Contact FOTP: OrdToxics@aol.com
Approval Memorandum
Interim Action Excavation
Site 36 -Fritzsche Army Airfield
Sewage Treatment Plant
Former Fort Ord
Introduction
On behalf of the Fort Ord Toxics Project (FOTP), Clearwater Revival Company (CRC) has prepared this independent analysis of the proposed interim action excavation Approval Memorandum for the Former Fort Ord Fritzsche Army Airfield (FAAF) Sewage Treatment Plant. CRC reviewed the following document:
Dept. of the Army, "Approval Memorandum, Proposed Interim Action Excavation, IA Areas 36A and 36B, Site 36 - Fritzsche Army Airfield Sewage Treatment Plant, Fort Ord, California," March 17, 1997.
Dept. of the Army, "Interim Action Record of Decision, Contaminated Surface Soil Remediation, Fort Ord, California," February 23, 1994.
Former Fort Ord is a Superfund site and the cleanup of chemical contamination at Fort Ord is required to be documented in a Superfund Record of Decision. The Army developed an Interim Action Record of Decision (IA ROD) for similar cleanup projects that meet certain eligibility requirements. The purpose of the Area 36 Approval Memorandum is to demonstrate that the proposed contaminated soil excavation meets the site eligibility requirements in the IA ROD. The IA ROD contains requirements for a site-specific analysis of potential impacts to groundwater as well as a decision process which ensures that a preference for treatment is demonstrated during interim action planning and execution.
The sewage treatment plant interim action calls for the removal of 190 cubic yards of contaminated soil from two evaporation ponds, removal of the ponds' concrete liners, confirmation sampling of the underlying soil, and disposal of the contaminated soil in the Operable Unit No. 2 landfill at Fort Ord. The Fort Ord Preliminary Remediation Goals have been established as target cleanup concentrations in soil for the pesticide chlordane, petroleum hydrocarbons as diesel, and the metals lead and cadmium.
Summary of Findings
CRC's independent review of the Approval Memorandum identified the following concerns with the interim action:
(1) The Area 36 interim action may be outside the scope of the IA ROD, and regulations may apply to the proposed interim action which were not identified in the IA ROD;
(2) The Approval Memorandum does not demonstrate "protection of human health", "protection of groundwater", and a "preference for treatment" as required by the IA ROD.
(3) Neither the IA ROD nor Approval Memorandum contains provisions for the decontamination and removal of concrete debris;
(4) The proposed soil confirmation sampling is narrow in scope; and,
(5) The proposed waste characterization sampling is narrow in scope.
Sewage Treatment Plant Description
Limited details on the inactive sewage treatment plant's operating history are provided in the reviewed documents. No information on the dates of operation, former wastewater discharge permits and discharge compliance history have been provided. No information is provided on the chemicals found in waste water treated at the plant. The dates of operation could be used to determine the environmental regulations which controlled the types of industrial waste water treated at the plant and the limited chemicals in the plants out-fall.
Based on a diagram included in the Approval Memorandum, the sewage treatment plant consisted of three primary components
An Imhoff tank, which has been removed;
Two sludge drying beds; and,
One 30,000-square foot and six 5,000-square foot evaporation ponds.
An Imhoff tank operates similarly to a septic tank, and is designed to separate solids from wastewater. Generally, up to 60 percent of the solids can be removed from the water. The settled solids would be transferred from the Imhoff tank to the two sludge ponds for drying. The sludge would be removed from the beds for land disposal when dried.
The evaporation ponds which are the target of the interim action would receive the wastewater containing residual solids from the Imhoff tank. These residual solids are apparently the soils proposed for excavation from the concrete lines ponds. The 30,000-square foot pond contains 50 cubic yards of soil in small isolated pockets, and one of the six 5,000-square foot ponds contains 140 cubic yards of soil in a 0.75-foot thick layer.
The source of the contaminants in the soil in the pond has not been attributed to any specific source. The contaminants found in the soils likely originated from waste oil and pesticide rinsate in industrial wastewater discharges to the sewage treatment plant.
<Analysis> The scope of the IA ROD addressed areas of limited surface soil contamination and was based on certain presumptions about the procedures required to complete this activity. The procedures proposed for the interim action at Area 36 are different from the procedures anticipated by the IA ROD. The proposed excavation apparently does not involve soil, but the removal of dried sewage solids, and the demolition of a former sewage treatment pond. The activity appears to be outside the scope of the IA ROD. Further analysis provided below indicates many of the interim action activities are not adequately addressed by the IA ROD. <>
<Analysis> Compliance with ARARs has not been demonstrated. Depending on the years of operation and the types of industrial wastes treated by the FAAF sewage treatment plant, the Toxic Pits Act (Health and Safety Code Section 25208 ) may be an applicable, or relevant and appropriate requirement (ARARs). The ROD does not address this potential ARAR. <>
Characterization and Screening Risk Evaluation
The sewage treatment plant ponds are one of the principal sources of contamination being investigated in Area 36. Three metals, beryllium, chromium and zinc, have been detected above background levels in deep soils. The depth to groundwater at Area 36 is reportedly 95 feet below ground surface. Information on groundwater quality was not provided in this document.
The Screening Risk Evaluation for Area 36 showed the presence of the following site related chemicals: bis(2-ethylhexyl)phthalate, cadmium, chlordane, chromium, copper, lead, selenium, mercury, and zinc in the evaporation ponds. From this list of chemicals chlordane (max. 0.19 ppm), cadmium (max. 40.7 ppm) and lead (max. 350 ppm) represented the greatest cancer and non-cancer risk and were selected as chemicals of concern for the interim action excavation.
TPH-Diesel (max. 830 ppm) was detected at the site but not evaluated in a screening risk evaluation. A target cleanup level for TPH-Diesel of 500 ppm has been established by the Army as a cleanup level. The Regional Water Quality Control Board (RWQCB) generally imposes a cleanup level of 100 ppm for TPH-Diesel. The RWQCB conditionally accepted the Army's 500 ppm target cleanup concentration. The four conditions imposed by the RWQCB on the Army's use of the 500 ppm cleanup concentration for TPH-Diesel are:
(1) The petroleum must be weathered, consisting of heavy (14 or more carbons) hydrocarbons;
(2) The depth to groundwater must range from 60 to 150 feet in depth;
(3) A soil partitioning model must be used at each site to evaluate potential groundwater impacts; and,
(4) The 500 ppm cleanup concentration must be protective of both human health and groundwater quality based on conservative site-specific data.
<Analysis> Three of the four conditions required for use of the 500 ppm cleanup level for TPH-Diesel have not been met. No site specific data was used to show that the TPH-Diesel was weathered and consisted of heavy hydrocarbons. Protection of groundwater has not been demonstrated as required by the IA ROD. No site specific soil partitioning model has been performed for TPH-Diesel or any of the site related chemicals. No site specific data has been used to determine if the conditional 500 ppm TPH-Diesel cleanup concentration is protective of human health. <>
<Analysis> The approval memorandum makes reference to soil and groundwater sampling data that is contained in a separate report. It is important to facilitate public review that documents such as the Approval Memorandum be self-contained.
Site Eligibility for IA
The principle purpose of the Approval Memorandum is to demonstration that the Area 36 interim action met the 10 site eligibility requirements contained in the IA ROD. The IA site must be characterized and target cleanup concentrations determined.
Two eligibility requirements limit soil excavations to less than 5,500 cubic yards of soil and less than 25 feet below ground surface. IA area also exclude liquid wastes, medical wastes, radionuclides, and sludges. The Approval Memorandum estimates an excavated soil volume of 190 cubic yards and provides a not to exceed soil volume of 300 cubic yards without regulatory agency notification. The thickness of soil in the pond is estimated as 0.75 feet. The pond is subterranean and no depth below ground surface is provided in the Approval Memorandum.
The remaining six eligibility requirements deal with the location of the interim action. An interim action is excluded in areas where it may impact biological and cultural resources, existing watercourses or wetlands, historic structures, oak trees, the coastal zone, and high risk ecological areas. Area 36 is reportedly not within any of the six areas excluded from interim actions.
<Analysis> The volume of the concrete liner to be excavated was not provided, though the removal of the liner is a key element of the interim action. The final depth below ground surface of the excavation is also not provided. Despite the omissions of these data, the interim action would likely fall within the limits established by the IA ROD for interim action eligibility. < >
<Analysis> The Approval Memorandum does not provide the results of site specific modeling used to evaluate groundwater impacts that is required by the IA ROD and by one of the interim action eligibility requirements (site characterization/target cleanup concentrations). The Approval Memorandum only references results of such a model performed for wastes in the Fort Ord landfill. This model did not use Area 36 site specific data. <>
<Analysis> The Approval Memorandum does not demonstrate that human health is protected as required by the IA ROD and by one of the interim action eligibility requirements (site characterization/target cleanup concentrations). A site specific analysis is required for TPH-Diesel as a condition of the 500 ppm cleanup level. TPH-Diesel was not included in the Screening Risk Evaluation for Area 36. <>
Implementation Process
The IA ROD presents an implementation process decision flowchart. The decision process contains requirements for confirmation sampling and further excavation, if warranted.
Eight confirmation samples will be collected from each pond area. Samples will be analyzed for TPH-diesel, chlordane, lead, and cadmium. The samples will be collected from each of the four walls of the excavation and four samples will be collected from the base of the excavation.
<Analysis> The concrete liner is located between the contaminated soil that is to be removed, and the underlying soil, from which confirmation samples will be collected. The IA ROD implementation process and approval memorandum make no specific reference to the decontamination or disposal of contaminated debris such as the pond's concrete liner. The expected treatment and final disposition of the concrete has not been provided. < >
<Analysis> The area of the two ponds are 30,000-square feet and 5,000-square feet. The same number of confirmation samples are proposed for each pond. It seems logical that six times the number of confirmation samples should be collected from the larger pond since it contains six times the area. < >
<Analysis> The confirmation samples analysis scope is limited to two metals. Other metals previously detected at the site should be included in the confirmation sampling. <>
Treatment Evaluation
The IA ROD presents a soil treatment options decision flowchart. The decision process is intended to ensure that the preference for treatment is met. The IA ROD proposes to dispose of the excavated soil in the Fort Ord landfill. No treatment or disposal method is provided for the concrete liner.
A four-point composite sample will be collected for each 100 yards of excavated soil to determine waste characteristics. Samples will be analyzed for TPH-diesel, chlordane, lead, and cadmium.
<Analysis> The decision to dispose of untreated soil in the Fort Ord landfill has not been justified through the decision process contained in the IA ROD. To reach the decision of landfilling wastes a determination had to be made that the excavated soil could not be treated to reduce mobility, toxicity and volume. No rationale for making this determination is provided in the Approval Memorandum.
<Analysis> Stockpile sampling does not adequately characterize the excavated soil for disposal. The Area 36 Screening Risk Evaluation indicates that cadmium, lead, zinc, mercury, copper and selenium were present in total concentrations that exceed the soluble threshold limit concentration (STLC) for waste classification. It appears that a additional tests are appropriate for soil stockpile sampling to determine if the soil exceeds state and RCRA hazardous waste concentration thresholds. The decision flow chart for soils treatment requires waste characterization information to determine a soil handling method that is consistent with the IA ROD requirements. <>
Summary
This interim action appears to be outside the scope of the IA ROD. The material to be removed from Area 36 appears to be a waste created during operation of a sewage treatment plant, which would not be within the scope of the surface soils the IA ROD is intended to address. The IA ROD also makes no allowances for the removal of contaminated concrete debris, and there is no information provided in the approval memorandum how this material will be decontaminated and disposed of.
If the IA ROD's scope is determined to include the interim action, a question remains as to whether or not the interim action would meet all ten of the eligibility requirements. To be eligible for an interim action the site must be adequately characterized and target cleanup concentrations must be determined. Based on the IA ROD's site-specific requirements for modeling potential impacts on groundwater quality and evaluating the target cleanup concentrations for TPH-Diesel this eligibility requirement was not met.
To ensures that a preference for treatment that reduces mobility, toxicity, and volume, the IA ROD contains a decision flowchart to determine soil treatment and disposal options. The proposed landfill disposal method for soil, and the unspecified disposal method for contaminated concrete debris method have not demonstrated consistency with this decision process.
The FOTP website is a SEEK MapCruzinTM project.
Created and Maintained by Michael R. Meuser
Copyright © 1997-1999 Fort Ord Toxics Project
All Rights Reserved