2014 Compliance Recertification Application (CRA-2014)
Compliance Application Review Documents (CARDs for Sections 194.14 & 194.15)
               Content of Compliance Certification Application,
             Content of Compliance Recertification Application(s)

15.0 Background (194.14 and 194.15)

	Section 194.15 states EPA's expectations for what should be in a compliance recertification application. Much of the information requirements parallel the requirements of Section 194.14, which applied primarily to the original application. Because of the related nature of sections 194.14 and 194.15, these sections are discussed together in this CARD. EPA's focus with this section is to require any compliance recertification application to include information on the changes to the disposal system and facilities since the previous certification or recertification. The information in this section is essentially updating the information in all aspects of the disposal system and waste related items. If items and assumptions have not changed, then EPA would not expect new information to be developed for those topics. It was EPA's intention that each Compliance Recertification Application (CRA) should clearly reference and/or summarize such unchanged information.
      For each CRA, EPA expects DOE to identify all systems and program changes implemented during the preceding five-year period. Any activity or assumption that deviated from what was described in the most recent compliance application would be considered a change. EPA also expects each CRA to summarize all changes that EPA reviewed and approved in the preceding five-year period (through modification of the certification or other processes). We further expect each CRA to indicate where new baseline program elements have been established as a result of changes, and to show which parts of the application have been revised accordingly. These expectations were outlined in the Compliance Application Guidance (Docket A-93-02, Item II-B-29) and the Guidance to the U.S. Department of Energy on Preparation for Recertification of the Waste Isolation Pilot Plant with 40 CFR Parts 191 and 194 (Docket A-98-49, Item II-B3-14). Recertification is defined in section 8(f) of the WIPP Land Withdrawal Act as a determination "whether or not the WIPP facility continues to be in compliance with the final disposal regulations." Thus, recertification is a process that evaluates changes at WIPP to determine if the facility continues to meet the requirements of EPA's disposal regulations, using appropriately updated information.

      EPA provided opportunities for public comment throughout the recertification process. All public comments received are listed, along with EPA's responses, in Appendix 15-B.

15.1 Requirement (194.14)

	Section 194.14 requirements are listed in Appendix 14-A below. Baseline documentation for section 194.14 was established at the time of the original recertification and approved by EPA. Changes to section 194.14 topics areas since the original certification are required by section 194.15 and discussed below in this CARD.

	Section 194.14 requirements are listed in Appendix 14-A below. Baseline documentation for section 194.14 was established at the time of the original recertification and approved by EPA. Changes to section 194.14 topics areas since the original certification are required by section 194.15 and discussed below in this CARD. Appendix 15-A contains the recertification requirements of section 194.15.

15.1.1 1998 Certification Decision (194.14)

	EPA expected the CCA to include, at a minimum, basic information about the WIPP site and disposal system design. In general, DOE's characterization of the WIPP site and disposal system was discussed in Chapters 2 and 3 of the CCA (Appendices GCR, Hydro and MASS). Other characteristics, design, location and construction information was primarily provided in CCA Chapter 7 and Appendices BACK, DEL, PCS, and SEAL. EPA concluded that DOE adequately addressed geology, geophysics, hydrogeology, hydrology, meteorology, climatology, potential pathways, and effects of waste and geochemistry of the disposal system and its vicinity and how these conditions are expected to change and interact over the regulatory time frame.

	EPA thoroughly reviewed DOE's CCA and the additional information submitted by DOE, and determined that DOE complied with each of the requirements of Section 194.14, conditioned upon DOE's implementation of the most robust panel closure system design (designated as Option D) with a slight modification (i.e., the use of Salado mass concrete instead of freshwater concrete).

	A complete description of EPA's 1998 Certification Decision for Section 194.14 can be obtained from EPA Air Docket, A-93-02, Items V-A-1 and V-B-2.

15.1.2 Changes in the 2004 CRA (194.14)

      Baseline documentation for section 194.14 was established at the time of the original certification and approved by EPA. See the CCA CARD 14 for details of EPA's review and EPA's approval. Changes to section 194.14 topic areas since the original certification (Docket ID No. EPA-HQ-OAR-2004-0025, Air Docket A-98-49). Any changes since the CCA are documented in each CRA submitted by DOE and reviewed by EPA under section 194.15 requirements.

15.1.3 Evaluation of Compliance for 2004 Recertification (194.14)

	The intent for section 194.14, Content of compliance certification application, was to provide the baseline information for the compliance application. In the CCA and supplemental information and the compliance performance assessment (the performance verification test or PAVT), DOE provided the baseline information on WIPP and important features, events and processes that could affect the disposal system's containment capabilities. The Option D panel closure requirement identified by EPA as a condition in the certification has been incorporated into DOE's performance assessments as required (see 2004 CRA CARD 23). Since DOE complied with the sections of 194.14 in the original certification, EPA found that DOE complied with all sections of 194.14 for the 2004 CRA (see Docket ID No. EPA-HQ-OAR-2004-0025).

15.1.4 2004 Recertification Decision (194.14)

	Based on a review and evaluation of the 2004 CRA and supplemental information provided by DOE (Docket ID No. EPA-HQ-OAR-2004-0025, Air Docket A-98-49), EPA determined that DOE continued to comply with the requirements for Section 194.14.

15.1.5 Changes in the 2009 CRA (194.14)

      Changes to section 194.14 topics areas since the original certification are required by section 194.15 and discussed below in the 2009 CARD 15 (FDMS Docket ID No. EPA-HQ-OAR-2009-0330, Air Docket A-98-49). Any changes since the CCA and the 2004 CRA are documented in the 2009 CRA submitted by DOE and reviewed by EPA under section 194.15 requirements.

15.1.6 Evaluation of Compliance for 2009 Recertification (194.14)

	Since DOE complied with the sections of 194.14 in the original certification and the subsequent 2004 and 2009 CRAs, EPA found that DOE complied with all sections of 194.14 for the 2009 CRA (Docket ID No. OAR-2009-0330).

15.1.7 2009 Recertification Decision (194.14)

	Based on EPA's review and evaluation of the 2009 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2009-0330, Air Docket A-98-49), EPA determined that DOE complied with the requirements of Section 194.14.

15.1.8 Changes in the 2014 CRA (194.14)

      Baseline documentation for section 194.14 was established at the time of the original certification and approved by EPA. See CCA CARD 14 for details of EPA's review and EPA's approval. Changes to section 194.14 topics areas since the original certification are required by section 194.15 and discussed below in this CARD. Any changes since the CCA and the 2004 and 2009 CRA are documented in the 2014 CRA submitted by DOE and reviewed by EPA under section 194.15 requirements.

15.1.9 Evaluation of Compliance for 2014 Recertification (194.14)

	The intent for section 194.14, Content of Compliance Certification Application, was to provide the baseline information for the original compliance application. In the CCA and supplemental information and the compliance performance assessment (the performance verification test or PAVT), DOE provided the baseline information on WIPP and important features, events and processes (FEPs) that could affect the disposal system's containment capabilities. Since DOE complied with the sections of 194.14 in the original certification and the 2004 CRA, EPA finds that DOE complies with all sections of 194.14 for the 2014 CRA.

	EPA did not receive any public comments on DOE's continued compliance with the content of compliance certification application requirements of Section 194.14.

15.1.10 2014 Recertification Decision (194.14)

      Based on EPA's review and evaluation of the 2014 CRA and supplemental information provided by DOE (Docket ID No. EPA-HQ-OAR-2014-0609), EPA determined that DOE complied with the requirements of Section 194.14.

15.2 Requirements (194.15(a) (1))

	(a) "In submitting documentation of continued compliance pursuant to section 8(f) of the WIPP LWA, the previous compliance application shall be updated to provide sufficient information for the Administrator to determine whether or not the WIPP continues to be in compliance with the disposal regulations. Updated documentation shall include:

 		(1) All additional geologic, geophysical, geochemical, hydrologic, and 				meteorological information."

15.2.1 Changes in the 2004 CRA (194.15(a) (1))

Earthquake and Seismic Information, Natural Resource Conditions

EPA reviewed DOE's geologic, geophysical, geochemical, hydrologic, and meteorological information and updates in the 2004 CRA. The following briefly describes the review found in EPA's CARD 15 for the 2004 CRA (Air Docket ID No. EPA-HQ-OAR-2004-0025).

Earthquake/Seismic Information
      DOE updated information on earthquakes within 150 miles of WIPP and identified, 14 earthquakes of Richter scale magnitude 3.0 or greater occurred between January 1, 1995 and September 30, 2002, the largest was a 5.3 magnitude earthquake in Brewster County, Texas. WIPP's design basis is for much larger earthquakes than those which have occurred in the immediate vicinity of WIPP (2004 CRA Chapter 2). A brief summary of DOE's updates for earthquake and seismic information can be found in EPA's 2004 CRA CARD 23, and EPA's Human Intrusion TSD located in Docket A-98-49, II-B2-38.
Natural Resources
      DOE reported that the major natural resources considered at the WIPP site, as identified in the CCA, continue to be potash, oil, and natural gas. The potash zone is still considered barren above the repository (see 2004 CRA, Section 15.1.2). The probability range for encountering a Castile brine pocket is between 0.01 to 0.60 was used in DOE's 2004 CRA PABC. Deep drilling rate (intrusion rate), calculated by extrapolating the past 100 years of data increased from 46.8 boreholes per km[2], used in the CCA, to 52.2 in the 2004 CRA.
      DOE reported an increase in the number of salt water disposal and injection wells within the nine-township area between 1997 to 2003 as follows: 1997, Injection Wells-26; 2003, Injection Wells-39. The average reported average injection rate was about 1,250 BWPD.
      A brief summary of DOE's updates for natural resources can be found in EPA's 2004 CRA CARD 23 and EPA's TSD Human Intrusion [Air Docket A-98-49 Item II-B1-10], and DOE's 2004 CRA Section 45).

Hydrologic Issues

(Air Docket ID No. EPA-HQ-OAR-2004-0025)

Geologic Model
	Included in DOE's 2004 CRA was a description of the formations that overlie WIPP, the Dewey Lake and the Santa Rosa. The Rustler Formation is the primary hydrologic unit of importance that overlies the Salado Formation and is considered the important because it contains the most transmissive units above the repository. The Culebra Dolomite is the most transmissive hydrostratigraphic unit within the Rustler and above the WIPP site. The Culebra transmissivity characteristics are zonal with higher transmissivity found in Nash Draw and lower transmissivity found to the east. DOE uses the observation variable transmissivity and the Culebra to development of the multiple transmissivity fields to calculate releases from the Culebra (2004 CRA Chapter <IP_ADDRESS> and Appendix PA Attachment TFIELD Air Docket ID No. EPA-HQ-OAR-2004-0025). A general description of fluid flow in the Rustler, the five members of the Rustler and the properties of each unit are provided in Figure 15-1 and Table 15-1 of EPA's CARD 15 for the 2009 CRA (Air Docket ID No. EPA-HQ-OAR-2004-0025).

DOE's characterization that the Culebra as fractured dolomite unit with non-uniform properties, both horizontally and vertically (CCA CARD 14). The Culebra exhibits both matrix and fracture (micro to macro) porosity. Flow within the Culebra occurs primarily within fractures, although flow also occurs within vugs where they are connected by fractures and, to some extent, within interparticle porosity where this porosity is higher. Flow in the Culebra is dominantly lateral and southward. DOE identified that the Culebra transmissivity exhibits a bimodal distribution (2004 CRA Appendix PA, Attachment TFIELD). In areas where the Culebra dolomite has transmissivity less than 4 x 10[-6] m[2]/s (10-5.4 m[2]/s), the Culebra is considered to be dominated by single (matrix) porosity. Above this transmissivity the Culebra is believed to have dual porosity so that fractures and the dolomite matrix are important.
	DOE stated that the Culebra is the most transmissive hydrostratigraphic unit at the WIPP site. The Magenta is the second most transmissive unit. Since the CCA DOE had obtained new hydraulic data for the Culebra and the Magenta confirming the range for transmissivity used in the CCA. Magenta well H-19b1, located just southeast of the site center, had a higher transmissivity (0.38 ft[2]/ day or 4.1 x 10[-7] m[2]/s) than the previous "highest" transmissivity well, H-6a, located within the WIPP LWA boundary. The Magenta transmissivity at H-6a was reported in CCA Appendix Hydro to be 0.3 ft[2]/day (3.2 x 10[-7] m[2]/s). DOE tested well locations in both the Culebra and Magenta. These test indicate the transmissivity of the Magenta is much lower than that of the Culebra.
	DOE's well tests indicate the Culebra transmissivity characteristics are zonal, with higher transmissivity found in Nash Draw and lower transmissivity found to the east of the WIPP site boundary. In between these areas the Culebra transmissivity is variable. DOE had postulated that this spatial transmissivity distribution is due to post-depositional processes and geologic controls (2004 CRA Chapter 2, p. 2-107) and claimed geologic controls are believed to include overburden thickness, dissolution of the upper Salado, and the occurrence of halite in the mudstone Rustler units above and below the Culebra (ibid). DOE uses the observation of a bimodal distribution of transmissivity and these geologic controls in the development of the transmissivity fields used to calculate releases from the Culebra (2004 CRA Chapter <IP_ADDRESS> and Appendix PA Attachment TFIELD).

Changes in Water Levels
	DOE monitored water levels in the Culebra in a network of over 30 wells. DOE also monitors a limited number of Magenta wells. In both units DOE recorded water level changes, but the source of the changes were unknown. DOE's investigation of the water level changes has focused on the Culebra because it is identified as the primary potential pathway for groundwater releases at WIPP. The water level has generally tended to increase, and was observed at the time of the CCA but became more widespread after DOE submitted the CCA. DOE reported the head distribution in the Culebra still indicated the flow is generally in the same direction as that of the CCA. There are several theories to explain the water level increases, including potash mining and petroleum industry brine injection. Water level changes as a response to precipitation [See Section 15.2.4 below for information in the 2009 CRA] is not considered to be a viable theory because wells do not respond to precipitation events.

Change in Culebra Radionuclide Travel Time
	The 2004 CRA performance assessment longer particle travel times through the Culebra to the WIPP site boundary were predicted compared to those calculated for the CCA. DOE had attributed the longer travel times to a reduced hydraulic gradient from the north to the south across the site. (See EPAs 2004 CARD 15, Air Docket ID No. EPA-HQ-OAR-2004-0025 for details).

Retardation of Radionuclides (Distribution Coefficients or Kds)
	Brine bearing radionuclides may be introduced into the Culebra via a borehole that intersects the repository and transported to accessible environment the transport time is by retardation due to sorption along the transport pathway. DOE's radionuclide sorption distribution coefficients (Kds) is described in DOE 2004 CRA Chapter 6, Section <IP_ADDRESS>.1. EPA's assessment of DOEs Kds used in the 2004 CRA is described in EPA's 2004 CRA CARD 15 (Air Docket ID No. EPA-HQ-OAR-2004-0025).
Water in the Air-Exhaust Shaft
      In 1995 DOE identified water in the WIPP exhaust shaft at a depth of about 80 feet and investigated the water source (2004 CRA Chapter <IP_ADDRESS>.2.2). DOE drilled investigative wells and hand-augured wells around the site surface facilities to determine the cause. These efforts found that flow into the shaft was primarily due the following (1) runoff of rainfall into and infiltration from the retention ponds located to the south of the WIPP surface facilities, and (2) infiltration of saline waters from the salt storage area, the salt storage evaporation pond, and perhaps remnants of the drilling and tailings pit used during the construction of the WIPP salt s seepage from a salt water evaporation pond. More descriptive details are found in the EPA's 2004 CARD 24 (Air Docket ID No. EPA-HQ-OAR-2004-0025).

Karst
	Due to public concern DOE reanalyzed existing information related to karst in the 2004 CRA. DOE's study concluded that karst outside of Nash Draw is limited to the horizon of the Magenta Member. The report concludes that the evidence of karst in Nash Draw eastward to the WIPP site is unwarranted (Docket A-98-49 II-B2-53).

Climatologic and meteorological conditions in the vicinity
	Climate conditions included in the 2004 CRA were provided in the annual reports (2004 CRA Chapter 2.5.2) and Table 2-14 and Figures 2-49 through Figure 2-56 of the 2004 CRA (Air Docket ID No. EPA-HQ-OAR-2004-0025). At the time of the 2004 CRA DOE did not alter the CCA assumptions about future climate in the performance assessment. (See EPA's 2004 CRA CARD 15 Air Docket ID No. EPA-HQ-OAR-2004-0025 for more details)

15.2.2 Evaluation of Compliance for 2004 Recertification (194.15(a) (1))

Earthquake and Seismic Information, Natural Resource Conditions

      EPA found DOE's information provided in the 2004 CRA related to earthquake and seismic information and natural resource conditions to be adequate. Details can be found in EPA's 2004 CRA CARD 15, Air Docket ID No. EPA-HQ-OAR-2004-0025.
Hydrologic Issues

Details of EPA's evaluation of DOE's hydrologic issues can be found in EPA 2004 CARD 15, Docket ID No. EPA-HQ-OAR-2004-0025.

Geologic Model
	EPA reviewed DOE's development of the transmissivity (T) fields (Docket A-98-49, Item II-B1-16) and concluded these T fields were adequate/

Changes in Water Levels
	EPA agreed with DOE that the water levels in the Culebra and other units are most likely due to anthropogenic sources and natural recharge can be eliminated because there is no response in well data to precipitation events EPA finds DOE's approach to the water level changes to be adequate.

Change in Culebra Radionuclide Travel Time
	EPA reviewed DOE's information in the 2004 CRA and supplemental information (Docket A-98-49, Item II-B2-35, response to comment G-7; Docket A-98-49, Item II-B2-59)/. EPA found that the longer travel times to be reasonable and based on appropriate data and modeling.

Retardation of Radionuclides (Distribution Coefficients or Kds)
	EPA concluded that the Kd values used in the 2004 CRA PABC were acceptable and adequate.
Water in the Air-Exhaust Shaft
	EPA accepted DOE's explanation of infiltration from the WIPP facility adequately accounts for the water movement.

Current climatologic and meteorological conditions in the vicinity
	EPA's review determined DOE's updated meteorological conditions in the 2004 CRA were adequate.

Karst Summary
	EPA believes that, on a regional scale, the groundwater basin model done by DOE reasonably predicted the current ground water flow regime and the geochemistry of the site. Based on the DOE's documentation and EPA evaluation of Karst formation (see EPA's Karst Docket TSD (Docket. EPA-HQ-OAR-2004-0025, Air Docket A-98-49, and ID No.Item II-B1-15) EPA concluded that karst will not be a pervasive process at WIPP that would affect WIPP's ability to contain radionuclides.

15.2.3 2004 Recertification Decision (194.15(a) (1))

	Based on a review and evaluation of the 2004 CRA and supplemental information provided by DOE (Docket ID No. EPA-HQ-OAR-2004-0025, Air Docket A-98-49), EPA
EPA determines that DOE continues to comply with the requirements for Section 194.15(A) (1).

15.2.4 Changes in the 2009 CRA (194.15(a) (1))

Hydrologic Issues

Geologic Model
	The geologic description and characteristics of the WIPP site did not change since the 2004 CRA. The Culebra freshwater hydraulic head contour map was updated with new well data annually (see Figure 15-6 of EPA 2009 CARD 15 (below).
	DOE performed a well network optimization study in 2003 to select new well locations that would decrease transmissivity uncertainty the greatest, to guide future decisions to plug old wells and to select the best locations for new wells to be drilled (2009 CRA Appendix HYDRO-2009, Section HYDRO-2.0). DOE plugged 17 wells mainly because of borehole conditions, and modified others to monitor other geologic units such as the Magenta (2009 CRA Appendix HYDRO-2009, Section HYDRO-4.0). DOE located many new wells based on the optimization study prediction that identified areas were the wells would be most valuable. Eighteen new Culebra monitoring wells were added to the WIPP network from April 2003 to October 2006 (2009 CRA Appendix HYDRO-2009, Section HYDRO-3.0, Figures 15.5 and 15.6 of this CARD). Twelve of these wells were drilled in locations to confirm the correlations proposed between Culebra transmissivity and various geologic conditions.
 Update Culebra values only based on recent new well testing, lowest values from SNL-15 pump tests.

	The Culebra continues to be the most transmissive hydrostratigraphic unit above the Salado (salt) Formation (2009 CRA Appendix PA-09 Section PA 2.1.4). The transmissivities measured in wells drilled since the 2004 CRA continue to confirm the range of transmissivities used in the PA calculations with modifications to the lowest values for the Culebra (Table 15-2 above). SNL-15, drilled due east of the WIPP site boundary (see Appendix HYDRO-2009, Figure HYDRO-1, Figures 15-5 and 15-6), exhibited very low hydraulic conductivity and transmissivity (Appendix HYDRO-2009 Section HYDRO-8.0), lowering the range in Table 15-2. Culebra transmissivity characteristics continue to be zonal in nature (2009 CRA Appendix TFIELD-09 Section 3.0).

DOE performed a peer review of the revised Culebra Hydrogeology Conceptual Model (CHCM) used in the WIPP performance assessment modeling. The purpose and scope of the peer review was to determine the adequacy and conduct an independent review of the "Culebra hydrogeology conceptual model for the purpose of establishing T fields to be used in PA calculations of radionuclide transport through the Culebra."

 The new conceptual model uses information gained from the new monitoring wells drilled and tested (Burgess et al. 2008) since the 2004 CRA. The original CCA conceptual model peer review panel found that the CHCM failed to correlate the detailed hydrogeology of the Culebra with its tested hydrologic character but that adequate data existed from hydraulic testing to develop a numerical model for PA. Inclusion of recent well data into the new conceptual model allowed DOE to develop transmissivity fields that are geologically based, consistent with observed groundwater heads, consistent with groundwater responses in Culebra pump test, and consistent with water chemistry .

Changes in Water Levels
	DOE monitored water levels with a network of 66 groundwater wells. DOE's network contains 46 Culebra, 17 Magenta, 1 Dewey Lake, and 2 Bell Canyon water wells (2009 CRA Appendix HYDRO-2009 Section HYDRO-5.0). Since the 2004 recertification DOE has made significant changes in the groundwater monitoring program (See Figure 15.6). DOE performed a Culebra monitoring-network optimization study (DOE Section <IP_ADDRESS>.2) to determine the optimum location for new wells to provide the best information and to select and remove (i.e., plug and abandon) wells that would have little impact on the quality of the data acquired. DOE has added 18 new wells and removed 17 wells since 2004 (CRA 2009 Appendix HYDRO Section HYDRO-4.0).

	DOE modified how water level data was acquired from the well monitor network. DOE continued to manually measure the water level at each well monthly, and has equipped most of the wells with instruments called TROLLs (downhole programmable pressure gauges that record pressure fluctuations that can be calibrated to water level changes) that generally records hourly measurements rather than monthly. One outgrowth of the use of TROLLs is that, for the first time, DOE found a few wells in Nash Draw responsd to rainfall events (CRA 2009 Appendix HYDRO, page HYDRO-16); see the section below.

	Generally the Culebra and Magenta continue to exhibit rising water levels around the WIPP site (CRA 2009 Appendix HYDRO Section HYDRO-5.5). TROLL data indicated that water levels respond to oil and gas drilling activities nearby (CRA 2009 Appendix HYDRO page HYDRO-31) as well as to rainfall events in Nash Draw. DOE also performed model studies to attempt to understand possible sources that may cause the water level increases (CRA 2009 Appendix HYDRO Section HYDRO-9.0), and concluded that poorly plugged oil, gas, and/or potash characterization wells are plausible sources for the water level increases.

Nash Draw Rainfall Impact on Culebra Water Levels

	DOE added instrumentation in all Culebra monitoring wells that are not used for water quality. TROLL(R) instruments installed in monitoring wells measure pressure changes in the water column and transmit real-time data to a computer at the surface at pre-programmed intervals. These monitoring wells are able to provide virtually continuous data, in this case hourly (DOE 2009 CRA, Section <IP_ADDRESS>.2).

	The higher temporal resolution of hydraulic head measurements enhanced understanding of water level changes in the Culebra. Many Culebra water-level changes previously considered unpredictable and anthropogenic in origin were demonstrated to be responses to rainfall in Nash Draw, while others can be conclusively linked to well drilling activities. Comparing daily rainfall measured at the WIPP weather station to the TROLL[(R)] pressure data reveals spikes in pressure that correlate with rainfall events of approximately 0.4 inches or more in 24 hours in Nash Draw which originate in Nash Draw creating a pressure pulse that propagates under Livingston Ridge and west to east across the WIPP site, decreasing in magnitude, over periods of days to months which is not an observation of rapid recharge of rainwater at the WIPP site, but a communication of pressure response across the WIPP site from Nash Draw and confirm previous suspicions that the Culebra is unconfined in portions of Nash Draw (Section 15.2.1 of this CARD, last paragraph). This understanding enhanced the development of the revised Culebra Hydrology Conceptual Model, which was peer reviewed in 2008 (2009 CRA Appendix HYDRO-2009 Section HYDRO-5.1).

Production Brine Well Cavity Collapse
	Oil and gas drillers who drill through the Salado (primarily salt) and Castile (salt and anhydrite) Formations are required to use salt saturated drilling fluid to assure a stable borehole through the salt. The is salt laden brine is produced by drilling, or converting, a well drilled into the shallow salt mainly on the Northwestern Platform north of the Delaware Basin. Salt saturated brine is produced by injecting fresh water into the salt, pumping the resultant salt saturated brine to the surface, and trucking it to oil and gas drilling locations that need the brine to drill through salt bearing strata in the Delaware Basin. This process of brine production creates a brine filled cavity that increases in size as saturated brine is produced. These brine filled brine production cavities are generally located close to the surface, on the order of 500 feet deep, in shallow salt, and near low cost sources of fresh water, such as the Capitan Reef. If the size of the cavity is not controlled and regulated, it may grow too large for the surface rock formations to support the cavity roof and collapse, thus creating a sink hole potentially expressing itself on the surface as a sink hole.

	In 2008 two brine production wells experienced cavity collapsed resulting in sink holes on the surface north of the Delaware Basin on the Northwest Platform These specific occurrences were not discussed in the 2009 CRA. Therefore, in its July 16, 2009 completeness letter (EPA 2009c), comment 2-33-2, EPA requested that DOE discuss the potential impact of such an event near WIPP. DOE's response is examined in Section 15.2.5 below.

Change in Culebra Radionuclide Travel Time
	The 2009 PABC calculations predict shorter travel time for a particle to travel through the Culebra to the WIPP site boundary than did the 2004 PABC. Three main changes contributed to these changes in flow time; BLM redefined the definition of minable potash in 2009 in particular within the WIPP site near the waste disposal panels, matrix distribution coefficients (Kds) decreased several orders of magnitude for most radionuclides when the increase in the organic ligand inventory was included, and SNL-14 confirmed the existence of the high-transmissivity zone in the southeastern portion of the WIPP site which creates a pathway for radionuclides to leave the Land Withdrawal Boundary. These changes make the travel time closer to that predicted in the original compliance certification.

Retardation of Radionuclides (Distribution Coefficients or Kds)
	DOE's method for determining retardation of radionuclides, Kds, in the 2009 recertification performance assessment calculations has not changed, but the Kds were recalculated for the 2009 PABC. EPA noted in completeness comment 3-C-25 that, "...increased concentrations of organic ligands indicates that the Kds...are potentially too high and overestimate the potential retardation in the Culebra."(EPA 2009c). DOE recalculated the Kds in response to EPA's comment using the new inventory data which, "...decreased several orders of magnitude..." (DOE 2010a page 52, item 2). These new Kds were used in the 2009 PABC calculations.

Water in the Air-Exhaust Shaft
	DOE reported in the 2004 CRA water, first reported in 1995 continues to flow in the WIPP exhaust shaft at a depth of about 80 feet. DOE drilled three additional shallow wells, PZ-13, PZ-14, and PZ-15, to evaluate the potential impact of the decommissioned and covered Site and Preliminary Design Validation (SPDV) mine tailing pile east of the WIPP air exhaust shaft 2009 CRA Section <IP_ADDRESS>.1). Evaluation of these wells showed that the SPDV pile may not contribute to shallow brine that continues to impact the exhaust shaft.

	In 2004 and 2005 DOE installed numerous infiltration controls to mitigate the impact of surface runoff on the shallow water found in the exhaust shaft. DOE installed a number of lined storm water ponds to capture run off from the various surface salt piles and surface facilities at WIPP. In 2008 some of the 15 shallow monitoring wells water level measurements declined for the first time, possibly indicating the first sign of the effectiveness of the infiltration controls.

Current climatologic and meteorological conditions in the vicinity
	As noted in the 2004 CRA Section 15.2.1 WIPP is located in the desert southwest with limited annual precipitation. Limited precipitation continues to be the norm since the retreat of the last ice sheet around 10,000 years ago. DOE provided updated information on recent climatic conditions in WIPP Annual Site Environmental Reports (DOE 2008d Chapter 5.3). The 2009 CRA Table 15-3 and Figures 15-1 through 15-5 provide recent meteorological information (2009 CRA Section <IP_ADDRESS>). DOE notes in the 2009 CRA Section <IP_ADDRESS> that no changes in climatic conditions occurred during 2002-2006 therefore, CCA assumptions about future climate in the performance assessment have not changed for this recertification.

Karst
      DOE reviewed and updated geologic data in Section 15.6.1 of the 2009 CRA. Since the 2003 data cutoff for the 2004 CRA, DOE undertook a monitoring well optimization program under which it expanded its monitoring well network, conducted extensive hydrologic testing, and added instrumentation that allowed more precise analysis of Culebra water levels. The resultant data, described in the 2009 CRA Section <IP_ADDRESS>, Hydrologic Information, and 2009 CRA Appendix HYDRO reinforced and enhanced the conceptual understanding of the Culebra hydrogeology, and allowed the integration of the tested hydrologic characteristics of the Culebra with its observed geologic characteristics.

      As a part of its recertification review in 2006, EPA required DOE to conduct additional investigations into the issue of karst because of public comments along with any the new hydrogeologic findings based on the Culebra Hydrology Conceptual Model Peer Review Panel conducted in in August 2008.

15.2.5 Evaluation of Compliance for 2009 Recertification (194.15(a) (1))

Earthquake/Seismic Information
	DOE provided information on recent seismic activity in the 2009 CRA Section <IP_ADDRESS> and Appendix DATA-2009 Section DATA-2.2. The analysis indicated an increase in seismic events, but concluded that "no significant or anomalous seismic events have occurred in the vicinity of the WIPP since the CRA-2004," and concluded these seismic events do not necessitate additional calculations need be made to the 2009 CRA. EPA found DOE's reporting and conclusions to be complete and adequate.

Natural Resources
      DOE monitored drilling activities in the Delaware Basin Monitoring Program and appropriately captured the drilling events that would affect the drilling rate used for the PA. The drilling rate had increased to 59.8 boreholes/km[2] in the 2009 PABC. EPA reviewed changes to the DBR parameter MAXFLOW and finds them to be reasonable.
      DOE's FEPs screening of the fluid injection parameters did not changed since the 2004 CRA and EPA considered the reported impact on injection activities to that CRA as adequate. Salt water disposal and injection wells within the nine-township area increased from 26 in 1997, to 39 in 2003, to 54 in 2008. The reported average injection rate was about 1,480 barrels of water per day (BWPD), compared to 1,250 BWPD average injection in 2003, with a 75% increase in total injection volume.  EPA reviewed DOE's analysis and finds information related to natural resources to be adequate.
                               Hydrologic Issues

Geologic Model
	In the 2009 PABC calculations DOE's conceptual model for the Culebra Hydrology Conceptual was modified by making the model-derived transmissivity fields more geologically based on new well data and testing. The model changes were based on extensive new hydrological investigations and testing conducted by the Department and DOE Contractors. The new T-field estimates were consistent with the T-geology correlation used in CRA-2004.

      EPA examined DOE's conceptual model peer review (Burgess et al. 2008) findings and model changes and found DOE's approach was adequate and reasonably documented. See the 2009 CRA CARD 27, Section 27.4.1, for additional detail.

Changes in Water Levels
	EPA agreed that the primary origin of water level changes was probably anthropogenic. Since the 2004 CRA, DOE has significantly improved the water well monitoring network and improved over all system understanding. EPA examined DOE's work and documentation since the 2004 CRA and found DOE's approach and conclusions to be adequate.

Nash Draw Rainfall Impact Culebra Water Levels
	The 2009 CRA Appendix-HYDRO Section HYDRO-5.1 described the characteristics of rainfall on Culebra Water levels. Hours to days after a rainfall event in Nash Draw some monitoring wells in Nash Draw show a variation in water level, specifically an increase in hydrostatic head (i.e., water pressure) in the vicinity of Nash Draw. This pressure increase slowly propagated east into the monitor well network around WIPP over weeks and months. The monitoring well network did not show any impact due to rainfall events east of Nash Draw at or near the Land Withdrawal Boundary. Therefore, this propagation eastward of rainfall in Nash Draw did not indicate infiltration from the surface near the WIPP but is an expression of the increase in water pressure in Nash Draw due to local rainfall events. EPA concurs that the rainfall event data in Nash Draw do not 1) indicate rapid infiltration is occurring at the WIPP site proper and 2) do not challenge the Culebra hydrology conceptualization.

Production Brine Well Cavity Collapse
      EPA asked DOE to evaluate the impact of a production brine well cavity. DOE's evaluation noted that this scenario is similar to potash mining taking place in the upper Salado Formation near WIPP; the applicable effects of the potash mining were included in DOE's 2009 CRA documentation. EPA examined DOE's response to completeness comments and relevant documentation in the 2009 CRA and found them to be adequate.

Change in Culebra Radionuclide Travel Time
	EPA examined the information DOE supplied in the 2009 CRA and determined that the decrease in travel times, compared to the 2004 CRA, are appropriate and reasonable. Particle travel time presumes particles are not retarded due to diffusion, sorption or adsorption. For the 2009 CRA median particle travel times (averaged over all simulations) decreased presuming three mining assumption; one assumed all Salado potash is mined within the LWB, and the other two assumed either no Salado potash is mined or only a portion i mined within the LWB. For the non-mining presumption travel times were 7,374 years; for the partially mined assumption travel times were 22,376, for the fully mine assumption travel times were 5,084. EPA found that the decreased travel time for the 2009 CRA to be reasonable and based on appropriate data and modeling done by DOE.

Retardation of Radionuclides (Distribution Coefficients or Kds)
	EPA noted in the October 19, 2009 completeness letter (EPA 2009c), comment 3-C-25 (EPA-HQ-OAR-2009-0330), that the impact of higher organic ligand concentrations on Kds in the updated WIPP inventory had not been included in the WIPP performance assessment by DOE. DOE agreed with EPA's comment and included new KD values in the 2009 PABC. EPA examined DOE's response and verified that these changes are included in the 2009 PABC and found them to be adequate.

Water in the Air-Exhaust Shaft
	EPA reviewed various 2009 CRA documents and evaluated DOE's proactive approach attempting to mitigate the potential surface sources of water in the air exhaust shaft. It appeared that the origin of this near surface water was derived from anthropogenic sources. EPA finds DOE's discussion of this issue to be adequate.

Current climatologic and meteorological conditions in the vicinity
	EPA examined 2009 CRA documentation and DOE's conclusions related to these topics and found that there are no expected changes in climate conditions and no significant changes in meteorological conditions have taken place in the vicinity of WIPP. EPA find DOE's conclusion to be adequate.

                           Karst in 2009 CRA Review

Karst-Background
      Concerns that active karst processes occur at the WIPP site were raised and addressed during the previous two certifications. During the 2004 recertification EPA conducted an exhaustive review of the issue. EPA found that karst did not impact the Land Withdrawal Area.

Karst and Hydrologic Data
      As part of its recertification review in 2006, EPA required that DOE conduct additional investigations into the karst issue and led to the Lorenz Report (2006a). Starting in 2003 DOE started to update the water monitor well program by first optimizing its monitoring well network, eventually generating data that enhanced the conceptual understanding of Culebra. The revised conceptual model, recalibrated T-fields, and karst studies were presented to the Revised Culebra Hydrogeology Peer Review Panel in August 2008. The panel concluded that arguments made by Lorenz (2006) and Powers (2008) have convinced the Panel that significant karst features are not present at the WIPP site.

      EPA found that in the 2009 CRADOE had appropriately excluded the effects of karst from the performance assessment calculations.

15.2.6 2009 Recertification Decision (194.15(a) (1))

	Based on a review and evaluation of the 2009 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2009-0330, Air Docket A-98-49), EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (1).

15.2.7 Changes in the 2014 CRA (194.15(a) (1))

Meteorological Conditions
	Meteorological conditions (wind, temperature, humidity precipitation) are included in the DOEs yearly Annual Site Environmental Reports which are updated through December 2011 and included in 2014 CRA Section <IP_ADDRESS>. DOE did not record any significant or anomalous meteorological conditions.

Earthquake/Seismic Information
      DOE updated information on earthquakes within an approximate 187 miles of the WIPP site and within the Delaware Basin. In Section <IP_ADDRESS> of the 2014 CRA. DOE reported 543 seismic events recorded within approximately 187 miles of the WIPP. One event that stood out had a magnitude of 2.4 and occurred on March 18, 2012 approximately 9.36 miles from the WIPP site. This was associated with a potash mine roof fall and caused no observable damage at the WIPP.

Natural Resources

      Major natural resources considered at the WIPP site continue to be potash, oil, and natural gas. The potash zone is still considered barren above the repository (see 2014 CRA, Section 15.1.2). Oil, natural gas, and fluid injection wells remain part of future WIPP scenarios. Exploration of those resources has affected future drilling rate predictions. DOE has continued to monitor drilling activities through the Delaware Basin Monitoring Program and has appropriately captured the drilling events that would affect the drilling rate used for the PA. Based on DOE monitoring, predicted drilling rates have increased to 67.3 boreholes/km[2] in the 2014 PA.

Hydrologic Issues

Geologic Model
	The Geologic model used by DOE in the 2009 CRA remains unchanged in the 2014 CRA (see Section 15.2.5 Evaluation of Compliance for 2009 Recertification (194.15(a) (1)).

Hydrogeologic Model
      Since the CRA-2009 DOE reported no new monitoring well locations, however several old monitoring wells were plugged or abandoned. DOE has reported steel-cased wells that were aging and needed to be re-drilled and replaced with non-steel-cased to withstand saline environment. EPA raised a question related to eliminating monitoring well SNL-13 to the Culebra groundwater analysis due to a sudden head increase. DOE responded that this well plug had to be pulled due to an oil-field truck hitting the well head requiring surface casing to be repaired and nearby oil and gas wells development. The rise and fall in other nearby Culebra wells were not observed. DOE updated the Culebra monitoring network optimization study and reported no significant modifications since the 2009 CRA.

Change in Culebra Radionuclide Travel Time
      DOE adopted the same Culebra transmissivity fields developed in the CRA-2009 PABC for the 2014-CRA during. Therefore, the particle travel time simulations for the 2014 CRA were the same as those reported in the 2009-CRA. For the non-mining assumption travel times were 7,374 years; for the partially mined assumption travel times were 22,376, for the fully mine assumption travel times were 5,084. EPA found that these particle travel times adopted in the 2009 CRA and adopted in the 2014-CRA as reasonable.

Retardation of Radionuclides (Distribution Coefficients or Kds)
      DOE re-evaluated the range of Kd values used to assess retardation of actinides during transport through the Culebra (Moody 2010) and the upper bound should be changed. DOE reduced the lower bounds to account for the possibility of higher organic ligand concentrations.
Water in the Air-Exhaust Shaft
	DOE has no new information or issues have been reported related to water in the air-exhaust shaft.

15.2.8 Evaluation of Compliance for 2014 Recertification (194.15(a) (1))

Meteorological Conditions
      EPA's evaluation of DOE's updated meteorological conditions were deemed as adequate and does on affect the WIPP PA predicted climate model.

Change in Culebra Radionuclide Travel Time
      DOE has not significantly modified the Culebra transmissivity fields during the CRA-2009 PABC. For the CRA-2014 these transmissivity fields remained unchanged.

Retardation of Radionuclides (Distribution Coefficients or Kds)
      Distribution coefficients used to model actinide transport through the Culebra for the CRA-2014 PA are consistent with the estimated organic ligand concentrations based on the CRA-2014 PA inventory for these compounds and are likely to provide a conservative assessment of actinide transport through the Culebra.
Water in the Air-Exhaust Shaft
      EPA has not identified any additional issues related water in the air exhaust shaft.

15.2.9 2014 Recertification Decision (194.15(a) (1))

Meteorological Conditions
      EPA determined that DOE's updated meteorological conditions continue to comply with the requirements for Section 194.15(a) (1).

Geologic Model, Hydrogeologic Model, Change in Culebra Radionuclide Travel Time, and Changes in Culebra Radionuclide Travel Time
      EPA agreed that the DOE's assumption that the Geologic and Hydrologic models need not be modified. EPA agreed that Culebra transmissivity fields and predicted travel times continue to comply with the requirements for Section 194.15(a) (1).

Retardation of Radionuclides (Distribution Coefficients or Kds)
      EPA determined that DOE's approach to determining Culebra dolomite Kds as implementation of continues to comply with the requirements for Section 194.15(a) (1).

	Based on a review and evaluation of the 2014 CRA and supplemental information provided by DOE (Docket ID No. EPA-HQ-OAR-2014-0609), EPA determined that DOE continues to comply with the requirements for Section 194.15(a) (1).

15.3 Monitored Parameters - Background (194.15 (a) (2))

	DOE monitors ten parameters selected during the CCA to verify predicted performance of the WIPP repository. The monitored parameters are listed in Table 15.3 below. EPA keeps abreast of DOE's monitoring during annual inspections of the parameter monitoring program to verify that DOE's process and monitoring programs are adequate. EPA continues to evaluate DOE's parameter monitoring program and their response to changes in parameters to be in compliance with this requirement.

15.3.1 Requirements (194.15(a) (2)

	(a) "In submitting documentation of continued compliance pursuant to section 8(f) of the WIPP LWA, the previous compliance application shall be updated to provide sufficient information for the Administrator to determine whether or not the WIPP continues to be in compliance with the disposal regulations. Updated documentation shall include:

		(2) All additional monitoring data, analyses and results

                      Table 15.3  -  Monitored Parameters
Geomechanical Parameters-			Waste Activity Parameter*-
      -Creep closure, 					-Waste Activity
	-Extent of deformation,
	-Initiation of brittle deformation, and 	Subsidence Parameter-
	-Displacement of deformation features.		-Subsidence measurements

Hydrological Parameters*-				Drilling Related Parameters*-
      -Culebra groundwater composition and 		-Drilling rate and
	-Change in Culebra groundwater flow 		-The probability of encountering a
	 direction.						 Castile brine reservoir.
            *Parameters exhibiting changes since the CCA approval.

15.3.2 Changes in the 2004 CRA (194.15(a) (2)

	DOE documented monitoring relevant changes since the CCA in Wagner 2003, 2004 CRA Chapters 2 and 7.2, 2004 CRA Appendix DATA, 2004 CRA Appendix MON 2004, and other parameter monitoring related documents.

15.3.3 Evaluation of Compliance for 2004 Recertification (194.15(a) (2))

      EPA reviewed Wagner 2003, 2004 CRA Chapters 2 and 7.2, 2004 CRA Appendix DATA, 2004 CRA Appendix MON 2004, and other parameter monitoring related documents. EPA also confirmed that DOE has not modified any of the parameter selection arguments or conclusions since the original CCA, nor have the parameter monitoring programs been changed.

	DOE determined that even though some monitored parameters have changed, no new parameters need to be added nor did the parameter monitoring programs need to be modified. DOE did not change any argument or conclusion that justified why a parameter was considered significant or insignificant for the 2004 CRA, nor did DOE change their pre-closure or post-closure program plans or activities.

	EPA did not receive any public comments on DOE's continued compliance with the content of recertification application(s) requirements of Section 194.15(a) (2).

15.3.4 2004 Recertification Decision (194.15(a) (2))

	Based on a review and evaluation of the 2004 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2004-0025, Air Docket A-98-49) as well as 2004 CRA CARDs 23 and 42, EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (2).

15.3.5 Changes in the 2009 CRA (194.15(a) (2)

	DOE documented monitoring relevant changes since the 2004 CRA in Wagner 2008a and 2008b, 2009 CRA Sections 15 and 42, 2009 CRA Appendix DATA-2009, 2009 CRA Appendix MON-2009, and other parameter monitoring related documents.

15.3.6 Evaluation of Compliance for 2009 Recertification (194.15(a) (2))

      EPA reviewed Wagner 2008a and 2008b, 2009 CRA Sections 15 and 42, 2009 CRA Appendix DATA-2009, 2009 CRA Appendix MON-2009, and other parameter monitoring related documents. EPA also confirmed that DOE has not modified any of the parameter selection arguments or conclusions since the original CCA and the 2004 CRA nor have the parameter monitoring programs been changed.

	DOE continues to conclude that even though some monitored parameters have changed, no new parameters need to be added nor did the parameter monitoring programs need to be modified. DOE did not change any argument or conclusion that justified why a parameter was considered significant or insignificant for the 2009 CRA nor did DOE change their pre-closure or post-closure program plans or activities.

	EPA did not receive any public comments on DOE's continued compliance with the content of recertification application(s) requirements of Section 194.15(a) (2).

15.3.7 2009 Recertification Decision (194.15(a) (2))

	Based on a review and evaluation of the 2009 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2009-0330, Air Docket A-98-49) as well as 2004 CRA CARDs 23 and 42, EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (2).

15.3.8 Changes in the 2014 CRA (194.15(a) (2)

	DOE documented monitoring relevant changes since the 2009 CRA in Wagner and Kullman 2010, Wagner et al. 2011, Wagner et al., 2012, and Wagner 2013, and the 2014 CRA Sections 15 and 42, 2014 CRA Appendix DATA-2014, 2014 CRA Appendix MON-2014, and other parameter monitoring related documents.

15.3.9 Evaluation of Compliance for 2014 Recertification (194.15(a) (2))

      EPA reviewed Wagner and Kullman 2010, Wagner et al. 2011, Wagner et al., 2012, and Wagner 2013, and the 2014 CRA Sections 15 and 42, 2014 CRA Appendix DATA-2014, 2014 CRA Appendix MON-2014, and other parameter monitoring related documents. EPA also confirmed that DOE has not modified any of the parameter selection arguments or conclusions since the original CCA and the 2004 CRA nor have the parameter monitoring programs been changed.

	DOE continues to conclude that even though some monitored parameters have changed, no new parameters need to be added nor did the parameter monitoring programs need to be modified. DOE did not change any argument or conclusion that justified why a parameter was considered significant or insignificant for the 2014 CRA nor did DOE change their pre-closure or post-closure program plans or activities.

	EPA did not receive any public comments on DOE's continued compliance with the content of recertification application(s) requirements of Section 194.15(a) (2).

15.3.10 2014 Recertification Decision (194.15(a) (2))

	Based on a review and evaluation of the 2014 CRA and supplemental information provided by DOE (Docket ID No. EPA-HQ-OAR-2014-0609) as well as 2014 CRA CARDs 23 and 42, EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (2).

15.4 Requirements (194.15(a) (3))

	(a) "In submitting documentation of continued compliance pursuant to section 8(f) of the WIPP LWA, the previous compliance application shall be updated to provide sufficient information for the Administrator to determine whether or not the WIPP continues to be in compliance with the disposal regulations. Updated documentation shall include:

	(3) All additional analyses and results of laboratory experiments conducted by the Department or its contractors as part of the WIPP program

15.4.1 Changes in The 2004 CRA (194.15(a) (3))

Supercompacted Waste
	DOE requested (Docket A-98-49, Item II-B2-15) EPA's approval for the disposal of supercompacted waste from INL. EPA required DOE to conduct several analyses of the effect of the denser waste form and higher amounts of cellulosic, plastic, and rubber materials (CPR) (see Docket A-98-49, Items II-B2-22 to B2-26 and Items II-B2-28 and II-B2-29). EPA's review of the subject culminated in an approval of the emplacement of the supercompacted waste in the WIPP and a requirement to keep the magnesium oxide safety factor at least 1.67 for the remainder of the panels (Docket A-98-49, Item II-B3-68).

STTP Experiments
	DOE conducted source term test plan (STTP) experiments to provide data on the concentrations of actinides, actinide-containing colloids, complexing agents, and other chemical reactants in simulated WIPP brine in contact with candidate backfill materials and actual transuranic (TRU) wastes (Docket A-98-49, Item II-B1-3). DOE indicated that the results of experiments had no relevance to WIPP conditions, because of the high carbon dioxide overpressure and relatively low pH (2004 CRA Appendix PA Attachment SOTERM-4.8). The Environmental Evaluation Group (EEG) contended that the experiments were relevant and indicated the presence of nesquehonite, a form of magnesium oxide that would have contributed to higher actinide solubility than DOE used in PA. The Agency reviewed the results of the STTP experiments and EEG's concerns and determined that the experiment with MgO was not relevant to repository conditions because of the high carbon dioxide partial pressure (See Docket A-98-49, Item II-B1-3 for a summary and additional references).

15.4.2 Evaluation of Compliance for 2004 Recertification (194.15(a)(3))

	EPA approved the supercompacted waste in a previous action (Docket A-98-49, Item II-B3-68), and the STTP experimental results were not applicable at WIPP, and therefore were not used in the WIPP performance assessment.

	EPA did not receive any public comments on DOE's continued compliance with the content of compliance recertification application(s) requirements of Section 194.15(a)(3).

15.4.3 2004 Recertification Decision (194.15(a) (3))

	Based on a review and evaluation of the 2004 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2004-0025, Air Docket A-98-49), EPA determined that DOE continues to comply with the requirements for Section 194.15(a) (3).

15.4.4 Changes in The 2009 CRA (194.15(a) (3))

	Experiments "analyses and results of laboratory experiments conducted" by DOE since the 2004 CRA include the following (from 2009 CRA Section 15.6.3 and DOE 2010f):

 Disturbed Rock Zone (DRZ) Experiments (DOE Section <IP_ADDRESS>)
 Waste Shear Strength Experiments (DOE Section <IP_ADDRESS>)
 Characterization and Qualification of MgO Experiments (DOE Section <IP_ADDRESS>)
 MgO Hydration and Carbonation Experiments (DOE Section <IP_ADDRESS>)
 Solubility of Neodymium (Nd) (III) Experiments (DOE Section <IP_ADDRESS>)
 Reduction of Higher Valent Pu (V/VI) by Iron Experiments (DOE Section <IP_ADDRESS>)
 Solubility of U (VI) in Carbonate-free WIPP Brine Experiments (<IP_ADDRESS>)
 Iron and Lead Corrosion Studies

15.4.5 Evaluation of Compliance for 2009 Recertification (194.15(a) (3))

      During EPA's review of the 2009 CRA EPA specifically examined DOE's 2009 CRA Section 15.6.3 and 2009 CRA Appendix DATA-2009 Section Data-9.0 and was unable to easily trace the information provided by DOE. EPA requested that DOE clarify the information and link reports to the appropriate experiments (Email dated March 12, 2010). DOE response (DOE 2010f includes EPA's email text) is summarized below:

Disturbed Rock Zone (DRZ) Experiments (DOE Section <IP_ADDRESS>)
      No changes were made in WIPP repository conditions or subsurface processes used in PA to establish compliance since the 2004 CRA based on these experiments. The DRZ analyses referenced in the 2009 CRA Section <IP_ADDRESS> under AP-133 are complete and documented in the report referenced in Appendix DATA-2009 Section DATA-9.0 (Park et al. 2007). Additional 2009 CRA information concerning the DRZ can be found in Appendix SOTERM-2009 SOTERM-2.2.5, Appendix DATA-2009 Section DATA-9.0; Park et al., 2007; ERMS 546370, Ismail 2007; ERMS 545755, Holcomb and Hardy 2001; ERMS 545575.
Waste Shear Strength Experiments (DOE Section <IP_ADDRESS>)
      No changes were made to the WIPP repository conditions used in PA to establish compliance since the 2004 CRA based on these experiments.
       The Waste Shear Strength analysis referenced in 2009 CRA Section <IP_ADDRESS> under AP-131 were completed and documented in the report referenced in 2009 CRA Appendix DATA-2009 Section DATA-9.0; Herrick et al., 2007; ERMS 546343. Planned Waste shear strength experiments under test plans TP 09-01 and TP 08-01 have not been started.
Characterization and Qualification of MgO Experiments (DOE Section <IP_ADDRESS>)
      No changes were made in PA as a result of MgO characterization studies. The specific analyses referenced in Section <IP_ADDRESS> were complete and documented in Appendix MgO-2009 Section MgO-3.2.3 (Results since the CRA-2004 in Characteristics of MgO) and Appendix DATA-2009 Section DATA-9.0. MgO Characterization, hydration and carbonation experiments were performed under AP-108, TP 00-07 and TP 06-03. Additional MgO characterization and qualification of vendor-provided MgO analyses were discussed in response to EPA's comments 1-C-1 and 1-C-2 (EPA 2009a). The MgO excess factor stands at 1.2 which EPA approved in 2008 (Reyes 2008) with conditions to calculate and track MgO on a room-by-room basis and verify that the reactivity of MgO is maintained 96 (mol) % (Appendix MgO-2009).
MgO Hydration and Carbonation Experiments (DOE Section <IP_ADDRESS>)
      No changes were made in PA as a result of MgO hydration analyses. MgO hydration and carbonation experiments are performed under AP-108, TP 00-07 and TP 06-03 and are ongoing. Completed MgO hydration analyses results are discussed in 2009 CRA Appendix MgO-2009 Section MgO-4.1.2 (Results since the 2004 CRA Regarding Hydration of MgO).
Solubility of Neodymium (Nd) (III) Experiments (DOE Section <IP_ADDRESS>)
      These data were summarized in Appendix SOTERM-2009 Section 3.6.2. A more detailed report entitled "Actinide (III) Solubility in WIPP Brine: Data Summary and Recommendations," and designated as report LCO-ACP-08 (Borkowski et al. 2009), was provided to the EPA. Although some of the actinide data were used indirectly for the development of uncertainties in solubility, these data supported existing PA assumptions and did not result in any changes (see Summary Report for 2009 CRA PABC, Section 2.2 (Clayton et al. 2009)).
Reduction of Higher Valent Pu (V/VI) by Iron Experiments (DOE Section <IP_ADDRESS>)
      These data were summarized in Appendix SOTERM-2009, Section 3.5.2. A more detailed report entitled "Reduction of Higher-Valent Plutonium by Iron Under Waste Isolation Pilot Plant (WIPP)-Relevant Conditions: Data Summary and Recommendations," and designated as report LCO-ACP-09 (Reed et al. 2010), was provided to the EPA via email on March 12, 2010. No changes were made in PA as a result of these analyses.
Solubility of U (VI) in Carbonate-free WIPP Brine Experiments (<IP_ADDRESS>)
      These data were summarized in 2009 CRA Appendix SOTERM-2009 Section 3.3.2. A more detailed report entitled "Actinide (VI) Solubility in Carbonate-free WIPP Brine: Data Summary and Recommendations," and designated as report LCO-ACP-10 (Lucchini et al. 2010), was provided to the EPA via email on February 8, 2010. No changes were made in PA as a result of these analyses.
Iron and Lead Corrosion Studies
      Iron and lead corrosion studies were initiated under TP 06-02 and TP 08-02. Iron and lead chemistry long-term experiments are in progress. The first six-month report for this activity was completed in late 2009 after submittal of the 2009 CRA (Roselle 2009). No changes were made in PA as a result of these analyses.
	EPA examined DOE's response to our comments (DOE 2010f) and found that DOE adequately documented experiments performed and ongoing since the 2004 CRA and that they have not been used in the 2009 CRA PAs.
	EPA did not receive any public comments on DOE's continued compliance with the content of compliance recertification application(s) requirements of Section 194.15(a) (3).

15.4.6 2009 Recertification Decision (194.15(a) (3))

	Based on a review and evaluation of the 2009 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2009-0330, Air Docket A-98-49), EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (3).

15.4.7 Changes in The 2014 CRA (194.15(a) (3))

      Experiments "analyses and results of laboratory experiments conducted" by DOE since the 2009 CRA include the following:

 Waste shear strength
 MgO hydration
 Hydromagnesite solubility
 Iron and lead corrosion
 H2 gas generation through radiolysis
 Actinide investigations
 Colloids

15.4.8 Evaluation of Compliance for 2014 Recertification (194.15(a) (3))

Waste Shear Strength Experiments (DOE Section <IP_ADDRESS>)
      In the 2014 compliance recertification application, DOE updated the mean and lower bound of the sampled values used in the sampled distribution for the TAUFAIL parameter. In the 2009 compliance recertification application the lower bound value was 0.05 Pa, while for the 2014 compliance recertification application the lower bound was increased to 2.22 Pa. The upper bound, 77 Pa, remained the same. An increase in the sampled lower value also increased the sample mean. DOE developed the TAUFAIL probability distribution using a suite of laboratory flume tests specifically designed to represent the range of values for WIPP waste.

      EPA agreed with DOE's upper `bounding' range value but had concerns with the derivation of DOE's lower `bounding' range value. The Agency was concerned that three of the five low shear-strength tests had highly scattered results. DOE attributed the scatter to pre-test sample damage and/or a high degree of variability in sample preparation, rather than testing an equivalent suite of samples. As a result, the low shear strength test results may not be truly representative of low shear strength samples. However, the EPA considers the use of DOE's lower bound value, which is higher than the 0.05 Pa (representative of bay muds) as more credible, despite the data scatter, than what had been used in prior performance assessments.

MgO Hydration
	Since the 2009-CRA, DOE has performed experiments to determine brucite and Phase 5 hydration rates using brines with the MgO engineered barrier. These rates have been incorporated into the geochemical modeling database. EPA finds these rates adequate but would also like to see rates reflective of the combination of the different brands of MgO being used in the repository see (EPA 201711 for more details).
Hydromagnesite solubility
      DOE has also examined hydromagnesite solubility in various experiments to update solubility values in the database. EPA's review identified that the measurements used in this experiment underestimated CO2 concentrations from the closed-system experimental conditions (see EPA 2017). Because of this concern, DOE should instead use hyrdomagnesite solubility values like those in Robie and Hemingway (1973).
Iron and Lead Corrosion Studies
	DOE updated the corrosion rates for both iron and lead inundated in brine based on experiments conducted at a range of CO2 concentrations. These experiments provided a new distribution of corrosion rates which, on average, resulted in a decreased corrosion rate. However, based on environmental conditions at the WIPP, EPA would like to see the lower bound values for these rates increased to account for nonzero CO2 concentrations in the repository, and to see corrosion rates that would account for rates affected by higher repository pressures[11].
H2 Gas Generation Through Radiolysis
      DOE has performed H2 (g) monitoring in WIPP Panels 3 and 4 and concluded that radiolytic H2 (g) generation is occurring. Because corrosion and microbial gas generation are thought to produce more gas than radiolysis, DOE has not included the contribution of radiolysis to overall gas generation. However, since microbial gas generation has been decreased for the 2014-CRA, radiolysis should be considered.
Actinide Investigations
	Since the 2009-CRA and 2009-PABC, DOE has conducted numerous investigations on thorium and uranium actinide solubility e.g., Borkowski et al. 2012 and Lucchini et al. 2013 in WIPP-relevant conditions. DOE has also investigated actinide complexation with organic ligands, borate, and other agents such as with Borkowski et al. 2012 and Borkowski et al. 2010. They have also examined actinide oxidation states in the WIPP such as with Reed et al. 2010. Results of the actinide solubility experiments have been included in determining actinide uncertainty distributions while actinide complexation experiments have been used to update the geochemical database. EPA accepts these experiments to be used as updates to the uncertainty distribution and database. However, data beyond DOE experiments should also be included in both the uncertainty distribution and the database so EPA can accept these items in future CRAs.
      DOE's plutonium oxidation experiments are fundamental to understanding WIPP geochemical conditions. Given experiments performed in similar conditions as WIPP, such as with Altmaier and Geckeis (2011), EPA concludes that Pu (III) will be a more dominant oxidation state than Pu (IV).
Colloids
	DOE has performed experiments to update the intrinsic and microbial colloid parameters. For example, DOE has performed experiments to understand Nd (III), Pu (III), Th (IV), and U (VI) intrinsic colloid formation in WIPP brines. They have also studied microbial colloid formation using native WIPP microorganisms20. EPA appreciates DOE's willingness to update these parameters. However, several key experimental parameters, such as filter sizes in intrinsic colloid experiments or experimental time in microbial colloids, introduce uncertainty into the updated values. As a result, EPA has identified that the values from the 2009-CRA are more appropriate to use in performance assessment than the 2014-CRA values.

15.4.9 2014 Recertification Decision (194.15(a) (3))

      Based on a review and evaluation of the 2014 CRA and supplemental information provided by DOE (Docket ID No. EPA-HQ-OAR-2014-0609), such as sensitivity studies requested by the Agency, EPA determines that DOE complies with the requirements for Section 194.15(a) (3) related to incorporating experimental results into the WIPP program. Please refer to the various technical support documents (Docket ID No. EPA-HQ-OAR-2014-0609) for details on EPA's evaluation.

15.5 Requirements (194.15(a) (4))

(a) "In submitting documentation of continued compliance pursuant to section 8(f) of the WIPP LWA, the previous compliance application shall be updated to provide sufficient information for the Administrator to determine whether or not the WIPP continues to be in compliance with the disposal regulations. Updated documentation shall include:

	(4) An identification of any activities or assumptions that deviate from the 	most recent compliance application

15.5.1 Changes in the 2004 CRA (194.15(a) (4))

      DOE made changes to several specific activities and assumptions, and to several categories of items. These items are outlined grouped in Table 15-4 of 2009 Recertification CARD 15 and Technical Support Documents (Docket A-98-49).

15.5.2 Evaluation of Compliance for 2004 Recertification (194.15(a) (4))

	EPA's review of these changes is presented in multiple CARDs and Technical Support Documents. In addition, the changes were incorporated in the 2004 PABC (see CARDs 23 and 24; FDMS Docket ID No. EPA-HQ-OAR-2004-0025, Air Docket A-98-49, Items II-B1-3, II-B1-10, II-B1-11, II-B1-15, II-B1-16, II-B1-17). EPA found DOE changes adequate and appropriately implemented in the CRA performance assessments.

	EPA did not receive any public comments on DOE's continued compliance with the content of compliance recertification application(s) requirements of Section 194.14(a) (4).

15.5.3 2004 Recertification Decision (194.15(a) (4))

	Based on a review and evaluation of the 2004 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2004-0025, Air Docket A-98-49), EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (4).

15.5.4 Changes in the 2009 CRA (194.15(a) (4))

      DOE made changes to several specific activities and assumptions, and to several categories of items. These items are grouped in Table 15-5 of 2009 Recertification CARD 15 and Technical Support Documents (FDMS Docket ID No. EPA-HQ-OAR-2009-0330, Air Docket A-98-49).

15.5.5 Evaluation of Compliance for 2009 Recertification (194.15(a) (4))

	EPA's review of these changes is presented in multiple 2009 CARDs and Technical Support Documents (TSDs). In addition, some changes were incorporated in the 2009 PABC (see 2009 CARDs 23 and 24; EPA 2010b-PABC review, EPA 2010g-Parameter report). EPA found DOE changes adequate and appropriately implemented in the 2009 PABC calculations.

	EPA did not receive any public comments on DOE's continued compliance with the content of compliance recertification application(s) requirements of Section 194.14(a) (4).

15.5.6 2009 Recertification Decision (194.15(a) (4))

	Based on a review and evaluation of the 2009 CRA, 2009 PABC, and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2009-0330, Air Docket A-98-49), EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (4).

15.5.7 Changes in the 2014 CRA (194.15(a) (4))

      DOE made changes to several specific activities and assumptions, and to several categories of items. These items are grouped in the table below and found in 2014 CRA Content of Compliance Recertification Application 40 CFR § 194.15 and Appendix PA-2014. They are also discussed in other CARDs as well as Technical Support Documents (Docket ID No. EPA-HQ-OAR-2014-0609).

Item
DOE
EPA Decision

Underground excavation
Panels 1 through 7 mined completely as of December 31, 2012. Panels 1 to 5 completely filled with waste as of December 28, 2012.
EPA has approved of mined waste panels.
Remote-handled TRU waste emplacement
RH waste emplaced in panels 4, 5, and 6. No waste in panels 1, 2, and 3.
EPA has approved of RH waste in Panels 4, 5 and 6.
RH-TRU waste container modifications
DOE planned change request for RH-TRU waste emplacement in shielded containers which can be handled as CH-TRU waste. Containers will continue to be recorded as RH-TRU waste.
EPA approved of the request on August 8, 2011 with the condition that DOE demonstrate procedures to ensure containers remain below dose rate of 200 mrem per hour.
Experiments in the repository
Detectors for the EXO project installed and data being collected. DOE also installed a dark matter time projection chamber and has started the LBRE.
EPA approved in 2009 and prior.
Salt disposal investigations
Planned change notice to initiate the Salt Disposal Investigations project and the additional Salt Defense Disposal Investigation.
EPA approved.
Neutron shielded canisters
Planned change notice to employ polyethylene lined containers for some RH-TRU waste.
Planned change notice not requiring EPA approval but included in inventory.
Magnesium oxide
Planned change notice to change MgO emplacement process to every other row of waste containers.
EPA approved in an email from Peake to Franco, July 13, 2012.
Repository Reconfiguration
Planned change request to relocate Panels 9 and 10 south of existing Panels 4 and 5.
EPA did not approve of repository reconfiguration.
Panel closure redesign
Planned change request for redesign using run-of-mine panel closure.
EPA submitted first set of questions and comments on this (Perrin 2011).
Update to drilling rate and borehole plugging patterns
Drilling rate increased from over 10,000 years and borehole plugging patterns changed.
Approved.
Modeling of open areas in repository
Additional volume was added to the WIPP experimental region.
Addressed in SEN2 study. Approved, but EPA believes there should be an independent technical review as well.
Revised estimate of probability of encountering pressurized brine
Revised distribution of probabilities associated with encountering brine created based on drilling data.
EPA rejected revision and provided an updated distribution. Updated probability addressed in SEN4 study and approved[23].
Revised corrosion rate of steel
Corrosion rate of steel updated based on new experimental results.
Approved for this CRA after addressing issues of decreased corrosion rates due to metal passivation on the SEN4 study[23].
Revised effective shear strength of WIPP waste
Revised lower bound for the waste shear strength based on experiments.
Suggested using the lower bound value from experiments instead of the experimental mean value. Addressed in SEN4 study and accepted[23].
Waste inventory update
Updated to include information collected since December 2011.
Accepted inventory update.
Revised repository water balance
New accounting for repository water balance and repository saturation as a result of updated corrosion rates.
Addressed in SEN4 study[23][,] Accepted but needs updating for next CRA.
Variable brine volume
Actinide solubility and organic ligand concentrations calculated as a function of potential volumes of brine released.
Accepted.
Revised colloid parameters
Updated colloid parameters based on new experimental data.
2009-CRA colloid parameter values are a better representation of the data than what was used for 2014-CRA[11][,]
Actinide solubility code
Solubility calculations performed using EQ3/6 for CRA-2014 instead of FMT code.
Accepted.
Culebra transmissivity fields
Updated based on revised hydrogeologic factors for the Culebra, carried over from CRA-2009 PABC.
Accepted[11].
Culebra matrix partition coefficients
Updated to account for higher organic ligand concentrations in WIPP waste inventory.
Accepted[11].
Radionuclide solubility
Baseline actinide solubility updated to reflect organic ligand content in the CRA-2014 waste inventory and for several brine volumes.
Accepted for this CRA. However, database used to calculate solubility needs additional updating[11].
Solubility uncertainty
Updated based on recently available results in published literature.
EPA found issues with how studies were chosen for the uncertainty distribution[11]. New distribution provided for SEN4 study showing the EPA provided distribution will increase releases, but releases will still remain below limits.

15.5.8 Evaluation of Compliance for 2014 Recertification (194.15(a) (4))

      EPA found many issues with the changes, and these issues which have been detailed in the supporting TSDs. As a means to address some of these issues, DOE implemented the Agency requested sensitivity studies which show continued compliance.

	EPA did not receive any public comments on DOE's continued compliance with the content of compliance recertification application(s) requirements of Section 194.14(a) (4).

15.5.9 2014 Recertification Decision (194.15(a) (4))

	Based on a review and evaluation of the 2014 CRA and supplemental information provided by DOE (Docket ID No. EPA-HQ-OAR-2014-0609), EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (4).

15.6 Requirements (194.15(a) (5))

	(a) "In submitting documentation of continued compliance pursuant to section 8(f) of the WIPP LWA, the previous compliance application shall be updated to provide sufficient information for the Administrator to determine whether or not the WIPP continues to be in compliance with the disposal regulations. Updated documentation shall include:

		  (5) A description of all waste emplaced in the disposal system since the most 		recent compliance certification or re-certification application. Such 			description shall consist of a description of the waste characteristics and waste 		components identified in §§194.24(b)(1) and 194.24(b)(2)

15.6.1 Changes in the 2004 CRA (194.15(a) (5)

	DOE updated this information for emplaced waste at the WIPP, waste stored at the waste generator sites, and waste anticipated to go to WIPP. This is discussed in multiple locations in the 2004 CRA, including Chapter 4, Appendix DATA, and Attachment F: Transuranic Waste Inventory Update Report, 2003, and Appendix TRU Waste. This information is further updated for the PABC in the PABC Inventory Report (Docket A-98-49, Item II-B2-60).

15.6.2 Evaluation of Compliance for 2004 Recertification (194.15(a) (5))

	In DOE's updated waste inventory information (Docket A-98-49, Item II-B2-60), DOE kept the same categories of waste used in the CCA, so that the major changes were changes to waste volumes. The radioactivity of the waste was estimated to decrease from the CCA, the contact-handled TRU waste volume is greater than in the CCA, while DOE estimates that there is more remote-handled waste in the inventory than there is allowable space in WIPP. Prior to the submission of the 2004 CRA, DOE requested to dispose of supercompacted waste. After a thorough analysis, EPA allowed this waste in the performance assessment.

	In addition, DOE proposed to dispose of some wastes from the Hanford waste site tank farms and what is known as K-Basin sludges. EPA allowed this material in the performance assessment since DOE may be able to demonstrate that it is TRU waste. DOE has proposed a public process to address the classification of the Hanford tank waste before DOE requests approval for disposal at WIPP. EPA identified that DOE appropriately provided the waste information and that the waste inventory is adequately included in the 2004 PABC. EPA's inventory review is discussed, at length, in 2004 CRA CARD 24 and the Technical Support Document for 194.24: Review of the Baseline Inventory used in the Compliance Recertification Application and the Performance Assessment Baseline Calculation (Docket A-98-49, Item II-B1-9).

15.6.3 2004 Recertification Decision (194.15(a) (5))

	Based on a review and evaluation of the 2004 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2004-0025, Air Docket A-98-49) as well as EPA's review discussed CRA CARD 24, EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (5).

15.6.4 Changes in the 2009 CRA (194.15(a) (5)

	DOE updated information for emplaced waste at the WIPP, waste stored at the waste generator sites, and waste anticipated to go to WIPP for the 2009 PABC. This is discussed in the 2009 CRA, including Appendix DATA-2009 Section DATA-7.0, and the Annual Transuranic Waste Inventory Report-2008 (ATWIR 2008). This information is further updated for the 2009 PABC in the Performance Assessment Inventory Report-2008 (PAIR 2008) and the Radionuclide Inventory Screening Analysis Report for the PABC-2009 (Fox et al. 2009). DOE has emplaced a total of 52,000m[3] of CH waste and 88m[3] of RH waste (ATWIR-2008 Section 3.1.1).

15.6.5 Evaluation of Compliance for 2009 Recertification (194.15(a) (5))

	DOE generally kept the same categories of waste for the 2009 PABC. The major changes were changes to waste volumes and radioactive content since the 2004 CRA. The radioactivity of the waste was estimated to decrease since the 2004 CRA principally because of the removal of Hanford tank waste from the WIPP bound waste category (EPA 2010f). This change also decreased the volume of both contact-handled and remote-handled waste in the inventory. EPA examined DOE's documentation to verify that the approach was adequate and reasonable (EPA 2010f Section 3.0). EPA found DOE's inventory estimates of waste projected to be emplaced at WIPP to be reasonable and adequate. EPA expects any changes in projected inventory by DOE, such as waste presently listed as not WIPP bound in the future inventory estimates, to be fully explained, justified, and confirmed by the use of a new compliant performance assessment calculation.

15.6.6 2009 Recertification Decision (194.15(a) (5))

	Based on a review and evaluation of the 2009 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2009-0330, Air Docket A-98-49) as well as EPA's review discussed CRA CARD 24, EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (5).

15.6.7 Changes in the 2014 CRA (194.15(a) (5)

	DOE updates for emplaced waste at the WIPP repository, waste stored at the waste generator sites, and waste anticipated to go to WIPP for the 2014 are discussed in the 2014 CRA, Appendix DATA-2014 Section DATA-7.0, and the Annual Transuranic Waste Inventory Report-2012 (ATWIR 2012). This information is further updated in the Performance Assessment Inventory Report-2013 (PAIR 2013) and the Radionuclide Inventory Screening Analysis Report for the PA-2014 (Van Soest 2012). DOE has emplaced a total of 55,200 m[3] of CH waste and 236 m[3] of RH waste (ATWIR-2012 Section 3.1.1). The projected volume of CH waste is 68,000 m[3] and of RH waste is 357m[3] (ATWIR-2012 Section 3.1.1)

      Total activity (Ci) is reported in the Section 3.3.2 of the ATWIR-2012, Table 3-13 of the ATWIR reported a decrease in both CH- and RH-TRU waste activity. The largest contributing waste stream to this net reduction from Hanford and Lawrence Livermore National Laboratory waste. These reductions, among others, are countered by less significant gains in other waste stream inventories to achieve the overall net decrease in activity. Total Activity in converted into EPA units and included in the CRA-2014 PA.

15.6.8 Evaluation of Compliance for 2014 Recertification (194.15(a) (5))

      DOE generally kept the same categories of waste for the 2014 PA. The major changes were changes to waste volumes and radioactive content since the 2009 CRA. The projected radioactivity of the waste was estimated decreased since the 2009 CRA and is attributed primarily due to removal of a portion of Savannah River waste. This change also decreased the volume of final projection of both contact-handled and remote-handled waste in the inventory. EPA found DOE's inventory estimates of waste projected to be emplaced at WIPP to be reasonable and adequate. EPA expects any changes in projected inventory by DOE presently listed as not WIPP bound waste, will be included in future inventory estimates. The increase needs to be fully explained, justified, and confirmed by the use of a new compliant performance assessment calculation.

15.6.9 2014 Recertification Decision (194.15(a) (5))

	Based on a review and evaluation of the 2014 CRA and supplemental information provided by DOE (Docket ID No. EPA-HQ-OAR-2014-0609) as well as EPA's review discussed CRA CARD 24, EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (5).

15.7 Requirements (194.15(a) (6))

	(a) "In submitting documentation of continued compliance pursuant to section 8(f) of the WIPP LWA, the previous compliance application shall be updated to provide sufficient information for the Administrator to determine whether or not the WIPP continues to be in compliance with the disposal regulations. Updated documentation shall include:

		(6) Any significant information not previously included in a compliance certification or re-certification application related to whether the disposal system continues to be in compliance with the disposal regulations

15.7.1 Changes in the 2004 CRA (194.15(a) (6))

	As part of the completeness review, EPA realized that the 2004 CRA PA calculations did not meet regulatory requirements that addressed uncertainty (40 CFR Part 194.34). EPA therefore required DOE to conduct another performance assessment. DOE conducted this additional performance assessment, termed the performance assessment baseline calculations (PABC-2004). This PA replaced the 2004 CRA PA for compliance purposes. A summary of the 2004 PABC review, including changes in the 2004 PABC from the 2004 CRA PA, is described in depth in Technical Support Document for Section 194.23: Review of the 2004 Compliance Recertification Performance Assessment Baseline Calculation (2004 PABC Review TSD, Docket A-98-48 Item II-B2-15). The changes can be grouped into two major categories: waste inventory and modeling assumptions. The waste inventory was updated to address discrepancies and changed situations in the baseline inventory. Modeling assumptions included addressing rates of microbial CPR degradation, reexamining different microbial processes in the repository that would affect geochemistry, actinide solubility and uncertainty distribution, organic ligand inventories, Culebra transmissivity, and updates to the BRAGFLO code.

	The Agency concluded that changes to the computer codes for modeling Salado Formation flow and transport have been properly implemented, as have changes in conceptual models and model parameters. The Agency finds that the approach taken by DOE for the modeling the Salado is acceptable.
	DOE made changes in the WIPP parameters for the 2004 PABC to accommodate the changes discussed above. The Agency reviewed the procedural adequacy of changes made to the parameter database for the 2004 PABC as well as the technical adequacy of all parameter database changes made since the PAVT. The review (Docket A-98-49, Item II-B1-16) show that the parameters used in the 2004 PABC were technically acceptable and appropriately documented.
15.7.2 Evaluation of Compliance for 2004 Recertification (194.15(a) (6))

	DOE adequately responded to EPA's requests by including EPA requirements in the 2004 PABC. EPA's main review of the 2004 PABC is provided in the 2004 PABC review document (A-98-49, Item II-B1-16) with additional discussion in 2004 CARDs 23 and 24. Based on our review, EPA finds that DOE adequately implemented EPA's required changes in the 2004 PABC. The 2004 PABC calculations show that the repository meets the numerical standards at 40 CFR 191.13 as well as the compliance assessment requirements for the undisturbed case.

	EPA did not receive any public comments on DOE's continued compliance with the content of compliance recertification application(s) requirements of Section 194.15(a) (6).

15.7.3 2004 Recertification Decision (194.15(a) (6))

	Based on a review and evaluation of the 2004 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2004-0025, Air Docket A-98-49), EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (6).

15.7.4 Changes in the 2009 CRA (194.15(a) (6))

	During EPA's initial completeness review of DOE's 2009 CRA documents EPA determined that the 2009 CRA PA calculations were incomplete because of recent changes in the waste inventory, in particular the significant changes in the quantities of some organic ligands. EPA directed DOE to conduct another performance assessment. DOE conducted this additional performance assessment, termed the 2009 performance assessment baseline calculations (2009 PABC). The 2009 PABC replaces the 2009 CRA performance assessment (PA) for compliance purposes and is described in depth in 2009 Technical Support Document for Section 194.23: Review of the 2009 Compliance Recertification Performance Assessment Baseline Calculation (FDMS Docket ID No. EPA-HQ-OAR-2009-0330, Air Docket A-98-49). The changes can be grouped into two major categories: waste inventory and modeling assumptions. 2009 PABC parameters were changed to accommodate these changes. Issues with waste inventory included changes to quantities of organic ligands. Modeling assumptions included changes to the Culebra Hydrogeology conceptual model and changes to various physical and chemical model parameters (e.g., CPR degradation rates, and drilling rate and borehole plugging patterns).

	EPA reviewed the changes incorporated into the 2009 CRA PA and the 2009 PABC concluding that the parameter, conceptual model, and other changes have been properly documented and implemented.

	DOE made changes in the WIPP parameters for the 2009 PABC to accommodate the changes discussed above. The Agency reviewed the procedural adequacy of changes made to the parameter database for the 2009 PABC as well as the technical adequacy of all parameter database changes made since the 2004 PABC. EPA 2010g shows that the parameters used in the 2009 PABC were technically acceptable and appropriately documented.

15.7.5 Evaluation of Compliance for 2009 Recertification (194.15(a) (6))

	DOE adequately responded to EPA's requests by including EPA requirements in the 2009 PABC. EPA's main review of the 2009 PABC is provided in the 2009 PABC review document with additional discussion in 2009 CRA CARDs 23 and 24 (FDMS Docket ID No. EPA-HQ-OAR-2009-0330, Air Docket A-98-49). Based on our review, EPA finds that DOE adequately implemented EPA's required changes in the 2009 PABC. The 2009 PABC calculations show that the repository meets the numerical standards at 40 CFR 191.13 as well as the compliance assessment requirements for the undisturbed case.

	EPA did not receive any public comments on DOE's continued compliance with the content of compliance recertification application(s) requirements of Section 194.15(a) (6).

15.7.6 2009 Recertification Decision (194.15(a) (6))

	Based on a review and evaluation of the 2009 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2009-0330, Air Docket A-98-49), EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (6).

15.7.7 Changes in the 2014 CRA (194.15(a) (6))

      During EPA's review of DOE's 2014 CRA documents, the Agency identified several technical concerns that, if addressed in WIPP PA, had the potential to increase calculated repository releases. At EPA's request, the DOE performed sensitivity studies to help evaluate the effect of those concerns on predictions of WIPP performance. The Agency's evaluations of the results of those studies are presented in Technical Support Document in Support of Sections 194.23 and 194.55: Analysis of EPA's Sensitivity Analysis Calculations That Support Recertification of the WIPP CRA-2014. (Docket ID No. EPA-HQ-OAR-2014-0609). While some of the Agency's concerns were found to increase calculated repository releases, the total mean releases, the upper 95% confidence limit on those means, and all individual vectors remained below the EPA's WIPP release limits in all sensitivity studies. EPA therefore concludes that although some of changes made to the performance calculations resulted in higher calculated releases, none of the increases exceeded regulatory limits. EPA has identified several technical concerns that fit in three broad categories: the probability of hitting a brine pocket, actinide solubility, and modeling repository conditions.

The probability of hitting a brine pocket
      Large volumes of pressurized brine may underlie the Castile Formation. If a borehole encounters a pocket of pressurized brine that also intrudes a waste panel, a release may occur. For 2014, DOE updated the parameter representing the probability of encountering a pressurized brine ("PBRINE") by basing the probability on voluntary drilling reports. EPA found technical concerns with this approach and provided an alternative approach utilizing geophysical data DOE previously collected. DOE incorporated this new PBRINE in the SEN4 study resulting in a slight increase in releases[23].

Actinide solubility
      EPA found inconsistencies in DOE's actinide uncertainty distribution used to address the difference between model calculations and experimental values. Experimental values for this uncertainty distribution are chosen using prescribed criteria, which DOE did not consistently follow[9]. EPA provided DOE with a new uncertainty distribution which was utilized in the SEN4 study. The new distribution contributed to a slight increase in releases, though still below regulatory limits[23].

      Actinide bearing colloids comprise a large fraction of total mobile actinides and are important due to their rapid movement in the subsurface. DOE has updated the colloid model using recently collected experimental data. The result of this update was a decrease in releases[11]. EPA has several issues with the experiments DOE chose to update this parameter as well as the calculations used to update it. As discussed in Section 194.15(A)(3) above, EPA has identified that the values from the 2009-CRA are more appropriate to use in performance assessment than the 2014-CRA values.
      DOE's plutonium oxidation experiments are fundamental to understanding WIPP geochemical conditions. Given experiments performed in similar conditions as WIPP, such as with Altmaier and Geckeis (2011), EPA concludes that Pu (III) will be a more dominant oxidation state than Pu (IV). DOE considers that the literature is contradictory  on this issue and does not support the technical argument presented by EPA justifying changing the proportions of Pu III/IV oxidation states. Thus, DOE continues to support the current oxidation state distribution as 50/50 and documented in Appendix SOTERM.

Modeling repository conditions
      The properties of the WIPP halite allow for the repository to encapsulate (i.e., creep close) the waste over the 10,000-year regulatory period and decrease permeability (i.e., heal). Currently, DOE models excavated areas in the WIPP underground only to partially creep close and heal in order to maximize brine flow into the repository in the models. EPA finds that a better interpretation of future repository conditions would be to model an end state that is less porous and permeable than what DOE used. Thus, EPA  requested DOE to analyze repository performance in the SEN3 study using different salt properties than the CRA-2014 PA. Results of the study did show a small increase in mean total calculated low probability releases[5].

      The parameter TAUFAIL represents waste shear strength and is used in calculating potential releases of waste materials from the WIPP repository when a drilling operator drills a borehole through the waste. Understanding waste shear strength is particularly important if a future borehole intersects a waste panel with consolidated waste and causes the transport of radionuclides into the surface. DOE has updated this parameter by collecting data using novel flume experiments. The EPA believes the DOE's overall approach of using experimental data to revise the TAUFAIL parameter is reasonable; however, the EPA had concerns with the DOE's lower "bounding" range value derived from the experiments. The Agency was concerned that three of the five low shear-strength tests had highly scattered results. The DOE attributed the scatter to pre-test sample damage and/or a high degree of variability in sample preparation, rather than testing an equivalent suite of samples. As a result, the mean of the low shear strength test results may not be truly representative of low shear strength samples. DOE addressed this in the SEN4 with results suggesting this change only provided a minor change to releases[23,25].

      Additional repository conditions EPA found issues with include DOE's corrosion model and the related repository water balance calculation. The corrosion model has been updated to incorporate new data from experiments. However, this update does not consider a decrease in corrosion rates due to metal passivation. These rates would further affect repository water balance, which is a byproduct of corrosion reactions. These concerns were addressed in the SEN4 study and showed minor contributions to releases[23,25].

	These technical concerns are outlined in the EPA's Technical Support Documents (Docket ID No. EPA-HQ-OAR-2014-0609). EPA reviewed the changes incorporated into the 2014 CRA PA and found DOE had not included all parameter or technical information available since the 2009 CRA. However, based on the results of EPA's requested suite of sensitivity studies that included some of these omissions, the Agency concludes that DOE's parameter values adopted in the 2014 CRA were adequate. Additionally, the Agency concludes those parameters DOE did not use in their 2014-CRA were adequately documented.

15.7.8 Evaluation of Compliance for 2014 Recertification (194.15(a) (6))

      DOE adequately responded to EPA's requests by including EPA requirements in the 2014 sensitivity studies. EPA's main review of the 2014-CRA and sensitivity studies is provided in the TSDs with additional discussion in 2014 CRA CARDs 23 and 24 (Docket ID No. EPA-HQ-OAR-2014-0609). Based on our review, EPA finds that DOE adequately implemented EPA's required changes. The calculations show that the repository meets the numerical standards at 40 CFR 191.13 as well as the compliance assessment requirements for the undisturbed case.

	EPA did not receive any public comments on DOE's continued compliance with the content of compliance recertification application(s) requirements of Section 194.15(a) (6).

15.7.9 2014 Recertification Decision (194.15(a) (6))

      Based on a review and evaluation of the 2014 CRA and supplemental information provided by DOE (Docket ID No. EPA-HQ-OAR-2014-0609), EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (6).

15.8 Requirements (194.15(a) (7))

      During the course of the completeness and technical review of each recertification, the Agency submits numerous requests to DOE for additional information. The docket categories in which these can be found are listed below.

	(a) "In submitting documentation of continued compliance pursuant to section 8(f) of the WIPP LWA, the previous compliance application shall be updated to provide sufficient information for the Administrator to determine whether or not the WIPP continues to be in compliance with the disposal regulations. Updated documentation shall include:

			(7) Any additional information requested by the Administrator or the 			Administrator's authorized representative."

15.8.2 Changes in the 2004 CRA (194.15(a) (7)

	During the course of the completeness and technical review of the 2004 CRA, the Agency submitted numerous requests to DOE for additional information. The docket categories in which these can be found are listed below.

	The information submitted by DOE and commenters, and developed by EPA can be found in the following categories for EPA Air Docket A-98-49.

1. 	QA Audits/Inspections, and their approvals -- Category II-A1.
2. 	WC Audits/Inspections, and their approvals -- Category II-A4.
3. 	Background/support documents (i.e., TSD's, fact sheets) -- Category II-B1.
4. 	Correspondence/information submitted by DOE (including responses to EPA requests, e.g., 2004 CRA completeness and technical issues) -- Category II-B2.
5. 	Correspondence/information sent to DOE by EPA (including completeness and technical requests for additional information) -- Category II-B3.
6. 	2004 CRA CARDs -- Category V-B2.

15.8.3 Evaluation of Compliance for 2004 Recertification (194.15(a) (7)

	The information provided by DOE is reviewed by EPA in the CARD and Technical Support Documents related to the particular topic. DOE responded to all requests for information made by EPA.

15.8.4 2004 Recertification Decision (194.15(a) (7))

	Based on a review and evaluation of the 2004 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2004-0025, Air Docket A-98-49), EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (7).

15.8.5 Changes in the 2009 CRA (194.15(a) (7))

	The Agency submitted numerous requests to DOE for additional information during the completeness and technical review of the 2009 CRA. The docket categories in which these can be found are listed below.

	The information submitted by DOE and commenters, and developed by EPA can be found in the following categories for EPA Air Docket A-98-49.

1. 	QA Audits/Inspections, and their approvals -- Category II-A1.
2. 	WC Audits/Inspections, and their approvals -- Category II-A4.
3. 	Background/support documents (i.e., 2009 TSD's, fact sheets) -- Category II-B1.
4. 	Correspondence/information submitted by DOE (including responses to EPA requests, e.g., 2009 CRA completeness and technical issues) -- Category II-B2.
5. 	Correspondence/information sent to DOE by EPA (including completeness and technical requests for additional information) -- Category II-B3.
6. 	2009 CRA CARDs -- Category V-B2.

15.8.6 Evaluation of Compliance for 2009 Recertification (194.15(a) (7))

	The information provided by DOE was reviewed by EPA in the CARDs and Technical Support Documents related to the particular topic. DOE responded to all requests for information made by EPA.

15.8.7 2009 Recertification Decision (194.15(a) (7))

	Based on a review and evaluation of the 2009 CRA and supplemental information provided by DOE (Docket ID No. EPA-HQ-OAR-2009-0330, Air Docket A-98-49), EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (7).

15.8.8 Changes in the 2014 CRA (194.15(a) (7)

      The Agency submitted numerous requests to DOE for additional information during the completeness and technical review of the 2014 CRA EPA-HQ-OAR-2014-0609. The docket categories in which these can be found are listed below.

	The information submitted by DOE and commenters, and developed by EPA can be found in the following categories for EPA Air Docket A-98-49.

1. 	QA Audits/Inspections, and their approvals --  Docket ID No. EPA-HQ-OAR 2014 CRA EPA-HQ-OAR-2014-06092.
2. 	Background/support documents (i.e., 2009 TSD's, fact sheets)  --  Docket ID No. EPA-HQ-OAR 2014-0609.
3. 	Correspondence/information sent to DOE by EPA (including completeness and technical requests for additional information)  --  These are provided on the docket with the following ID Numbers: EPA-HQ-OAR 2014-0005; EPA-HQ-OAR 2014-0006; EPA-HQ-OAR 2014-0609-0009; EPA-HQ-OAR 2014-0609-0010; EPA-HQ-OAR 2014-0024; EPA-HQ-OAR 2014-0025; EPA-HQ-OAR 2014-0028; EPA-HQ-OAR 2014-0029;EPA-HQ-OAR 2014-0037.
4. 	Correspondence/information submitted by DOE (including responses to EPA requests, e.g., 2014 CRA completeness and technical issues)  --  These are provided on the docket with the following ID Numbers: EPA-HQ-OAR 2014-0609-0005; EPA-HQ-OAR 2014-0609-004; EPA-HQ-OAR 2014-0609-0006; EPA-HQ-OAR 2014-0609-0011; EPA-HQ-OAR 2014-0609-0030; EPA-HQ-OAR 2014-0609-0031; EPA-HQ-OAR 2014-0609-0032; EPA-HQ-OAR 2014-0609-0034; EPA-HQ-OAR 2014-0609-0038.

15.8.9 Evaluation of Compliance for 2014 Recertification (194.15(a) (7))

      The information provided by DOE is reviewed by EPA in the CARDs and Technical Support Documents related to the particular topic. DOE responded to all requests for information made by EPA.

15.8.10 2014 Recertification Decision (194.15(a) (7))

      Based on a review and evaluation of the 2014 CRA and supplemental information provided by DOE (Docket ID No. EPA-HQ-OAR-2014-0609) EPA determines that DOE continues to comply with the requirements for Section 194.15(a) (7).

15.9 Requirements (194.15(b))

	(b) "To the extent that information required for a re-certification of compliance remains valid and has been submitted in previous certification or re-certification application(s), such information need not be duplicated in subsequent applications; such information may be summarized and referenced."

15.9.1 Changes in the 2004 CRA (194.15(b))

	DOE provided information in a format similar to that provided for the CCA. This included a main volume with appendices. DOE did summarize topics and provided new information where appropriate. DOE did consolidate some appendices relative to the CCA and did not submit appendices which did not change (e.g., the Geological Characterization Report of Appendix GCR).

15.9.2 Evaluation of Compliance for 2004 Recertification (194.15(b))

	DOE provided relevant information from the CCA and updated information in the 2004 CRA and in response to EPA's requests, including a new performance assessment.

	EPA did not receive any public comments on DOE's continued compliance with the content of compliance recertification application(s) requirements of Section 194.15(b).

15.9.3 2004 Recertification Decision (194.15(b))

	Based on a review and evaluation of the 2004 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2004-0025, Air Docket A-98-49), EPA determines that DOE continues to comply with the requirements for Section 194.194.15(b).

15.9.4 Changes in the 2009 CRA (194.15(b))

	DOE provided information in a modified format compared to the original CCA and the 2004 CRA to make the review by EPA and others generally simpler. DOE adopted the same format that EPA uses to document compliance with regulation 40 CFR 194, EPA's compliance application review documents (CARDs). Rather than use one main document with chapters that describe particular technical topics as done in the CCA and 2004 CRA DOE followed the EPA CARD format where each section of the rule requirements has a specific section dedicated to that requirement. This included a DOE rule section with supporting appendices. DOE continued to summarize topics and provided new information where appropriate. DOE did consolidate some appendices and remove some appendices in the 2009 CRA, especially for information that did not change.

15.9.5 Evaluation of Compliance for 2009 Recertification (194.15(b))

	DOE provided relevant information from the CCA, the 2004 CRA, and updated information in the 2009 CRA and in response to EPA's requests, including a new performance assessment.
	EPA did not receive any public comments on DOE's continued compliance with the content of compliance recertification application(s) requirements of Section 194.15(b).

15.9.6 2009 Recertification Decision (194.15(b))

	Based on a review and evaluation of the 2009 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2009-0330, Air Docket A-98-49), EPA determines that DOE continues to comply with the requirements for Section 194.15(b).

15.9.7 Changes in the 2014 CRA (194.15(b))

      DOE adopted the same format that EPA uses to document compliance with regulation 40 CFR 194, EPA's compliance application review documents (CARDs). Rather than use one main document with chapters that describe particular technical topics as done in the CCA and 2004 CRA DOE followed the EPA CARD format where each section of the rule requirements has a specific section dedicated to that requirement. This included a DOE rule section with supporting appendices. DOE continued to summarize topics and provided new information where appropriate. DOE did remove some appendices and add new ones in the 2014 CRA.

15.9.8 Evaluation of the 2014 Recertification (194.15(b))

      DOE provided relevant information from the CCA, the 2004 CRA, and the 2009 CRA and updated information in the 2014 CRA and in response to EPA's requests, including a sensitivity study to address issues related to the 2014 CRA PA.

	EPA did not receive any public comments on DOE's continued compliance with the content of compliance recertification application(s) requirements of Section 194.15(b).

15.9.9 2014 Recertification Decision (194.15(b))

      Based on a review and evaluation of the 2014 CRA and supplemental information provided by DOE (FDMS Docket ID No. EPA-HQ-OAR-2014-0609), EPA determines that DOE continues to comply with the requirements for Section 194.15(b).

Appendix 14-A
Requirements (194.14)

§ 194.14 Content of compliance certification application.

Any compliance application shall include:

(a) A current description of the natural and engineered features that may affect the performance of the disposal system. The description of the disposal system shall include, at a minimum, the following information:

      (1) The location of the disposal system and the controlled area;
      (2) A description of the geology, geophysics, hydrogeology, hydrology, and geochemistry of the disposal system and its vicinity and how these conditions
      are expected to change and interact over the regulatory time frame.
      Such description shall include, at a minimum:

      (i) Existing fluids and fluid hydraulic potential, including brine pockets, in
      and near the disposal system; and
      (ii) Existing higher permeability anhydrite interbeds located at or near the
      horizon of the waste.
      (3) The presence and characteristics of potential pathways for transport of
      waste from the disposal system to the accessible environment including, but
      not limited to: Existing boreholes, solution features, breccia pipes, and
      other potentially permeable features, such as interbeds.
      (4) The projected geophysical, hydrogeologic and geochemical conditions of the disposal system due to the presence of waste including, but not limited to, the effects of production of heat or gases from the waste.

(b) A description of the design of the disposal system including:

      (1) Information on materials of construction including, but not limited to: Geologic media, structural materials, engineered barriers, general arrangement, and approximate dimensions; and
      (2) Computer codes and standards that have been applied to the design
      and construction of the disposal system.

(c) Results of assessments conducted pursuant to this part.

(d) A description of input parameters associated with assessments conducted
pursuant to this part and the basis for selecting those input parameters.

(e) Documentation of measures taken to meet the assurance requirements of
this part.

(f) A description of waste acceptance criteria and actions taken to assure adherence
to such criteria.

(g) A description of background radiation in air, soil and water in the vicinity
of the disposal system and the procedures employed to determine such
radiation.

(h) One or more topographic map(s) of the vicinity of the disposal system.
The contour interval shall be sufficient to show clearly the pattern of surface
water flow in the vicinity of the disposal system. The map(s) shall include
standard map notations and symbols, and, in addition, shall show boundaries
of the controlled area and the location of any active, inactive, and abandoned
injection and withdrawal wells in the controlled area and in the vicinity of
the disposal system.

(i) A description of past and current climatologic and meteorologic conditions
in the vicinity of the disposal system and how these conditions are
expected to change over the regulatory time frame.

(j) The information required elsewhere in this part or any additional information,
analyses, tests, or records determined by the Administrator or the Administrator's authorized representative to be necessary for determining compliance with this part.

Appendix 14-A
Requirements (194.14)

§ 194.14 Content of compliance certification application.

Any compliance application shall include:

(a) A current description of the natural and engineered features that may affect the performance of the disposal system. The description of the disposal system shall include, at a minimum, the following information:

      (1) The location of the disposal system and the controlled area;
      (2) A description of the geology, geophysics, hydrogeology, hydrology, and geochemistry of the disposal system and its vicinity and how these conditions
      are expected to change and interact over the regulatory time frame.
      Such description shall include, at a minimum:

      (i) Existing fluids and fluid hydraulic potential, including brine pockets, in
      and near the disposal system; and
      (ii) Existing higher permeability anhydrite interbeds located at or near the
      horizon of the waste.
      (3) The presence and characteristics of potential pathways for transport of
      waste from the disposal system to the accessible environment including, but
      not limited to: Existing boreholes, solution features, breccia pipes, and
      other potentially permeable features, such as interbeds.
      (4) The projected geophysical, hydrogeologic and geochemical conditions of the disposal system due to the presence of waste including, but not limited to, the effects of production of heat or gases from the waste.

(b) A description of the design of the disposal system including:

      (1) Information on materials of construction including, but not limited to: Geologic media, structural materials, engineered barriers, general arrangement, and approximate dimensions; and
      (2) Computer codes and standards that have been applied to the design
      and construction of the disposal system.

(c) Results of assessments conducted pursuant to this part.

(d) A description of input parameters associated with assessments conducted
pursuant to this part and the basis for selecting those input parameters.

(e) Documentation of measures taken to meet the assurance requirements of
this part.

(f) A description of waste acceptance criteria and actions taken to assure adherence
to such criteria.

(g) A description of background radiation in air, soil and water in the vicinity
of the disposal system and the procedures employed to determine such
radiation.

(h) One or more topographic map(s) of the vicinity of the disposal system.
The contour interval shall be sufficient to show clearly the pattern of surface
water flow in the vicinity of the disposal system. The map(s) shall include
standard map notations and symbols, and, in addition, shall show boundaries
of the controlled area and the location of any active, inactive, and abandoned
injection and withdrawal wells in the controlled area and in the vicinity of
the disposal system.

(i) A description of past and current climatologic and meteorologic conditions
in the vicinity of the disposal system and how these conditions are
expected to change over the regulatory time frame.

(j) The information required elsewhere in this part or any additional information,
analyses, tests, or records determined by the Administrator or the Administrator's authorized representative to be necessary for determining compliance with this part.

Appendix 15-A
Requirements (194.15)

§ 194.15 Content of compliance re-certification application(s).

(a) In submitting documentation of continued compliance pursuant to section 8(f) of the WIPP LWA, the previous compliance application shall be updated to provide sufficient information for the Administrator to determine whether or not the WIPP continues to be in compliance with the disposal regulations. Updated documentation shall include:

 All additional geologic, geophysical, geochemical, hydrologic, and meteorologic information;

 All additional monitoring data, analyses and results;

 All additional analyses and results of laboratory experiments conducted by the Department or its contractors as part of the WIPP program;

 An identification of any activities or assumptions that deviate from the most recent compliance application;

 A description of all waste emplaced in the disposal system since the most recent compliance certification or re-certification application. Such description shall consist of a description of the waste characteristics and waste components identified in §§ 194.24(b)(1) and 194.24(b)(2);

 Any significant information not previously included in a compliance certification or re-certification application related to whether the disposal system continues to be in compliance with the disposal regulations; and

      (7) Any additional information requested by the Administrator or the

            (b) To the extent that information required for a re-certification of compliance remains valid and has been submittedin previous certification or recertification application(s), such information need not be duplicated in subsequent applications; such information may be summarized and referenced.

                                 Appendix 15-B

                        Responses to CRA-2014 Comments

Issue 1:	Inadvertent drilling intrusion into the repository and pressurized brine

L. Chaturvedi (7/14/2015):
The comments in this document are an expansion of the verbal comments presented by
the author at the Environmental Protection Agency's (EPA) public meeting on the 2014
Waste Isolation Pilot Plant (WIPP) Compliance Recertification Application (CRA) in
Albuquerque on June 17, 2015.

Many parameters are used in the 10,000 year probabilistic risk assessment (formally
known as "performance assessment" or P.A.) to demonstrate compliance with the EPA
standards (40 CFR 191 and 40 CFR 194) for the WIPP nuclear waste repository. One of
these parameters is PBRINE which specifies the probability that an inadvertent drilling
intrusion into the excavated region of the repository encounters pressurized brine in the
Castile Formation located about 227 meter (750 feet) below the repository. The original
1996 WIPP Compliance Certification Application (CCA) used a uniform distribution
between 0.01 and 0.60 with a mean value of 0.305 for this parameter. In other words,
the Department of Energy (DOE) estimated that the probability of encountering a
pressurized brine reservoir underlying the WIPP repository was between 1 and 60%.
Performance assessment calculations were performed using this range for this
parameter in 1996 P.A. While the values of other parameters were revised in the 2004
and 2009 CRA, the value of PBRINE was not changed. In the 2014 CRA, however, the
DOE has proposed changing the value of PBRINE to a range of 0.063 to 0.19, with a
mean (and default value) of 0.127. In other words, DOE has reduced the probability of
brine encounter from a mean of 30% from CCA until now, to 12.7% in the 2014 CRA.
(Kirchner et al., 2012).

In response to questions/comments from EPA regarding this change, the DOE has
repeated the arguments given by Kirchner et al. (2012). This document analyses the
DOE position and makes a recommendation.

Recommendation
The justifications provided for changing the numerical value distribution for this
parameter, that has been used for the past 18 years in the WIPP P.A., are invalid. If the
issue is to be reopened, however, closer attention needs to be paid to the data from the
deepening and testing of WIPP-12 well in 1982. That data indicates higher rather than
lower probability (compared to that used in the CCA and two CRAs) of pressurized
Castile brine encounter under the WIPP repository. Based on the data from the testing
of WIPP-12 and the results of the Time Domain Electro-Magnetic (TDEM) geophysical
survey (The Earth Technologies Corporation,1988), the New Mexico Environmental
Evaluation Group (EEG) recommended a fixed value of 0.6 (60%) for this parameter.
(Neill et al., 1998, Section 2.11). It is recommended that this value be used instead of
the value proposed by DOE.

A General Observation
A general observation appears pertinent here. A case can be made that most, if not all,
the changes proposed by DOE since the EPA's certification decision in 1998, and
accepted by EPA and New Mexico NMED, have been in the direction of less
conservatism. These changes have generally been made in the name of cost-saving,
efficiency, or removal of redundancy. These changes include the value/range of P.A.
parameters, other assumptions in the P.A., frequency and rigor of inspections, criteria
for waste acceptance and documentation, monitoring, and materials and design used
for closing and sealing the underground openings. There was much discussion at the
public meeting on June 17, 2015 regarding the connection between the Valentine Day
2014 accident/incident at WIPP and the CRA. While both DOE and EPA correctly
pointed out that the CRA is for post-closure long-term safety, whereas the accident was
during operational period, perhaps the connection between the two lies in this trend
towards less conservatism. While the bad decisions that reduce the operational safety
may result in an accident in our lifetime and thus allow us to take remedial measures,
the impact of decisions made for long-term P.A. may not be apparent for many
generations in the future and therefore require more care now.

Discussion
The case for using the lower probability for the parameter PBRINE in the 2014 CRA is
outlined in Kirchner et al. (2012). This Sandia National Laboratory (SNL) memorandum
bases its recommendation for the lower probability on three factors:
      :: Additional drilling of oil and gas wells in the vicinity of WIPP and reported encounters with Castile brine.
      :: Re-examination of Time Domain Electro-Magnetic (TDEM) geophysical survey data from 1987.
      :: Assumption of occurrence of brine only in vertical fractures in the upper Castile
      anhydrite Formation (which implies that the volume in a given "brine pocket" would be limited.)
There are a number of problems in the Kirchner et al. (2012) analysis and these are
discussed below.

Additional Drilling Data
During the 1980s and 90s, the EEG repeatedly pointed out in published reports, papers,
and presentations (Chaturvedi, et al., 1997) that WIPP is located in a resource rich area
and the 4 mile by 4 mile WIPP site would be a conspicuous island essentially without
wells in the middle of thousands of oil and gas wells occupying the land surrounding it.
This outcome has come sooner than expected and one only has to take a look at Fig.1
of Kirchner et al. (2012) to be convinced that WIPP is situated in the middle of a prolific
oil and gas field, which may attract the attention of future drillers to the relatively virgin
land in the middle, the 4 mile by 4 mile WIPP site. The few gaps remaining in the
immediate vicinity of the WIPP site boundary are due to shallower potash resources set
aside by New Mexico and federal authorities. Now, the DOE has turned this negative
aspect of the WIPP site to calculate a lower probability of encountering the Castile brine
by a future driller into the WIPP area, by stating that very few of the new wells have
encountered brine. It is important to note that neither Kirchner et al. (2012) nor the
recent DOE response to EPA's questions on this subject, have outlined any systematic
process of collecting the brine encounter data from the commercial drillers. It is a well-known fact that the commercial oil and gas drillers aim for a much deeper zone and that
an encounter with pressurized brine at a shallower zone is only a nuisance that they
would try to overcome as soon as possible without making a fuss and publicizing it.
Even if the DOE had an understanding with some operators, it would be a serious
economic hardship for them to stop drilling and let DOE observe or test the brine. They
are only interested in getting to the target horizon at depth as soon as possible and
would avoid getting a government agency involved in the operation, unless absolutely
required with stiff penalties for not complying, or incentives to do so. No such
requirement or incentives appear to be in place.

Kirchner et al. (2012) has skirted this issue by repeating an argument used by Powers
et al.(1996), who argued that:
"pressurized brine pockets of a size sufficient to impact the repository would produce a
large enough flow as to threaten overflow of the surface storage pits, and hence require
measurement and intervention by the drillers. Therefore, such "non-reported" brine
intercepts are of no consequence to WIPP performance."
The argument does not make sense, because while the driller would have to deal with
such an encounter, why would they inform the WIPP folks or another government
agency? And wouldn't this un-reported encounter influence the probability calculation?
Also, an estimate of the probability of encountering brine should include lower artesian
pressure encounters that may not be a major nuisance to the driller.

The TDEM Data
The second argument in favor of decreasing the probability is the unreliability of the