TESTIMONY OF DR. NEIL D. WILLIAMS; February 26, 1999.
Dr. Williams received a Ph.D. in Geotechnical Engineering,
University of California, Berkley, 1982; a M.S. in
Geotechnical Engineering, Utah State University, 1979; and a
B.S. in Civil/Structural Engineering, Utah State University,
Dr. Williams has prepared Permit Applications for more than
50 RCRA facilities and wrote his Ph.D. on High Level Waste
Containment. He conducted a comparison between WIPP and 4
other hazardous or mixed waste facilities--3 permitted and 1
NMED, SRIC, CCNS and other parties objected to Dr.
Williams' testimony. The parties stated that the issue for
these hearings was whether WIPP complies with the
Miscellaneous Unit standards and that no foundation had been
laid that the other facilities are required to comply with
these standards. They also argued that none of the other
facilities are deep underground facilities. The DOE admitted
that there are no other deep geologic repositories like WIPP
and that other Miscellaneous Units that exist in this country
are completely different from WIPP and cannot be used for
comparison. However, the Hearing Officer decided to allow the
testimony, although he stated that it was a "close
Dr. Williams said that WIPP has the best containment of any
facility in the United States. He compared WIPP to 4 other
"state of the art" facilities: FERNALD (Ohio),
HIGHWAY 36 (Colorado), EMELLE (Alabama), and WAKE/CHATHAM
COUNTY (North Carolina). He compared six factors as follows:
1. GEOLOGY and HYDROLOGY: At WIPP the Culebra is the
water-bearing member closest to the Repository. The Salado,
in which the repository is sited, has 3 primary members: pure
halite, impure halite, and anhydrite. All have very low
hydraulic conductivities. Conductivity is a material property
related to impermeability. Conductivity describes the ability
of water to move through a formation. The lower the
conductivity is, the lower the ability of water to flow
through the material. Key properties at WIPP that are
favorable for containment are: the low hydraulic
conductivities of the Salado, the distance to the first
available groundwater (in the Culebra), and the repository's
inward (by design) hydraulic gradient. This gradient directs
flow toward the facility, which impedes migration away from
Wake/Chatham County has one billion times higher potential
flow than WIPP. At WIPP the water bearing unit is more than
1300 feet away whereas here it is only 8 feet away.
Fernald is about one trillion times more permeable, and
depth to groundwater is about 70 feet. It is located in an
area of geology poorly suited for containment.
Highway 36 has excellent geology but is still one million
times more permeable than WIPP, and water is about 190 feet
below the lining systems.
Emelle is about one million times more permeable and has no
inward hydraulic gradient. Depth to ground water is about one
foot below the
2. CONTAINMENT: Again, WIPP is separated by more than
1300 feet of low- permeability evaporites from the primary
water-bearing unit. Access shafts will be sealed.
Wake/Chatham County relies on the low permeability of its
materials and on the maintenance of a low level of leachate
about the liner.
Fernald relies on a double composite lining system and
relies almost entirely on this man-made system because of the
Highway 36 relies on geology but also has a double
composite lining system.
Emelle also has a double composite lining system.
The conductivity of the Salado formation is many times less
than that of any of the lining systems at these sites. WIPP
does not need
Since the conductivity of the lining materials is up to
millions of times higher than that of the Salado, the liner
would look more like a drainage layer than a lining system.
3. WASTE CHARACTERISTICS: WIPP is for transuranic and
hazardous materials. Wake/Chatham County is a low-level waste
(LLW) facility and has no transuranics. Fernald is designated
for residual radioactive waste from an inactive processing
site as well as hazardous materials both from on-
and off-site. Fernald does not accept hazardous materials
prohibited by "land ban" disposal regulations.
Highway 36 and Emelle both take all hazardous waste
classifications after treatment or pretreatment. They accept
no radioactive waste, and waste must meet land disposal ban
requirements. [WIPP will not be subject to land ban disposal
requirements because Congress eliminated compliance in the
LWA. Dr. Williams said this
is not important because liquid is not allowed at WIPP.]
4. LEACHATE CHARACTERISTICS: Surface water is prevented
from entering WIPP down the shafts, and liquids that are in
the shafts are collected and removed. There is a small amount
of liquid migration from the Salado, but it is primarily under
the waste areas and is much smaller than any of the liquid
amount allowed at the other facilities (although the amount
after closure was not specified). It is unlikely that free
liquids will ever get into the repository level but will
instead mostly stay in the disturbed rock zone. Wake/Chatham
County is designed for infiltration of 7,900 gallons/week of
liquid. Fernald is designed for about 2,600 gallons/week
after closures. Highway 36
is designed for 16 million gallons/week when open and an
unknown amount after closures. Emelle is similar to Highway
36 and Fernald.
5. MIGRATION POTENTIAL: Dr. Williams used boundary
conditions that would be used by RCRA in his comparisons as
well as a onedimensional transport model looking at transport
mechanisms which was written by the Environmental Protection
Agency (EPA) for RCRA facilities. The model looks at 3
transport mechanisms: advection, dispersion, and diffusion.
Since WIPP's hydraulic conductivity is so low, chemical
diffusion is the most dominant mechanism. The model used is
conservative because all attenuation retardation conditions
are removed from the model and because it is assumed that any
liquid that forms has relatively high concentrations of
hazardous constituents. At WIPP it is assumed that the liquid
will be below the waste and not in contact with it. Migration
was evaluated at 80 years (the RCRA time frame for the Permit)
and at 300 years (the evaluation of WIPP in the Permit
Application). At 80 years a 10% concentration could migrate
about 2.4 meters from the repository and at 300 years about
3.4 meters. This is less than at any of the other 4
6. POTENTIAL IMPACTS TO THE RECEPTOR: WIPP is more
isolated than the other facilities and is geologically stable.
There are no pathways to potential receptors because of the
Salado Formation and the shaft closure systems. There are few
residents or wells nearby and no concentrations of farming.
The Pecos River is about 12 miles away. Some of the other
sites are similar to WIPP in isolation, but most have more
wells and residents close by. Some have heavy agricultural
development as well as nearby streams and rivers. Even so,
the facilities have performed very well.
HIGHLIGHTS OF CROSS-EXAMINATION OF DR. WILLIAMS:
Of the 5 facilities, only WIPP could be permitted under the
New Mexico Hazardous Waste Act (HWA), and none of the others
could be permitted for transuranic (TRU) mixed waste. None of
the other sites are in known potash mining or oil and gas
drilling areas, and none have oil and gas resources within
Highway 36 and Emelle have limitations for total PCBs in
their RCRA permits.
There is actually very limited performance data on the 4
facilities. Wake/Chatham County is not permitted yet, and
Fernald is just beginning to
dispose of low-level waste.
Dr. Williams does not believe that a roof collapse or an
explosion in the WIPP site would create a pathway through the
shafts. He does not think explosion is a credible event
because of the nature of the waste.
If the entire repository were full of liquid mixed with
waste would still only migrate about 3.4 meters in 300 years.
However, the only way to fill the repository with water would
be to pump water into it.
Characterization is not so important at WIPP because the
Salado containment is so good.
Dr. Williams has worked on hundreds of RCRA facilities and
none are exempt from land ban disposal restrictions. However,
WIPP would be exempt from these restrictions.
None of the 4 comparison sites are built in karst.