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, 1977.

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 not-yet-permitted.

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 call."

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 primary 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 the facility.

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 lining system.

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 lining system 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 poor geology.

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 a liner. 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 facilities.

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 their boundaries.

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, the 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.