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Dr. Williams referred to a color cross-section poster showing the three areas in and near the WIPP site: the Land Withdrawal Area, the Margin Area, and Nash Draw. Each area has separate hydrological characteristics, including water locations and rates of migration. Conditions found in one area are not necessarily found in another. LAND WITHDRAWAL AREA (WIPP FACILITY)
The DOE never said there was no moisture migration through other members of the Rustler besides the dolomites (the Magenta and the Culebra). It just takes a long time. The dolomites have high conductivities. The dolomites are highly fractured and highly transmissive and extend across the site. The Salado is halite, impure halite, anhydrite and clay layers. All have very low conductivities and are barriers to liquid migration. Water migrates through soils, then through the Santa Rosa Formation and accumulates at the low permeability barrier of the Dewey Lake Redbeds in the weathered or fractured top of the Dewey Lake where it perches. The WIPP facility itself causes this. This horizon was not saturated before construction was started. Then the DOE excavated basins for water in the caliche. The DOE could get rid of this water by lining the ponds, pumping water from the formation, or in other ways. The vertical conductivity of this area is low. The horizontal conductivity in this area is higher so the water will spread laterally. MARGIN AREA
Completing WIPP-33 would have no useful purpose. We are concerned with what happens within the WIPP site and out to the compliance point. More than adequate work has been done to show that the DOE will find contamination if the contamination leaves the repository. NASH DRAW AREA
The first primary water-bearing zone above the repository is the Culebra. It is very well understood and is the first primary pathway for lateral migration away from the repository. Though there is some water at the interface between the Rustler and the Salado, the conductivity is low. The interface area is not a water-bearing zone that could be a primary pathway. The Culebra is also the most productive water-bearing zone above the repository. The shafts are connections from the repository to the surface. The shafts do not constitute a pathway to the Culebra either before or after they are closed. To be able to migrate to the Culebra, the shafts would have to be filled with water. There is not enough water to do this. The materials in the shaft seals are chosen for both short- and long-term closure. Dr. Williams compared the most conventional lining systems. The Salado is great for containment. Dr. Phillips said pressurized brine could be a driving force to push contaminants out of the repository. Dr. Williams stated that there is not enough brine coming into the repository to saturate the waste. Even Dr. Bredehoeft said the brine level would not reach up to the waste material for at least 2,000 years. The repository has been open for 10 years and the observed brine inflow rate is much lower than was anticipated. The brine comes from the consolidation of clay in the anhydrite layers. Also, the EPA looked at water injection as a breach scenario and concluded that it was a very low probability phenomenon. Potentiometric data show that there is a southerly flow, not westerly as Dr. Phillips claims. All units in Nash Draw could contain water because of the fracturing, dissolution, etc. in that area. The Nash Draw, however, is separate from the WIPP site conditions. There is very low conductivity in the confining units at the site and the fractures are filled there. The primary pathway out of the repository would be vertical to the Culebra. Over time, contamination would move only 2.4 meters in 80 years and just over 4 meters in 100 years out of the repository. The anhydrite layers above and below the repository are not pathways because there are no receptors at the end of the anhydrite beds. The anhydrite layers have very low conductivities outside of the Disturbed Rock Zone (DRZ). The DRZ extends out only 6 to 16 1/2 feet and changes as a function of time. Marker Bed 139 has a very low impact on constituent migration. Marker Bed 139 is about 6 feet below the repository and has higher conductivities only in the DRZ. Otherwise, the conductivities of Marker Bed 139 are about 10-9 or 10-14/sec. with an inward hydraulic gradient so it is a barrier, not a pathway. There is water in the Santa Rosa Formation/Dewey Lake Redbeds interface. This is not, however, the primary pathway. The primary pathway is from the repository to the Culebra to the facility boundary, or the point of compliance. For this reason, the Santa Rosa Formation does not need to be monitored. There are no karst features in the Land Withdrawal Area. There are karst features in the Margin Area and Nash Draw Area. These karst features are too far away to affect the repository and do not need to be considered under RCRA. Dr. Phillips' model of the regional water balance is flawed. There are a number of assumptions in the model that are not consistent with conditions in the WIPP site or even in the surrounding area. Dr. Phillips neglects important components such as soil moisture, groundwater flow into and out of the catch basin, etc. so the model is very inaccurate. Water balance is not performed. Also, Dr. Phillips made mistakes in his calculations. Most significantly, when he calculated the brine evaporation rate, he multiplied 1.17 times the fresh water evaporation rate. Dr. Phillips should have divided. This leads to a 34% error in the brine evaporation rate. Dr. Phillips also used an average annual precipitation rate of 14.21 inches/year when he should have used 12.67 inches/year. This is a 12% difference. However, these two errors are small compared to neglecting many important flow components. Rainwater recharge is different in the WIPP site and in the Nash Draw Area. In Nash Draw, there is rapid infiltration of almost fresh water. This does not exist at the WIPP site, which is shown by the filled gypsum fractures in the Dewey Lake Redbeds.
Migration out of the repository will only be a few meters during the RCRA time frame. The basis for the distinction between the Nash Draw Area and the Land Withdrawal Area is that the hydrology is different and the properties of the materials are different The Culebra is continuous so one would expect a response between WIPP-13, WIPP-25 and WIPP-30 during the multi-well pump tests. ERDA-9 is not drilled vertically so it could be closer than 93 feet from the repository footprint at the bottom. It is possible that ERDA-9 is a potential pathway before the WIPP site is closed. The Santa Rosa Formation/Dewey Lake Redbeds water is a perched water-bearing zone or a saturated zone above an unsaturated zone. Unconfined potentiometric surface rises above the confining layer. It would be better to call it a confined zone because perched is isolated. Dr. Chaturvedi mischaracterized what the DOE said when he claimed the DOE identified the water table in the Dewey Lake Redbeds for the EPA. The source of water in the exhaust shaft is immaterial because the amount of liquid coming down the shaft is 0 to 100 gallons/week. A maximum of 1,300 gallons/week could be managed in the repository. Water has been coming in since 1995 when it was discovered. More boreholes are needed to assess the extent of the 80 acres. No one has done a water balance study to test the hypothesis that the water is a local occurrence. Dr. Williams studied RCRA compliance for the WIPP site for about one year. The Idaho National Engineering and Environmental Laboratory (INEEL) opened 9,000 drums of waste in order to inspect for liquids. The waste was dispositioned as WIPP certified waste. The report on these wastes does not state that the waste drums were opened, but that they were "examined." Dr. Williams interprets that to mean that the waste drums were opened and that the DOE measured the average liquid content. Dr. Williams has looked at deep geologic disposal of mine ash in coalmines. WIPP is the first deep geologic disposal facility in the United States for mixed transuranic (TRU) waste. Dr. Williams has not evaluated anything at WIPP other than what is at the site. Dr. Williams stated that WIPP is the best containment of all the facilities he knows of. Dr. Williams has not observed RCRA disposal of TRU mixed waste elsewhere because WIPP is the first disposal facility for TRU mixed waste. Early on the DOE identified about 17 potential deep geologic disposal sites around the country. Dr. Williams has not compared the containment at WIPP with any of these 17 potential sites. Most mixed waste facilities have fingerprinting, but it depends on the facility. The Fernald Mixed Waste Facility is on-site so the facility is where the wastes are already located. [The DOE's Fernald site processed various uranium compounds into uranium metal. The Fernald site is located 20 miles northwest of Cincinnati, Ohio.] If the waste is outside of Fernald's Waste Acceptance Criteria (WAC), however, the waste has to go off-site. Dr. Williams would think that pyrophoric materials would be segregated out and disposed of separately. [Pyrophoric materials are materials that ignite spontaneously upon exposure to air.] The Santa Rosa Formation is not present in Nash Draw or the Margin Area. The Dewey Lake Redbeds is present in all three locations. The conductivity of the Dewey Lake Redbeds has been measured at other places than WQSP-6A, but Dr. Williams did not know where. Dr. Williams' color cross-section poster shows halite in the lower un-named member across the whole site. The isopach map from Sandia Report 82-1069, which Dr. Powers co-authored, does not this. Dr. Williams says he cannot say why because the isopach map does not show the Land Withdrawal boundary. When the witness was shown a map by Dr. Phillips that had the Land Withdrawal boundary mapped, Dr. Williams said the boundary on his document was clearly different from that on Dr. Phillips' map. The halite boundary is close to the western boundary of the Land Withdrawal Area. Dr. Williams' cross-section is idealized and he didn't want to quibble about a few feet. Dr. Phillips said that the difference was a mile or more. Dr. Williams then said the cross-section was only demonstrative and was not precise. It is difficult to look at a picture of core to identify the open conditions that could have been caused by the drilling itself. It would be necessary to look at the geotechnical logs and hydraulic data. It is possible to get into real trouble by just looking at pictures of core. It is necessary to look at the core itself. The core is located at the WIPP Core Library. Dissolution of halite occurred in 2 time frames. First, there was some dissolution during or shortly after the deposition of the formation. More recently, there was dissolution at the halite boundary that is of only limited extent (a few feet). Some dissolution residues that were described in the earlier work were reconsidered since the DOE drilled the shafts and saw the exposed beds and logged them in detail. Where the DOE thought that before they had dissolution residues, they found that this was not the case. What the DOE looks for is evidence of recent dissolution along the contact boundaries. This is only limited. WIPP-33
Dr. Williams was asked, "Since the caverns in WIPP-33 are not found in the Culebra, from where does the water flow to these caverns?" The primary pathway is not to WIPP-33. The Magenta is immaterial for the primary pathway, which is southerly. Dr. Williams has not seen a flow path for the Magenta but stated that the probability of the Magenta being a pathway is so low that it does not warrant consideration. If fluids migrate through the shaft, they will meet the Culebra which would be a hydraulic barrier from the Magenta. The Culebra is the most transmissive formation. The Culebra is first, so everything will go into it first. It is not impossible though that the Magenta could be a pathway. The brine aquifer is absent in the Land Withdrawal Area. It is possible, however, that there is a thin layer of dissolution residue extending into the Margin Area that shows up in H3, H6, P6, P12, P13, P14, and WIPP-33, among others. Low Total Dissolved Solids (TDS) in the water in the Land Withdrawal Area could cause dissolution within the Rustler. However, there are completely different conditions in the site area and Nash Draw. The Dewey Lake Redbeds area a very tight formation with gypsum filling in fractures, low vertical conductivity, and very low lateral conductivity. There is no direct recharge of the Rustler where there is a tight Dewey Lake formation in the Land Withdrawal Area. Dr. Williams referred to brine inflow into the repository as the driving force described by Dr. Phillips. Dr. Philips was actually describing brine from the pressurized brine reservoir beneath the repository. Dr. Williams said that the surface water divide is not consistent with the ground water divide, although Dr. Phillips' described them as about the same in his dissertation. Dr. Phillips' model is inconsistent, but Dr. Williams did not know where the groundwater divide was in all locations. There is southerly flow through the catch basin. Also there are open contours in the Culebra within the catch basin. The Program Plan for Hydrologic Investigation for the Los Medaņos Area states that a divide to the east is suspected and that holes should be drilled from P-18. Dr. Williams did not know why the wells were not drilled there. If a correction were made to Dr. Phillips' calculation error, there would be .73 times as much inflow. If 12.67 inches/year of rainfall were used in the calculations, there would be .89 times as much rainfall as is stated in Dr. Phillips' dissertation. That would mean the amount of water in Laguna Grande would come from a smaller amount of rainfall. Dr. Williams disagreed that this would mean the infiltration rate would increase as a percentage of rainfall because, as Dr. Williams stated, Dr. Phillips' whole model is completely wrong. Dr. Phillips never evaluated the percolation of rainfall through arid soils, soil moisture, and changes in soil moisture over time. DOE's Comment No. 108 states that the point of compliance should be at the Land Withdrawal boundary, not where the monitoring wells are going to be located. Alternatively, the DOE would like the point of compliance to be at the locations of the current monitoring wells. The point of compliance would actually only be the down gradient WQSP wells. WIPP-33 has caverns in the Magenta. It is hard to describe the direction
of groundwater flow in the Magenta at WIPP-33. The orientation of the
caverns would be the best indication, but Dr. Williams was not sure what
that is.
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