Environmental Engineering Reference
In-Depth Information
11.3.6.6 Average Weekly Quantity
The average weekly quantity (AWQ) is the average of all of the daily
quantities determined during a calendar week. A calendar week must
start on Sunday and end on Saturday and be completely within the
reporting month. A weekly average is not computed for any week that
does not meet these criteria.
∑
dq
+
dq
+
dq
+…+
dq
1
2 3
ing calendarweek)
n
(11.6)
AWQ(kg/day)
=
n
(testsdur
11.3.6.7 Minimum Concentration
The minimum concentration is the lowest instantaneous value
recorded during the reporting period.
11.3.6.8 Maximum Concentration
The maximum concentration is the highest instantaneous value
recorded during the reporting period.
11.3.6.9 Bacteriological Reporting
Bacteriological reporting is used for reporting fecal coliform test
results. To make this calculation, the geometric mean calculation is
used and all monthly geometric means are computed using all the test
values. Note that weekly geometric means are computed using the same
selection criteria discussed for average weekly concentration and quan-
tity calculations. The easiest way to make this calculation is to use a
calculator that can perform logarithmic (log) or
n
th root functions:
⎡
⎣
⎢
log
X
+
log
X
+
log
X
+…
lo
g
X
⎤
⎦
⎥
1
2
3
n
Geometric Mean
=
Antilog
(11.7)
n
(number of tests)
or
GeometricMean =
n
xx
× ×…×
x
n
1
2
referenCes and reCoMMended reading
Metcalf & Eddy. (1991).
Wastewater engineering: Treatment, disposal,
reuse
, 3rd ed. New York: McGraw-Hill.
Metcalf & Eddy. (2003).
Wastewater engineering: Treatment, disposal,
reuse
, 4th ed. New York: McGraw-Hill.
