MIL-HDBK-1005/9A
These conditions will corrode metal and concrete, cause odor
concentration exceeds 10 ppm.
b) Under certain circumstances, provision of a third
LET should be considered. At larger Naval installations subject
to periodic surges in ship traffic in port, the capability to
process sudden, abnormally high oily waste flows may warrant
extra reserve capacity. At smaller Naval installations where
available land area imposes layout restrictions, three reduced
volume LETs may be necessary to provide operating flexibility for
normal peak flow occurrences and for tank cleaning downtime. Due
to the different characteristics of shore waste, a third LET
should be considered for treatment of shore-generated oily waste
at shore facilities where large volumes of shore-generated oily
waste are to be treated with ship oily waste.
3.10.2.1 Basis of Sizing. Estimates are required of the numbers
and types of berthed ships discharging to the pierside collection
system and SWOBs. Nominal shipboard oily waste generation rates
are 50,000 gpd (189,270 L/d) for aircraft carriers and 3,750 gpd
(14,195 L/d) for other classes of ships. Estimates of barge and
tank truck delivery volumes and frequencies should be compiled
from historical records.
Alternatively, LET size could be based on analysis of
Qdaily, Qmaximum, and Qpeak established for design of pierside
collection systems. Refer to paragraph 3.8.1.2 for methodology
for determining these flow rates.
3.10.2.2 Layout. Use rectangular, reinforced concrete tanks.
The following guidelines for LET layout are suggested. See
Figure 15 for a schematic of a LET.
LET 7-Day Capacity
Characteristic
0.1 to 0.5 Mgal
1.0 to 1.5 Mgal
Length:Width
3:1
5:1
Depth-ft (m)
10(3.05)
20(6.1)
Freeboard-ft (m)
1.5(0.5)
1.5(0.5)
131
Previous Page
