Leaking Water Lines
Ruptured waterlines also represent a significant source of artificial recharge within the Central Plateau.
Unlike sanitary sewage systems, where the location and volume of the discharges are known, leaking
water lines represent a far more difficult problem to diagnose. Like sewer systems, these leaks have
the potential to flush contaminants from the vadose zone into the groundwater, or to simply accelerate
the movement of contaminants within the groundwater flow system. Over the past few years, a number
of leaks have been detected in areas around the tank farm waste management areas that clearly have
contributed to groundwater contamination.
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A number of separate actions may be needed to address the issues created by the
deterioration of the water system. The primary efforts should focus on upgrading
the system to provide for the long-term needs of the Hanford Site.
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A systematic evaluation of the water lines will be performed to determine if any of these water lines
are located near waste sites that are subject to near-term remedial or closure actions. Moving water
lines away from waste sites that are to be isolated with surface barriers will eliminate the potential
for leaking lines to flush contaminants from the vadose zone. In some situations, a field survey of the
lines will be performed to identify areas where this type of situation may exist. Finally, water lines
to certain inactive facilities may not be needed and could simply be capped and shutdown.
Accelerated actions related to the treatment of Hanford's water lines have several components. They
include eliminating water lines near waste sites when possible and testing them to assure
they are not leaking when they cannot be eliminated. In addition, pumps in the Hanford Site water
supply system will be changed to reduce water line pressure, so that leaks are less likely to occur
and less water will be lost if they do. Repair and removal of leaking water lines is currently handled as
failure occurs. This strategy provides for accomplishing the work needed to protect groundwater by 2008.
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