TABLE 33
Summary Table of  SO  (in ppb) at Monitoring Stations Front Street, River Bend, LaSalle Road,
2
Grace Church, Sarnia
SO  1-hour Ontario MOE AAQC is 250 ppb
2
SO  1-year Ontario MOE AAQC is 20 ppb
2
Location
Front St.
River Bend
LaSalle Road
Grace Church
Year
Annual
Max 1h
Annual
Max 1h
Annual
Max 1h
Annual
Max 1h
Mean
Mean
Mean
Mean
1990
11
270
7
224
6
175
4
120
1991
10
307
8
289
6
125
3
131
1992
9
276
9
310
5
199
3
172
1993
9
226
9
233
5
168
5
177
1994
9
208
9
280
5
129
5
168
1995
7
247
9
343
4
120
1996
10
249
10
278
3
314
1997
9
283
9
233
5
118
Site was closed
1998
9
262
10
226
6
167
in 1995
1999
11
245
9
226
6
171
2000
10
236
8
231
5
129
2001
11
237
9
473
5
146
2002
10
238
7
222
5
131
Data from monitoring stations in Sarnia and Corunna
annual average objective of  20 ppb.  Figures 3 and 4
(Figures 3 and 4) show little change in annual average
illustrate the annual level averages for SO  at the Front
2
sulphur dioxide concentrations over the past decade.
St and River Bend monitoring stations.
Concentrations remained approximately one-half  of  the
42