Storm Duration
(hours)
|
Rain Intensity
(inches per hour)
|
Average Total Rain
(inches)
| |
---|---|---|---|
0.5
|
1.8
|
0.9
| |
1
|
1.1
|
1.1
| |
2
|
0.7
|
1.3
| |
3
|
0.5
|
1.5
| |
6
|
0.3
|
1.7
| |
12
|
0.2
|
2.0
| |
24
|
0.1
|
2.3
|
(Note: The above applicability criteria are specifically stated
in 1983 Wisconsin Act 416 for inclusion in this article. Utility companies
responsible for energy repair work should enter into a memorandum
of agreement with the Building Inspector clearly stating their responsibilities
if their activities may be included under any of the above applicability
criteria.)
|
[Note: There are several ways to meet this particle size performance
objective, depending on the pumping rate. As an example, if the pumping
rate is very low (one gallon per minute), then an inclined or vertical
enlargement pipe (about eight inches in diameter for one gallon per
minute) several feet long would be an adequate control device to restrict
the discharge of 100 micron and larger particles. As the pumping rate
increases, then the device must be enlarged. At a moderate pumping
rate (100 gallons per minute), a vertical section of corrugated steel
pipe, or concrete pipe section, or other small tank (about 4 1/2 feet
across for a pumping rate of 100 gallons per minute) several feet
tall would be adequate. With these pipe sections or small tanks, inlet
baffles would be needed to minimize turbulence. With very large pumping
rates (10,000 gallons per minute), sediment basins (about 35 feet
in diameter for a pumping rate of 10,000 gallons per minute) at least
three feet in depth with a simple (but adequately sized) pipe outlet
would be needed. More sophisticated control devices (such as swirl
concentrators or hydrocyclones) could be specially fabricated that
would generally be smaller than the simple sedimentation devices described
above, but they would not be required.]
|