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[September 2001 Groundwater report Table of Contents]
Prepared For
Camp Stanley Storage Activity
Boerne, Texas
MARCH 2002
Groundwater monitoring scoped under the AETC Contract F41689-96-D-0710, Delivery Order 5084, was performed the week of September 10, 2001 at CSSA.� Groundwater monitoring conducted under this Order began at the June 2001 sampling event and will continue through the December 2001 sampling event.� AFCEE/ERD and AFCEE/ERC provide technical oversight of the monitoring program with consent from CSSA.
The current objectives of the groundwater-monitoring program are to determine groundwater flow direction, water levels, groundwater contaminant concentrations for characterization purposes, and identify seasonal variations in physical and chemical properties.� Appendix A identifies the DQOs for CSSA�s groundwater monitoring program, along with an evaluation of whether each DQO has been attained.� The objectives listed in the table also reference appropriate sections of the Order.� Overall DQOs for the investigations at CSSA are provided in Volume 1-1 behind the RFI Addendum tab (Section 11).
Twenty-six water level measurements were recorded in feet above mean sea level (MSL) during the September 2001 monitoring event.� Water level measurements were taken from wells CS-1, CS-2, CS-3, CS-4, CS-9, CS-10, CS-16, CS-D, CS-G, CS-H, CS-I, CS-MW1-LGR, CS-MW2-LGR, CS-MW3-LGR, CS-MW4-LGR, CS-MW5-LGR, CS-MW6-LGR, CS-MW6-CC, CS-MW6-BS, CS-MW7-LGR, CS-MW7-CC, CS-MW8-LGR, CS-MW8-CC, CS-MW9-LGR, CS-MW9-CC, and CS-MW9-BS.� All water levels were measured with an e-line except for CS-10, which was measured with an air-line apparatus.� An average groundwater elevation for Well FO-20 for the week of September 10 was obtained from City of Fair Oaks Water Utilities.� Groundwater elevations derived from water level measurements are measured against MSL and are summarized in Table 1-1.
Groundwater levels increased 23.96 feet on average between June 11, 2001, and September 13, 2001.� This increase was calculated by averaging the groundwater elevation changes for each well, as shown in Table 1-2.� Also presented, in Table 1-2, are groundwater elevation changes by separate formation.� The Lower Glen Rose Formation increased 32.53 feet, the Bexar Shale increased 23.65 feet, and the Cow Creek Formation increased 22.50 feet on average.� The current groundwater elevations may be compared to the historical groundwater elevations from October 1992 through March 2000 that are shown in the Environmental Encyclopedia, Volume 5, Introduction to the Groundwater Monitoring Program at Camp Stanley (Parsons2001), specifically Table 3.
An average groundwater elevation for each formation in the Middle Trinity aquifer is provided in Table 1-1.� The average elevation was calculated by using groundwater elevations from wells screened only in that formation.� The average groundwater elevations were calculated from 13 wells screened in the Lower Glen Rose, two screened in the Bexar Shale, and four screened in the Cow Creek and were 1140.5, 1098.2, and 1095.8 feet above MSL, respectively.� Although the Bexar Shale and Cow Creek wells have similar average groundwater elevations, significant differences in groundwater elevations can be observed within the CS-MW9 cluster.� CS-MW9-BS (Bexar Shale) had a groundwater elevation of 1106.8 feet and CS-MW9-CC (Cow Creek) had a groundwater elevation of 1079.5 feet above MSL.� The groundwater elevation difference between these two wells is 27.3 feet.� By comparison, the groundwater elevation difference between wells in the CS-MW6 cluster, specifically CS-MW6-BS and CS-MW6-CC was 1.2 feet.� The relationship between water levels in the formations will continue to be evaluated as data are collected from existing and future wells to be installed.
A groundwater potentiometric surface map using the September 2001 groundwater elevations is shown in Figure 2-1.� Among the cluster wells CS-MW1-LGR through CS-MW9-LGR, only the water level measurements collected from Lower Glen Rose wells were used in creating this figure.� The September 2001 potentiometric surface map shows a variety of flow directions.� The general groundwater gradient to the southeast was approximately 0.0067 feet/feet.� Groundwater flow directions and gradients during past monitoring events are provided in Table 3 of the Introduction to the Groundwater Monitoring Program at Camp Stanley for comparison (Volume 5, Groundwater).
The overall observation from the September 2001 potentiometric surface map (Figure 2-1) is that CSSA wells exhibited a wide range of groundwater elevations.� The water level measurements seem to indicate that groundwater elevations were somewhat higher in the central and northwestern portions of CSSA.� Overall, the groundwater elevations generally decline towards the southeast with Well CS-1 having the lowest groundwater elevation of all measured wells.
In the area of Building 90, at the southwest corner of CSSA, potentiometric surface maps were created using September 2001 groundwater elevations from Lower Glen Rose and Cow Creek wells (Figures 2-2 and 2-3).� The Cow Creek potentiometric surface map indicates that groundwater elevations decline toward the north at Building 90 and the Lower Glen Rose potentiometric surface map indicates groundwater elevations also decline toward the north at Building 90.
Other exceptions to the general southeast groundwater gradient are apparent.� Well CS-MW4-LGR in the central portion of CSSA had one of the highest groundwater elevations at 1184.5 feet MSL.� In addition, CS-MW6-LGR had a lower groundwater elevation than Well CS-MW7-LGR situated to the southeast, and CS-MW8-LGR located to the south.� Finally, CS-I groundwater elevation was 13.5 feet above the groundwater elevation measured in CS-G, located to the west.
As shown in Figure 2-1, water levels at CSSA show much variability.� This variability is likely associated with various factors: 1) differences in well completion depths and formations penetrated; 2) differences in recharge rates due to increased secondary porosity associated with the Salado Creek floodplain; 3) differences in recharge rates due to increased secondary porosity associated with the fault zone; and 4) unknown pumping rates from public and private water supply wells located off-post but near the CSSA boundary.� Most potentiometric surface maps prepared to date for CSSA are based on water levels from wells with different completion depths, with the exception of Figures 2-2 and 2-3.� Additional information concerning this issue is included in the Introduction to the Groundwater Monitoring Program (Volume 5, Groundwater).� Because several wells depicted on Figure 2-1 are open to multiple water-bearing zones, contour maps should be considered qualitatively.� The differences in water levels across CSSA may stem from differences in the way various wells are completed.� Wells CS-D, CS-2, CS-3, CS-4, CS-MW1-LGR, and CS-MW2-LGR are open-hole completions in the Lower Glen Rose or the Lower Glen Rose and upper portion of the Bexar Shale.� Well CS-16 is open in the Lower Glen Rose, Bexar Shale, and Cow Creek.� Water levels obtained from some wells (i.e., CS-16 and CS-D) represent water levels measured from three different formations, while wells completed in the Lower Glen Rose only represent the water level for one formation.� Interpretation of data for the potentiometric map is complicated by these two types of water elevation data.
Precipitation data collected from the meteorological station at Well CS-16 between October 5, 1998 and September 13, 2001, are shown in Figure 3.� Water level data from the Well CS-16 transducer could not be downloaded during the September monitoring event due to a technical malfunction.� Some of the Well CS-16 groundwater elevation data since the last monitoring event in June 2001 is therefore missing from Figure 3.
As noted earlier, groundwater levels increased 23.96 feet on average between June 11, 2001 and September 13, 2001.� During this period, there were 17 rainfall events with a total precipitation of 14.73 inches.� During the previous quarter when groundwater levels decreased 47.5 feet, there were 18 rainfall events with a total precipitation of 6.58 inches.
Groundwater sampling of on-post wells was performed September 10 through September 14, 2001.� Twenty-four on-post wells were sampled:� CS-1, CS-2, CS-9, CS-10, CS-16, CS-D, CS-G, CS-H, CS-I, CS-MW1-LGR, CS-MW2-LGR, CS-MW3-LGR, CS-MW4-LGR, CS-MW5-LGR, CS-MW6-LGR, CS-MW6-BS, CS-MW6-CC, CS-MW7-LGR, CS-MW7-CC, CS-MW8-LGR, CS-MW8-CC, CS-MW9-LGR, CS-MW9-BS, and CS-MW9-CC.
Wells CS-G and CS-H were sampled with a bailer during this sampling event.� Bladder pumps had not been installed in these wells as of September 2001.� Well CS-11 could not be sampled during this event because the pump controller was not operational.
The analytical program for on-post wells includes metals and VOCs only.� Samples from the high-capacity water supply wells CS-1, CS-9, and CS-10 were analyzed for the full VOC list along with acetone and methyl-ethyl-ketone (MEK).� The remaining wells were analyzed for a reduced list of VOCs, based on historical knowledge of the CSSA groundwater plumes.� This reduced list which has been approved by USEPA and TNRCC includes: 1,1-dichloroethene, bromodichloromethane, chloroform, cis-1,2-dichloroethane, dibromo-chloromethane, methylene chloride, trichloroethene, tetrachloroethene, trans-1,2-dichloroethane and vinyl chloride.� For initial sampling at a newly installed monitoring well, groundwater was also analyzed for cations and anions.
The data package DO5084-11 contains analytical results for this sampling event.� The data package was received by Parsons on November 15, 2001, was subsequently verified and validated, and submitted to AFCEE on December 18, 2001 for review.� AFCEE approved the data packages in January 2002.� All the detected concentrations of cations, anions, metals, and VOCs are presented in Table 4.� Full analytical results for September 2001 are presented in Appendix B.� Historical VOC and metals data can be found in Tables 6 and 7, respectively, of the Introduction to the Quarterly Groundwater Monitoring Program at CSSA (Parsons 2001) as well as in the Cumulative On-Post Analytical Data presented in Appendix C.
Two newly installed monitoring wells were sampled for the first time during the September 2001 event, CS-MW7-LGR and CS-MW7-CC.� No VOC analytes were detected in either of these wells.� Similar to the analytical results obtained during the June 2001 monitoring event, the only VOC concentrations above the RL identified in any of the monitoring wells installed in 2001 occurred in CS-MW5-LGR.� This well had a cis-1,2-DCE concentration of 1.90 �g/L and PCE concentration of 1.7 �g/L during this monitoring event.� The cis-1,2-DCE level was also 1.90 �g/L in the June 2001 monitoring event.� The PCE concentration increased from the June 2001 reported concentration of 1.10 �g/L.� TCE was reported in CS-MW5-LGR during June 2001 at a concentration of 1.7�g/L and the September 2001 reported concentration increased to 2.0 �g/L.�
MCLs for PCE, TCE, and cis-1,2-DCE were exceeded in Well CS-16 during the September 2001 sampling event.� The PCE concentration was 140.0 �g/L, the TCE concentration was 170.0 �g/L, and the cis-1,2-DCE concentration was 150.0 �g/L.� Concentrations of these compounds in Well CS-16 increased from the levels found during the June 2001 monitoring event.� The June 2001 levels of PCE, TCE, and cis-1,2-DCE were 75 �g/L, 73.0 �g/L, and 73.0 �g/L, respectively.� Chloroform and trans-1,2-DCE, compounds that have sporadically been detected in Well CS-16, were detected in September 2001 at concentrations of 0.15 �g/L and 1.5 �g/L, respectively.The PCE (120.0 �g/L), TCE (170.0 �g/L), and cis-1,2-DCE (140.0 �g/L) concentrations in Well CS-D were also above MCLs.� Well CS-D is located approximately 500 feet west of Well CS-16.� The June 2001 levels of PCE (110.0 �g/L), TCE (140.0 �g/L), and cis-1,2-DCE (130.0 �g/L) in CS-D were slightly lower than the results from September 2001.� Well CS-D also had a trans-1,2-DCE concentration of 0.61 �g/L and chloroform was detected below its RL at 0.15 �g/L.
Concentrations of PCE, TCE, cis-1,2-DCE, and trans-1,2-DCE in Well CS-MW1-LGR, located approximately 1,975 feet south-southwest of Well CS-16, were 24.00 �g/L, 30.00 �g/L, 29.0 �g/L, and 0.26 �g/L, respectively.� The concentrations of these compounds remained relatively unchanged from the June 2001 levels of 21.0 �g/L, 30.0 �g/L, 27.0 �g/L, and 0.27 �g/L, respectively.� The MCLs for PCE and TCE were exceeded in Well CS-MW1-LGR.
PCE and TCE concentrations were above the MCLs in CS-MW2-LGR at concentrations of 13.0 �g/L and 9.4 �g/L, respectively.� CS-MW2-LGR is located approximately 2,125 feet south-southeast of Well CS-16.� A cis-1,2-DCE concentration of 4.60 �g/L and a trans-1,2-DCE concentration of 0.19 �g/L were also reported.�
Well CS-MW8-LGR reported a sub RL concentration of 0.64 �g/L for PCE.� The RL for PCE is 1.4 �g/L.� In the June 2001 event, CS-MW8-LGR had a PCE concentration of 1.1 �g/L and a TCE concentration of 0.18 �g/L.� The recent September results show a decrease in levels of both PCE and TCE in CS-MW8-LGR.
The water supply wells, CS-1, CS-9, and CS-10 did not have any VOC concentrations that exceeded the RL.� Off-post Well CS-1 had a sub-RL PCE concentration of 0.14 �g/L and a sub-RL TCE concentration of 0.29 �g/L that was similar to the June 2001 level of 0.19 �g/L.� PCE was not found in Wells CS-9 or CS-10 during this monitoring event after being detected for the first time in these wells in March 2001.� Well CS-10 had one VOC analyte detected, a sub-RL chloroform concentration of 0.29 �g/L.� Well CS-9 had no VOC detections whatsoever.� Well CS-11 was not sampled due to an inoperable pump controller.
Several occurrences of metals concentrations exceeded MCLs during this monitoring event.� Well CS-I exhibited a lead concentration of 0.0193 mg/L, which exceeds the action level (AL) of 0.015 mg/L.� The lead AL was also exceeded in Wells CS-G and CS-H, which had lead concentrations of 0.0369 mg/L and 0.047 mg/L, respectively.� The term �action level� is used here because USEPA�s Safe Drinking Water Standards list action levels only�no MCL is defined�for lead.� The action level determines the treatment requirements a water system is required to complete according to 40 CFR141.80(c).
Iron concentrations from Wells CS-2, CS-G, CS-H, CS-I, CS-MW-1-LGR, CS-MW3-LGR, CS-MW6-CC, and CS-MW7-LGR were above the secondary standards level set for iron by the USEPA of 0.3 mg/L.� Concentrations were reported in these wells ranging from 0.308 mg/L to the maximum of 28.227 mg/L in Well CS-MW3-LGR.� Secondary standards as set by the USEPA are non-enforceable guidelines regulating contaminants that may cause cosmetic effects (such as skin or tooth discoloration) or aesthetic effects (such as taste, odor, or color) in drinking water.� None of these wells are drinking water wells.
The zinc concentration reported in June 2001 from Well CS-I was 3,470 mg/L.� At that time, a comparison to the September 2001 sampling result was recommended. �The current zinc concentration of 2.921 mg/L, along with the historical range of concentrations from 1.51 mg/L to 9.9 mg/L, indicate that the June 2001 result may not be reliable.� No other CSSA wells, including the remaining newly installed wells, exhibited metals levels that surpassed the MCLs/ALs during this monitoring event.�
Samples collected from 14 newly-installed CSSA monitoring wells during the September 2001 sampling event were analyzed for cations and anions.� Further evaluation of the cation and anion data from all new monitoring wells will be initiated as new wells are completed.� A future groundwater monitoring report will include a detailed evaluation and data summary after sufficient cation and anion data are collected.
An average increase in water levels of 23.96 feet occurred between June 2001 and September 2001 (These are separate formations and open boreholes).� Approximately 14.73 inches of rain fell at CSSA between June 11, 2001 and September 11, 2001, compared to 6.58 inches of rain between March 2001 and June 2001 when groundwater levels decreased 47.5 feet.
The groundwater elevation map for September 2001 indicates a variety of groundwater flow directions.� It is likely that the groundwater extraction from both on- and off-post drinking water wells, differential recharge from recent rain events, and differences in well compilation techniques are contributing to this complex gradient picture.�
In the vicinity of Building 90/AOC 65 (the presumed source of off-post contamination) local groundwater flow in the Lower Glen Rose and Cow Creek water producing zones appear to be to the north.�
Initial sampling at the two newly-installed monitoring wells, CS-MW7-LGR and CS-MW7-CC, did not have indicate VOCs detected above the RL.�
MCLs for PCE, TCE, and cis-1,2-DCE were exceeded in Well CS-16 during the September 2001 monitoring event.� Concentrations of these compounds in Well CS-16 were 170.00 mg/L, 140.00 mg/L, and 150.00 mg/L, respectively.
Well CS-D reported PCE (120.0 �g/L), TCE (170.0 �g/L), and cis-1,2-DCE (140.0 �g/L) concentrations above the MCLs.
On-post drinking water supply Wells CS-1, CS-9, and CS-10, did not have any VOC concentrations reported that exceeded the RL.
Samples from three North Pasture wells found elevated levels of lead.� Well CS-I exhibited a lead concentration of 0.0193 mg/L, which exceeds the AL of 0.015 mg/L.� The lead AL was also exceeded in Wells CS-G and CS-H, which had lead concentrations of 0.0369 mg/L and 0.047 mg/L, respectively.� During previous sampling events, elevated levels of lead have periodically been identified in these wells.
Wells CS-2, CS-G, CS-H, CS-I, CS-MW-1-LGR, CS-MW3-LGR, CS-MW6-CC, and CS-MW7-LGR reported iron concentrations ranging from 0.308 mg/L to the maximum of 28.227 mg/L.� These concentrations are above the secondary standards level set for iron by the USEPA of 0.3 mg/L.
The zinc concentration reported in June 2001 for Well CS-I of 3,470 mg/L was not confirmed by the September 2001 reported concentration of 2.921 mg/L.� The historical range of concentrations for zinc from this well is 1.51 mg/L to 9.9 mg/L, suggesting the June 2001 result may not be a reliable result.
Well CS-11 could not be sampled due to a malfunctioning pump controller.
Appendix A - Evaluation of Data Quality Objectives Attainment
| Activity | Objectives | Action | Objective Attained? | Recommendations |
| Field Sampling | Conduct field sampling in accordance with procedures defined in the project work plan, SAP, QAPP, and HSP. | All sampling was conducted in accordance with the procedures described in the project plans.� | Yes. | NA |
| Characterization of Environmental Setting (Hydrogeology) | Prepare water-level contour and/or potentiometric maps (B.3.A.1(e)(1)) | Potentiometric surface map was prepared based on water levels measured in each of CSSA�s wells the week of September 10, 2001.� In addition, an average water level for a Fair Oaks Ranch Utilities well (F0-20, northwest of CSSA) was also obtained.� | To the extent possible with data available.� Due to the limited data available and the fact that wells are completed across multiple water-bearing units, potentiometric maps should only be used for regional water flow direction, not local.� Furthermore, pumping in the area likely affects the natural groundwater flow direction.� | When unit-specific water level information is available, prepare water level map for each unit.� Until then, water levels in all CSSA wells should continue to be measured and all data should be mapped together due to the lack of data for any one zone. |
| Describe the flow system, including the vertical and horizontal components of flow (B.3.A.1(e)(3)). | Potentiometric maps were created using September 2001 water level data, and horizontal flow direction was tentatively identified.� Insufficient data are currently available to determine vertical component of flow. | As described above, due to the lack of aquifer-specific water level information, potentiometric surface maps should only be used as an estimate of regional flow direction, not local. | Same as above. | |
| Identify any temporal changes in hydraulic gradients due to seasonal influences (B.3.A.1(e)(4)). | Downloaded data from continuous-reading transducer at CS-16 and continuous-reading weather station adjacent to CS-16.� Graphed water levels at this well against precipitation. | Information provided by CS-16 transducer-weather station is a start to identifying temporal changes.� Very rapid changes in water levels have been observed at CS-16 after precipitation.� However, CS-16 is completed in three units; therefore, the unit-specific effect is not known. | Install transducers in several cluster wells, after installation is complete, to determine effects of precipitation on each unit.� Wells where rapid effects are noticed, such as at wells CS-D and CS-MW1-LGR (both completed in the Glen Rose only), should also be considered for transducer installation. | |
| Contamination Characterization (Ground Water Contamination) | Characterize the horizontal and vertical extent of any immiscible or dissolved plume(s) originating from the Facility ((B.3.C.1(a)) | Samples for laboratory analysis were collected from all of the CSSA wells, except wells CS-3 and CS-4, which are located adjacent to Well 2 and except for CS-11, which had a malfunctioning pump controller.� | No.� There are currently insufficient data to determine the horizontal or vertical extent of groundwater contamination.� | As described above, additional wells are currently being installed which will help in determining horizontal and vertical extent of contamination. |
| Determine the horizontal and vertical concentration profiles of all constituents of potential concern (COPCs) in the groundwater that are measured by EPA-approved procedures (B.3.C.1(d)).� COPCs are those chemicals that have been detected in groundwater in the past and their daughter (breakdown) products. | Groundwater samples were collected from wells CS-1, CS-2, CS-9, CS-10, CS-16, CS-D, CS-G, CS-H, CS-I, CS-MW-1-LGR, CS-MW-2-LGR, CS-MW-3-LGR, CS‑MW-4-LGR, CS‑MW-5-LGR, CS-MW-6-LGR, CS-MW-6-BS, CS-MW-6-CC, CS‑MW-7-LGR, CS-MW-7-CC, CS-MW-8-LGR, CS-MW-8-CC, CS-MW-9-LGR, CS-MW-9-BS, and CS‑MW-9-CC.� Samples were analyzed for the selected VOCs using EPA method SW8260B, arsenic by SW7060A, cadmium by SW7131A, lead by SW7421, mercury by SW7470A, and barium, chromium, copper, nickel, and zinc by SW6010B.� Analyses were conducted in accordance with the AFCEE QAPP, version 3.0 and approved variances.� All reporting limits were below MCLs, as listed below: | No | Additional wells to be installed to assist in defining the horizontal and vertical concentrations of COPCs. | |
| | Analyte���������������� RL (�g/L)����� MCL (ug/L) Bromodichloromethane 0.8 100
Barium����������������� 5��������������� 2000 | see above | see above | |
| Contamination Characterization (Ground Water Contamination) | Meet AFCEE QAPP quality assurance requirements. | Samples were analyzed in accordance with the AFCEE QAPP, v 3.0, and approved variances. All data were verified by a chemist.� | Yes. | NA |
| All data flagged with a �U,� �J,� and �F� are usable for characterizing contamination. | Yes. | NA | ||
| The method detection limit study for arsenic, cadmium, and lead were not performed within a year of the analyses, as required by the AFCEE QAPP. | The laboratory performed new MDL studies in February 2001 for these metals and the new MDL values were found to be almost identical to the previous MDLs and all met the associated AFCEE QAPP requirements.� MDLs for these three metals are well below MCLs.� In addition, the laboratory performed daily calibrations and RL verifications for these metals, both of which demonstrate the laboratory�s ability to detect and quantitate these metals at RL levels.� These daily analyses also indicate that concentrations above the laboratory RL for these compounds were not affected by the expired MDL study. | Use results for groundwater characterization purposes. |