Comments on "1993 Annual Water Monitoring Report
LEHR Environmental Restoration University of California at Davis, US DOE,"
G. Fred Lee, PhD, DEE
Technical Advisor, DSCSOC
Paragraph 4 states that this site is polluting groundwaters with total and hexavalent chromium, nitrate, selenium, nickel, chloroform, carbon 14 and tritium. We need to understand the difference between what was said in the 1993 Annual Water Monitoring Report and what is accepted today. I do not remember that recently there has been any discussion of any pollution of groundwaters by selenium and nickel at the LEHR site. What has changed between 1993 and today with respect to this issue?
Page ix, paragraph 1, states that Putah Creek's chemical characteristics are controlled by the UC Davis wastewater treatment plant discharges where it states that this treatment plant recharges Putah Creek. The word "recharge" is inappropriate. No discussion is presented, however, on whether the LEHR site is influencing Putah Creek water quality through either direct discharges of stormwater runoff or indirect discharges through the UCD campus wastewater treatment plant. This is the issue of concern that should have been addressed.
Page x, first paragraph, discusses the use of spiked samples to establish accuracy. That approach does not necessarily establish that the results are accurate. Accuracy can be reliably established through independent analytical methods which was not done in this study. There could readily be constituents in the sample that interfere with the primary analysis which would not interfere with the spiked samples. Another way to check on accuracy is through the use of standard, realistic samples of known composition. These samples must have about the same sample background matrix as the site waters in order to properly serve as an appropriate basis for judging accuracy.
Page x, paragraph 2, discusses what is called "representativeness." Representativeness is more than simply trip blanks, laboratory method blanks, etc. Again, the authors of this section have not properly described the issues. Representativeness must be assessed based on a more detailed study of the area which shows that the sampling frequency and location was adequate to be representative.
Page xxiii under the section, Upgradient Wells, indicates that UCD 17 is the upgradient well for the HSU-2 while UCD 18 is the upgradient well for HSU-1. It is highly likely that only one upgradient well for each HSU is deficient compared to what is needed to properly describe upgradient groundwater characteristics, and thereby, enable the reliable detection of the impact of the site on downgradient characteristics.
Overall, the discussion of the groundwater and surface water quality monitoring data focuses for groundwater on potential increases in the chemical concentrations of constituents including groundwaters at or downgradient of the site compared to upgradient. At this time, there is insufficient upgradient groundwater monitoring to know the magnitude of this increase.
Overall, this discussion falls far short of reliably addressing key issues. The issue is not whether there is an increase in constituents; the issue is whether there is an increase in constituents that significantly impairs the designated beneficial uses of the groundwaters at the site. These data need to be re-analyzed with respect to this issue. Without it, the report is highly deficient.
Overall, the study design for the surface water discharges falls far short of what is needed to reliably address the impact of the LEHR site on Putah Creek water quality.
Another significant deficiency with this report is that there is no discussion of water chemistry. While the term, "water chemistry," is frequently used in the report, this term is used inappropriately. The term that should have been used in this report is "water chemical characteristics" rather than "water chemistry." Examination of these data should be conducted to see whether any aquatic chemistry - reactions are, in fact, taking place in the aquifer system that would influence the composition of the water, such as transformations that impact on the hazardous impact of a waste component.
Table 6A presents some of the data in which too many significant figures are used for certain parameters, such as turbidity. This table also contains some errors in the analysis of the data where less-than values are compared to actual measured values for a relative percent difference value. This cannot be reliably done by the procedures used.
Some of the data presented in Table 6A show that the laboratory that did the sample collection and analysis had significant problems for certain parameters. Chromium is a particularly important chemical, and there are certain problems when analyzing total chromium versus hexavalent chromium. There are a number of situations where the amount of total chromium is less than hexavalent. None of these errors are sufficient to indicate significant problems with analytical procedures such as sample handling.
The data presented in Table 6B for PCD indicate that a far too abbreviated set of analyses are being conducted compared to what should be conducted to properly characterize Putah Creek water quality. This set of analyses needs to be expanded significantly.
Table 6B for the fall quarter 1993 indicates that the sewage treatment plant discharge contains high concentrations of ammonia compared to what should be allowed to be discharged. This ammonia will be toxic to aquatic life. Note that this ammonia is derived, in part, from the LEHR site.
Table 9A should have included a 500 mg/l TDS value under the MCL. While this is not a proper MCL, it is a useful guideline to determine when excessive TDS is present in a water sample. This table shows that there is significant pollution of the groundwaters with TDS occurring associated with the site. This pollution is impairing the use of this groundwater for domestic water supply purposes and, therefore, according to Chapter 15, must be corrected.
Another very important deficiency with this data review is the failure to properly address the issue of how well this groundwater monitoring approach properly describes the areal extent of pollution of groundwaters by the site. This is the most important issue that has to first be addressed in any groundwater pollution investigation.
Table 9A for alkalinity shows that the site is apparently polluting groundwaters with alkalinity. This appears to be part of the TDS increase. This is of significance as it will adversely affect the use of these groundwaters for domestic water supply purposes.
In the same table, it is clear that there is something wrong with the sampling - analytical procedures for chemical oxygen demand. The fluctuations in COD in the samples that are noted from quarter to quarter represent problems in analyses. The groundwater characteristics cannot vary by this magnitude. All of the COD data are, therefore, suspect.
In Table 9A, there are data for total dissolved solids and for electrical conductivity obtained in the field. In any analysis of this type, a comparison should be made between the TDS results and the EC-F results to see if they show a consistent ratio. If they do not, this indicates analytical errors or something peculiar about the characteristics of the water.
Table 9A presents EH - field data. It is not clear what the units are, since these are not presented. If they are assumed to be millivolts, which is what they should be relative to hydrogen, then it appears that this water is somewhat below what it should be for a fully oxygenated water. Dissolved oxygen should be measured in the groundwater samples to determine whether there are conditions where low DO occurs. This is important, since it impacts the behavior of a number of constituents of concern.
The turbidity data in Table 9A for a number of samples contain excessive significant figures. These figures should be rounded off to more properly reflect the reliability of the analysis.
Some of the samples, such as wells 01 and 04, indicate improper well design and/or development, which makes the results from these wells unreliable.
Many of the arsenic data presented in Table 9B were developed with analytical procedures that are not adequate to detect arsenic at potentially significant concentrations. Further work needs to be done to see if the site is not contributing arsenic to the water. It appears that there is potential for an increase in arsenic above what could become the new drinking water MCL for arsenic of about 2 µg/L.
Table 9B lists the MCL for lead as 50 ug/L. This has been changed to 15 ug/L. There are, therefore, values in the table which indicate that the site may be contributing lead to the groundwater, causing it to have excessive concentrations.
It also appears that nickel may be contributed by the site to the groundwaters.
An insufficient number of upgradient monitoring wells exist to properly define the upgradient groundwater characteristics. Several more groundwater monitoring wells for each HSU must be installed in order to determine the upgradient groundwater characteristics.
The well location map provided in this report does not include all of the wells for which these data are reported. This needs to be corrected so that the data can be properly examined.
There is an apparent increase in TDS within and downgradient of the site which appears to be due to the site. This increase in TDS is of sufficient magnitude to require groundwater cleanup in order to eliminate the impairment that is occurring in the potential use of downgradient groundwaters for domestic water supply purposes. If it can be shown that there would be sufficient dilution of this TDS before it reaches off-site properties, then such clean-up would not be necessary; however, it appears from the location of the wells with the high TDS that this is very unlikely.
It appears that the site is contributing significant chromium to the groundwaters. This is a problem that would affect the use of this groundwater for domestic water supply purposes and, therefore, has to be controlled before the groundwater leaves the site. It also appears that nickel may be contributed by the site to the groundwaters, especially for Well 23.
Selenium derived from the site appears to be polluting groundwater.
Table 9C shows that the site is polluting groundwaters by calcium. While there is no MCL for calcium, any increase in calcium and magnesium leads to increased hardness which is detrimental to the use of the groundwater for domestic water supply purposes. The same situation appears for chloride. The chloride increases the corrosion rates of pipe fixtures, etc.
Table 9C makes an error in not listing an MCL for iron.
The site appears to be polluting the groundwaters with a number of conventional pollutants such as calcium, magnesium, chloride and alkalinity.
The site is polluting groundwaters by nitrate.
While analytical data are presented for phosphate in groundwater, there is no need for further phosphate analyses. For groundwater systems, phosphate is not a parameter that will be detrimental to domestic water supply at the concentrations being found.
The site appears to be contributing potassium to the groundwaters. It is contributing sodium. The increase in sodium is sufficient to be detrimental to the use of the groundwater for domestic water supply purposes. Therefore it must be remediated.
Similarly, there is a significant increase in sulfate in some of the groundwater samples. In some cases, while these are below the MCL, it is part of the overall groundwater pollution by bulk constituents that occurs at this site.
The site is polluting groundwaters with certain VOC's, such as the 1,1-dichloroethene and 1,1-dichloroethane. Remediation of this pollution must be accomplished.
The authors of this report have made a significant error in listing the MCL for various individual trihalomethane components as 100 ug/L. The 100 ug/L drinking water MCL is for total trihalomethane. It is a value that is applicable to chlorinated domestic water supplies where there is a balance between degree of disinfection - potential for waterborne disease and cancer associated with total trihalomethane. The balancing between disinfection and cancer is not applicable to polluted groundwaters derived from inappropriate handling of VOC's such as chloroform. Under these conditions, the one in one million cancer risk should be used. For chloroform the appropriate MCL should be about 0.2 ug/L, not 100 ug/L as is listed.
The site is polluting certain wells with chloroform and methylene chloride.
Table 9F provides data for DDT, but it does not list an MCL. The US EPA as part of developing water quality criteria did provide information on DDT that sets a health risk. This number should be incorporated in this table as a guideline.
This study was significantly deficient in that the chlorinated pesticide of greatest concern is chlordane. It appears from the information that chlordane was not analyzed for in the groundwater samples. If the situation is still occurring, then that needs to be immediately corrected.
The site is polluting groundwater through tritium above drinking water MCL's.
In this report, such as Table 10, there is a table of number of samples, number of detections, maximum values and locations of maximum values. Such information is essentially worthless and is uninterpretable. I suggest that it be deleted and that more time be spent on more appropriate data analyses.
The data in Tables 11A, 11B, etc. from Putah Creek show that this sampling program is significantly deficient in failing to measure dissolved oxygen. Also, BOD should be measured.
Table 11B for hexavalent chromium lists the MCL as NA. The US EPA has a water quality criterion MCL value for hexavalent chromium of 10 ug/L. There are exceedances of this value in Putah Creek. Further, some of the analytical methods used for hexavalent chromium have detection limits of 20 ug/L. It appears that the person who made up this table does not understand that water quality criteria and standards for aquatic life should be used as the appropriate standard to judge excessive concentrations for surface waters. This is a significant error in the presentation of the results of this report and needs to be corrected. The information provided in this table for MCL values is inadequate for copper, lead, hexavalent chromium and mercury.
From the data provided in Table 11B, UCD's wastewater discharge is discharging hexavalent chromium at above the US EPA criteria and thereby polluting Putah Creek throughout the reach near the LEHR site with excessive chromium concentrations. It also appears that UCD at times is discharging significantly elevated concentrations of lead which would be of concern.
Table 11C presents data for ammonia for a couple of quarters. This data should be examined with respect to the unionized ammonia considering temperature and pH.
A problem occurs with the iron MCL value. There is an MCL value for iron.
UCD's wastewater discharge is adding significant phosphate to Putah Creek. This will contribute to the excessive fertility of the Creek.
Data for kjeldahl nitrogen should be continued to be provided for Putah Creek and the UCD sewage treatment plant discharge. The data in Table 11C indicate that UCD is contributing potentially significant concentrations of organic nitrogen to Putah Creek which will, under Creek conditions, convert to ammonia.
Table 11D contains the same errors as listed above with respect to MCL's for the various VOC's. UCD is apparently contributing potentially significant concentrations of chloroform in its wastewater discharges to Putah Creek.
Table 11F should have used water quality criteria values for the various pesticides from the US EPA Gold Book as an indication of appropriate concentrations.
The Groundwater Elevation Contour maps are not in sufficient detail with respect to offsite contours to enable a determination to be made as to whether there are localized areas where the flow of groundwaters is different than the general flow. Additional offsite wells should be installed in order to determine the flow direction for groundwater, especially along the south border. Further, there is insufficient information at this time around Landfill 3 to know what direction the flow is occurring.
This report has placed too much emphasis on STIFF and HYPER diagrams and not enough on a proper interpretation of the chemical characteristics of the groundwaters relative to potential water quality problems. This is a water quality investigation, not a geochemical investigation. Emphasis in this study should be shifted to water quality away from geochemistry data presentation.
The groundwater monitoring program that has been conducted through 1993 is significantly deficient compared to what is necessary to properly define the potential impact on groundwater quality caused by the LEHR site. There are insufficient numbers of wells and inadequate spacing of wells, both upgradient and downgradient, to determine the full impact of this site on groundwater quality. There is no question that significant pollution of groundwaters is occurring by conventional pollutants as well as hazardous constituents, including radioactive constituents. At this time, it is not clear which way the groundwater is moving, especially on the south side of the LEHR site. The surface water monitoring program for Putah Creek is grossly deficient and needs to be completely revamped.
There are also significant deficiencies in the presentation and interpretation of the data that need to be corrected in this report as well as future reports.
What other monitoring is being done associated with the LEHR site by UCD or others, such as on Putah Creek, domestic wastewater discharge, cooling tower discharges, the homeowners' wells near the LEHR site who are being supplied bottled water, and the Nishi well near Landfill 3? A study of this type should compare the results of this study period to all other data that are being collected during this period in the same area. Further, a comparison should be made between this data set and the previous data sets that have been collected at the LEHR site.
At the June 13, 1995 RPM meeting, there was a preliminary proposal made to delete certain analyses from certain wells since the results over the past three years have been non-detect. A complete data set for 1994 should be available for review, and a detailed comparison be developed on the information provided by this data set, including comparisons to previous sets, etc. as discussed herein, should be made.
One of the problems with starting to delete certain analyses at this point is the lack of understanding of the specific sources of constituents that are polluting groundwaters that are arising from the site. Until the sources are well understood, it is not possible to determine that what are now non-detects will be significant values in the future due to the fact that the groundwater plumes of pollutants are moving toward a particular well. The very poor understanding of the groundwater hydrogeology and the associated pollution plume that exists at this time precludes any significant decrease in monitoring. In fact, because of the complexity of the site, the multiple sources and the clear indication that the site is, in fact, polluting groundwaters with a variety of constituents means that there is need to expand the monitoring program.
Studies on Putah Creek must include water column and sediment toxicity tests using a suite of sensitive organisms. Further, fish and other organisms should be collected from Putah Creek above, at and below the LEHR site and analyzed for body burden for the various constituents of concern.
One of the key components of the RI/FS Work Plan which must ultimately be carried out is what is called herein a "gradient analysis" where the potential pollutants at each site are analyzed at the site and then in the soil and associated waters that could be polluted by the wastes as a function of distance from the waste disposal area or area of contamination. This gradient analysis would be necessary to determine the extent of clean-up for the site. It cannot be assumed that simply cleaning up the waste pits will necessarily shut off significant sources of pollutants that have moved from the pits to the surrounding soils.
There is need to sample the large ag wells that are just east of the site on at least a quarterly basis when they are being used. These wells could have a significant impact on groundwater movement in the region.
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