in evaluation of these possible impacts.

3.3.4.1 Average Daily Pattern

Figure 25 shows a plot of the diurnal pattern of the hourly PM2.5 concentrations collected for the 12 month period the PM2.5 BAM was in operation.

This data shows that there is no corresponding peak in concentration during the daytime work hours as was seen in the PM10 data. There is a slight increase during the daytime, but it is actually mirrored by an increase in the late evening and early morning hours. The 95% confidence intervals do increase during the day, indicating more variation in the hourly concentrations, but that may also be due to the typical meteorological variations that occur during the daytime hours.

There is no peak during the morning and afternoon rush hours, indicating that the direct influence of the highways is muted due to the distance from the Park. This is also indicated in the previous examination of the detailed daily and monthly data.

These data suggest that there may only be a slight effect from the nearby sources the diesel exhaust from the Transfer Station haul trucks.

3.3.4.2 Day of Week Pattern

Figure 26 shows the day of week dependence for PM2.5. There is no strong trend to be shown, with only 2-3 ug/m3 difference between the days. The difference between Saturdays, at 18 ug/m3 and Wednesdays at 23 ug/m3, may be significant, but is likely due to lessened highway influence. The data for Sundays, at 19 ug/m3, may lead to a similar conclusion. However, there is no strong dependence showing nearby sources to be an issue.

33.5. Sources of Particulate Matter Impacting the Park

There are several nearby and distant sources that potentially impact the air quality at Harrison Park:

Stationary Sources

• Transfer Station

• Berkeley Recycling Center

• Pacific Refining and Foundry

• Precision Technical Coatings

Mobile Sources

• 1-80

• Gilman Avenue

• Nearby city streets

Since all of these sources are upwind to Harrison Park, they affect the air quality in general. However, the magnitude of that impact and the ability to discern one source from the others is uncertain except for the Transfer Station. No direct data is available for any particular source other than the Berkeley Recycling Center, and the evidence from that source suggests its downwind fence line influence is on the order of 5 ug/m3. However, that influence is likely diluted by the distance the plume must be transported before impacting the monitoring site at Harrison Park.

The data, do however, conclusively link daytime operations from the Transfer Station to increased levels of PM10 at the monitoring site. There appears to be little impact from PM2.5 from the Transfer Station operations, based on the PM2.5 data. Figure 27 shows the superimposed PM10 and PM2.5 diurnal patterns. It clearly shows that there is no correlation between the two parameters and that the PM10 dominates during the work day of the Transfer Station. Coupled with the directional influence of the meteorology, it shows conclusively that the Transfer Station is the primary source for the high concentrations seen at the monitoring site in Harrison Park.

Based on the available data, the impact from the Transfer Station to the monitoring site appears to be approximately 16 ug/m3. This was obtained by comparing the background level of 39 ug/m3 with the daytime (7 AM to 5 PM) average of 55 ug/m3.

33.6 Park Usage Patterns

As determined by the Parks, Recreation, and Waterfront Department, the Park usage pattern is generally just a few hours per week. This is based on both field maintenance schedules and use schedules that are organized by city staff.

Usage:

The field is used by children, generally aged 8-16 every weekday from 4:00 to 7:00 and Saturdays from 8-5. Most children are there once or twice a week for 1 1/2-2 hours. At the most a child is there three times a week for 1 1/2-2 hours (two practices and a Saturday game). Adults livery few] are there weekdays from 7-9:30 and Sundays from 9-5. Most adults are there once a week for 2 hours. A small number of adults are there twice a week for two hours.

The fields are shut down June 15th to September 1 there is no summer activity on the fields. The east field is shut down December 1-March 1 there is no activity on this field. The west field is open December 1-March 1 on Sunday mornings from 9-1 for adult play. There are no children on the west field from December 1 to March 1.

33.7 Exposure Breakdown

When various time periods are broken down in to averages, it is seen that the averages for the workday are increased over non-work hours and background levels by approximately 16 ug/m3. The concentration for play time, from 4 PM to 7 PM, is 41 ug/m3 -only slightly above the background level of 39 ug/m3. The off-hours level of 36 ug/m3 reflects the similar background concentration.

3.4 Data Comparison

3.4.1 Bay Area PM10 and PM2.5 Concentrations

Tables 6 and 7 contain the monthly data from the Bay Area Air Quality Management District PM10 and PM2.5 monitoring network. These data put the background and monitoring data from this report in context to nearby communities. The BAAQMD uses EPA federal reference or federal reference equivalent methods, as was done at Harrison Park. Several of the BAAQMD sites utilize the same equipment as was used at Harrison Park for this study. The BAAQMD data sets are comprised of every one in six day monitoring schedule. These data were subsequently averaged (arithmetic average) into a monthly value. Based on standard practice, this frequency is considered representative of overall trends and therefore can be compared with other data sets such as the Harrison data set.

These data show that the concentrations measured at Harrison Park are approximately a factor of two higher for PM10 than most of the area monitoring sites, and a factor of 1.5 higher for PM2.5 than most of the area monitoring sites.

Conclusive reasons for these disparities are beyond the scope of this report, but several factors may come into play. First, the siting of the Harrison Park monitoring site does not conform to the standard siting that is performed for standard ambient air monitoring stations. The proximity to the Transfer Station site, and the proximity to the major highways and surface streets are both factors that would lead to higher than average concentrations. Furthermore, the presence of several moderate to large industrial sources directly upwind contribute to the overall burden of particulate matter in the ambient air.

Standard ambient air monitoring stations avoid these factors and are sited to provide a representativeness for the majority of the population, which do not live in essentially industrial areas. Therefore, it's partially an "apples and oranges" argument the two situations are not the same.

However, the comparison is valid in terms of comparing what a "typical" Bay Area resident would be exposed to. The concentrations cited in Tables 6 and 7 represent the air that a typical resident would breathe. Therefore, concerned individuals should take appropriate precautions as cited in the health evaluation report contained in the appendix.

FR=Fremont LV=Livermore PT=Pittsburgh CC=Concord BI=Bethel Island RI=Richmond SR=San Rafael NP=Napa SF=San Francisco RC=Redwood City SJ=San Jose TU=San Jose Tully St. VA=Vallejo ST=Santa Rosa

3.4.2 California PM10 Concentrations

The California Air Resources Board (CARB) conducts ambient air monitoring throughout the State of California for the same purpose as the BAAQMD to determine the quality of air that the majority of California residents breathe. Monitoring is conducted to determine compliance with Federal and State air quality standards, as cited earlier in this report.

Table 8 contains the results from PM10 monitoring in the air basins throughout the state. There is no comparable PM2.5 table for PM2.5 as it has not been criteria pollutant for the state in previous years.

These data show that most areas are exposed to lower concentrations of PM10, however, there are a few exceptions. The two main exceptions are the San Joaquin valley and the South Coast.

4. CONCLUSIONS

The data presented in this report show that elevated concentrations of PM10 and PM2.5 are present at Harrison Park due to local industrial sources, particularly the City of Berkeley Transfer Station. These concentrations exceed the California air quality standards for a large number of days, 70 in 2001 and 135 in 2002. Both numbers of exceedances would constitute being out of compliance with the standards.

The health evaluation presented in this report suggests that users with impaired health or breathing disorders consider carefully the amount of time that is spent in the area. While the higher concentrations are present during times of the day when most children are not present, the overall concentrations are consistent with possibly unhealthful air quality.

Appendices

1. Data Files -on CD
2. Hexavalent Chromium Sampling
3. BAAQMD Audit Report
4. Risk Evaluation Report-Dr. Charles E. Lambert
5. Berkeley Recycling Center Report

Appendix 2. Hexavalent Chromium Sampling

Introduction

Part of the Harrison Park development was the construction of a skateboard park on the southeast corner of the lot. During construction, it was determined that the groundwater in that area was contaminated by hexavalent chromium. Construction was stopped until an appropriate remediation could be determined.

Concern about this contamination and the possible inhalation exposure route to persons in the area lead to the proposal to conduct air sampling in the area.

Technical Approach

The approach that was used to collect data on ambient air concentrations of hexavalent chromium was based the CARB Method MLDO39, which stipulates the use of sodium carbonate impregnated cellulose filters that are sampled through a total particulate inlet at 10 L/min for 24 hours. The analysis consists of ion chromatography with post-column derivitization and detection by UV.

The analysis was conducted by Philips Analytical Services of BC, Canada. Of the few laboratories able to do the CARB method, this one has been proven through past use to provide high quality results. The detection limit for this analysis was 20 ng/sample. With a flow rate of 10 liter per minute over a 24-hour period, the concentration that could be detected in air would be 1.4 ng/m3.

The sampling was conducted at the northeast corner of the homeless shelter lot, inside the fence. Figure A-2 shows a photograph of the sampling set up. (not included)

Sampling was conducted in accordance with CARB's 1 in 12 day schedule for hexavalent chromium sampling. Sampling commenced on June 30, 2001 and continued through November 21, 2001. The sampling event for December 3, 2001 failed due to rain on that day that short circuited the control equipment. After consultation with city staff, it was determined that there was no need to continue given the equipment problems and the lack of any positive results to date. All previous samples had been returned as non-detects.

Table A-2 contains the results of these tests, showing the complete set of non-detects. The quality assurance samples submitted with the field samples -blanks and spikes showed acceptable results, confirming the validity of the data.

Conclusions

The use of the CARB hexavalent chromium sampling and analysis method showed consistent non detects over the approximately 6 month sampling period. All QA data was satisfactory, and combined with the field results, this data set shows the ambient air concentration to be less than 1.4 ng/m3.

Appendix 3. BAAQMD Audit

On December 18, 2002, the audit group from the Bay Area Air Quality Management District audited the monitoring equipment in use. The findings showed that the system passed all acceptance criteria and was working satisfactorily. The audit report is included as Figure A-2.

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