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302 Chapter 9 Cross-Connection Control

Backflow preventer
replaced by spool piece

Main freshwater
line
Pump prime line

High-pressure fire line
seawater

Saltwater suction line
for fire protection

Figure 9.4 Salt Water pumped into Freshwater Line

• The shipyard fire protection system utilized seawater that was pumped by both
electric and diesel-driven pumps.
• The pumps were primed by potable city water.
With the potable priming line left open and the pumps maintaining pressure in the fire
lines, raw salt water was pumped through the priming lines, through the spool sleeve piece,
to the ship repair facility and the restaurant.

9.2.5 Paraquat in the Water System
“Yellow gushy stuff” poured from some of the faucets in a small town in Maryland, and the
state of Maryland placed a ban on drinking the water supply. Residents were warned not to
use the water for cooking, bathing, drinking, or any other purpose except for flushing toilets.
The incident drew widespread attention and made the local newspapers. In addition, it
was the lead story on the ABC news affiliate in Washington, D.C., and virtually all the