Page 242 - Vessel Sanitation Program 2018 Operations Manual

VSP 2018 Operations Manual
13.7
13.7.1 Background
13.7.2 Introduction
13.7.3 Cross-Connection Survey
Annex 13.7: Sample Cross-Connection Control Program Guideline; 189
Sample Cross-Connection Control Program Guideline
Unprotected CROSS-CONNECTIONS to the POTABLE WATER system can
result in mild changes to the aesthetic quality of the water affecting taste, odor,
and color or severe changes that can result in illness or death. The purpose of a
CROSS-CONNECTION control program is to identify these connections and
provide appropriate protection.
Use this outline to either develop a comprehensive CROSS-CONNECTION
control program or update and maintain an existing program.
One of the first steps in developing a CROSS-CONNECTION control program
is to conduct a thorough survey of the POTABLE WATER system to identify all
actual or potential CROSS-CONNECTIONS. Although an initial survey of the
vessel can be time consuming, it is essential to ensure that all connections are
identified so that appropriate protection can be decided on.
Protection of POTABLE WATER can take two forms—containment or
complete protection. Although the former may be the objective for a water
supplier and requires less time and detail, the latter is the objective for this
guidance.
Example: A surveyor enters a structure and identifies numerous connections to
the POTABLE WATER—both nonhealth-HAZARD and health-HAZARD
connections. For containment purposes, an RP ASSEMBLY on the exterior
supply line downstream of the water meter would contain all of the HAZARDS
within the structure but would do nothing to protect the individual connections
within the facility. If complete protection is the goal, each CROSS-
CONNECTION in the structure must be identified and a decision made as to the
appropriate BACKFLOW PREVENTION METHOD to be used. For vessels
under VSP, the goal is complete protection.
Surveyors should be
• Knowledgeable in basic plumbing.
• Knowledgeable in the principles of BACKFLOW, including
BACKSIPHONAGE and BACKPRESSURE.
• Able to identify both potential and actual CROSS-CONNECTIONS.
• Familiar with the level of HAZARD posed by each connection.
Surveyors should physically inspect all areas of the vessel supplied with
POTABLE WATER. The best approach for this may be to go deck by deck,
starting with the decks with connections that pose the greatest risk to health.