Informational Notices: Tilson Air Quality
Final Report on the Air Quality Monitoring Program
(July 1998 to June 2000)
Volume I.
Summary of Ambient Air Quality Monitoring Program
Manitoba Conservation
August 10, 2000
Background
Concerns had been raised by residents in the Tilston area that the oil and gas activities in the region may be affecting local air quality with potential impacts to their health and livestock. In response to these concerns, Manitoba Conservation had conducted an outdoor air quality monitoring program for various air pollutants from July 1998 to June 2000.
Manitoba Conservation has previously released interim reports which summarized the air quality monitoring activities that had been undertaken in the Tilston area and the air quality monitoring data that had been collected. The first report was released in August 1999; updates were released in November 1999, January 2000, March 2000, April 2000, and June 2000. Volume I of this final report provides a summary of all the monitoring that has been undertaken since the beginning of the program. Volume II contains all of the monitoring data collected.
Monitoring Activities
The Tilston air quality monitoring program, which was first started in July 1998, had developed and expanded since that time as additional air quality issues arose. The program was developed in consultation with the Tilston Community Advisory Group (CAG).
At the start of the monitoring program in July 1998, Manitoba Conservation only conducted limited outdoor air monitoring for sulphur dioxide in W. Campbell's farm yard (Farm Yard #1) in the Rural Municipality of Albert (9-6-29). This monitoring location was 1.6 km (1 mile) directly east of the Tundra Oil and Gas Ltd. oil battery located at 8-8-6-29 W.P.M. ("the battery").
The air quality monitoring program was expanded in early 1999 because of additional questions that had arisen regarding the air quality in the area. The sulphur dioxide monitor was re-located from its original location at W. Campbell's farm to a monitoring trailer on J. Anderson's farm yard (Farm Yard #2) about 1 km south at 4-6-29 W.P.M. This new location was selected in order to measure sulphur dioxide levels in another area where health concerns had been reported. Moving the monitoring site also allowed the trailer to be connected to a telephone line. Data from the sulphur dioxide monitor could then be directly accessed by Manitoba Conservation staff in Brandon and Winnipeg.
A second sulphur dioxide monitoring site was established near the oil well furthest east of the battery (6-9 Well Site). A monitoring trailer, also with a telephone connection, had been placed on the site. This site was chosen to give an indication of air quality in an area closer to the battery. Wind speed and direction were monitored at this location since air flows were relatively unobstructed by buildings or shelter belts.
In addition to the two sulphur dioxide monitors, two hydrogen sulphide monitors were obtained. These instruments, which were able to monitor environmental levels of hydrogen sulphide in the parts per billion range, were located with the two sulphur dioxide monitors.
Continuous monitoring at the two new locations started in the beginning of April 1999 for sulphur dioxide and at the end of April 1999 for hydrogen sulphide. One of the hydrogen sulphide monitors was removed from service for about 6 weeks in June and July. This monitor was returned to its supplier for maintenance because it had not been functioning reliably; it was placed back into operation on July 27th in the trailer located at the 6-9 Well Site.
Sampling for volatile organic compounds (VOC's) was also undertaken as part of the expanded monitoring program. Samples of 1-hour duration were taken using a SUMMA canister; these samples were then shipped to the Environment Canada lab in Ottawa for analysis. A limited number of volatile organic compound (VOC) samples were taken in the area in the spring of 1999. The VOC sampling program continued during the summer with the collection of a VOC sample about once per week; these samples were collected under varying conditions and at different locations in the area of interest. Additional equipment was also obtained to enable VOC sample collection throughout the day (i.e., samples of 24-hour duration) as an alternate means of collecting VOC samples. This equipment was installed September 1, 1999 at the Farm Yard #2 site.
Monitoring for aldehydes and ketones was undertaken starting on August 13, 1999 when aldehyde/ketone monitor was installed at the Farm Yard #2 site. Once a week, a 24-hour sample was collected for later analysis by Environment Canada. Aldehydes (such as formaldehyde) and ketones (such as acetone) are classes of chemical compounds which are known to be irritating to the eyes and throat at higher concentrations.
A sulphuric acid mist sampler was installed on October 1, 1999 at the 6-9 Well Site monitoring station. This sampler collected and analyzed 1-hour air samples for sulphuric acid. However, this instrument was less sensitive than the other types of samplers and so could only provide information on somewhat higher environmental levels of pollutants. Monitoring with the sulphuric acid mist sampler was discontinued in December 1999.
In addition to the stationary monitors, Manitoba Conservation also purchased a portable analyzer to measure both hydrogen sulphide and sulphur dioxide. This instrument allowed staff to measure levels of these two air contaminants in other locations in the area; however, the portable analyzer was not able to measure contaminant levels as low as the fixed hydrogen sulphide and sulphur dioxide monitors could. Sampling was undertaken both randomly and on a planned basis.
In June 2000, the Tilston air quality monitoring program was discontinued. At the end of this program, the program had been monitoring for sulphur dioxide and hydrogen sulphide at the two monitoring locations (i.e., Farm Yard #2 and 6-9 Well Site), and volatile organic compounds (VOC's) and aldehydes and ketones at the Farm Yard #2 site.
Summary of Air Quality Monitoring Results
Sulphur DioxideSulphur dioxide was the first air pollutant to be monitored in the Tilston area. Consequently, more data are available for this air contaminant than for any of the other pollutants.
The sulphur dioxide monitoring data collected during the monitoring program are summarized in Tables 1a, 1b, and 1c for each of the three sulphur dioxide monitoring sites. (Note: The first monitoring location (i.e., Farm Yard #1) was only operated until March 1999.) The three monitoring sites and the battery are shown in Figure 1.
Table 1a. Station # 6111 At Farm Yard #1 Site - Sulphur Dioxide (SO2)
(Parts Per Million (PPM))
Date |
Percentage of Data that is Valid |
Average |
Maximum Data Values 1-HOUR : 24-HOUR |
Number of Samples Above Air Quality Objective 1-HOUR : 24-HOUR |
||
JUL 22/98 – MAR 31/99 |
92 |
0.00 |
1.05 |
0.05 |
4 |
0 |
JUL/98 |
96 |
0.00 |
0.00 |
0.00 |
0 |
0 |
AUG/98 |
96 |
0.00 |
1.05 |
0.05 |
4 |
0 |
SEP/98 |
96 |
0.00 |
0.00 |
0.00 |
0 |
0 |
OCT/98 |
96 |
0.00 |
0.00 |
0.00 |
0 |
0 |
NOV/98 |
96 |
0.00 |
0.00 |
0.00 |
0 |
0 |
DEC/98 |
96 |
0.00 |
0.00 |
0.00 |
0 |
0 |
JAN/99 |
74 |
0.00 |
0.00 |
0.00 |
0 |
0 |
FEB/99 |
96 |
0.00 |
0.00 |
0.00 |
0 |
0 |
MAR/99 (end of monitoring) |
88 |
0.00 |
0.00 |
0.00 |
0 |
0 |
Manitoba Air Quality Objectives for SO2:
1-hour average: 0.34 ppm
24-hour average: 0.11 ppm
Table 1b. Station # 6113 At 6-9 Well Site - Sulphur Dioxide (SO2)
(Parts Per Million (PPM))
| Date | Percentage of Data that is Valid |
Average |
Maximum Data Values 1-HOUR : 24-HOUR |
Number of Samples Above Air Quality Objective 1-HOUR : 24-HOUR |
||
| APR 16/99 –JUNE 16/00 | 94 |
0.00 |
0.06 |
0.01 |
0 |
0 |
| APR/99 | 93 |
0.00 |
0.00 |
0.00 |
0 |
0 |
| MAY/99 | 95 |
0.00 |
0.02 |
0.00 |
0 |
0 |
| JUN/99 | 82 |
0.00 |
0.03 |
0.00 |
0 |
0 |
| JUL/99 | 96 |
0.00 |
0.03 |
0.00 |
0 |
0 |
| AUG/99 | 96 |
0.00 |
0.02 |
0.00 |
0 |
0 |
| SEPT/99 | 96 |
0.00 |
0.03 |
0.00 |
0 |
0 |
| OCT/99 | 95 |
0.00 |
0.04 |
0.01 |
0 |
0 |
| NOV/99 | 95 |
0.00 |
0.04 |
0.01 |
0 |
0 |
| DEC/99 | 92 |
0.00 |
0.03 |
0.00 |
0 |
0 |
| JAN/00 | 95 |
0.00 |
0.03 |
0.00 |
0 |
0 |
| FEB/00 | 95 |
0.00 |
0.06 |
0.01 |
0 |
0 |
| MAR/00 | 96 |
0.00 |
0.03 |
0.00 |
0 |
0 |
| APR/00 | 94 |
0.00 |
0.03 |
0.00 |
0 |
0 |
| MAY/00 | 91 |
0.00 |
0.02 |
0.00 |
0 |
0 |
| JUNE 1-16/00 (end of monitoring) |
91 |
0.00 |
0.03 |
0.00 |
0 |
0 |
Manitoba Air Quality Objectives for SO2:
1-hour average: 0.34 ppm
24-hour average: 0.11 ppm
Table 1c. Station # 6112 At Farm Yard #2 Site - Sulphur Dioxide (SO2)
(Parts Per Million (PPM))
| Date | Percentage of Data that is Valid |
Average |
Maximum Data Values 1-HOUR : 24-HOUR |
Number of Samples Above Air Quality Objective 1-HOUR : 24-HOUR |
||
| APR 7/99 – JUNE 4/00 | 94 |
0.00 |
0.02 |
0.01 |
0 |
0 |
| APR/99 | 92 |
0.00 |
0.00 |
0.00 |
0 |
0 |
| MAY/99 | 95 |
0.00 |
0.02 |
0.00 |
0 |
0 |
| JUN/99 | 94 |
0.00 |
0.00 |
0.00 |
0 |
0 |
| JUL/99 | 94 |
0.00 |
0.00 |
0.00 |
0 |
0 |
| AUG/99 | 95 |
0.00 |
0.02 |
0.00 |
0 |
0 |
| SEPT/99 | 96 |
0.00 |
0.00 |
0.00 |
0 |
0 |
| OCT/99 | 94 |
0.00 |
0.00 |
0.00 |
0 |
0 |
| NOV/99 | 96 |
0.00 |
0.00 |
0.00 |
0 |
0 |
| DEC/99 | 93 |
0.00 |
0.00 |
0.00 |
0 |
0 |
| JAN/00 | 88 |
0.00 |
0.00 |
0.00 |
0 |
0 |
| FEB/00 | 95 |
0.00 |
0.02 |
0.01 |
0 |
0 |
| MAR/00 | 92 |
0.00 |
0.00 |
0.00 |
0 |
0 |
| APR/00 | 93 |
0.00 |
0.00 |
0.00 |
0 |
0 |
| MAY/00 | 96 |
0.00 |
0.00 |
0.00 |
0 |
0 |
| JUNE 1-4/00 (end of monitoring) |
96 |
0.00 |
0.00 |
0.00 |
0 |
0 |
Manitoba Air Quality Objectives for SO2:
1-hour average: 0.34 ppm
24-hour average: 0.11 ppm
At the first monitoring location (i.e., Farm Yard #1), the sulphur dioxide monitor had not detected any sulphur dioxide in the period from July to December 1998 except for a two-week period in August 1998. At this time, the monitoring equipment recorded sulphur dioxide gas for short durations on 9 occasions. During the week of January 4 to January 11, 1999, however, the monitor apparently recorded elevated levels of sulphur dioxide for extended periods of time. There were, however, significant uncertainties regarding the validity of the January data because of technical difficulties with the air quality monitoring support systems, inconsistencies with a concurrent informal health survey of the area, and inconsistency with emissions from the battery. After a thorough review, no conclusive statement could be made regarding the air quality in the area based on the data recorded during this week. For the remainder of the sulphur dioxide monitoring conducted at this site, sulphur dioxide had not been detected.
Except for relatively few occasions of very low readings, no sulphur dioxide had been detected at the sulphur dioxide monitors located at the two new monitoring sites of the expanded air quality monitoring program (See Tables 1b and 1c). Sulphur dioxide was detected at these two stationsless than two percent of the time.The sulphur dioxide concentrations measured were significantly below both the 1-hour and 24-hour air quality objectives of 0.34 ppm and 0.11 ppm, respectively. The maximum recorded 1-hour average sulphur dioxide concentrations were 0.06 ppm at the 6-9 Well Site (February 4, 2000) and 0.02 ppm at the Farm Yard #1 site (May 28, 1999; August 13, 1999; February 11, 2000).
No levels of sulphur dioxide were ever recorded on the less sensitiveportable analyzer during periodic monitoring at various locations in the area of complaints.
Hydrogen Sulphide
Monitoring for hydrogen sulphide took place at the two new monitoring sites (i.e., Farm Yard #2 and 6-9 Well Site) starting at the end of April 1999. One of the hydrogen sulphide monitors was removed from service for maintenance for about 6 weeks in June and July 1999. No reliable data were available for this monitor for the period from May 5, 1999 to July 27, 1999.
The hydrogen sulphide monitoring data collected during the monitoring program are summarized in Tables 2a and 2b.
Table 2a. Station # 6113 At 6-9 Well Site - Hydrogen Sulphide (H2S)
(Parts Per Billion (PPB))
| Date | Percentage of Data that is Valid |
Average |
Maximum Data Values 1-HOUR : 24-HOUR |
Number of Samples Above Air Quality Objective 1-HOUR |
|
| MAY 7/99 –JUNE 16/00 | 83 |
0.14 |
36.0 |
6.5 |
12 |
| MAY/99 | 93 |
0.04 |
6.5 |
0.8 |
0 |
| JUN/99 | 24 |
0.12 |
6.1 |
0.9 |
0 |
| JUL/99 | 15 |
0.74 |
9.8 |
1.9 |
0 |
| AUG/99 | 96 |
0.76 |
36.0 |
6.5 |
10 |
| SEPT/99 | 96 |
0.15 |
5.9 |
1.1 |
0 |
| OCT/99 | 94 |
0.03 |
1.4 |
0.2 |
0 |
| NOV/99 | 95 |
0.15 |
11.2 |
1.1 |
1 |
| DEC/99 | 92 |
0.08 |
8.2 |
0.7 |
0 |
| JAN/00 | 95 |
0.04 |
9.1 |
0.5 |
0 |
| FEB/00 | 95 |
0.02 |
1.4 |
0.2 |
0 |
| MAR/00 | 95 |
0.01 |
2.1 |
0.2 |
0 |
| APR/00 | 95 |
0.02 |
4.7 |
0.4 |
0 |
| MAY/00 | 91 |
0.09 |
4.3 |
0.6 |
0 |
| JUNE 1-8/00 (end of monitoring) |
91 |
0.09 |
11.6 |
1.0 |
1 |
Manitoba Ambient Air Quality Objective for H2S:
1-hour average: 11.0 ppb
Table 2b. Station # 6112 At Farm Yard #2 Site - Hydrogen Sulphide (H2S)
(Parts Per Billion (PPB))
| Date | Percent of Data that Is Valid |
Average |
Maximum Data Values 1-HOUR : 24-HOUR |
Number of Samples Above Air Quality Objective 1-HOUR |
|
| MAY 5/99 –JUNE 4/00 | 87 |
0.04 |
23.2 |
2.1 |
4 |
| MAY/99 | 0 |
-- |
-- |
-- |
0 |
| JUN/99 | 70 |
0.02 |
1.2 |
0.2 |
0 |
| JUL/99 | 94 |
0.12 |
21.4 |
2.1 |
1 |
| AUG/99 | 96 |
0.17 |
7.5 |
1.1 |
0 |
| SEPT/99 | 96 |
0.03 |
2.4 |
0.3 |
0 |
| OCT/99 | 95 |
0.01 |
0.9 |
0.1 |
0 |
| NOV/99 | 96 |
0.01 |
1.2 |
0.1 |
0 |
| DEC/99 | 93 |
0.04 |
11.5 |
1.0 |
2 |
| JAN/00 | 95 |
0.00 |
1.5 |
0.1 |
0 |
| FEB/00 | 95 |
0.05 |
23.2 |
1.3 |
1 |
| MAR/00 | 96 |
0.00 |
0.0 |
0.0 |
0 |
| APR/00 | 93 |
0.00 |
0.0 |
0.0 |
0 |
| MAY/00 | 96 |
0.02 |
3.3 |
0.3 |
0 |
| JUNE 1-4/00 (end of monitoring) |
96 |
0.00 |
0.0 |
0.0 |
0 |
Manitoba Ambient Air Quality Objective for H2S:
1-hour average: 11.0 ppb
Low levels of hydrogen sulphide have been detected on several occasions at both monitoring stations, usually in the early hours of the day. For most of these occasions, the levels recorded did not exceed the provincial air quality guideline for hydrogen sulphide of 11 parts per billion (ppb); however, if any local residents had been in the area at the time, they might have been able to smell some hydrogen sulphide. At the monitor at the 6-9 Well Site, the levels of hydrogen sulphide tended to be slightly higher than at the Farm Yard #2 site. Hydrogen sulphide was detected by the instruments at the two sites less than 7% of the time.
Elevated levels of hydrogen sulphide (i.e., above the provincial air quality guideline of 11 ppb) were detected on occasion. Most of these incidents appeared to occur during the early morning hours under calm wind conditions. (These incidents are described in Table 3.) While the hydrogen sulphide levels during these incidents could have been smelled, the levels were much less than levels reported in the literature as causing health effects such as irritation to occur (e.g., about 2,000 ppb in asthmatics following a 30-minute exposure).
Table 3. Exceedances of the H2S Air Quality Guideline
| Monitoring Site | Date | Time |
Hourly Average H2S Concentration (ppb) |
Wind Speed - Wind Direction(1) |
| Farm Yard #2 | July 10, 1999 | 22:00 |
21.4 |
2.1 km/hr - SSW (209o) |
| December 29, 1999 | 18:00 |
11.3 |
10.9 km/hr - NW (319o) | |
20:00 |
11.5 |
8.0 km/hr - ENE (62o) | ||
| February 7, 2000 | 7:00 |
23.2 |
2.4 km/hr - W (263o) | |
| 6-9 Well Site | August 6, 1999 | 1:00 |
15.1 |
7.3 km/hr - WSW (255o) |
6:00 |
21.1 |
4.0 km/hr - NE (44o) | ||
| August 10, 1999 | 1:00 |
12.5 |
6.3 km/hr - W (262o) | |
2:00 |
13.0 |
7.1 km/hr - W (263o) | ||
| August 13, 1999 | 6:00 |
15.0 |
3.2 km/hr - WNW (289o) | |
| August 24, 1999 | 2:00 |
13.4 |
6.1 km/hr - W (271o) | |
3:00 |
15.1 |
5.3 km/hr - WSW (257o) | ||
5:00 |
27.6 |
6.3 km/hr - WSW (258o) | ||
6:00 |
27.2 |
3.3 km/hr - W (263o) | ||
7:00 |
36.0 |
4.9 km/hr - W (262o) | ||
| November 5, 1999 | 17:00 |
11.2 |
8.7 km/hr - W (259o) | |
| June 7, 2000 | 5:00 |
11.6 |
2.0 km/hr - W (267o) |
(1) The wind direction is defined as the direction from which the wind is blowing. The wind direction is given both by sector (e.g.¸ SSW) and degrees (e.g., 209o) where North is 0o, East is 90o, South is 180o and West is 270o.
No levels of hydrogen sulphide were recorded on the less sensitive portable analyzer during monitoring at various locations in the area of complaints.
Sulphuric Acid Mist
The sulphuric acid monitor, on short-term loan from Environment Canada, did not detect any sulphuric acid mist in the vicinity of the 6-9 Well Site during the 2 months that it was operated. This monitor was returned to Environment Canada in December 1999.
Volatile Organic Compounds (VOC's)
In total, 18 1-hour and 42 24-hour air samples for determining volatile organic compounds (VOC) were taken in the area. The VOC data are summarized in Table 4.
While the total number of samples was relatively limited, they did provide some indication of the VOC's (both natural and man-made) present in the area. Many of these compounds are widespread and would be present in an air sample taken anywhere in the province, especially considering the low detection limit of the analysis for the VOC's.
In downtown Winnipeg, 24-hour VOC samples have been taken every six days since 1990. In general, the levels of VOC's measured in the Tilston samples were similar to or less than levels observed in Winnipeg during the years from 1990 to 1998. Many of the VOC's in the Tilston samples, especially those reported at extremely low concentrations, were near the lower limit of detection of the methodology used to measure the VOC's. For some of the VOC's, air quality criteria were available from Ontario or Quebec; the levels measured for these VOC's were found to be substantially less than their criteria.
Somewhat higher than expected concentrations of Freon 113 and dichloromethane were detected in the first four VOC samples. It was later determined that the Freon 113 and dichloromethane levels were the result of trace contamination of the valve on the SUMMA canister used to collect the samples.
A 1-hour VOC sample was taken on August 23, 1999 at a time and location where hydrogen sulphide could be smelled. Reviewing the results for this sample did not reveal any significant differences from other VOC samples that have been taken. Only 5 of the 147 compounds were higher (but not significantly so) than in previous samples from the Tilston area. The levels of these compounds were within the range of the levels measured in Winnipeg and were substantially less than any available air quality guidelines.
BTEX
The BTEX compounds (benzene, toluene, ethyl benzene, and xylene), which are a subgroup of the VOC's, had been raised as an air quality issue in the Tilston area since these compounds are associated with hydrocarbon contamination, especially of soils. In the VOC samples collected, the levels of BTEX compounds were within the range of levels found in Winnipeg; they were also significantly less than Ontario's or Quebec's air quality standards for these compounds.
The air concentrations of the BTEX compounds are summarized in Table 5a for the 1-hour samples and in Table 5b for the 24-hour samples. Also shown are the relevant Ontario and Quebec air quality guidelines.
Table 5a. Comparison of Winnipeg and Tilston BTEX Concentrations
(1-hour samples)
| Compound | Number of Samples |
Average (µg/m3) |
Minimum (µg/m3) |
Maximum (µg/m3) |
Ontario Air Quality Standard(3) (µg/m3) |
WINNIPEG(1) - (1990 - 1998) |
|||||
| Benzene | 501 |
1.89 |
0.39 |
12.00 |
N/A |
| Toluene | 500 |
5.98 |
1.26 |
54.40 |
2,000 |
| Ethyl benzene | 501 |
0.88 |
0.05 |
6.49 |
4,000 |
| m-Xylene and p-Xylene | 501 |
3.28 |
0.01 |
21.20 |
2,300 |
| o-Xylene | 501 |
1.23 |
0.01 |
9.46 |
2,300 |
TILSTON(2) |
|||||
| Benzene | 18 |
0.31 |
0.12 |
0.66 |
N/A |
| Toluene | 18 |
2.12 |
0.15 |
11.61 |
2,000 |
| Ethyl benzene | 18 |
0.16 |
0.02 |
0.74 |
4,000 |
| m-Xylene and p-Xylene | 18 |
0.41 |
0.04 |
2.12 |
2,300 |
| o-Xylene | 18 |
0.16 |
0.02 |
0.86 |
2,300 |
Table 5b. Comparison of Winnipeg and Tilston BTEX Concentrations
(24-hour samples)
| Compound | Number of Samples |
Average (µg/m3) |
Minimum (µg/m3) |
Maximum (µg/m3) |
Ontario Air Quality Standard(5) (µg/m3) |
WINNIPEG(1) - (1990 - 1998) |
|||||
| Benzene | 501 |
1.89 |
0.39 |
12.00 |
10(6) |
| Toluene | 500 |
5.98 |
1.26 |
54.40 |
2,000 |
| Ethyl benzene | 501 |
0.88 |
0.05 |
6.49 |
N/A |
| m-Xylene and p-Xylene | 501 |
3.28 |
0.01 |
21.20 |
2,300 |
| o-Xylene | 501 |
1.23 |
0.01 |
9.46 |
2,300 |
TILSTON(4) |
|||||
| Benzene | 42 |
0.57 |
0.20 |
1.90 |
10(6) |
| Toluene | 42 |
0.75 |
0.20 |
7.23 |
2,000 |
| Ethyl benzene | 42 |
0.16 |
0.05 |
1.58 |
N/A |
| m-Xylene and p-Xylene | 42 |
0.43 |
0.08 |
5.82 |
2,300 |
| o-Xylene | 42 |
0.16 |
0.03 |
2.02 |
2,300 |
(1) Winnipeg: 24-hour samples
(2) Tilston: 1-hour samples
(3) Ontario Point of Impingement Standard (half-hour average)
(4) Tilston: 24-hour samples
(5) Ontario Ambient Air Quality Criteria (24-hour average)
(6) Quebec Air Quality Guideline for benzene (24-hour average)
N/A: not available
Aldehydes and Ketones
Since the start of the monitoring in August 1999, 40 aldehyde and ketone samples were taken. The levels were comparable to levels measured in Winnipeg and were less than any of the available air quality criteria. The air concentrations of the aldehydes and ketones are summarized in Table 6. Also shown are any air quality guidelines that are available.
Table 6. Tilston Air Quality - Aldehyde and Ketone Monitoring Data (µg/m3)
| Compounds | Tilston |
Winnipeg |
Ontario Air Quality Criteria (µg/m3) |
|||||
(August 1999 - May 2000) |
(March 1997 - June 1997) |
|||||||
Average |
Min. |
Max. |
Average |
Min. |
Max. |
|||
| Formaldehyde | 1.11 |
0.51 |
3.68 |
3.19 |
1.58 |
9.09 |
65 |
24-hour |
| Acetaldehyde | 0.88 |
0.34 |
4.45 |
1.54 |
0.96 |
3.76 |
500 |
24-hour |
| Acrolein | 0.03 |
0.00 |
0.37 |
0.12 |
0.04 |
0.39 |
24 |
24-hour |
| Acetone | 2.33 |
0.88 |
5.79 |
4.23 |
2.12 |
8.12 |
48,000 |
24-hour |
| Propionaldehyde | 0.24 |
0.07 |
1.07 |
0.45 |
0.22 |
0.92 |
3 |
24-hour |
| Crotonaldehyde | 0.02 |
0.00 |
0.23 |
0.15 |
0.04 |
0.68 |
--- |
--- |
| Methyl ethyl ketone | 0.47 |
0.18 |
2.25 |
1.51 |
0.60 |
6.53 |
31,000 |
1-hour |
| Benzaldehyde | 0.02 |
0.00 |
0.15 |
0.23 |
0.10 |
0.69 |
--- |
--- |
| 2-Pentanone/ Isovaleraldehyde | 0.12 |
0.00 |
1.31 |
0.30 |
0.05 |
1.17 |
--- |
--- |
| Valeraldehyde | 0.03 |
0.00 |
0.18 |
0.16 |
0.00 |
0.46 |
--- |
--- |
| o-Tolualdehyde | 0.00 |
0.00 |
0.00 |
0.03 |
0.00 |
0.50 |
--- |
--- |
| m-Tolualdehyde | 0.00 |
0.00 |
0.00 |
0.10 |
0.00 |
0.26 |
--- |
--- |
| p-Tolualdehyde | 0.00 |
0.00 |
0.00 |
0.02 |
0.00 |
0.11 |
--- |
--- |
| Methyl isobutyl ketone | 0.01 |
0.00 |
0.12 |
0.22 |
0.00 |
0.99 |
--- |
--- |
| Hexanal | 0.06 |
0.00 |
0.25 |
0.32 |
0.06 |
1.55 |
--- |
--- |
| 2,5-Dimethyl benzaldehyde | 0.00 |
0.00 |
0.00 |
0.00 |
0.00 |
0.00 |
--- |
--- |
Wind Speed and Direction
Wind speed and wind direction had been monitored at the Farm Yard #1 site from July 1998 to March 1999 and at the trailer at the 6-9 Well Site from early April 1999 to June 2000. Wind roses showing the average wind speed and direction for these two sites are shown in Figures 2 and 3. For each direction, the length of each bar reflects the frequency of wind from that direction and the width of the components of the bar indicates the wind speed. For example, in Figure 3, the wind was from the west about 11% of the time and the maximum wind speed was over 50 km/hr.
Figure 2. Wind Rose - Farm Yard #1 (July 22, 1998 to March 31, 1999)
Figure 3. Wind Rose 6-9 Well Site (April 18, 1999 to June 15, 2000).
Several differences are apparent between the two wind roses; at the 6-9 Well Site there was a higher frequency of winds from the south and the north-west sector and a lower frequency of winds from the north-east sector compared with the Farm Yard #1 site. These differences may have been due to several factors, including: i) buildings obstructing the wind flow when the monitor was located at the Farm Yard #1 site; and ii) a seasonal effect since different times of the year were monitored at the two sites (i.e., late summer through winter at the Farm Yard #1 site compared with all seasons at the 6-9 Well Site).
In Figure 4, the wind rose plots hydrogen sulphide concentration against wind direction for the 6-9 Well Site. For each direction, the length of each bar reflects the frequency of wind from that direction, while the width of the components indicates the hydrogen sulphide concentration. The wind was from the west about 11% of the time and the maximum hydrogen sulphide concentration was in the range of 36.0 to 40.0 ppb. A similar wind rose could not be developed for the Farm Yard #2 site because no wind data were collected at that site.
Figure 4. Tilston hydrogen sulphide wind rose: wind direction versus hydrogen sulphide concentration at 6-9 well site (May 7, 1999 to June 16, 2000)
Winds that are from the West-South-West through West could carry emissions from the battery to the 6-9 Well Site. Winds from the West-North-West through North-West could carry emissions from the battery to the Farm Yard #2 site.
For most of the monitoring period, the wind monitor used for the measurement of wind speed and direction had a threshold sensitivity for wind direction of 1.1 m/s (2.5 mph or 4 km/hr) at a 10 degree displacement. When the wind speed was 4 km/hr or lower, the wind may have been unable to move the wind vane sufficiently to accurately measure the wind direction. A new wind monitor, installed on March 28, 2000 at the 6-9 Well Site, had a lower threshold sensitivity (i.e., 0.5 m/s or 1.8 km/hr).
Review of Air Quality in the Tilston Area
From the data collected during this air quality monitoring program, several conclusions can be made:
i) During the initial monitoring that was undertaken at the Farm Yard #1 site, sulphur dioxide was detected during a brief, two-week period in August 1998; on 4 of these occasions, the provincial ambient air quality objective for sulphur dioxide was exceeded.
ii) At the two expanded monitoring stations (i.e., Farm Yard #2 and 6-9 Well Site), sulphur dioxide was not detected except for a few occasions of low levels of sulphur dioxide at the 6-9 Well Site and the Farm Yard #2 site. The levels measured were all below the provincial air quality objective.
iii) Hydrogen sulphide was occasionally measured at low levels, especially at the monitor located at the 6-9 Well Site east of the 8-8-6-29 W.P.M. battery. On a relatively few occasions at both monitoring stations, the Manitoba air quality guideline of 11 ppb was exceeded.
iv) VOC's, including BTEX compounds, were similar or lower than the levels measured in Winnipeg. For those VOC's which had air quality guidelines, the levels measured were significantly less than the guidelines.
v) The aldehyde and ketone levels were similar to or less than levels measured in Winnipeg. For those which had available air quality criteria, the levels were significantly less than the criteria.
Based on the air quality monitoring data collected by the monitoring program, hydrogen sulphide seemed to be the only air contaminant that exceeded the provincial air quality guideline. The provincial guideline is based on the protection from annoyance due to odour. During incidents when the guideline was exceeded, hydrogen sulphide may have been detectable by smell but the levels were significantly less than levels reported in the published literature as causing health effects such as irritation.
Overall, the air quality monitoring program has shown that the air quality in the Tilston area is good, most of the time. The levels of air pollutants detected in the outdoor air in the Tilston area have met the air quality guidelines, except on some infrequent occasions.
For further information on the air quality monitoring program, please contact:
Manager, Air Quality Management Section
Manitoba Conservation
Suite 160, 123 Main Street
Winnipeg, Manitoba R3C 1A5
Tel: 204-945-7046
Fax: 204-948-2357
e-mail: dbezak@gov.mb.ca
Acknowledgements
This ambient air quality monitoring program could not have been undertaken without the assistance of many others. Manitoba Conservation would like to acknowledge and thank Environment Canada for providing sampling equipment and analytical services, Reeve Manson Moir of the Rural Municipality of Albert for providing field support to the monitoring program, and Bill Campbell, Jim and Wendy Anderson and Tundra Oil and Gas Ltd. for providing monitoring sites on their respective properties. As well, Manitoba Conservation would like to thank the members of the Tilston Community Advisory Group (CAG) for their input in developing the air quality monitoring program and for serving as a forum to exchange information and discuss issues related to oil and gas environmental matters.
