action must be taken to close the isolation valves
on drains located below the CHT tank overflow
line discharge and divert upper deck drains over-
board to preclude flooding of space. In the event
of leakage or snagging of the transfer hoses, close
valve F (shown in figures 8-5 and 8-6) at the deck
connection only (closure of pier valve may cause
the discharge hose to rupture). Line up pump
discharge diverter valve C for overboard
discharge, to prevent overflow or backup of
drains located below the tank overflow.
At-Sea Mode
In order to set the CHT system up for the At-
sea mode (refer to figures 8-5 and 8-6) set soil and
waste drain diverter valves H and J to the OVER-
BOARD position. Open pump discharge valves
B and set pump discharge diverter valve C to the
overboard position. Check to insure that gag scup-
per valve at the hull in the pump discharge line
is open. Set the discharge pump controller selec-
tor switches to the MAN1 position. After the
pumps lose suction, set both controller selector
switches to the AUTO position. Open the tank
washdown supply valve and wash the tank for 30
minutes. Close the tank washdown supply valve.
Set the controller selector switches to MAN1 posi-
tion. After loss of pump suction, set controller
switches in the OFF position. Close pump suc-
tion valves A, discharge valves B, and, in the
strainer system only, close the inflow stopvalves
G.
For CHT systems outfitted will comminutors
and aeration systems, secure the comminutor after
setting the soil drain diverter valves. Close air
blower discharge valve M and secure air blower,
or close ship supply valve N after tank washdown
procedures have been completed and the pump
has lost suction. If an air aspirator system is in-
stalled, shut the system down and secure the
aspiration pump.
The CHT system is now secured with all soil
and waste being discharged overboard through the
gravity drainage system.
For additional information on the CHT
system and its components, refer to the manufac-
turers technical manuals and Naval Ships
Technical Manual, Chapter 593.
NOISE POLLUTION
Hearing loss problems have been and continue
to be a source of concern within the Navy, both
ashore and afloat. In the Navy the loss of hear-
ing can occur from exposure to impulse or blast
noise (i.e., gunfire, rockets, etc.) or from con-
tinuous or intermittent sounds such as jet or pro-
peller aircraft, marine engines, boiler equipment
operations, and any of a myriad of noise sources
associated with industrial type activities (such as
shipyards). Hearing loss may be temporary, and
will disappear after a brief period of nonexposure,
or it may become permanent through repeated
exposures to intense noise levels. The loss of hear-
ing sensitivity is generally in the higher frequen-
cies of 4000-6000 Hertz (Hz) with many people
sustaining extensive impairment before the all im-
portant speech range of 500-3000 Hz is ap-
preciably affected.
The Navy recognized noise pollution to be a
problem and started to combat it through the
Hearing Conservation Program. The main pur-
pose of this program is to establish and imple-
ment an effective occupational noise control and
hearing conservation program which has as its
goal the elimination/prevention of hearing loss.
HEARING CONSERVATION
PROGRAM
Hearing loss associated with exposure to
hazardous noise and the high cost of compensa-
tion claims have highlighted a significant problem
which requires action to reduce or eliminate
hazardous occupational noise levels. An effective
occupational noise control and hearing conserva-
tion program will prevent or reduce the exposure
of personnel to potentially hazardous noise. Such
programs will incorporate the following elements:
1. Identification of hazardous noise areas and
their sources.
2. Elimination or reduction of noise levels
through the use of engineering controls.
3. Periodic hearing testing of noise-exposed
personnel to evaluate program effectiveness.
4. Education of all hands in the commands
program and their individual responsibilities.
5. Strict enforcement of all prescribed occupa-
tional noise control and hearing conservation
measures including disciplinary action for
violators and supervisors, as necessary.
Chapter 8ENVIRONMENTAL POLLUTION
8-19