12 May 2003
Including change 1, 19 January 2007
Ship Oily Waste Generation. Collection may take the form of transfer
systems to trucks or barges, or a facility pipeline system. Coordinate with
environmental requirements to provide an environmentally acceptable collection system
with the most economical life cycle cost.
Primary sources of ship-generated oily wastewater are bilges, oily waste
holding tanks for collecting lubricating oils and water contaminated fuel, condensate
lines, and tank cleaning water. Sonar dome pumping water is not normally collected as
part of the oily waste collection system. The oil content in the bilge water normally
varies from 0.01 percent (100 ppm) to 1.0 percent (10,000 ppm). The rest is mostly
saltwater of unknown chloride content. The oil content of ship discharges overboard is
limited to 20 ppm or less within 12 nautical miles of the nearest land. In ports that
restrict the direct discharge of ballast water, the ballast water can be discharged from
most ships (other than tankers) through a large diameter piping system to a ship waste
oily barge (SWOB) or a YON vessel. Compensating ballast water can also be
discharged directly to a pier collection system provided the liquid can discharged by
gravity flow (from ship to pier connection) and the back pressure can be kept to a
minimum. The Navy policy on classification of oily wastewater is that the oily waste and
waste oil (OWWO) become a waste only upon removal from the ship. In general, bilge
water should be treated like any other waste.
Pumping Equipment. Provide basket or bar type screens on a pump
inlet that can be easily removed and cleaned from an easily accessible and safe
Determine pump capacity and operating cycle. In order to reduce
mechanical formation of emulsion at oily waste treatment plants, use positive
displacement pumps (in lieu of centrifugal pumps) with pressure relief valves. Pumps
should pass solids having a diameter 3 mm (0.125 in).
Provide controls suitable for Class I, Division 1, Group D hazardous
classification. Use float or sonic type level controllers for pump control and alarm. Air
bubbler type controllers must not be used. Provide a discharge pump control valve to
minimize surge effects on equalization basins located at oily waste treatment plants.
(This requirement is not applicable for positive displacement pumps.) Provide an alarm
system for overflow or power failure. Provide manual override of automatic pump
controllers. Low-level alarm conditions must lock out all pumps and must require
Piping Systems. Piping requirements are similar to requirements for
sewage systems. (See paragraph 3-7 and the associated subparagraphs.) Piping
material is typically galvanized steel. However, some local environmental regulations
require double-wall piping systems. Consult with the Activity and the cognizant
NAVFAC EFD/EFA OR USACE DISTRICT. Provide pipe hangers and associated
support assemblies in accordance with paragraph 2-4.1.3. Identify oily waste outlets on
piers and wharves and color-code in accordance with Chapter 6.