Evaluation of the Impact of LEHR Site Waste Disposal on
Putah Creek Water Quality

G. Fred Lee, PhD, DEE Anne Jones-Lee, PhD
G. Fred Lee & Associates

October 22, 1995

The DSCSOC and the public are concerned that UCD and DOE past and current waste disposal practices at the LEHR national Superfund site have polluted and continue to pollute Putah Creek. This pollution could be adverse to people who recreate in the Creek or use aquatic life taken from the Creek as food; fish and other aquatic life and wildlife; as well as groundwater resources in the vicinity of the Creek due to Putah Creek's recharge of groundwaters in the area. Putah Creek is designated by the state of California as a stream that can be used for domestic water supply, groundwater recharge, propagation of fish, aquatic life and wildlife and for contact recreation. In accord with state and federal regulations, each of these uses must be protected from wastes present at and discharged from the UCD - DOE national Superfund site.

A superficial review of the results of DOE studies on the impact of the LEHR site on Putah Creek leads to the conclusion that the LEHR site wastes have not polluted - adversely impacted the beneficial uses of Putah Creek. However, a critical in-depth review of these DOE studies shows that thus far UCD and DOE have not properly examined the impact of LEHR site wastes on Putah Creek water quality. A summary of LEHR site Putah Creek water quality issues is presented in this report.

Pathways of LEHR Site Wastes to Putah Creek

There are several pathways by which LEHR site wastes can reach Putah Creek. The flood control levee between the LEHR site and Putah Creek prevents direct runoff from the LEHR site to Putah Creek except at two locations. One location is along Old Davis Road where a culvert enables surface water runoff from the LEHR site to discharge directly to Putah Creek. Part of the past and current stormwater management program for the western part of the LEHR site involves pumping stormwater from the LEHR site to a pipe that crosses Old Davis Road which discharges to the drainage ditch along the road that drains to Putah Creek.

During the time that the LEHR site was active, there were a number of situations where the radium-226 and strontium-90 waste management facilities located on the west side of LEHR along Old Davis Road overflowed. This overflow, carrying some of the wastes and radioisotopes, is reported to have been discharged to the drainage ditches along Old Davis Road and, therefore, likely entered Putah Creek. At this time, to the knowledge of the author, the pollution of soils along this drainage ditch by radioactivity and otherwise hazardous chemicals has not been investigated. This is an area that needs attention.

Another pathway by which waste-derived constituents from the LEHR site could have in the past and currently reach Putah Creek is through the domestic wastewater system at the LEHR site where wastewaters from this site are transported via pipe to the UCD campus wastewater treatment plant. This plant, after treatment which is not specifically designed to remove hazardous chemicals, discharges the treated wastewaters to Putah Creek just west of Old Davis Road. The fact that wastewaters developed at the current LEHR site are discharged to the UCD wastewater treatment plant and from this plant to Putah Creek, makes the operations of this plant and its discharges to Putah Creek of special concern to the LEHR site investigation and remediation program.

The third pathway by which wastes from the LEHR site could reach Putah Creek is on the eastern edge of the LEHR site property where some entity constructed a drainage ditch through UCD Campus Landfill No. 3 exposing hazardous and deleterious wastes to waters that pass through this ditch to Putah Creek. This drainage ditch appears to have been constructed to drain stormwater runoff from the UCD campus and/or I-80. Recent studies on UCD Campus Landfill No. 3 show that a variety of hazardous chemicals are present in this landfill and, therefore, some of these chemicals could be contributed to Putah Creek via drainage waters that pass through the landfill.

A fourth pathway that could result in some hazardous waste components reaching the environment where part of them could reach Putah Creek is through the translocation of wastes through terrestrial plant roots to the vegetation. The vegetation in turn could be carried by wind or animals to the Putah Creek system. While it is unlikely that this has been a significant pathway for waste transport to Putah Creek, it may have been a significant pathway for exposure of wildlife to LEHR site wastes. Thus far, the potential for translocation of wastes to the surface via terrestrial plant roots to the vegetation has apparently not been investigated. This is an area that needs to be investigated.

DOE LEHR Site Investigations

Several years ago, DOE through its contractors, conducted a comprehensive study of Putah Creek water quality for the purpose of defining whether Putah Creek, at that time, was being polluted by LEHR site wastes. In addition to taking water samples, there were some sediment samples taken; however, the approach that was used in examining the sediments for residual pollutants was not properly conducted. There could have been and still be pollution of sediments under the surface layer of Putah Creek sediments which would not have been detected by the methods used. Further, no studies were conducted to determine if the water or sediments were toxic to aquatic life. This was and continues to be a significant deficiency in the DOE studies conducted on Putah Creek water quality.

Another significant deficiency with past and current Putah Creek water quality studies is the failure to examine aquatic life in the Creek for bioaccumulation of hazardous chemicals including radioisotopes. In the 1994 RI/FS Workplan developed by DOE, it was stated that bioacccumulation studies would be conducted if excessive concentrations of constituents that tend to bioaccumulate were found in the water. This reasoning is flawed in that the bioaccumulation of constituents in organism tissue is a much more sensitive, reliable approach to determining whether excessive concentrations of constituents have been discharged to Putah Creek from the LEHR site and UCD waste management activities. Chemical sampling, as practiced by DOE, only collects a spot sample which represents the situation at the time of sampling. Collecting organism tissue for chemical analysis determines directly whether excessive bioaccumulation has, in fact, occurred. Further, it integrates the recent exposure history of the organism to pollutants in Putah Creek that tend to bioaccumulate within organism tissue.

During the past couple of years, DOE has been conducting a monitoring program of Putah Creek water quality where at quarterly intervals, a sample of Putah Creek water was taken upstream above Old Davis Road which is also above where the UCD campus wastewater treatment plant discharges to Putah Creek. This discharge was also sampled quarterly as part of this program. This is justified since current LEHR site wastewaters are being discharged to this treatment plant.

Another sampling station on Putah Creek is located downstream above where the ditch that cuts through Landfill No. 3 discharges to Putah Creek. This sampling location would not necessarily sample any pollutants that reach Putah Creek from the exposure of the wastes at Landfill No. 3.

There is need to immediately change the DOE sampling program for Putah Creek to move the downstream station further downstream so that it does, in fact, have the opportunity to pick up discharges to the Creek from the drainage ditch that cuts through Landfill No. 3.

There is also need to immediately conduct a comprehensive aquatic life sampling program to determine if waste-derived pollutants from the LEHR site are bioaccumulating in aquatic life to a sufficient extent to be adverse to higher trophic level aquatic and terrestrial organisms as well as to the use of fish and other organisms taken from Putah Creek as food.

Putah Creek near LEHR is intensively fished. Since last January when the author first became involved in Putah Creek water quality issues, he has repeatedly observed individuals fishing in Putah Creek. While it is unknown whether any fish are being caught and eaten, there is sufficient concern about this situation to justify a comprehensive study of bioaccumulation of constituents in fish and other aquatic life along Putah Creek. This sampling of fish should include downstream of where the drainage ditch that cuts through Landfill No. 3 enters Putah Creek. Of particular concern would be the release of PCBs from Landfill No. 3 to Putah Creek which could bioaccumulate in fish tissue.

While not only a LEHR site issue, there is no question that the current LEHR site activities of discharge of domestic wastewaters are contributing to a hazardous condition that exists in Putah Creek through the exposure of swimmers and others who contact recreate in the Creek. Throughout late spring and this summer, the author has repeatedly observed individuals swimming and/or recreating in Putah Creek waters. These individuals are being exposed to enteric pathogens such as Cryptosporidium, Giardia, and enteroviruses present in UCD's wastewater treatment plant discharges to Putah Creek.

The current UCD treatment of wastewaters that are discharged to Putah Creek is not adequate to remove these organisms from the wastewater discharge. It is now well known that these organisms are present in domestic wastewaters and would be expected to be present in wastewaters generated at the LEHR site as well as on the UCD campus. There is need to monitor the UCD wastewater discharges for Cryptosporidium and enteroviruses and, if found, significantly improve the wastewater treatment provided by UCD in its campus treatment plant to eliminate the exposure of those recreating in Putah Creek to these organisms.

It should be noted that Cryptosporidium was the cause of the Milwaukee waterborne outbreak of April 1993 in which about 400,000 people became ill and 100 died. This outbreak has led to a general recognition that domestic water supplies and domestic wastewaters are not being adequately treated to protect public health. The Putah Creek situation where people are swimming within a short distance of where the UCD wastewaters are discharged to Putah Creek under conditions where there is little dilution of these wastewaters before individuals swim in these waters represents a potentially particularly hazardous situation that should be immediately addressed.

DOE and its contractors and those who have reviewed the DOE Putah Creek studies, including the "1994 Annual Water Monitoring Report, LEHR Environmental Restoration, University of California at Davis" released in July 1995, have repeatedly made significant errors in assessing the potential critical concentrations of chemical constituents in Putah Creek waters. Examination of the tables in which the Putah Creek water quality data has been presented such as Tables B.1 through B.4 in the 1995 Annual Data Report, show that the concentrations of constituents found in Putah Creek water samples were compared to the "MCL" for the constituent. The MCL value used was the drinking water standard for the constituents listed. While Putah Creek does recharge groundwaters that could become drinking water for someone downgradient of LEHR, Putah Creek is not used directly for domestic water supply.

The appropriate water quality standard that should have been used to examine whether LEHR site derived wastes are adverse to the beneficial uses of Putah Creek would have been the lower of the drinking water MCL or the US EPA water quality criterion for protection of aquatic life. With few exceptions, the critical concentrations that should have been used by DOE to examine whether wastes derived from the LEHR site are adverse to Putah Creek are the US EPA water quality criteria since these are generally much lower than the drinking water standard.

For example for mercury, a 2 g/L MCL was used to determine whether excessive mercury was found in the Putah Creek water samples. The proper criterion for such a comparison is about 0.012 g/L. This is the value that is designed to protect humans from adverse impacts of mercury through eating fish taken from the waters with mercury levels above this amount. The standard that was used to determine if there was excessive mercury in Putah Creek waters and UCD wastewater discharges was about 160 times higher than it should have been.

Examination of the data in the 1995 Data Report for mercury shows another problem with how the DOE studies were conducted on Putah Creek water quality where an analytical method for mercury that only detected mercury down to 0.2 g/L was used. The analytical method that should have been used should have been capable of detecting mercury below the US EPA water quality criterion of 0.012 g/L. The analytical method used was about a factor of 10 less sensitive than it should have been to protect the public from excessive exposure to mercury.

The use of inappropriate analytical procedures to detect mercury at potentially significant levels could have resulted in humans being exposed to excessive concentrations of mercury through the consumption of fish taken from Putah Creek. Further, since the toxicity of mercury to aquatic life is less than the detection limit used for mercury analyses used by DOE in its Putah Creek water quality studies, mercury could have been and continue to be toxic to aquatic life in Creek waters at concentrations below those that could be detected by the analytical methods used.

The situation with mercury is not atypical of several other constituents. Similar problems occur with chromium. DOE and its contractors, as well as the reviewers of the DOE Data Reports, list the critical concentration of chromium as 50 g/L. The US EPA has for years listed the critical concentration of chromium to aquatic life for toxicity at about 12 g/L. As of March 4, 1995 as part of implementation of the National Toxics Rule, the US EPA imposed a chromium standard for California of 10 g/L. This is the detection limit that is being used by DOE in its Putah Creek studies. These studies have shown that at times UCD wastewater discharges to Putah Creek contain chromium above the US EPA criterion that is designed to protect aquatic life from toxicity. Further, any credible studies of chromium impacts should include the use of analytical methods significantly below the detection limit used to measure chromium in water.

The chromium situation is of particular concern since UCD has recently proposed to add a substantial increase in chromium load to its campus landfill wastewater treatment plant arising from the discharge of the UCD West Landfill leachate-polluted groundwaters that are being recovered from a pump-and-treat operation in an attempt to stop the further spread of this pollution. There is a significant potential that the additional chromium that is being added to the UCD campus sewage treatment plant that is derived from the UCD West Landfill polluted groundwaters could lead to excessive chromium in Putah Creek compared to the US EPA criterion/standard that was imposed on California as part of implementation of the National Toxics Rule.

One of the issues of particular concern about the addition of chromium to the UCD campus wastewater treatment plant is that this chromium and/or the additional flow could upset the operations of this plant. This situation is of importance to LEHR since the current LEHR site activities could be contributing to pollution of Putah Creek via the UCD wastewater treatment plant discharge of inadequately treated wastewaters to the Creek.

UCD has recently released a report in which it is claimed that the current wastewater treatment plant can readily accept the additional flow and chromium and continue to provide adequate treatment of its wastewaters. However, examination of the technical basis for that statement shows that it is fundamentally flawed in that UCD in conducting this analysis focused on BOD and suspended solids in treatment plant effluent and not on toxic chemicals. Minor excursions of suspended solids and BOD above the treatment plant discharge limit will likely have limited adverse impact on the beneficial uses of Putah Creek. However, increased loading of toxics to Putah Creek because of the increased flow or the disruption of the treatment plant operations by chromium or some other unidentified chemical in the West Landfill polluted groundwaters could further aggravate the current situation where UCD is now at times contributing aquatic life toxicity to Putah Creek in the form of excessive ammonia.

The LEHR site data show that at times the ammonia present in UCD's wastewater discharges to Putah Creek could lead to aquatic life toxicity. This situation has evidently been ignored by the regulatory agencies, DOE and its contractors, etc. This situation arises from the fact that those responsible for conducting and reviewing these studies failed to critically analyze the data obtained in them for potential impacts on Putah Creek water quality. The increased flow to the UCD wastewater treatment plant could lead to increased aquatic life toxicity in its wastewater discharges. It is important to note that current LEHR site activities through its wastewater discharges to the UCD wastewater treatment plant could be contributing to this problem.

Similar kinds of problems occur with the DOE studies for cadmium, copper and several other elements and compounds that have been monitored by DOE in its Putah Creek studies. Basically, DOE in conducting these studies has failed to implement a credible reliable program for investigating the impact of the LEHR site wastes on Putah Creek water quality. Further, regulatory agencies responsible for supervising the DOE studies have not detected the significant problems that exist in how these studies were conducted, and especially, in the presentation and interpretation of the data generated from them.


Overall, the UCD - DOE studies on Putah Creek have not reliably investigated the potential for UCD and DOE derived wastes from the LEHR site to adversely impact Putah Creek water quality. There is need to develop a reliable monitoring program of Putah Creek water, sediments and aquatic life to determine what, if any, hazardous residual chemicals are present in the Creek system and whether there are any discharges of hazardous or deleterious chemicals from the current LEHR site activities to Putah Creek that are adversely impacting the beneficial uses of this waterbody.

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