Meanwhile, Back at the Ranch

Meanwhile, Back at the Ranch Newsletter of the Frontier Fertilizer Superfund Oversight Group Fall-Winter 2003 Volume 6, issue 2

Update of Work at the Site

This past summer and fall the Frontier Fertilizer Superfund Oversight Group (FFSOG) met with representatives from EPA, their contractor (CH2MHill), and the State Department of Toxic Based on monitoring data and Substances to discuss progress at the Frontier site, a schedule of groundwater model results, future activities, and questions regarding the Risk Assessment done EPA and its contractor for the site. designed a system to fully The FFSOG was also introduced to EPA’s new Project Manager for contain the plume of the Frontier site, Bonnie Arthur. Bonnie is taking over for long- contaminated groundwater, time Project Manager, Janet Rosati, who is leaving to complete and to extract, transport and work on a large federal superfund site in Hawaii. remove contaminants. EPA developed plans to install new high capacity extraction wells In the previous year, EPA and its contractor completed a series of in the areas of high groundwater and soil samplings to determine current levels and concentration of contaminants extent of soil and groundwater contamination. Some of the data showed that, while contaminant concentrations were generally near the former disposal basin decreasing in the upper two water-bearing zones (the S1 and S2), and in the neighborhood. levels were increasing in some locations in the A1 aquifer. High concentrations of contaminants also remain in the soil and groundwater in the area of the old disposal basin and in the New high capacity extraction groundwater in the area of Arroyo and Caricia in the Mace Ranch wells have been installed in 11 housing development. (Mace Ranch 11 is the development just the field south of the Mace north of the Frontier site.) Ranch 11 housing development near Arroyo and in the eastern portion of the The downward movement was of concern to the FFSOG; if well field. Another new unchecked, downward movement of contaminants could eventually extraction well was installed threaten the city’s drinking water aquifer. Data showed that in the field just north of the horizontal movement of the contaminated groundwater had site of the old disposal basin, generally slowed considerably and was being largely contained by replacing an old, smaller the pump and treat system but that vertical movement was not. capacity extraction well at that site. The new wells were installed only in the S2 EPA completed extensive pump testing last year to gather aquifer, as data showed that additional data for aquifer transmissive properties. These data were the contamination in the S1 used in revising the groundwater model. The pump tests also give was being captured with the an indication of the extent of influence the well has on groundwater existing system, but that movement and contaminant removal. contamination in the S2 was 1 escaping downward. The new wells will draw contamination out of * Modeling Efforts the S2 and prevent further downward movement. * Figures EPA also installed four piezometers (smaller wells to measure water * Future Plans and Timelines levels) between the subdivision and the Frontier property. The * Risk Assessment piezometers will help evaluate the effectiveness of the extraction Questions wells in preventing further downward movement. * RAMCO Update Piping to connect all the wells to the system occurred through the * Call for Volunteers fall and winter. * Contribute

In This Issue: * Update of Work at Site

The older extraction wells have been upgraded as of the old disposal basin. The levels appeared to well. The upgraded system appears to be fall somewhat through the winter, but were still working well, and is capturing 3 to 5 times the well above the MCLs. amount of contaminant it was capturing a year ago. EPA would like to increase the level of water

pumped by the system, but they are nearly at their discharge limits with the city of Davis. The second Supplemental Remedial (Treated water is discharged into the city’s waste Investigation (RI) Report was released in water treatment system.) As a result, the January of 2003. The RI summarized the CPT, removal action this past summer and fall focused hydro punch, and soil sampling data collected on the upper water bearing zones, the S1 and S2. over the previous year. Monitoring data revealed Pumping from the underlying A1 aquifer will be that carbon tetrachloride (CCl4) was high on the part of the feasibility study currently underway. eastern portion of the site and the neighborhood, To pump from the A1 aquifer, EPA would like in particular near Cresta Court. This past and may need higher capacity. The system is summer, EPA installed monitoring wells at the currently nearly at the maximum with extraction end of Cresta Court and capacity of 70gpm (gallons per minute). EPA east of the current well field to keep an eye on has applied to the city to increase that to 85gpm. contamination in these areas. There were also Eventually, EPA may need to pump closer to high levels of pesticides in the old disposal basin 250gpm, but would need to find alternative and just north of it, as usual, and in the area of discharge locations. One option is to use OW 11 in the S2 and A1 aquifers on Arroyo. injection wells, as has been done in the past. The new extraction wells should help remove However, the injections wells are screened in the these high levels of contamination. S1 which is tight soil, so not much water can be

pushed into them. Injecting water in the shallow zones can also increase downward groundwater In general, levels of contaminants in the S1 and movement. Another option might be to use the S2 in the area of Mace Ranch 11 have been water for irrigation, but the salinity may be too decreasing, but this is more likely due to the high unless the water is diluted with clean water. downward movement than to the pump and treat (At the LEHR site on campus, Davis’s other system at this point. As mentioned above, levels federal superfund site, this is what is done with of some of the contaminants have been the “cleaned” groundwater.) increasing in the A1, the lower aquifer. Fourth quarter 2002 monitoring showed high levels of pesticides in the A1 in Ow11, X7, and at the site Modeling Efforts 2 EPA’s contractor, CH2MHill, has been developing a computer groundwater flow model to help with some of the cleanup activities. The CPT-24 model is a tool to help design the extraction CPT-23 system and further hydrologic understanding. It CPT-25 gives EPA the ability to examine the ground- CPT-22 water flow in a 3-dimensional system, and will allow them to evaluate extraction well effectiveness. The model incorporates all the data input from the pump and treat system and monitoring wells and allows EPA to look at the CPT-41 effect of new wells on the system. With the upgraded system in place, EPA defined the CPT-51 “target volumes” (see figures, page 3). The target volumes are roughly the volume of contaminated groundwater where concentrations Consistently 0 to 0.5 Below MCL of contaminants exceed the MCLs. All of this Intermittantly 0.5 to 1 Above MCL N Consistently 1 to 1.001 Above MCL 0 250 500 750 1000 contaminated groundwater must be captured, so All wells are shown as circles CPTs that helped define Target Volume this establishes the boundaries around the wells are shown as squares Historical concentrations FIGURE 1-3 with high levels. The target volumes drive the were compared to MCLs for: Target Volume for S-2 Zone pump and treat system design. DCP (5 ug/L), EDB (0.05 ug/L), Frontier Fertilizer 2003 Model Update DBCP (0.2 ug/L), and CCl4 (0.5 ug/L)

Pump tests on some of the new extraction wells helped improve understanding of the effects of pumping from the lower aquifers. There was a question as to the effect on the shallow groundwater from pumping of nearby city wells. There was concern that pumping from these wells could result in pulling contamination downward to the lower aquifers. City well 29 is the nearest city well to the site, at the corner of Alhambra and 5th Street. This well is screened between 600 and 1400 feet below ground, well below the A1 aquifer. EPA commissioned a pump test of well 29. Pumping of this well for 7 hours did not affect the water levels at the site.

3 CPT-23

CPT-25

CPT-22 CPT-27

CPT-41

CPT-51

Consistently 0 to 0.5 Below MCL Intermittantly 0.5 to 1 Above MCL N Consistently 1 to 1.001 Above MCL 0 250 500 750 1000 All wells are shown as circles CPTs that helped define Target Volume are shown as squares

Historical concentrations FIGURE 1-2 were compared to MCLs for: Target Volume for S-1 Zone DCP (5 ug/L), EDB (0.05 ug/L), Frontier Fertilizer 2003 Model Update DBCP (0.2 ug/L), and CCl4 (0.5 ug/L)

As the result of input by the FFSOG and other reviewers, CH2MHill made several changes to the model. To ensure complete capture and that the boundaries are wide enough so that new wells or a change in pumping volume do not affect the model boundaries, the modeled area was increased to 5 by 5 miles square. More detail about discharge and regional pumping effects were also added to the model. The model now includes half the city.

The overall goal of the model was to develop and improve a tool to evaluate site groundwater conditions and to estimate whether more extraction wells were needed to contain the contamination. The model estimated that 4 additional wells in the S2 were needed to capture the contamination and prevent further lateral and vertical movement of contaminated groundwater. These wells have been installed, as mentioned earlier. A contingency analysis indicated as many as 7 additional wells may be needed.

4 The model can now be used to evaluate the current extraction system performance in Future Plans and Timelines capturing the target volumes in the S1, S2, and A1. All the groundwater within the target volume should go into the extraction wells for This past summer/fall activities were the last total containment. Lack of containment indicates stages of the removal action. EPA is now a modeling problem, and EPA will need to adjust beginning to work on the Feasibility Study (FS) the model based on what is learned from looking at alternatives for the final remedy for additional data collected with operation of the the contaminated soil and possible Dense Non upgraded system. With the upgraded model, Aqueous Phase Liquid (DNAPL). Tons of EPA can then simulate the effect of adding more highly contaminated soil remain on the Frontier extraction wells and develop a plan for more site in the area of the old disposal basin and must wells. If new wells are needed, however, the be removed or treated in some way before any pumping volume would increase to above 80gpm other work can proceed on the old Frontier and would exceed the maximum discharge Fertilizer site. (The city of Davis proposes allowed by the city. EPA is currently soliciting redevelopment of that site and received funding the city for increased discharge capacity. from EPA to develop a plan for that.) The DNAPL is essentially pure pesticide that sank down into the soil under the old disposal basin One criticism of the model has been that it is and currently rests between the S1 and S2 calculated for average water-level data from1997 aquifers. This serves as a source for the to the present, and then the current pumping was contamination in the groundwater, as the added to the model. It is not reflective of DNAPL slowly dissolves in the groundwater current conditions with the new expanded moving past it, and future plans must take into extraction system in place. FFSOG’s technical consideration removing or treating the DNAPL. advisor believes there needs to be some Removal would hasten cleanup of the uncertainty analysis of how future hydrologic contaminated groundwater. conditions and water demand may affect the predicted groundwater contaminant capture. The There are no “off the shelf” treatments for these calculations should have included the effect on pesticides, so EPA is presently developing tables vertical flow of increased pumping as the city of of possible treatments, and will probably propose Davis grows. More city pumping can pull a treatability study to determine the best options. contamination downward, and the system needs The FS will also look at alternatives to the pump- to continue to prevent that. A significant drought and-treat-forever option. Part of the plan might could also have an effect on containment and include removal of the contaminated soil and capture. DNAPL as mentioned above. In the absence of any suitable treatment or safe removal plan for Though EPA concedes that it is definitely possible that groundwater pumping around Davis will increase in coming years with new development or that a drought could occur, these possibilities were not included in the scope of the present model, as EPA’s plans are to update extraction as known conditions dictate. Since EPA intends to move forward with the model as it is, it will be important to look closely at regular monitoring reports to see how accurate the model is at predicting.

5 the DNAPL, stabilization and containment may upon, operation and maintenance of the system be the goal. The endgame is to prevent receptors will continue; in the case of the pump and treat from being affected. system, possibly for decades. Every five years thereafter will be an analysis of the effectiveness Once a Proposed Plan (PP) is determined, there of the final remedy. The FFSOG will remain will be a public meeting before selection of a part of this process and part of the plan preferred alternative. Then a record of decision development. (ROD) will be issued followed by remedial (RD) design and then remedial action (RA). After Tentative Time-Line: implementation of whatever remedy is decided Feasibility Study begins May 2003 committed to providing QA/AC data for the gas ROD December 2004 sample results. When asked what would trigger Draft FS February 2004 an additional risk assessment, EPA’s project RD March 2005 manager replied that discovery of increasing Final FS July 2004 concentrations would trigger this. RA August 2005 During these discussions, the question arose of Final PP September 2004 doing an ecological risk assessment or screening animals like squirrels or birds that inhabit the Risk Assessment Frontier site itself. The animals on the At previous meetings with EPA, there have been contaminated site have gone through multiple many questions about the adequacy of the site generations. An ecological risk assessment Risk Assessment (RA), in particular in relation would evaluate pathways to flora and fauna on to the gases rising up from the contamination in the site and if a significant risk exists, then there the groundwater. The risk assessment performed could be some animal testing to determine for the site was based on potential exposure to possible effects. The ecological assessment was carcinogens and concluded that the levels of the to begin in December, 2003 and continue for 6 contaminants rising into the air in the area of the months. One of CH2MHill’s biologists is Mace Ranch 11 homes were too low to pose a conducting the assessment. cancer risk to homeowners. Some of the contaminants are also endocrine disrupters or Do you have concerns relating to the risk reproductive toxins. Little is known about how assessment and some of the issues brought up long-term exposure to even very low levels here? If so what is your level of concern? Do might affect the reproductive system, especially you believe EPA should do more testing and in the developing fetus or child. Some of the analysis of the gases rising from the groundwater questions asked how the risk calculations were in the area of the homes in Mace Ranch 11? Do done and whether they were protective of you believe EPA should test air inside homes for children and infants and were they protective of presence of these contaminants? Or are you risks from endocrine disruptors as well as cancer satisfied with the conclusions reached in the RA? risk. EPA’s toxicologist for the site believes that Contact us at 530-756-6856 or the protective level for cancer is also protective [email protected]. for endocrine disruption. There were also questions about gas collection Update on RAMCO Development at Site methodology and the fact that there appeared to The FFSOG has received several phone calls be insufficient quality control and quality related to development activities taking place on assurance. In response to questions regarding the RAMCO way gas samples were taken and handled, EPA property south of the Mace Ranch 11 Neighbors are concerned that RAMCO’s neighborhood. RAMCO Enterprises has activities might interfere with timely clean up of constructed an east-west roadway through its the superfund site. As described in our last property and is installing underground utilities. newsletter, there were several conditions agreed 6 upon by RAMCO, the city of Davis and EPA FFSOG will keep the community informed of that had to be met in order for RAMCO to move ongoing development activities on the RAMCO forward. Most important, EPA stipulated that if site. RAMCO did proceed with development of the property, any improvements constructed by RAMCO that interfered with EPA’s work could be removed, modified, or disabled by EPA and Calling for Volunteers! their contractors if needed, the cost to be borne by the developer. Another condition concerned The FFSOG’s Board of Directors is a EPA’s well field which is within RAMCO’s volunteer group working to keep the property. The parcel containing the well field, community informed of and involved in the termed the Remainder Parcel, is underlain with progress in the clean up of contamination at high levels of groundwater contaminants that are the Frontier Fertilizer Federal Superfund site. the subject of EPA’s response action at the Site. Two of our long-term members have recently Development of this parcel cannot take place left the board. We could use your help. until EPA’s work in the area is complete. A Would you be interested in serving on our small portion of the parcel just north of the old Board of Directors? If you are interested or disposal basin on the Frontier Fertilizer property, would like more information on what it is we has high levels of contamination in the soil from do, contact us at [email protected] or 1 to 30 feet below ground surface. The roadway call us at 530-756-6856. as originally proposed by RAMCO was to run through this portion. Due to the high levels of FFSOG is a non-profit public benefit corporation formed in the State of California. FFSOG is formed as a community oversight soil contamination in this area, an agreement was group dedicated to keeping the larger community informed of reached with the city of Davis, EPA and progress in EPA’s clean-up activities at the Frontier Fertilizer RAMCO that the roadway was to be built as two superfund site and to facilitating meaningful public input into the process. temporary cul-de-sacs ending on either side of the contaminated soil area, designed so that they Please help us in our efforts. Make your tax- may be connected at a later date. deductible contribution payable to FFSOG. Last fall, RAMCO again approached EPA, ____Add me to your mailing list. requesting to build the road as a through street, ____I would like to make a donation to contrary to the agreement previously reached with EPA and the city. EPA again informed FFSOG in the amount of: ____$10 RAMCO that it would not be possible to ____$25____$100____Other. construct a through street, as it would seriously impact EPA’s work there, including ongoing ____I cannot make a donation at this time but installation of new wells and their supporting infrastructure. Two recent incidents illustrate the would like future information. problems that can occur when RAMCO and EPA Please contact FFSOG at 3010 Loyola Drive, are trying to conduct concurrent operations in the Davis, CA. 95616, (530) 756-6856, or same area. In September, a subcontractor [email protected]. Please include working for RAMCO accidentally severed a your name and contact information. control conductor associated with an extraction Check out our website at well, resulting in the well being taken off line for www.dcn.davis.ca.us/go/ffsog. 5 hours. In October, a subcontractor working for Thank you for supporting FFSOG. RAMCO accidentally severed EPA’s discharge FFSOG Board of Directors: pipe to the sanitary sewer. As a result, EPA had Joseph Calger Wendy Cohen Dennis Edgerley Chris to shut down the entire pump and treat system Hawkes Beth Kelly Pam Nieberg Elias Rashmawi for nearly 24 hours. Clearly, even with carefully FFSOG Technical Advisor: Steve Deverel, PhD planned operations, disruptions can occur that Frontier Fertilizer Superfund Oversight Group, 3010 Loyola Drive, Davis, CA. 95616; (530) 756-6856 impair EPA’s ability to complete it work. The 7 FFSOG is a non-profit public benefit corporation formed in the State of California. FFSOG is dedicated to oversight during the investigation, remediation, and mitigation work addressing the contamination at and as a result of the Frontier Fertilizer site, informing the public of progress via the FFSOG newsletter, website, newspaper articles, and public meetings, and facilitating meaningful public input into the process and decisions.