July 4, 2008

Mr. James Bearzi, Chief

New Mexico Environment Department

Hazardous Waste Bureau

2905 Rodeo Park Drive East, Building 1

Santa Fe, New Mexico 87505-6303

 

Dear Mr. Bearzi,

Citizen Action and Registered Geologist Robert Gilkeson are in receipt of your June 23, 2008 letter that was an answer to Unresolved Issues Related to the Sandia National Laboratories Mixed Waste Landfill (June 2, 2008 Citizen Action Letter). All of the issues are still unresolved by your June 23, 2008 letter. Factual matters of record are not addressed by your letter 

The purpose of this letter is to bring attention to the facts on the following topics.

- 1. The historical documents in the New Mexico Environment Department (NMED) Administrative Record (AR) are proof that there were never any reliable monitoring wells at the Mixed Waste Landfill (MWL). NMED has not enforced the requirements under RCRA for a reliable network of monitoring wells installed at the point of compliance for either of the two groundwater flow systems - 1) the water table in the alluvial fan sediments (AFS), and 2) the productive Ancestral Rio Grande (ARG) sediments located below the AFS. (See, e.g., 40 CFR 271.22(a)(2)(i) ).

- 2. NMED has not enforced the requirement under RCRA to determine the groundwater flow rate and direction for the two groundwater flow systems below the MWL.

- 3. The high concentrations of dissolved nickel in two of the MWL monitoring wells are evidence of a plume at the water table below the MWL. NMED is not enforcing the requirement of the Resource Conservation and Recovery Act (RCRA) to investigate the nature and extent of the plume.

- 4. Citizen Action and Registered Geologist Robert H. Gilkeson repeat the request for NMED to have the Environmental Protection Agency (EPA) Kerr Research Laboratory do a detailed review of the Moats Evaluation or retract it.

- 5. The NMED claim that a dirt cover will protect public health from the wastes buried in the MWL is in contradiction to the NMED claim that an identical dirt cover will not afford protection of public health for a much smaller disposal site at the Los Alamos National Laboratory.

- 6. Rather than present a truthful description of a failed monitoring network for the MWL at the public hearing on the soil cover, NMED put public health and safety at risk by presenting false data that the monitoring wells were at appropriate locations and that they produced reliable water quality data proving there was no contamination of groundwater

- Topic 1. There were never any reliable monitoring wells at the Sandia MWL.

Citizen Action and Robert Gilkeson disagree with the disingenuous statement in your June 23, 2008 letter that "[t]he totality of evidence indicates that wells at the MWL have provided representative and reliable hydrochemical data for making a decision on the MWL remedy."

In fact, the “totality of the evidence” in the NMED AR for the MWL is that from day one, the NMED was aware that there were never any reliable monitoring wells at the MWL. Figure 1 shows the locations of the seven monitoring wells at the Sandia MWL. The first four monitoring wells (BW1, MW1, MW2 and MW3) were installed in 1988 and 1989 based on the assumption that the direction of groundwater flow at the water table below the MWL was to the northwest. However, the water levels measured in the four wells over all time from when the wells were installed to the present, determined that the direction of groundwater flow at the water table was always to the southwest and therefore, well MW3 was the only downgradient monitoring well.

DOE/SNL knew in May 1991 from the Tiger Team Assessment of SNL ((p. 3-59) that

“The number and placement of wells at the mixed waste landfill is not sufficient to characterize the effect of the mixed waste landfill on groundwater.”

The deficiencies in the monitoring well network that were described by the DOE Tiger Team were never resolved at any time to provide reliable data for selection of the dirt cover as an appropriate remedy or for meeting the requirements of a risk assessment that was protective of public health.

In 1994, the U.S. Environmental Protection Agency (EPA) issued a Notice of Deficiency (NOD) that described the mistakes in the locations of monitoring wells because of the southwest direction of groundwater flow. The 1994 EPA NOD is NMED AR 00643-006460. The pertinent excerpt from the 1994 EPA NOD is pasted below

"Based on the southwest gradient flow of groundwater, the MWL monitoring wells are located crossgradient instead of downgradient from the MWL; therefore, contaminants emanating from the MWL may not be detected in the monitoring wells" (p.6, NMED AR 006440).

 Nevertheless, NMED has always allowed DOE/SNL to publish annual groundwater monitoring reports that make the claim that the monitoring wells are reliable for detection of contaminants emanating from the MWL. Two examples of the "coverup" of the unreliable data collected over the years from the network of MWL monitoring wells are the excerpts pasted below from the DOE/SNL Annual Groundwater Reports for 2000 and 2008 for groundwater monitoring data from the Sandia Mixed Waste Landfill.

From the 2000 DOE/SNL Report:

"The MWL has a monitoring network of seven wells. The monitoring network includes one upgradient (background well), five downgradient/crossgradient wells, and one onsite well. Groundwater at the MWL generally flows from east to west with a northwest component. NMED approved of a change in sampling frequency to annual based on the fact that no groundwater contamination from the MWL has been detected in groundwater throughout the course of groundwater monitoring at the landfill." (p. 3-14 to 3-15)

From the 2008 DOE/SNL Report:

"Groundwater in the area of the MWL has been extensively characterized since 1990 for major ion chemistry, volatile organic compounds (VOCs), nitrate, metals, radionuclides, and perchlorate. Sixteen years of data indicate that groundwater has not been contaminated by releases from the MWL. The MWL monitoring well network consists of seven wells... This network includes one background well (MWL-BW1), one on-site well (MWL-MW4), and five downgradient or cross-gradient wells (MWL-MW1, MWL-MW2, MWL-MW3, MWL-MW5, and MWL-MW6)." (p. 1-1)

 The DOE/SNL reports do not inform the reader of the NMED Notice of Deficiency issued in 1998 that described there was only one downgradient well (well MWL-MW3), and that the on-site well (MWL-MW4) never produced reliable contaminant data. Nor does DOE/SNL inform that there was no upgradient monitoring well to characterize background water quality. Instead, the 2000 report states that NMED has approved an annual sampling schedule because the network of monitoring wells have not detected any contamination. The 2008 DOE/SNL monitoring report informs the reader that "sixteen years of data indicate that groundwater has not been contaminated by releases from the MWL. However, over the years, nothing was done to address the fact that monitoring well MW3 was the only downgradient monitoring well and the onsite well MW4 also did not produce reliable and representative water samples for detection of contamination at the water table below Trench D.

The unreliable network of monitoring wells at the MWL is described in detail in the October 30, 1998 NMED Notice of Deficiency. NMED, subsequent to your assumption of duties as Hazardous Waste Bureau (HWB) Chief did not resolve the deficiencies in the 1998 NOD. Our previous letters have repeatedly called to your attention deficiencies in the monitoring network. You fail to respond with technically defensible reasons why the historical data from the defective network of monitoring wells should be acceptable for decisions on the remedy for the MWL.

 NMED NOD (October 30, 1998 - AR 010983 to 010990).

- P.2-3 #37  – “The water-table map indicates that there is only one  downgradient monitor well at the Mixed Waste Landfill. Normally, a minimum of three downgradient wells is required for an adequate  detection monitoring system." 

To the present time, well MW3 was always the only downgradient well installed to monitor contamination at the water table. However, well MW3 never produced reliable and representative water samples because of 1) the mud-rotary drilling method invaded the sampling zone with bentonite clay drilling mud, 2) corrosion of the stainless steel well screen (known from 1992¹), and 3) the water sampling methods that pumped the well to dryness and collected samples seven days later from the water that trickled into the well. 

Both the bentonite clay used in the mud-rotary drilling and the corroded stainless steel screens have properties to prevent the detection of many contaminants of potential concern for the wastes buried in the MWL. In addition, the improper sampling methods aerated the water samples and made the samples unreliable for detection and measurement of many contaminants including VOCs (solvents), trace metals and the radionuclides including plutonium, americium, uranium, cesium, strontium-90, etc.

A 1993 report by the NMED Oversight Bureau described the unreliable water quality data produced from the high-flow sampling methods that were used in the MWL monitoring wells, but over the years to the present time the high-flow purge to dry sampling methods were always used. The pertinent excerpt from the 1993 NMED Oversight Bureau Report is pasted below:

Initial Assessment of the Ground-water Monitoring Programs at Sandia National Laboratories and the Inhalation Toxicology Research Institute, KAFB, New Mexico (June 1993 NMED DOE Oversight and Monitoring Program, p.11) states: “Concerns/Recommendations:

3. ITRI has demonstrated sampling practices in the past that do not adequately follow EPA guidelines resulting in the following problems:

a)       excessive flow rates during VOC sampling

b)       entrained air during VOC sampling and

c)       purged volumes that are estimated instead of measured.”

The 1998 NMED NOD ordered the installation of two new monitoring wells west of the MWL with screens installed across the water table. The pertinent excerpts from the 1998 NOD are pasted below:

P.4 #37 – "After the two new wells [aka wells MW5 and MW6] are installed and the water-table map is revised, the HRMB will reevaluate the adequacy of the detection monitoring system."

P. 7 #39—It is hoped that a more reliable horizontal gradient can be determined after the two new wells [MW5 and MW6] are installed.”

The locations of wells MW5 and MW6 are displayed on Figure 1. Figure 2 is a schematic of the installation features of all seven monitoring wells at the MWL. Figure 2 shows that the screens in well MW5 and MW6 were installed greater than 35 feet and greater than 50 feet, respectively, below the water table. The two wells are not useful either for detection of contamination at the water table nor for improving knowledge of the direction of groundwater flow at the water table or the hydraulic gradient at the water table. The two wells did not meet their intended purpose, but NMED has not required replacement of either well. Instead, NMED has allowed DOE/SNL to present water quality data from the two wells as reliable to support the claim that the MWL has not contaminated the groundwater.

Additional problems that have prevented well MW5 from producing reliable and representative water samples is that 1) mistakes in well construction contaminated the screened interval with the bentonite clay/cement backfill materials and 2) the well screen is installed across both geologic formations - the fine-grained sediments and the productive Ancestral Rio Grande Deposits. The well is not useful for measuring the hydraulic properties of either formation or the water quality in either formation.

 It was a mistake that NMED did not order DOE/SNL to replace wells MW5 and MW6 in 2000 because the wells did not meet the requirements of the 1998 NOD. The mistake is exacerbated because NMED has allowed DOE/SNL to use the wells as reliable downgradient detection wells. In addition, NMED has not enforced the requirement of the NMED Sandia Consent Order (April 29, 2004) for replacement of the two wells. The requirement in Section VIII.A on page 63 of the Consent Order is pasted below:

"In the event of a well or piezometer failure, or if a well or piezometer is any way no longer usable for its intended purpose, it must be replaced with an equivalent well or piezometer." 

The required action by the NMED 1998 NOD and the Sandia Consent Order is for well MW5 to be plugged and abandoned and replaced with a new well at the point of compliance with the screen installed in the productive ARG sediments. Figure 2 shows that well MW6 is the only monitoring well installed with a screen only in the ARG sediments. RCRA Subpart F and the Consent Order require the installation of monitoring wells in the ARG sediments at the point of compliance. Well MW6 should be retained for monitoring water levels but the well is too distant from the MWL to meet RCRA requirements for a point of compliance detection monitoring well. NMED should order DOE/SNL to install a minimum of three downgradient monitoring wells in the ARG sediments that meet RCRA point of compliance requirements and one background monitoring well in the ARG sediments at an appropriate upgradient location.

The 1994 EPA NOD describes the purpose for monitoring well MW4:

 "[Well] MWL-MW4 was installed in March 1993 to resolve uncertainties regarding the direction and rate of groundwater flow beneath the MWL and to help evaluate the adequacy of the existing well network." (p. 6 - AR00640) 

However, the 1998 NMED NOD brought attention to the mistakes in the installation of monitoring well MW4 that prevented the well from ever providing reliable and representative water samples for detection of contamination at the water table below Trench D, where 270,000 gallons of reactor coolant water were dumped. The pertinent excerpt from the 1998 NOD is pasted below: 

P. 7 #38 – Well MW4. “The top of the upper screen of MW4 is located approximately 22 ft below the water table. MW4 is of no value for determining the elevation of the water table (and therefore the horizontal direction of ground-water flow and the horizontal gradient).” “Also, because the top of the upper screen of MWL-MW4 is located 22 ft below the water table, the well is of little value for detecting any groundwater contamination." 

Nevertheless, the water quality data from well MW4 were presented in DOE/SNL reports over the past decade as important knowledge that contaminants from the MWL have not contaminated groundwater. NMED should have required replacement of well MW4 when the mistake in well construction was first recognized. An additional requirement to replace well MW4 is Section VIII in the NMED Sandia Consent Order:

"In the event of a well or piezometer failure, or if a well or piezometer is any way no longer usable for its intended purpose, it must be replaced with an equivalent well or piezometer." (p. 63 in Section VIII.A)

- Topic 2. NMED has not enforced the requirement under the HSWA Permit or RCRA to determine the groundwater flow rate and direction for the two groundwater flow systems below the MWL.  

The 1994 EPA NOD described the monitoring well network that was required to determine the groundwater flow rate and direction for the two groundwater flow systems below the MWL. The pertinent excerpt from the 1994 NOD is pasted below: 

"HSWA Permit Section R. 3. b.1) e) requires the facility to describe the representative water level based on data obtained from groundwater monitoring wells installed upgradient and downgradient of the potential contaminant source (i.e., MWL)." (p. 5 - AR 005439) 

The requirement in RCRA 40 CFR §264.98(e) is pasted below:

(e) The owner or operator must determine the ground-water flow rate and direction in the uppermost aquifer at least annually.

Topic 1 presents the proof that an appropriate network of monitoring wells was never installed at the MWL for determining the groundwater flow rate or direction in either flow system - 1) at the water table in the alluvial fan sediments (AFS) or 2) in the deeper Ancestral Rio Grande (ARG) sediments. 

In addition, the hydraulic properties of either the AFS or the ARG sediments were never accurately measured. The inaccurate and unreliable hydraulic properties are presented in the 2002 Sandia Report by Goering et al., (Sandia Report SAND2002-4098). 

Goering et al, (2002) used data from pumping tests that were identified in the 1998 NMED NOD as unreliable. The pertinent excerpt from the 1998 NMED NOD is pasted below:

P.7 #50 – "The pumping tests for monitor wells MWL-BW1, MWL-MW1, MWL-MW2, MWL-MW3, and MWL-MW4 (upper screen) appear to have failed because the yield of each well was too small to permit a successful pumping test to be conducted. The pumping test conducted on MWL-MW4 (lower screen) also appears to have failed, possibly because the pumping rate was not high enough to stress the aquifer. Taking into account that the plots are semi-log, none of the drawdown curves appears to have a form which matches that of a type curve. Therefore, the reported values for hydraulic conductivity and transmissivity are considered by the HRMB [previous name of NMED HWB] to be unreliable." 

Additional reasons why incorrect hydraulic conductivity values were determined from the 1994 pumping tests and the later slug tests performed in 2001 in wells BW1, MW2, and MW3 are: 1) the mud-rotary drilling method that was used to install the monitoring wells and 2) the pump to dry sampling methods that caused damage to the ability of the wells to produce water. The deleterious effects of the mud-rotary drilling method is described in the May 27, 1994 letter to Carlson, DOE, from Benito Garcia, Chief of the NMED HRMB, that stated: 

P. 3 #11. …"The hydraulic conductivity of the aquifer is unknown; the poor capacity of the wells at the MWL may have more to do with the drilling methodology (mud-rotary) having a detrimental effect on the hydraulic characteristics of the aquifer sediments than natural conditions." (AR at 006224).  

P.3 #13. "Mud rotary is considered to be the worse [sic] drilling technology available for the installation of ground water monitoring wells. This is due to the potential detrimental impacts to the hydraulic characteristics of aquifer sediments and water quality. Other better drilling technologies were in existence at the time the MWL wells were drilled." (AR at 006224).

The findings in the 1994 letter by Chief Garcia that monitoring wells drilled with the mud-rotary method would not provide accurate measurements of hydraulic conductivity is well understood in the monitoring-well industry. It was a mistake for NMED to allow new slug tests to be performed in the monitoring wells in 2001 and to use all of the pump tests and slug tests to calculate hydraulic conductivity values in Goering et al (2002).

A further mistake in Goering et al (2002) was the performance of slug tests in 2001 in the lower screen in well MW4 and in well MW5. The hydraulic conductivity values measured in the two screened intervals were used in Goering et al (2002) to represent the hydraulic properties of the Ancestral Rio Grande Sediments. However, Figure 2 shows that in both wells, most of the length of the screen is installed in the fine-grained alluvial fan sediments. The hydraulic conductivity values measured in the two screened intervals are an average of the AFS and ARG sediments but Goering et al (2002) made the mistake to use the spurious values as representative of the ARG sediments.

 NMED issued a Notice of Violation to the Waste Isolation Pilot Plant (WIPP) (November 26, 2007) for failure to “monitor the hydraulic gradients of the hydrological flow systems at WIPP accurately…” on an annual basis. The MWL has never met this requirement on any basis, let alone an annualized basis. The US EPA 1994 NOD noted site-specific water level maps should be provided for the MWL and that the Module IV Section R was not being complied with. Site-specific water level maps were never provided for the MWL up to the present time.

Figure 3 shows that the regional Sandia groundwater map continues to be used for the MWL without a site specific map as required by RCRA (40 CFR 264.98 (e) ). Note that Figure 3 does not present the water levels measured in wells MW4, MW5 and MW6 because the screens in the wells are installed too deep below the water table. The level data posted on Figure 3 for MW1, MW2 and MW3 specifically show that the direction of groundwater flow at the water table below the MWL is to the southwest. However, the contour lines on Figure 3 continue to misrepresent the groundwater flow to be to the northwest thus misinforming about the site specific flow of the groundwater for either of the two flow systems beneath the MWL. RCRA requires accurate representation of both flow systems and that has never been accomplished. 

NMED is fining the Waste Isolation Pilot Plant (WIPP) for not having characterization of the water levels in a perched zone. NMED is ignoring the violation of the MWL to not have characterization on an annual basis for the direction and rate of groundwater flow at the water table in the AFS sediments and for the regional groundwater in the ARG sediments. NMED thus shows lack of consistency in its enforcement for WIPP and the absence of enforcement for the Sandia MWL.

NMED should require DOE/SNL to install networks of monitoring wells at the MWL with drilling methods that do not damage the hydraulic properties of the AFS and ARG sediments. NMED should require properly designed pumping tests in all of the new monitoring wells. NMED should order DOE/SNL to retract Goering et al (2002). In fact, NMED should issue a Notice of Violation to DOE/SNL for failure to determine the groundwater flow rate and direction in the two groundwater flow systems below the MWL on an annual basis as required by RCRA 40 CFR §264.98(e).

- Topic 3. The high concentrations of dissolved nickel in two of the MWL monitoring wells is evidence of a contaminant plume at the water table below the MWL. NMED is not enforcing the requirement of the Resource Conservation and Recovery Act (RCRA) to investigate the nature and extent of the plume. 

The 1998 NMED NOD identified a release of nickel to the subsurface below the MWL. The pertinent excerpts are pasted below:

P.2 #23 D. "There is evidence of possible nickel contamination at concentrations ranging from 11.8-23.5 mg/kg in soil samples collected at depths of about 70-100 ft." 

P.3, #46 “Data derived from soil sampling beneath the landfill indicate that nickel is a possible contaminant at the MWL.” 

Table 1 presents the nickel concentrations in water samples produced from the four monitoring wells with stainless steel screens installed across the water table. Elevated concentrations of dissolved nickel and an increase in dissolved concentrations over time were measured for the water samples collected from well MW1 compared to the water quality data from the other three wells. Data over time from the monitoring wells BW1 and MW2 that are most distant from the MWL show nickel concentration at low levels compared to the high and increasing levels measured over time in well MW1 and more recently in well MW3. For the most recent sampling event, the measured concentration of dissolved nickel were high values 284 ug/L in well MW1 and 120 ug/L in MW3 compared to a very low value of 5.41 ug/L in well MW2.

Table 1. Total and Dissolved Nickel Measured in the Water Samples Produced From Monitoring Well MWL-MW1, -MW-3, -BW1 and - MW2 at the Sandia Mixed Waste Landfill. 

- Well MW1 - Well MW3 - Well BW1 - Well MW2

Nickel (ug/L) Nickel (ug/L) Nickel (ug/L) Nickel (ug/L)

Date T / D T / D T / D T/D

 

09 - 90 46 / 43 ND^a<40/ND< 40 ND<40/ND<40 ND<40/ND<40

01 - 91 NA^b / NA NA / NA NA / NA NA / NA

04 - 91 NA / NA NA / NA NA / NA NA / NA

10 - 91 NA / NA NA / NA NA / NA NA / NA

07 - 92 150 / 63 66 / 43 ND<40/ND<40 ND<40 / ND<40 01 - 93 78 / NA 26 (j)^c / NA ND < 40 / NA ND < 40 / NA 04 - 93 97 / 94 37 (j) / 33 (j) 7.5 / 16 14 (j) / 13 (j) 11 - 93 95 / NA ND < 40 / NA ND < 40 / NA ND < 40 / NA

05 - 94 110 / NA ND <40 / NA NA / NA ND < 40 / NA

10 - 94 130 / NA ND < 40 / NA 9.8 (j) / NA ND < 40 / NA

04 - 95 120 / NA NA / NA 9.3 (j) / NA 7.5 (j) / NA

10 - 95 107 / NA 7.99 (j) / NA 1.96 (j) / NA NA / NA

04 - 96 145 / NA 3.67 (j) / NA ND < 0.81 / NA 3.42 (j) / NA

04 - 97 NA / NA NA / NA NA / NA NA / NA

10 - 97 NA / NA NA / NA NA / NA NA / NA

04 - 98 398 / 538 36.2 / 28.5 2.9 (j) / NA 5 (j) / 4

11 - 98 490 / 467 18 / 18.3 7.19 / 9.47 4.49 / 3.42

04 - 99 266 / 313 31 / 31.3 12.8 / 14.3 5.31 / 4.37

04 - 00 279 / 281 25.1 / NA 16.5 / NA 124 / NA

04 - 01 252 / NA 14.1 / NA 191 / NA 88.2 / NA

04 - 02 265 / NA 96.1 / NA 13.6 / NA 89.7 / NA

04 - 03 374 / NA NA / 69.4 26.6 / NA 52 / NA

04 - 04 401 / NA 56 / NA 33.2 / NA 10.5 / NA

04 - 05 424 / 405 17.3 / 11.5 35.5 / NA 10.5 / NA

04 - 06 477 / NA 157 / NA NA / NA 6. 76 / NA

04 - 07 436 / 284 84.8 / 120 NA / NA 7.34 / 5.41

 

T = Concentration of total nickel measured in an unfiltered water sample

D = Concentration of dissolved nickel measured in a filtered water sample

ug/L = micrograms per liter or parts per billion

ND^a = nickel was not detected at the listed minimum detection level

NA^b = nickel was not analyzed in samples collected on this date

(j)^c = the listed value is an estimated value

- The NMED approved background for total and dissolved nickel in

groundwater is 28 ug/L.

- In 1974, EPA set the drinking water standard for nickel at 100 ug/L. EPA remanded the drinking water standard for nickel on February 9, 1995 and has not set a new standard.

- The World Health Organization Guideline Value is that drinking water shall not contain nickel at concentrations greater than 30 ug/L.

If all the dissolved nickel were from corrosion of the stainless steel well screens, similar concentrations of nickel would be expected in all the wells. The markedly higher levels of dissolved nickel measured first in well MW1and now in MW3 are evidence of a nickel plume at the water table below the MWL. Other contaminants may be present in the plume but are masked from detection because of the corroded screens and the improper high-flow purge to dry sampling methods. The plume needs to be investigated which requires the installation of a new monitoring well to the north of the MWL at the point of compliance in alignment with well MW1. NMED has ordered MW1 to be plugged and abandoned. NMED should additionally order to install a new monitoring well on the north side of the dump at the point of compliance.

 There is no technical basis for the NMED acceptance over the past fifteen years of the claim by DOE/SNL that the high nickel values are only from the corroded well screens. In addition, the corroded screens have well-known properties that prevented the wells from producing reliable and representative water samples. Another issue is the inconsistent practice by the NMED at Sandia and at LANL. When LANL recently claimed that corrosion was responsible for the high levels of nickel measured in one of the LANL characterization wells, NMED found the LANL position to be "speculation" and ordered LANL to replace the well.² NMED should have required replacement of the four wells at the Sandia MWL at first "speculation" by DOE/SNL that the high levels were because of corrosion.

- Topic 4. Citizen Action and Registered Geologist Robert H. Gilkeson repeat the request for NMED to have the Environmental Protection Agency (EPA) Kerr Research Laboratory do a detailed review of the Moats Evaluation

NMED stated it stands behind the conclusions of the report Evaluation of the Representativeness and Reliability of Groundwater Monitoring Well Data, Mixed Waste Landfill, Sandia National Laboratories, by W. Moats, et al., November 2006 (Moats Evaluation). Registered Geologist Robert Gilkeson relies on his own findings that are borne out in the findings of the EPA Kerr Laboratory, and the National Academy of Sciences (NAS) to conclude that the Moats Evaluation is a failed analysis for the assessment of the reliability and representativeness for any well at the MWL. 

The Moats Evaluation was modeled after the statistical strategy used in the LANL Well Screen Analysis Report (WSAR) for the assessment of the reliability of the LANL characterization wells. However, both the EPA Kerr Lab³ and the NAS⁴ wrote reports that the assessment scheme in the WSAR was not credible. The Moats Evaluation was a study of only the water quality data produced from the MWL wells. However, two reports by the EPA Kerr Laboratory and a report by the National Academies of Science present conclusions that water quality data alone cannot be used to prove that monitoring wells produce water samples that are reliable for knowledge of groundwater contamination. 

In fact, the assessment scheme in the Moats Evaluation is even less credible because the Moats Evaluation made an important modification to the LANL scheme. The modification was to calculate a median value for all of the analytical data for selected discrete constituents collected over time from each of the MWL wells. An important constituent in the Moats Evaluation was the trace metal cadmium. However, as a general rule cadmium concentrations were very low and often not detected in the water samples. The Moats Evaluation made an assumption that cadmium was always present in the water samples from the MWL wells and made cadmium appear to be always present. When cadmium was not detected in a water sample, the Moats Evaluation made cadmium appear to be present by assigning a value of 50% of the detection limit.

In fact, the new mineralogy created by the mud-rotary drilling and the corroded stainless steel screens may have adsorbed the trace metal constituents such as cadmium and completely removed them from the groundwater. The fabrication in the Moats Evaluation that the constituents were still present is unacceptable scientifically. The purpose of the Moats Evaluation was to determine if the wells were reliable, but that purpose was defeated by the improper statistical methodology of assuming a constituent such as cadmium being present when the analytical method said there was no detection of the constituent. The proper method for assessing the wells would have been a trend analysis comparing changes in measured concentration of constituents such as cadmium that occurred from the first to the most recent water samples. The Moats Evaluation did not include any trend analysis of the water quality data.

We repeat the request of Citizen Action, Mr. Gilkeson and the Albuquerque Groundwater Protection Advisory Board that the Moats Evaluation be sent to the EPA Kerr Laboratory for review or that it be retracted. At this time, the EPA Kerr Lab is reviewing the latest revision of the LANL Well Screen Analysis Report (WSAR). Earlier reviews of the WSAR rejected the statistical methodology used by the Moats Evaluation. The Moats Evaluation has become NMED's coverup for use of the unreliable data from the network of MWL monitoring wells to defend the decision for the use of the soil cover. Please inform Citizen Action of NMED response to this request, either review by EPA Kerr Lab or retraction.

- Topic 5. The NMED claim that a dirt cover will protect public health from the wastes buried in the MWL is in contradiction to the NMED claim that an identical dirt cover will not afford protection of public health for a much smaller disposal site at the Los Alamos National Laboratory.

 

The remedy required by NMED for the Sandia MWL is only a soil cover draped over the surface of the dump with a design identical to the soil cover proposed for MDA H at LANL. NMED praises the soil cover for the MWL but is critical of the cover proposed for MDA H. The NMED criticism is pasted below⁵:

“In order to ensure the continued performance of an ET cover, the Permittees proposed to conduct regular maintenance and monitoring throughout the 100-year institutional control period once the vegetative cover has been established. However, this alternative, similar to other containment alternatives listed by the Permittees, does not address the plume of VOCs and tritium that are currently present in the soil pore gas in the vicinity of MDA H. This ET cover also does not prevent future releases of these compounds to the subsurface from the shafts at MDA H.”

Hakonson⁶ states that “Controlling aqueous transport of volatile contaminants does not necessarily control vapor phase transport. In fact, maintaining low soil moisture content of cover and backfill soils to reduce aqueous phase transport may be associated with increases in vapor phase transport of volatile contaminants (Jury, 1987).”

 Similarly to LANL, the soil cover at the MWL does not address the VOCs and tritium that are currently present beneath the dump in far greater amounts than measured at MDA H. The soil cover will also not prevent the future releases of those compounds to the subsurface beneath the MWL. The shafts at MDA H are similar to the unlined pits and trenches at the MWL. However, NMED is requiring much more protection for MDA H with far less contaminants in volume and type than for the MWL. No encapsulation of MWL pits and trenches, and no soil-vapor extraction system is required at the MWL. At MDA H (p.12):

“NMED therefore has determined that it is appropriate to implement Alternative 3b (complete encapsulation of the shafts), along with a soil-vapor extraction system, at MDA H to prevent biointrusion and eliminate the VOC contaminant source detected in soil pore gas so that the drinking water resource can be conservatively protected.

“Alternative 3b will isolate the shafts from the environmental media to offer the greatest protection against potential intrusion of plants and animals, and accidental human access. This complete encapsulation alternative will prevent water from entering the shafts, and thus minimize the potential for contaminant migration into the surrounding tuff through aqueous phase transport.”

NMED is requiring that (p.13):

“To conservatively protect the regional groundwater from contamination by VOCs in soil pore gas, the Permittees will be required to operate the SVE [Soil-Vapor Extraction] until VOCs in soil pore gas are reduced to levels at which any of the detected VOCs, in contact with groundwater, theoretically could result in concentrations above half of the lower of the respective MCLs or Water Quality Control Commission (WQCC) standards. For example, TCE in soil pore gas must be reduced to a concentration below 1100 μg/m3 in vapor phase to meet the established criteria. Installation of a SVE system will require the installation of vapor monitoring extraction wells in the vicinity of MDA H and extending the depth of existing boreholes to the Otowi member of the Bandelier Tuff.”

At the Sandi MWL, NMED plans to leave poorly understood soil gas contamination with VOCs and tritium unmonitored beneath a soil cover that increases the potential for the volatile contaminants to contaminate the groundwater. The level of PCE contamination measured in the soil gas below the MWL required that an active soil vapor extraction (SVE) should have been installed 15 years ago.  

NMED does not have accurate knowledge of the nature and extent of solvent contamination in the vadose zone below the MWL. Accurate and detailed characterization of the known vapor plume below the MWL should have been accomplished before NMED selected the soil cover as the remedy. 

At MDA H, “NMED questions the long-term reliability of the engineered ET [evapotranspiration] cover in preventing the intrusion of deep-rooting plants and burrowing animals. According to the conceptual design of the engineered ET cover for MDA H, the total depth of the cover is approximately 4.5 feet over the existing surface layer. Based on the Permittees’ findings at MDA H (LANL 2005), the site specific deep-rooting plants can extend roots to depths as deep as 23 feet (7 meters), and local burrowing animals can excavate to depths deep to 10 feet (3 meters).” (Emphasis supplied).

The depth of the soil cover proposed for the MWL is 4.25 ft (MWL Design Report, 1999, p.3). At the MWL, Hakonson reports that ants can burrow beyond 5 meters for three species of ants. (p.37). Hakonson states, “The mixture of grasses that SNL/NM intends to use in reseeding the MWL is lumped within the herbaceous plant category. These data show that deep root habits are quite common in woody and herbaceous species across most of the terrestrial biomes, far deeper than the traditional view has held up to now. The implications for the MWL are that no matter what vegetation is planted on the landfill, if moisture penetrates beneath the ET cover, roots can be expected to follow.” (P. 31-32).

 - Topic 6. Rather than present a truthful description of a failed monitoring network for the MWL at the public hearing on the soil cover, NMED put public health and safety at risk by presenting false data that the monitoring wells were at appropriate locations and that they produced reliable water quality data proving there was no contamination of groundwater. 

Based on the totality of the evidence in the NMED administrative record, there was no correction of the problems cited in the 1994 EPA NOD, the 1994 letter of Benito Garcia, and the 1998 NMED NOD. The monitoring wells for detection of contamination and the background water quality well were in the wrong locations because of the southwest direction of groundwater flow, the well screens were improperly placed, the stainless steel well screens were corroded for more than the past fifteen years, the improper sampling methods pumped the wells to dryness and collected samples seven days later from the water that trickled into the wells, and the flow velocities for the MWL were based on unreliable data from pumping tests and slug tests. These problems noted in the administrative record were independently confirmed by studies of Mr. Gilkeson beginning in 2006. Moreover, the findings of Mr. Gilkeson, the NODs, and NMED letter were stated in 1991 by the DOE Tiger Team.

DOE/SNL knew in May 1991 from the Tiger Team Assessment of SNL ((p. 3-59) that “The number and placement of wells at the mixed waste landfill is not sufficient to characterize the effect of the mixed waste landfill on groundwater.”

 The NMED Administrative Record is proof there was never a reliable network of monitoring wells at the Sandia MWL. The refusal of NMED to recognize this historical record of failure leaves the public at risk. The additional proof that the monitoring network was never reliable are the new NMED orders for DOE/SNL to replace three of the MWL monitoring wells. For the new wells, the NMED does not allow stainless steel well screens nor organic or bentonite clay drilling fluids. NMED now requires DOE/SNL to install monitoring wells appropriate to the southwest flow of groundwater and to install wells as close as possible to the downgradient boundary of the MWL. These new NMED orders reveal that the necessary conditions for reliable monitoring were unsatisfied from the date of the earlier installation of the MWL wells. Corrosion was identified in 1992 for wells BW1, MW1, MW2, and MW3. The wells were not replaced. The existence of corrosion made the wells unusable and unreliable as monitoring wells for over a decade. New monitoring wells will require a period of several years to provide the data necessary to select the appropriate remedy for the MWL. In fact, the new data from a reliable network of monitoring wells may require excavation of the wastes buried in the MWL as was required for other radioactive and hazardous waste dumps in the near vicinity of the MWL.

The letter of June 28, 2008 continues to misrepresent that the prior data from obviously flawed monitoring wells was reliable. That position is not scientific or justifiable in light of the administrative record. Thus the “totality of the evidence” is actually that there was never representative and reliable data for making a decision on the MWL remedy of a dirt cover and a "blind" fate and transport model for watching the performance of the dirt cover.

Concerning the MWL dirt cover, a 2007 report by the NAS: “Long-Term Institutional Management of U.S. Department of Energy Legacy Waste Sites” points out that “Stewardship” (covering waste with dirt and instituting institutional controls) of waste sites will be difficult if not impossible to achieve."

The 2007 NAS report on Plans and Practices for Groundwater Protection at the Los Alamos National Laboratory (2007) states (p.68):

“Numerical models combine information on geology, geochemistry, infiltration, regional groundwater fluxes and waste discharges in a manner that quantifies understanding of the physical/chemical processes and interactions involved in the transport of contaminants. Information gained during the process of model development provides valuable insight on the validity of the conceptualization implemented in the numerical model. Though many “solutions” are possible, comparison of predicted results to actual measurements [i.e., monitoring wells at hot spots] provides an estimate of the level of understanding of the flow and transport processes moving contaminants away from their initial disposal locations.”

SNL has never put in monitoring wells at the identified “hot spots” for the solvents, such as PCE or for tritium at the MWL to verify the accuracy of the fate and transport model. Installation of monitoring wells at the known "hot spots" for indicator parameters PCE and tritium is mandatory because the MWL fate and transport model identifies these contaminants with the greatest danger for groundwater contamination. Protection of groundwater requires monitoring of the "hot spots" with active collection of soil gas samples immediately below the MWL and with the installation of monitoring wells at the water table. (40 CFR 264.98 (a) ).

 

Sincerely,

 David B. McCoy, Executive Director

Citizen Action New Mexico

POB 4276

Albuquerque, NM 87196-4276

505 262-1862

This email address is being protected from spambots. You need JavaScript enabled to view it.

 

Robert Gilkeson, Registered Geologist

PO Box 670

Los Alamos, NM 87544

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cc: Attorney General Gary King, Marcy Leavitt, NMED Director of Water and Waste Division

1. Sandia Mixed Waste Landfill Monitoring Well Locations

 

 

 

 

 

 

Source: Shaw Environmental, Inc. Albuquerque, New Mexico

 

 

 

 

 

 

Figure 2. Schematic of MWL Monitoring Well Completions

 

 

 

 

 

 

 

Source: Sandia National Laboratories Report SAND2002-4098, December, 2002

 

 

Figure 3. Potentiometric surface for the Region of the Sandia Mixed Waste

Landfill. (Displayed on the center of the map as the MWL).

 

 

 

 

Source: Sandia Mixed Waste Landfill Annual Groundwater Monitoring Report - Spring

2007 Sampling Event, Report received by NMED on March 5, 2008