NEW: Annual Report - George Mason University

Total Alkalinity (mg/L CaCO3), Noman Cole Lab
110
100
90
80
70
60
50
40
30
Station 7: June-Sept
20
1980 1985 1990 1995 2000 2005
YEAR
Total alkalinity as measured by
Noman Cole lab personnel
exhibited a rise from 1983 to
1990 and has been on a slow
decline since that time (Figure
88). The trend line at 2003 was
similar to the value in 1983.
This parameter showed a
significant linear decline over
the long term study period at a
rate of 0.29 mg/L per year
(Table 11).
Figure 88. Long term trend in Total Alkalinity (NC Lab Data). Station 7. Gunston Cove.
Total Alkalinity (mg/L CaCO3), Noman Cole Lab
150
100
50
Station 9: June-Sept
0
1980 1985 1990 1995 2000 2005
YEAR
In the river a similar pattern
was observed (Figure 89).
Interestingly, alkalinity in the
river in 2003 was mostly above
the long term trend line. Linear
trends in this parameter were
not detected by regression
analysis (Table 11).
Figure 89. Long term trend in Total Alkalinity (NC Lab Data). Station 9. Potomac
mainstem.
75