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Risks from Salt Cavern Disposal
Overview
- No leaks or releases have been observed from the limited number
of caverns used for disposal.
- There is some concern about the potential for risks from caverns.
- During the cavern filling process, the injection pressures
used are relatively low, such that it is unlikely for wastes
or brine to be released
- Fluid releases from the cavern may occur following cavern
closure when internal pressures have built up
Possible Scenarios Under Which Caverns Might Leak or Fail
Possible scenarios under which salt caverns might leak or fail
include:
- Inadvertent intrusion
- Newly drilled well punctures old closed disposal cavern
and fluids quickly move to the surface
- Cavern seal fails and fluids move up the casing string until
the casing leaks to groundwater
- Casing failure at depth of cavern
- Casing failure at a shallow depth
- Loss of integrity through cracks or leaky insoluble layers
(e.g., anhydrite layers)
- Partial collapse of the cavern roof
- Cavern seal intact
- Cavern seal fails and casing fails at depth of cavern
- Cavern seal fails and casing fails at a shallow depth
Analysis of the Risk to Human Health
DOE funded Argonne National Laboratory to conduct an analysis
of the risk to human health through drinking water contaminated
by releases of NOW and NORM from disposal caverns.
Estimated Cancer and Non-cancer Risks – Results of Risk
Analysis
- Cancer risk [goal: excess cancer risk 10-4 –
10-6]
| |
Chemical Risk |
Radiological Risk |
| Best-estimate |
10-9 – 10-18 |
10-15 – 10-23 |
| Worst-case |
10-8 – 10-17 |
10-15 – 10-23 |
| 100% release |
10-7 – 10-16 |
10-13 – 10-22 |
- Non-cancer risk [goal: hazard index <1.0]
| |
Chemical Risk |
Radiological Risk |
| Best-estimate |
10-5 – 10-8 |
NA |
| Worst-case |
10-5 – 10-7 |
NA |
| 100% release |
10-3 – 10-7 |
NA |
- Cavern disposal poses very low human health risks, even if
all caverns leak or fail
- The radiological risks are many orders of magnitude smaller
than the chemical risks
For More Information
For more information, see:
 Risk
Analyses for Disposing Nonhazardous Oil Field Wastes in Salt Caverns,
December 1997, D. Tomasko et al., Argonne National Laboratory.
(430 KB)
Disposal
of NORM-Contaminated Oil Field Wastes in Salt Caverns, August
1998, J.A. Veil et al., Argonne National Laboratory. (430
KB)
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