MIL-HDBK-1005/16
I/I at installations before resorting to use of the data and
nomographs offered in WEF MOP FD-5. The guidance provided in WEF
MOP FD-5 is based on municipally derived empirical data for flow
situations in which dry-weather wastewater flow ratios are
expected to govern. These relationships may not be appropriate
for installations with significant non-resident populations
and/or severe I/I problems.
b)
Add the maximum 24-hour flows from any other
sources.
3.3.2.4
Domestic Flow, Peak Flow. To determine the peak flow
for a resident population, multiply the annual average flow by
the ratio of peak flow to annual average flow based on wastewater
flow data for the facilities being studied. If no data are
available, see Chapter 3 in WEF MOP FD-5 for methods of
estimating ratios for typical domestic wastewater. Designers are
cautioned to carefully consider the impact of resident and non-
resident populations and I/I at installations before resorting to
use of the data and nomographs offered in WEF MOP FD-5. The
guidance provided in WEF MOP FD-5 is based on municipally derived
empirical data for flow situations in which dry-weather
wastewater flow ratios are expected to govern. These
relationships may not be appropriate for installations with
significant non-resident populations and/or severe I/I problems.
In these situations, careful consideration and allowance for I/I
flows must be made when developing peak design flow rates.
Consider coincident peaks from other sources. For a
nonresident population, assume that a peak flow of three times
the average nonresidential flow is coincident with resident peak
flow (i.e., daily contribution uniform over 8-hour shift).
For installations where the average domestic flow for nonresident
population will exceed 0.4 mgd (1.5 ML/d) or constitute more than
20 percent of the total average flow, investigate flow variations
from nonresidents in the installation itself or at an
installation similar to the one proposed. Note that peak flows
can vary widely at specific installations. At Hurlburt Field it
was found that residential population flows had a peaking factor
of 3, while base operations had a peaking factor of approximately
7. This illustrates the need to accurately evaluate and account
for peak flows from all sources, such as flows from vehicle and
aircraft washing facilities and other industrial flows that occur
during specific hours. If these flows coincide with peak
domestic flows, they should be added to the peak flows.
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