Pacific Southwest, Region 9: Superfund
Serving Arizona, California, Hawaii, Nevada, the Pacific Islands, and Tribal Nations
Waste Disposal, Inc.
Record of Decision
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|Date||Title / pdf File|
|12/27/93||Waste Disposal, Inc. Soil and Subsurface Gas Operable Unit Record of Decision|
Record of Decision:
Waste Disposal, Inc. Site,
Santa Fe Springs, CA,
WASTE DISPOSAL, INC.
SOIL AND SUBSURFACE GAS OPERABLE UNIT
RECORD OF DECISION
Waste Disposal, Inc. Superfund Site
Santa Fe Springs, California
United States Environmental Protection Agency
Region 9 - San Francisco, California
TABLE OF CONTENTS
Record of Decision for Waste Disposal, Inc. Superfund Site
Santa Fe Springs, California
|Part I Declaration|
|1.0||Site Name and Location||1-1|
|2.0||Statement and Basis of Purpose||1-1|
|3.0||Assessment of Site||1-1|
|4.0||Description of the Selected Remedy||1-1|
|Part II Decision Summary|
|1.0||Site Name, Location, and Description||2-1|
|4.0||Highlights of Community Participation||2-4|
|5.0||Scope and Role of Operable Unit||2-5|
|6.0||Summary of Site Characteristics||2-5|
|7.0||Summary of Site Risks||2-6|
|8.0||Description of Alternatives||2-7|
|8.1 Alternative 1: No Action||2-7|
|8.2 Alternative 2: Fencing, Revegetation, and Institutional Controls||2-7|
|8.3 Alternative 3: Containment||2-9|
|8.3.1 Option A: Multi-Layered Soil Cover||2-10|
|8.3.2 Option B: Asphalt Cap without Excavation||2-10|
|8.3.3 Option C: RCRA-equivalent Asphalt Cap with Limited Excavation||2-10|
|8.3.4 Option D: Multi-Layered Hazardous Waste Final Cover||2-12|
|8.4 Alternative 4: Excavation and Off-site Disposal||2-12|
|9.0||Summary of Comparative Analysis of Alternatives||2-13|
|10.0||The Selected Remedy||2-17|
|10.1 Clean-up Standards||2-19|
|10.2 Limited Excavation and Consolidation||2-20|
|10.3 Passive Venting System||2-21|
|10.4 RCRA-equivalent Impermeable Cap||2-21|
|10.5 Gas Monitoring, and Active Gas Extraction and Treatment||2-21|
|10.6 Institutional Controls||2-22|
|10.7 Annual Inspection||2-23|
|10.9 Design Options||2-23|
Table of Contents
|11.1 Protection of Human Health and the Environment||2-25|
|11.2 Compliance with Applicable or Relevant and Appropriate Requirements||2-25|
|11.3 Cost Effectiveness||2-26|
|11.4 Use of Permanent Solutions and Alternative Treatment Technologies to the Maximum Extent Practicable||2-26|
|11.5 Preference for Treatment as a Principal Element||2-27|
|12.0||Documentation of Significant Changes||2-27|
|Part III Responsiveness Summary|
|2.0||Summary of Responses to Major Issues and Concerns||3-2|
|2.1 Health Concerns and Site Risks||3-2|
|2.2 Aesthetics and Future Land Use||3-3|
|2.3 Effectiveness of Remedy||3-4|
|3.0||Detailed Response to Comments||3-4|
|3.1 Comments from Ernest Brown & Company||3-4|
|3.2 Department of Toxic Substances Control, Comments to the Feasibility Study Report for Soils and Subsurface Gas||3-7|
|3.3 Water Replenishment District of Southern California||3-9|
|3.4 Department of Toxic Substances Control Comments to WDI Proposed Plan||3-11|
|3.5 Bear, Kotob, Ruby & Gross, on behalf of Dr. Adeline Bennett||3-12|
|3.6 State of California Department of Health Services||3-13|
|3.7 City of Santa Fe Springs||3-15|
|3.8 Albert L. Sharp, Mayor Pro Tem, City of Santa Fe Springs||3-19|
|3.9 Phil Campbell||3-20|
|4.0||Public Meeting Comments||3-20|
PART I DECLARATION FOR THE RECORD OF DECISION
1.0 Site Name and Location
Waste Disposal, Incorporated (CERCLIS ID #CAD980884357)
Los Nietos Road at Greenleaf Avenue
Santa Fe Springs, California
2.0 Statement of Basis and Purpose
This decision document presents the selected remedial action for the Waste Disposal, Inc. site in Santa Fe Springs, California, which was chosen in accordance with CERCLA, as amended by SARA, and, to the extent practicable, the National Oil and Hazardous Substances Pollution Contingency Plan. This decision is based on the Administrative Record for this site.
The State of California agrees with the selected remedy.
3.0 Assessment of the Site
Actual or threatened releases of hazardous substances from the site, if not addressed by implementing the response action selected in this Record of Decision, may present an imminent and substantial endangerment to public health, welfare, or the environment.
4.0 Description of the Remedy
This operable unit is the first of two planned operable units for the site. An operable unit is a discrete portion of a response action under CERCLA. The first operable unit addresses contaminated soil and subsurface gases. This action addresses the principal threat at the site, which is exposure to contaminated soil, through containment and institutional controls.
The major components of the selected remedy include:
× Consolidation of contaminated soil beneath a multilayered,
× Capping approximately 17 acres of the 43-acre site with above
mentioned cap (approximately 75% asphalt, 25% vegetation top
× Extraction and treatment by flaring of subsurface gases, if
× Institutional controls that restrict future use of properties with
residual contamination that pose an exposure risk; and
× Groundwater monitoring.
5.0 Statutory Determinations
The selected remedy is protective of human health and the environment, complies with Federal and State requirements that are legally applicable or relevant and appropriate to the remedial action, and is cost-effective. This remedy uses permanent solutions and alternative treatment (or resource recovery) technologies to the maximum extent practicable for this site. However, because treatment of the principal threat of the site was not found to be practicable, this remedy does not satisfy the statutory preference for treatment as a principal element. Because this remedy will result in hazardous substances remaining on-site above health-based levels, a review will be conducted within five years after commencement of the remedial action to ensure that the remedy continues to provide adequate protection of human health and the environment.
This ROD will be followed by another operable unit ROD which will address groundwater and the final remediation of the Site.
John C. Wise Date
Deputy Regional Administrator
United States Environmental Protection Agency
PART II DECISION SUMMARY
1.0 Site Name, Location, and Description
The Waste Disposal, Inc. (WDI) Superfund site is located in the city of Santa Fe Springs, Los Angeles County, California, on a 43-acre parcel of land. The facility is bordered on the northwest by Santa Fe Springs Road, on the northeast by Fedco Food Distribution Center (Fedco) and St. Paul High School, on the southwest by Lost Nietos Road, and on the southeast by Greenleaf Avenue (see Figure 1). Residences are located across from the facility on Greenleaf Avenue. The remaining areas on and across Los Nietos Road and Santa Fe Springs Road are occupied by industrial complexes.
2.0 Site History
The WDI site contains a 42 million gallon capacity concrete reservoir originally constructed for crude petroleum storage. The reservoir was decommissioned in the late 1920s for product storage, and was subsequently used for disposing of a variety of industrial wastes. Aerial investigations, records searches and previous site sampling indicate the surrounding grounds also were used as unlined sumps for disposal. Disposal activities continued unregulated until 1949, and thereafter under permit from Los Angeles County, until closure in 1964. Documentation on disposal was sporadic, but investigations have shown that drilling muds, sludges, tank bottoms, various industrial wastes, and construction debris and other solid wastes were disposed at WDI.
WDI stopped accepting wastes in 1964, bringing in fill and covering the site, including the reservoir. Across most of the site, between 5-15 feet of clean fill, cover the contaminated soil. However, several areas have contaminated surface soil (within the first five feet). Since 1966, when grading was completed, the site has been divided into multiple lots, and various businesses have developed on the site (see Figure 2). The area over the reservoir, however, is vacant, except for one small portion covered with an asphalt parking lot used for recreational vehicle storage.
3.0 Enforcement Activities
The site was placed on the National Priorities List (NPL) in July of 1987. After the site was listed, EPA sent General Notice Letters to 28 Potentially Responsible Parties (PRPs). The list included current and former property owners, generators, and transporters identified during the PRP Search. At that time, no party came forward with a good faith offer to conduct the Remedial Investigation (RI), so EPA began the RI. In 1988, EPA undertook a removal action, erecting a fence around
Figure 1 Site Location Map
Figure 2 Facility Plan
one corner of the site to improve site security and prevent accidental exposure to surface contamination.
EPA completed the RI in November 1990, and initiated a Feasibility Study (FS). The State of California expressed reservations about the groundwater data, and suggested that EPA conduct further sampling. In January 1992, EPA began three quarters of groundwater monitoring, culminating in the January 1993 Groundwater Sampling Report. However, the data did not conclusively identify a source for groundwater contamination on site, and EPA decided to divide the site into two operable units so that more information could be collected for groundwater without delaying the decision for the remaining contaminated media. In August 1993, EPA completed the FS for contaminated soils and subsurface gases.
4.0 Highlights of Community Participation
EPA released the Proposed Plan for Contaminated Soil and Subsurface Gases to the public on August 12, 1993, at the same time making the Administrative Record available in the information repository maintained at the Santa Fe Springs City Library. EPA also mailed the Proposed Plan to interested individuals on the mailing list.
A public comment period was held from August 12, 1993 through October 31, 1993. This comment period included two extensions, one requested by the City of Santa Fe Springs and the second requested by a PRP. During the public comment period, EPA conducted a public meeting, held September 1, 1993 in Santa Fe Springs. At this meeting, representatives from EPA presented the Proposed Plan, answered questions about the site and the remedial alternatives under consideration, and accepted comments from the public. The notice of availability of the RI reports, FS, Proposed Plan, and the rest of the administrative record, the start of the comment period and the scheduled Public Meeting was published in both the Los Angeles Times (Southeast Section Edition) and the Whittier Daily News on August 12, 1993. EPA also published two additional notices in these papers announcing the extensions to the public comment period on September 23, 1993 and October 22, 1993.
In addition to the official Proposed Plan public meeting mentioned above, EPA presented its Proposed Plan to the Santa Fe Springs City Council on August 26, 1993 and the City Planning and Development Office on September 9, 1993. EPA also conducted an informative meeting for the parents of St. Paul High School, which is located adjacent to the site, on September 9, 1993.
During its meetings with the community, EPA heard from some members of the community that they felt overwhelmed by the Superfund process, and that without more time to think and study the information provided, they would not be able to adequately understand the issues and provide their comments. EPA committed to more community involvement during the design process, so the community would have several more opportunities to provide input and make their feelings known. This open design process will require more public meetings than generally required during the design phase, but will ultimately lead to a remedy design that incorporates more input from both the public and the involved regulatory agencies that should be more acceptable to all concerned parties.
More of the community's concerns can be found in the transcript of the public meeting. EPA's responses can be found in the Responsiveness Summary, Part III of this ROD.
5.0 Scope and Role of Operable Unit
As with many Superfund sites, the contamination at the WDI site cover several environmental media, and each must be addressed in order to reduce the risks posed by the site. The work at WDI has been divided into two operable units (OUs). These are:
× OU One - Contaminated Soils and Subsurface Gas
× OU Two - Contamination in the Groundwater
The first OU is the subject of this ROD. More data will be collected before a decision will be made concerning contaminated groundwater found beneath the site.
6.0 Summary of Site Characteristics
Because the RI conducted by EPA is the most recent and extensive investigation to date, the site characteristics are based primarily on its findings. The Final Remedial Investigation Report of November 1989 (Ebasco), as well as the media-specific reports (available in the Administrative Record), should be referred to for a detailed description and analysis of contaminants found at the site.
The contamination present on-site at WDI exists in the soil and groundwater matrices, and in the form of subsurface gases. Present in on-site soils are large amounts of oil well drilling muds and sludges and waste products, metals, low concentrations of volatile organic compounds and semivolatile organic compounds, low concentrations of pesticides and PCBs, and lead. Methane is the most prevalent subsurface gas, with the highest concentrations in the reservoir area. Volatile organic compounds also were detected in the subsurface gas. Groundwater samples contained several metals in concentrations above MCLs, as well as volatile organic compounds. Because this ROD only covers soils and subsurface gases, this document does not discuss groundwater characteristics in further detail.
The remedial investigation generated a large quantity of data, which can be found in the Final RI Report. Samples were taken at St. Paul High School to establish background levels. Background levels for the area established in the US Geologic Survey (USGS) Professional Paper 1270, Element Concentrations in Soils and Other Surficial Materials of the Conterminous United States, have also been taken into account. The primary contaminants in soils at WDI are the drilling muds and oil-field wastes appearing as black oily material or tar-like sludge. The constituents of these wastes (in levels greater than those detected in the background) include:
× Metals - arsenic, beryllium, thallium, and lead
× Volatile Organic Compounds - toluene, methylene chloride, acetone,
ethylbenzene, 2-butanone, and xylene
× Semivolatile Organic Compounds - benzo(a)pyrene, 2-chlorophenol,
naphthalene, 2-methylnaphthalene, 4-nitrophenol, phenanthrene,
chrysene, 1,4-dichlorobenzene, benzo(a)anthracene, anthracene,
pyrene, phenanthrene, pentachlorophenol, and fluorene
× Pesticides - DDD, DDE, DDT, alpha- and gamma-chlordane, and
dieldrin in surface soils
× PCBs in the surface soils
In the twenty six soil vapor monitoring wells, sampling revealed ten gases present in the subsurface. These gases were methane, benzene, 1,1,1-trichloroethane, 1,2-dibromoethane, 1,2-dicloroethane, carbon tetrachloride, chloroform, tetrachloroethane, trichloroethene, and vinyl chloride.
There are also barrels containing investigation derived wastes (mainly soils from the installation of wells). and barrels containing various debris and wastes from previous industrial activities. All of these will be addressed through this ROD.
7.0 Summary of Site Risks
The information on site risks is taken from the Final Endangerment Assessment of November 1989, with additional information provided in the Feasibility Study of August, 1993. These documents should be consulted if greater detail is needed.
Under current site conditions, possible exposure pathways consist of direct contact with contaminated surface soils and inhalation of airborne particulates and volatiles by students and nearby residents. The average risks, both cancer and non-cancer, are based on the average contaminant concentration for the site and a typical exposure scenario. The maximum risks are based on the highest concentrations observed at the site for each contaminant combined into one "composite sample" that represents the source of contamination and the maximum plausible exposure scenario (even if the chance for exposure to the highest level of contamination is very small). The future risk scenario assumes an exposure to residents with homes built on the site, and no protective measures taken. This provides the maximum exposure scenario for which protective actions can be taken.
For the WDI site, the highest risks are posed by arsenic, thallium, benzene, pesticides, PCBs, and vinyl chloride. These risks for current exposure scenarios are almost within what EPA considers acceptable without any remedial action, but can pose an elevated threat to future users of the site. Arsenic presents the highest threat at the site, but is also found in background soils in the Santa Fe Springs area. The background levels, recognized by the US Geologic Survey as averaging 6.5 mg/kg and found in the background samples at 2.3 mg/kg, are within the EPA acceptable risk range for residential exposure. Some on-site samples, however, detected arsenic at significantly higher levels than background.
8.0 Description of Alternatives
The alternatives summarized here were presented in the Proposed Plan. A detailed evaluation of all the alternatives is presented in the Feasibility Study (FS) Report for Soils and Subsurface Gas dated August 2, 1993. (The FS, Proposed Plan, and the rest of the Administrative Record can be found at the Santa Fe Springs City Library on Telegraph Road.) Several alternatives were screened out prior to the nine-criteria analysis used to evaluate the alternatives presented in the Proposed Plan, including complete excavation and off-site disposal of contaminated soils, and on-and off-site incineration.
8.1 Alternative 1: No Action
The No Action alternative, required by the National Oil and Hazardous Substances Pollution Contingency Plan (NCP) (40 CFR 300.430(e)(6)), provides, among other things, an analysis of the risk posed by the facility if no remedial action is conducted. Therefore, it is used as a baseline alternative against which other alternatives are measured. With this alternative, there would be no reduction of toxicity, volume or mobility of the contaminants. The only actions that would take place would be re-seeding of any areas where vegetation was disturbed by on-site activities during the investigation, periodic monitoring required by CERCLA (because wastes will be left on-site), and five year reviews to evaluate site conditions over time.
8.2 Alternative 2: Fencing, Revegetation, and Institutional Controls
Site access would be restricted under this alternative. The site would be fenced to prevent direct contact with the contamination exposed at the site. The perimeter fence along Greenleaf Avenue and St. Paul's High School would be augmented to a minimum height of seven feet and topped with barbed wire and razor ribbon to prevent access by trespassers. The rest of the perimeter fence would be inspected and repaired where necessary. Figure 3 shows the proposed fencing diagram for this alternative. Areas disturbed during the remedial investigation would be revegetated.
Figure 3 Fencing Diagram
Institutional controls would be implemented to restrict land use. The purpose of these controls would be to prevent exposure to contaminated media, and would include placing a notice on the deed, preventing the use of the groundwater beneath the site, preventing development on parcels within the site boundary that could cause exposure to contamination, and restrictions on the use of the fenced parcels. While the property owners would have some discretion to propose future uses, the institutional controls will ensure that any future use is protective of human health.
Because wastes would remain on-site, annual monitoring along with a series of five-year reviews to evaluate changes in site conditions would be required for this alternative. Annual monitoring would include soil, subsurface gas, and groundwater media. The barrels of waste material currently on the property would be properly disposed off-site.
8.3 Alternative 3: Containment
There are four options to this alternative, all of which entail some type of cap over the contaminated areas. Excavation is included for some of the options of this alternative. Excavated materials would be consolidated under the cap. Option A is a multi-layer soil cap, Option B is an asphalt cap, Option C is a RCRA-equivalent asphalt cap, and Option D is an impermeable hazardous waste RCRA cap. The goal of this alternative is to prevent exposure to contamination, so land use decisions would take exposure scenarios into consideration.
Land use restrictions would be implemented to prevent activities that might breach or damage the cap. Restrictions also would be implemented to prevent the use of the groundwater in the shallow aquifer underneath the site, and to restrict use of properties with residual contamination so that potential contact with contamination beneath the properties is prevented.
The containment options might also require a landfill gas venting and treatment system, since the gases would no longer be able to slowly permeate the existing soil cap and release to the atmosphere. With a cap in place, the landfill gases generated might migrate laterally from under the cap and infiltrate surrounding buildings. More testing and sampling would be done to determine the volume and extent of gas generation, but a venting remedy is likely to be necessary. To prevent migration of landfill gases, a combination of passive and active venting would be installed. Passive venting consists of perforated plastic tubing which provides gases a means of transport to the surface for treatment. The active portion of the system consists of a blower which would pull gases to the surface through the vapor wells installed in the reservoir. The treatment would be simple flaring of the gases, with any condensation generated from this process being contained and disposed off-site.
Because the wastes would remain on-site for all options under this alternative, 5-year reviews would be required. The annual monitoring strategy for all the options of this alternative would include cap stability evaluations, in addition to monitoring groundwater and subsurface gas contaminant levels over time.
8.3.1 Option A: Multi-Lavered Soil Cover
This option involves the installation of a multi-layered soil cap over all accessible waste handling areas and the reservoir. The lower layer would be a compact clay layer having a low permeability. The upper layer would be topsoil and vegetation. Option A provides erosion and moisture control and controls off-site migration of contaminated dust. The cap would cover approximately 860,000 square feet (approximation based on aerial photographs). This area corresponds to Areas 3, 4, 6, 7, and most of Area 2. (See Figure 4 for the cap area.) The barrels of soil from the remedial investigation (soils from the well drilling) would be consolidated under the cap. The remaining barrels of waste materials would be disposed off-site. The entire site, with the exception of the businesses presently operating, would be fenced and posted.
8.3.2 Option B: Asphalt Cap without Excavation
This option would place a six-inch asphalt cap (four inches of gravel overlain by two inches of asphalt) over any exposed soil areas of the site. This would provide an additional physical barrier between the contaminated soils and the surface population. Like Option A, no excavation of contaminated material would be done on the site. The only earth moving work would be consolidating the barreled investigation derived wastes (IDW) under the cap, and perhaps some addition of soil to even up site grade for installation of the asphalt cap. The asphalt would cover approximately 860,000 ft, the same area as Option A.
8.3.3 Option C: RCRA-equivalent Asphalt Cap with Limited Excavationn
The cap material for this option itself is similar to Option B, but this option would cover a smaller area of the site because the limited excavation would consolidate the contaminated material under a smaller space. The intent of the excavation is to remove the contaminated soils found in the sumps and other areas to the background (or a 10[-6] excess cancer risk) level for the contaminants of concern, and consolidate them under the cap so that some parcels on the property can be free from some of the institutional controls. An additional Flexible Membrane Liner (FML) would also be added underneath the asphalt cap to reduce the possibility of rainwater infiltration. With the membrane liner and gas remedy system, this cap would meet the substantive requirement of the more extensive RCRA cap described as Option 4. The estimated area covered by this option is 750,000 ft. Figure 5 presents the area to be capped and the areas to be excavated.
Figure 4 Area to be Capped for Alternatives 3A and 3B
Figure 5 Areas to be Excavated and Capped for Alternatives 3C and 3D
8.3.4 Option D: Multi-Layered Hazardous Waste Final Cover
For Alternative 3, Option D, a multi-layered cap meeting the requirements for surface impoundment/landfill closure, as defined in 40 CFR 264.221 and 264.228, would be installed. The cap would cover approximately 750,000 square feet, the same area as that of Option C, shown in Figure 5. Limited excavation would be done to consolidate contamination not currently contained and protected by asphalt or structures. This alternative would provide erosion and moisture control and prohibit upward vertical migration of contaminants (liquid, solid, gas/vapor) through a series of low permeability layers and synthetic liners. Figure 6 shows a schematic of a full RCRA cap structure.
Figure 6 Cross-section Schematic of a Full-RCRA Cap
8.4 Alternative 4: Excavation and Off-site Disposal
This alternative would excavate contaminated material and dispose of it at an off-site facility permitted to accept such wastes. In the FS, two options to this alternative were presented: (A) excavation of only the areas described in the Alternative 3 options, with subsequent fencing and institutional controls of the reservoir area, and (B) complete excavation of all contaminated soils at the site, including the reservoir and Area 2,. The option for complete excavation was discarded due to the very high cost, increased short term risks, and the small increase in long term effectiveness versus the other alternatives.
The alternative presented in the Proposed Plan was Option A, limited excavation (as explained for Alternatives 3C and 3D), off-site disposal, fencing of the remainder of the property, and institutional controls.
9.0 Summary of Comparative Analysis of Alternatives
The NCP sets forth nine criteria to be used for a detailed, comparative analysis of alternatives that have been retained after the screening portion of the Feasibility Study. The nine criteria are as follows:
× Compliance with ARARs
× Overall protection of human health and the environment
× Long-term effectiveness and permanence
× Reduction of toxicity, mobility, or volume through treatment
× Short-term effectiveness
× State acceptance
× Community acceptance
A detailed analysis was presented in the Feasibility Study, while a summary was in the Proposed Plan, not including an evaluation of State and Community acceptance. The comment period on the Proposed Plan provided this information, which is included in Table 1. For a more detailed evaluation of the alternatives and the nine criteria, please refer to Chapter 5 of the Feasibility Study of August 2, 1993.
10.0 The Selected Remedy
Based upon consideration of the requirements of CERCLA, the detailed analysis of the alternatives using the nine criteria, and public comments, EPA has determined that a hybrid of Alternatives 3A and 3C is the most appropriate alternative for the WDI Superfund Site. The goal of the remedy is to provide a permanent barrier to the contaminated soil, prevent rainwater from infiltrating the contaminated soils and carrying the contamination into the groundwater, prevent gases from migrating off the property, and maximize the beneficial end use of the site to the extent practicable.
The selected remedy is protective, meets ARARs, and is effective for the long-term and is permanent. While it does not meet the statutory preference for treatment of the principle threat, landfill gases may be treated if necessary. The selected remedy is constructable with readily available materials and common construction techniques, so is considered implementable. Short-term risks will be slightly elevated during construction, but measures will be taken to minimize the impacts. Since the cap will be impermeable, groundwater will be protected, thus further reducing the risks posed by the site.
This remedy is considered cost effective, and has been accepted by the State of California. During the design process, the community will have the opportunity to participate in determining the ultimate configuration of the remedy, so that community acceptance, as much as possible, will be achieved.
Concerns of both the citizens and the City Council of the City of Santa Fe Springs, were that EPA's Proposed Plan (Alternative 3C was the preferred alternative) would result in an unattractive mound of black asphalt that would be useless to all concerned, as well as an eyesore to the residents of Santa Fe Springs and the students of St. Paul High School. As a result, the decision for the final configuration of the cap will be made during the design phase of the project with input and involvement from the community. This involvement provides for public meetings describing the design as it develops through the design process, and input into the decision-making processes in determining the configuration and final design of the cap. The cap will be required to meet an impermeable standard of 10[-7] cm/sec. Materials that will be used to achieve this performance standard will be evaluated during the design phase.
With the selected remedy, the site will be capped with an impermeable, RCRA-equivalent cap, with the surface configuration to be determined during design. For cost estimating purposes, EPA estimates that a liner will cover the capped area, with approximately 75% of the cap surface asphalt, and the remainder of the cap area a soil and vegetation cover. This configuration of the remedy will be protective and provide for a more attractive solution to the site problems.
The following are the key components of the selected remedy:
× Excavating designated areas to clean-up standards (see Table 2)
× Consolidating excavated materials within Area 2
× Placing perforated piping for the passive gas extraction system
throughout area to be capped (Figure 5)
× Constructing RCRA-equivalent, impermeable cap over the reservoir
and designated areas (see Figure 7 for estimated final
× Monitoring gases that emanate from the site, and installation of
an extraction and treatment system if constituents and volume of
gases require it
× Implementing institutional controls so that future use of the site
is compatible with the remedial goals and the integrity of the cap
is maintained, parcels that have residual contamination are
restricted from activities that could lead to exposure to
contaminated soils, and shallow groundwater use is prohibited
Figure 7 Approximate Configuration of Selected Remedy Cap
10.1 Clean-up Standards
The purpose of the excavation of the selected remedy is to remove the sump material from the undeveloped areas and consolidate the contaminated material. Since no ARARs were identified for clean-up standards for soils, the standards for the excavation are based upon either background, or health based levels (preliminary remediation goals, or PRGs, were used, and are explained in the Feasibility Study) for the contaminants without detectable background levels. The clean-up standards have been established so that the contaminated soils and sump materials are removed, while soils at or near background levels are left in place. Table 2 presents the contaminants of concern, the health based PRG (based on residential exposure), the background level, if any, and the clean-up standard.
The clean-up standard for arsenic higher than background was selected. This decision was based on several factors. First, background levels in soils pose an excess cancer risk to residents ranging from approximately 2.5 x 10[-6], based on samples from St. Paul High Schhol, to almost 7 x 10[-6], based on USGS background levels for the general area. Secondly, the areas to be excavated are currently zoned for light industrial use, and any proposed development would be limited to industrial use only. The PRG for industrial soil exposure is 3.3 mg/kg, so the clean-up standard of 10.0 mg/kg, which is three times the PRG, would yield a risk of approximately 3 x 10[-6] for industrial use. This approximates the current risk posed to residents in the area from the natural, background soils. Lastly, the institutional controls that will be placed on the properties will ensure that none of the properties are used for residential purposes.
10.2 Limited Excavation and Consolidation
The areas to be excavated are identified in Figure 5. These areas were chosen because of the levels of contamination found at and beneath the surface, the accessibility of the selected areas since they are vacant, and remediation will maximize economic redevelopment opportunities. No businesses or buildings would be disrupted by this excavation. Other areas of the site where contamination was discovered are covered either with buildings, pavement, or both. These structures prevent direct contact with any existing contamination beneath the soil, and therefore meet the main goal of this remedy, which is to prevent direct contact with the contaminated soils.
The excavated material will be moved to the Area 2 portion of the site, where the cap will be placed. The existing clean surface fill will be pushed back so that the excavated material can be covered over by clean fill prior to the placing of the first layer of the cap. The final grade of the site will be made such that drainage and run-off is uniform and directed to the storm drains, and that there will be no collection of standing water on the cap. The excavated portions will be refilled with clean fill, compacted, and graded.
Dust suppression will be employed during the excavation, so that the potential for contaminant migration during excavation is greatly reduced. Suppression techniques include water or polymer spraying on the surface, wind breaks, and other methods for reducing the amount of migrating dust. Air monitoring will also be required during the excavation to ensure that any subsurface gases encountered during the excavation are dealt with properly, and that the activities at the site are not adversely impacting local air quality.
10.3 Passive Venting System
Since methane, the major component of subsurface gases detected at the site, is lighter than air, it tends to move upward through the soil until it arrives at the surface, where it is released into the atmosphere. If buildings occupy the space above the area where methane is generated, the gas could collect and pose a fire or explosion hazard. The gas could also migrate laterally if there is not an outlet in the vertical direction. For this reason, perforated piping will be placed on the surface of the site, prior to the placement of the cap. The piping will direct the rising gases to the surface atmosphere, where they can be vented or treated if necessary. If an active gas extraction system is necessary (the volume of subsurface gases is high, or its components require extraction), the passive system will be piped to the active extraction system and all the gas will be treated in one flaring system (if volume is sufficient to burn). If the risks posed by the gases cannot be mitigated by flaring, an alternate treatment such as carbon adsorption will be evaluated and implemented. Section 10.5 discusses the active gas extraction and treatment component of the remedy.
10.4 RCRA-equivalent Impermeable Cap
The actual cap will be constructed as a multi-layer, impermeable cap that meets the substantive requirements of RCRA. Its components will be determined during the design phase, but its final configuration will have a permeability of 10[-7] cm/sec, which will provide protection of groundwater as well as maintain the performance of the cap over the long-term. For cost analysis purposes, it was assumed that the preferred alternative in the Proposed Plan, Alternative 3C, would comprise the major portion of the cap, with approximately 563,000 ft of the site capped with a flexible membrane, gravel, and asphalt. The remaining 190,000 ft will be covered with a multi-layered vegetation cap.
10.5 Gas Monitoring, and Active Gas Extraction and Treatment
Prior to any excavation or construction, the vapor wells will be sampled to estimate the volume of gases beneath the site and determine the proper gas treatment components. A flux chamber may be used to estimate the volume and make-up of gases permeating the existing soil cover of the site, since the cap will prevent the permeation of gases to the atmosphere that is presumably occurring. Once these data are collected, an analysis will be performed to determine if an active gas extraction system is necessary. If the volume of gases rising to the surface warrant treatment, an active system must be put in place so that the gases may be treated by flaring. If there are chlorinated components to the extracted gases, a wet scrubber may be necessary for the flare.
The active system would utilize existing vapor wells as extraction wells. The gases would be pulled from the wells by a blower, and directed to a flare, where they will be destroyed. If the volume of methane is not high enough to allow burning, then another treatment, such as carbon adsorption, will be used.
10.6 Institutional Controls
Institutional controls are legal restrictions placed on a property to restrict types of use. In general, institutional controls are either (1) government controls imposed by state or local governments; or (2) proprietary controls, such as deed restrictions, whereby a party holding an interest in a parcel of property restricts the use of that property. The purpose of institutional controls is to prevent use of the site that could facilitate contact with contaminated soils. The restriction on use of the property will depend on the level of contamination that exists on the parcel, and the risks posed by that contamination. The institutional controls may vary from a simple notice on the deed stating that contamination exists on the property (if the contamination is deep and low-level), to restrictions on digging or excavation that could expose the contaminated soil. Restrictions will also be made for the use of groundwater beneath the site.
There will also be restrictions on the compatible uses of the capped areas of the site. Since the purpose of these restrictions is to maintain the integrity of the cap, only those uses that will not adversely affect the cap will be allowed. Some of the compatible uses include recreation (e.g., tennis and basketball courts, miniature golf), and light storage. Uses that are not compatible include heavy equipment storage, enclosed buildings, and any structure that would need to break the integrity of the asphalt in order to be built. While EPA recognizes that there may be isolated cases where the cap may be breached and suitably repaired, EPA will discourage all but the most substantive justifications for tampering with the remedy and the integrity of the cap.
Restrictions placed on the properties with residual contamination will be determined during negotiations with each property owner. In general, if there is contamination beneath a property that can pose a health risk, there will be a restriction placed on the property. At the very least, the restriction in the deed will state that contaminated material exists beneath the site. The deed restriction will be utilized when contamination is at least 15 feet deep, and the likelihood for direct contact, even with construction activities, is minimal.
For contamination that lies within the first 15 feet, a determination will be made as to whether the contamination poses a health threat. For arsenic, for example, levels less than 10.0 mg/kg will not require any additional restriction other than a notice. For arsenic levels greater than 10.0 mg/kg, restrictions will require that suitable mitigation measures be implemented to protect workers and surrounding residents from the risks posed by the contamination and the potential exposure. These measures would include sampling prior to any work being performed, worker protection and dust suppression during any construction, and remediation if necessary. A similar determination will be made for other contaminants found on the properties. The final development of the institutional controls will be made during negotiations in the design phase.
Vegetation planted on the soil and clay cap must be low-maintenance and drought tolerant. Also, the root systems of the selected plants will be fairly shallow, so that the roots do not penetrate the clay layer. The plants will also be chosen to maximize erosion protection along the slopes. At a minimum, the vegetation should be sustainable for the climate of Santa Fe Springs without irrigation (after initial planting) and require little maintenance. Once the vegetation begins growing, only minimal work will be required for upkeep and maintenance.
10.7 Annual Inspection
All components of the remedy will be inspected and evaluated not less than annually. Special circumstances (such as earthquakes or heavy rains) may require additional inspections. Monitoring will be conducted as required by ARARs, and include groundwater sampling, vapor well sampling, and flare performance and emissions (if there is a flare). The site will also be inspected to ensure that the cap integrity is maintained, and that institutional controls are in effect. Operation and maintenance will be conducted to ensure that the remedy maintains its effectiveness.
A detailed cost description of each of the components of the remedy is included in the FS. The estimated cost for the selected remedy is shown in Table 3 as a present worth value, and includes annual monitoring for 30 years and appropriate 5-year reviews.
10.9 Design Options
During the Public Comment period, several suggestions were made to enhance the selected remedy. These included a block retaining wall between the site and the St. Paul High School athletic fields, and a gas trench near the border of the site to prevent gas migration onto those fields. These suggestions will be taken into account during the design, since they may be somewhat mutually exclusive given current site conditions (especially the trees along the border). The trench may also be incompatible with the gas extraction system.
11.0 Statutory Determinations
EPA must select remedies that are protective of human health and the environment, comply with applicable or relevant and appropriate requirements (unless a statutory waiver is justified), are cost-effective, and utilize permanent solutions and alternative treatment technologies or resource recovery technologies to the maximum extent practicable. In addition, CERCLA includes a preference for remedies that employ treatment that permanently and significantly reduce the toxicity, mobility, or volume of hazardous wastes as their principal element. The following sections discuss how the selected remedy meets these statutory requirements.
11.1 Protection of Human Health and the Environment
The selected remedy protects human health and the environment through the reduction of direct contact with contaminated soil by constructing a multi-layered cap. The cap will also reduce the potential for rainwater to leach contaminants from the soil into the groundwater. The gas venting component of the remedy will reduce the potential for migration of subsurface gases laterally from the site, and will treat the gases, if necessary, to reduce the impact to local air quality.
Institutional controls will be implemented so that permanent restrictions will be in place to notify future land owners of the extent and risks of residual contamination. The restrictions placed on the parcels will prevent inadvertent contact with contaminated soil for the parcels where no excavation or capping will take place. For the capped area, the institutional controls will maintain the integrity of the cap so that contaminated material is effectively contained.
There are some short-term risks associated with this remedy while excavation and consolidation of the contaminated soils are performed. However, dust suppression measures will be taken to minimize this risk.
11.2 Compliance with Applicable or Relevant and Appropriate Requirements
The specific regulations that are applicable or relevant and appropriate for the WDI site are listed below. All of these regulations are action-specific ARARs. For a description of the regulations, see Table 2-3 of the Feasibility Study. This list constitutes EPA's determination of the ARARS for the activities outlined as the selected remedy. The ARARs identified for WDI for the selected remedy are:
Hazardous Waste Control Act (HWCA) (State equivalent of RCRA) that are Relevant and Appropriate:
× Monitoring for Interim Status Facilities, 22 CCR
[Para] 66265.97 (a) - (d)
× Landfill Closure and Post-closure Care, 22 CCR
[Para] 66265.310 (a), (c)
× Seismic Design Standards, 22 CCR [Para] 66265.25 (b)
California Integrated Waste Management Board Regulations that are Relevant and Appropriate:
× Gas Monitoring and Control During Closure and Post-closure, 14
CCR Chapter 3, [Para] 17783-17783.15
× Post Closure Land Use, 14 CCR [Para] 17796
South Coast Air Quality Management District (SCAQMD) Regulations that are Applicable:
× Regulation IV
- Rule 401 - Visible Emissions
- Rule 402 - Nuisance
- Rule 403 - Fugitive Dust
- Rule 404 - Particulate matter (Concentration)
- Rule 405 - Solid Particulate Matter
- Rule 407 - Liquid and Gaseous Air Contaminants
- Rule 408 - Circumvention
- Rule 409 - Combustion
- Rule 473 - Disposal of Solid and Liquid Wastes
× Regulation XI
- Rule 1150.2 - Control of gaseous emissions from inactive
South Coast Air Quality Management District (SCAQMD) Regulations that are Relevant and Appropriate:
× Regulation IX - Standards of Performance of new Stationary Sources
× Regulation X - National Emission Standards for Hazardous Air
× Regulation XI -
- Rule 1108.1 - Emulsified Asphalt
- Rule 1150 - Excavation of Landfill Site
In addition, the guidance document, EPA/530-SW-89-047, July 1989, "Final Covers on Hazardous Waste Landfills and Surface Impoundments" will be used in implementing the selected remedy.
11.3 Cost Effectiveness
EPA believes this remedy will significantly reduce the risks at this site by eliminating the pathway for direct contact with contaminated soil. This remedy will also reduce the potential for rainwater leaching contaminants from the soil into the groundwater by the construction and maintenance of the impermeable cap. This will be done at an estimated cost of approximately $5,170,000, which EPA considers reasonable for the risk reduction that will be achieved.
11.4 Use of Permanent Solutions and Alternative Treatment Technologies to the Maximum Extent Practicable
The selected remedy utilizes permanent solutions and alternative treatment technologies (or resource recovery) to the maximum extent practicable. However, the treatment of the principal threats of the site was evaluated in the FS and screened out because it was not found to be practicable. The remedy consists of proven technologies, common construction materials and practices, and incorporates EPA guidance for closing permitted landfills to provide a protective, permanent solution to the site problems.
11.5 Preference for Treatment as a Principal Element
It was determined that treatment of the principal threats of the site was not practicable for this site. The main contaminant posing site risks, arsenic, is not readily treatable in the soil. However, treatment is a contingency of the subsurface gas component of the remedy. EPA believes that the selected remedy, though not implementing treatment as part of its principal element, is protective for the long-term and currently implementable.
12.0 Documentation of Significant Changes
The Proposed Plan for the Waste Disposal, Inc. Superfund Site was released for public comment in August 1993. An Asphalt Cap with Flexible Membrane Liner was the main component of the remedy, with limited excavation and consolidation of some contaminated soils under the proposed cap. EPA has reviewed all written and verbal comments submitted during the public comment period, and has made its decision with only minor changes to the remedy.
Instead of a full asphalt cover over the capped area of the site, the cap with consist of a multi-layered, RCRA-equivalent cap with a performance standard permeability of 10-7 cm/sec. The components and final configuration of the cap will be determined during the design phase, with additional community involvement in making those final determinations. The decision was made to allow for greater public participation during the design phase in response to public comments and City concerns for the aesthetics of the finished remedy. This has a small effect on cost, and impacts long-term effectiveness slightly, since some of the cap surface may be vegetation which might be easier to breach than asphalt. However, since the cap will be essentially impermeable, the selected remedy will still be protective of human health and the environment.
Additional design options were added as a result of comments received during the comment period. A block retaining wall between the site and St. Paul High School will be considered in order to provide more security for the site, as well as block the view of the site from the school. A gravel trench for gas migration prevention will also be considered. However, current site conditions must be carefully evaluated and adequate involvement from the High School, because in order to implement both design options, the trees currently growing between the site and the High School may have to be removed.
PART III RESPONSIVENESS SUMMARY
This Responsiveness Summary provides EPA's response to comments received on the Proposed Plan for Contaminated Soil and Subsurface Gas at WDI. The Proposed Plan was made available for public review and comment on August 12, 1993. During a public meeting on September 1, 1993 EPA presented the alternatives for addressing the soil and subsurface gas contamination, described EPA's preferred alternative, answered questions, and received public comments on the Proposed Plan. EPA also made a presentation to the Santa Fe Springs City Council on August 26, 1993, and to the parents of St. Paul High School students on September 9, 1993.
The public comment period ended on October 31, 1993. In addition to the comments received during the public meeting, EPA received the following comment letters:
× Ernest Brown & Company, Public Comment on Preferred Alternative
Waste Disposal, Inc. Superfund Site, September 9, 1993
× Department of Toxic Substances Control, Waste Disposal, Inc.
Feasibility Study Report for Soils and Subsurface Gas, September
× Water Replenishment District of Southern California, Proposed Plan
for Contaminated Soil and Subsurface Gas for Waste Disposal, Inc.,
Santa Fe Springs, California, September 10, 1993
× Department of Toxic Substances Control, Comments to Waste
Disposal, Inc. Proposed Plan, September 10, 1993
× Bear, Kotob, Ruby & Gross, Waste Disposal Inc. in Santa Fe Springs
- Superfund Site, on behalf of Dr. Adeline Bennett, September 15,
× Department of Health Services comments of the Proposed Plan,
September 21, 1993
× City of Santa Fe Springs, City of Santa Fe Springs' Comments on
EPA Proposed Remediation Plan for Waste Disposal, Inc. Superfund
Site, October 8, 1993
× Albert L. Sharp, City of Santa Fe Springs Mayor Pro Tem, Proposed
Soils Remedy for the Waste Disposal, Inc. Superfund Site Santa
Fe Springs, California, October 8, 1993
× Phil Campbell, letter of support for EPA's preferred alternative,
October 29, 1993
Copies of these letters, as well as additional correspondence that relates to the comment letters EPA received during the comment period, are attached to this document as Attachment A.
The remainder of this responsiveness summary is divided into three sections. Section 2 is a summary of major issues and concerns raised by the comments and EPA's response to these concerns. Section 3 includes each written comment received and EPA's detailed response to each comment. Section4 includes the comments received during the Public Meeting and EPA's response to them.
2.0 Summary of Responses to Major Issues and Concerns
There were several issues and comments that were brought to EPA's attention during the public comment period. Some of these were raised formally during the Public Meeting, but many were also expressed during the meeting with the parents of St. Paul High School, as well as EPA's presentation to the Santa Fe Springs City Council. As a result, EPA has committed to increased community involvement during the design process, and will solicit more comments from the community as the project progresses. The following are concerns related to the decision for the remedy.
2.1 Health Concerns and Site Risks
One of the main concerns is that of a potential health threat, both to the citizens of Santa Fe Springs and the students of St. Paul High School. As explained in the Feasibility Study and during the Public Meeting, EPA considers the site a potential health threat, based on assumptions made for future use of the site. The site does not currently pose a risk to nearby residents, students, or workers, since there is no activity that would expose persons to the contamination. However, if the site is opened up for development, one of the first things that would happen would be digging for foundations of buildings, in which case contaminated soil would become exposed to the atmosphere, greatly increasing the chances for human exposure. There also exists some surface contamination that trespassers could become exposed to, if they chose to cross the currently fenced site.
In order to protect the health of the community, the pathway through which the population can be exposed must be eliminated. EPA has chosen to place a physical barrier between the community and the contaminated soils, which pose the highest risk at the WDI site. In order to keep the physical barrier protective, EPA will also implement restrictions on use of the physical barrier, or cap, so that it protects people from exposure to the contaminated soils beneath. These restrictions will be placed on any property within the site boundary where contamination exists above a health concern.
Conversely, some members of the community feel that since the site poses no current threat, nothing should be done at the site. EPA, however, feels that it is necessary to act prior to any exposure occurring. The no-action approach fails to take into account the potential threat of contaminants travelling to the groundwater. Since rainwater can leach contaminants out of the soil and into the groundwater, rainwater must be prevented from entering the soil. This is the other main goal for the cap. Leaving the site in its current condition would provide no protection.
2.2 Aesthetics and Future Land Use
Much of the interest and concern for this site concerns ultimate use of the site, and what it will look like to passers-by, students, and nearby residents. EPA has taken these concerns into account by committing to a design process that will allow for greater public involvement.
In the Proposed Plan, EPA's preferred alternative called for a multi-layered cap with an asphalt top layer over the reservoir area. However, this would not have been simply a mounded hill of black asphalt; the cap would have been designed to allow for uniform drainage, and would have changed the current topography very little. In this Record of Decision, EPA has modified the alternative somewhat by requiring a multi-layered, impermeable cap, with the final configuration determined during the design phase. Again, this will allow for greater public involvement during the design of the remedy.
The future use of the site has not yet been decided. It is hoped that EPA, the City of Santa Fe Springs, and the property owners can come to a mutually agreeable decision regarding future use of the capped property. Community input will also be solicited during the discussions of final use. EPA insists that any activity protect the integrity of the cap, and that the activity be included in the design of the final remedy. Once the cap is in place, it should not be breached. EPA recognizes that there may be cases where the cap may be breached and suitably repaired, however, EPA will discourage all but the most substantive justifications for tampering with the remedy. Any foundations or poles that need to be installed for planned future activities should be installed at the time of cap construction, so that the cap retains its protectiveness.
2.3 Effectiveness of Remedy
The other major concern of the community was the effectiveness of the remedy, or how to ensure that the remedy is protective, especially for the students of St. Paul High School. EPA is confident that the remedy will be protective, since the remedy design will follow EPA guidance established and proven by previous efforts with landfill sites. Also, with future monitoring and evaluations, EPA will ensure that the chosen remedy remains protective and effective. If the analysis of the data shows that the remedy is not performing according to expectations, and that contaminant levels are increasing or spreading, the remedy decision will be reevaluated.
3.0 Detailed Response to Comments
3.1 Comments from Ernest Brown & Company
A. RCRA-Equivalent Cap
1. Depth of Liner: While the EPA has expressed a desire to facilitate the reuse of the property where the proposed cap is to be placed, the present cap configuration prevents viable economic use of that property. Provisions should be made to place the impermeable liner and the consolidated excavated soil at a greater depth with relation to the asphalt surface. Since the consolidated excavated (i.e., contaminated) materials lie directly under asphalt and thin membrane, there is virtually no ability to place the type of minimal subsurface foundations necessary for likely use. For instance, any RV parking or other storage uses would require a series of fence posts and lamp posts which require shallow subsurface foundations.
Response: Since the purpose of the institutional controls for the cap area is to maintain the integrity of the cap, even if the liner and contaminated soils were below placed at a greater depth with relation to the asphalt surface, there would still not be any allowable activity that would breach the cap. Since the cap is multi-layered, each component must be considered part of the whole and integral to the protection offered. One component cannot be breached and still have cap integrity maintained. As discussed in the institutional controls section of the ROD, future use plans need to be addressed during design, so that any needed foundations or post holes can be incorporated into the design and constructed during the implementation of the remedy.
2. Composition of liner: In-depth consideration should be given to substituting a one foot clay liner in lieu of the proposed flexible membrane liner now being proposed. Such a clay liner may be more durable and may serve as an equal or superior barrier to infiltration of rainwater. The cost of a clay may also be more economical to construct. If a synthetic membrane is truly deemed the best alternative, testing and/or statistical results should be included in the ROD showing durability and longevity data on the proposed synthetic liner.
Response: EPA has considered the comment, and has decided on a performance-based standard for this remedy, rather than calling out specific materials in this Record of Decision. The Proposed Plan called for a RCRA-equivalent, impermeable, multi-layered cap (membrane liner, gravel and asphalt). This ROD requires a permeability of 10[-7] cm/sec for the final cap configuration, with a combination of surface configurations based upon community input. That said, the replacement of a membrane liner with a clay layer is not likely, based upon the poor performance of clay layers in dry climates like Santa Fe Springs. Cracking caused by drying of the clay (desiccation) can be irreversible, opening a pathway to the contamination and nullifying the protection of the cap. During design, the final low-permeability layer/top layer configuration will be determined, with additional public input into the decision.
B. Contaminated Soils:
1. Characterization: If the Preferred Alternative is implemented, there should be a more complete characterization of the contaminated soils to be excavated from the former waste handling areas (e.g. areas 3, 4, 6, 7, and Toxo Spray Dust area). Upon review of the Final Remedial Investigation Report (1989), there appears to be an insufficient number of borings placed in these areas (only two borings in some areas) and insufficient laboratory analyses performed. In particular, there appears to be too little data (e.g., only 3-4 analyses in some areas) regarding the lateral and vertical extent of volatile organics, semi-volatile organics, pesticides, PCBs, and metals.
Response: The determination of the extent of excavation will be made based on on-site sampling to ensure that the excavation meets the clean-up standard established in this ROD. EPA feels that based on the RI data, as well as previous studies that outlined the extent of the sumps, the contamination in the designated areas will be removed to the levels established in this document.
2. Movement Across Property Boundaries: The Preferred Alternative contemplates moving contaminated soils onto the center property partly owned by the Pitts Grandchildren's Trust prior to capping. In the absence of express authorization from the Trust, this action, regardless of how logical in the macro sense or how well-intended, constitutes a trespass. The Trust would like confirmation by the EPA that it must obtain the permission of the Trust, or take the property and pay just compensation under the 5th Amendment, prior to implementing the Preferred Alternative.
Response: EPA does not concur with the Trust's assertions. As a preliminary matter, EPA notes that the issue only arises with respect to soils that are being moved onto the Trust's property from property not owned by the Trust. Some of the contaminated soil that is being consolidated will be moved from areas that are already partially owned by the Trust. Furthermore, for several reasons, EPA does not believe that the movement of the contaminated soils from the areas not owned by the Trust would constitute a trespass or a taking.
First, EPA has broad regulatory authority under Section 104(a) of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), 42 U.S.C. [Para]9604(a), to perform such remedial action as it believes is necessary to protect human health and the environment as long as the remedial action is consistent with the National Contingency Plan. The selected remedial action at the WDI Site is a proper exercise of EPA's regulatory power to abate a public nuisance and is not a trespass or a taking. Second, EPA notes that the center property partly owned by the Trust already contains contaminated soils and, in fact, is the most contaminated portion of the entire Superfund Site. Unless a Superfund remedial action is performed, the land owned by the Trust cannot be used for any purpose and has no real market value. Thus the remedial action would not cause any diminution in the value of the property or any injury or damage to the Trust. Finally, EPA observes that the Trust, as the current owner of contaminated property at the Site, is a potentially responsible party (PRP) pursuant to Section 107(a)(1) of CERCLA, 42 U.S.C. [Para]9607(a)(1), and is thereby jointly and severally liable for the costs of the response action. Accordingly, if the contaminated soils from the perimeter areas were transported to a disposal facility off-site, rather than being consolidated in the center property, the total cost of the response action would be significantly higher and the Trust, as a PRP, would be liable for that higher total cost.
Whether a particular action constitutes a trespass or a taking is, of course, ultimately a judicial determination. If this issue were to be litigated, EPA reserves all of its rights to present the above legal arguments and any other legal arguments that might be pertinent. However, since the Trust is a potentially responsible party, EPA will be attempting to have further discussions with the Trust in an effort to negotiate a settlement resolving the Trust's liability under CERCLA Section 122, 42 U.S.C. [Para]9622.
C. Vegetation/Greenbelt Option
As part owners of the area which is proposed to be capped under the Preferred Alternative, the Pitts Grandchildren's Trust strenuously objects to any vegetation or greenbelt option which would make business ventures on the central property impossible. The EPA should continue its prior commitment to work hard in order to implement a remedy which allows for the maximum economic use of the property. A vegetation/greenbelt option would constitute a Taking under the 5th Amendment for which just compensation (i.e., lost profits on a yearly basis indefinitely) must be paid.
Response: The community, the property owners, and the City have expressed various concerns about the future use of the property. Some of the concerns emphasize future economic use, others emphasize safety, and still others focus on aesthetics. In the selected remedy EPA has attempted to address and balance those various competing concerns. Some of the specifics regarding the future uses of the Site will be determined during the design phase after further consultation with the interested parties.
The selected remedy contemplates some landscaped vegetation as a component of the cap. For many of the same reasons set forth in the response to the preceding comment, EPA does not believe that the landscaping would constitute a taking. As part of the remedial action, the landscaping would be a proper exercise of EPA's regulatory authority. Furthermore, since the Trust's property cannot presently be used for any business purpose, the selection of a remedy that included a greenbelt would not cause any diminution in the value of the property.
3.2 Department of Toxic Substances Control, Comments to the Feasibility Study Report for Soils and Subsurface Gas
1. The Department has in the earlier comments to the draft Feasibility
Study (FS) stated that the acronyms STLCs and TTLCs were not correctly
used and could mislead the reader. They are still found in certain
places in the final FS to imply that if they are below STLCs and/or
TTLCs, they are not hazardous. As stated in the Health & Safety Code
Section 66699, STLCs/TTLCs are used to determine if any waste is
hazardous waste or not (Underlined for emphasis. See the definition
Response: EPA recognizes that the use of STLCs/TTLCs is inappropriate for the discussion of the extent of contamination. However, previous studies referred to in the FS utilized this analysis, and it would be inappropriate for EPA to alter the discussion of these previous studies. EPA also recognizes, however, that in lieu of background levels or health-based risk standards, the comparison of a material to its concentration that determines a hazardous waste is better than simply stating the results of the sampling. Without some kind of reference or context, the values may be meaningless to many of the readers.
2. The Department is concerned with any contaminated soils left in place,
regardless of the alternative selected for the final remedy. The State
has regulations on land use and definitely require some form of deed
restrictions placed on the main reservoir and any other areas that have
contaminated soils if they do not meet the requirements for an
unrestricted land use. Unrestricted land use means that the land must
meet risk criteria for residential land use.
Response: The selected remedy requires an evaluation of the contamination found on each parcel, with appropriate restrictions placed on parcels can pose a health risk. Please refer to Section 10.6 of the ROD for a more detailed description of the institutional controls. The final determination of restrictions for each property will be made during negotiations in design.
3. In relation to concerns presented by the community with regards to
seismic activities, the following regulations should be considered as
ARARs and be taken into consideration during the design phase:
a. CCR Title 23, Section 2547 which states that structures which
control surface drainage, erosion or gas should be designed to
withstand the Maximum Credible Earthquake (MCE) without damage.
b. CCR Title 22, Section 67108 which states that cover system and
containment control features should be designed to withstand the MCE
without the level of public health and environmental protection
afforded by the original design being decreased.
c. CCR Tile (22) 67418 which states that the cover be designed to
accommodate the forces of earthquakes.
Response: EPA made a final ARARs determination in a letter to the State dated December 7, 1993. The regulations identified in parts (b) and (c) above have been repealed and are now incorporated into Title 22 CCR [Para]66264.25 (b), which has been included as an ARAR. The regulation identified in part (a) is duplicative of the regulations in (b) and (c), so EPA does not consider it to be an ARAR.
4. The Department would like to make a few minor comments on the
discussion on the risk assessment so they will reflect the current
thinking on this subject:
a. In the 3rd paragraph of Section 1.12, the risk were based on the
average (geometric mean) of the contaminant concentration. DTSC
generally uses the 95% Upper Confidence Level for this value.
b. In Table 1-9, the age and the average weight given fits a "Student"
better than an "Off-site Adult Residents".
c. The Dermal Absorption Factors used were lower than currently
acceptable values. For example, the dermal absorption factors for the
Carcinogen PAHs and PCBs were stated as 0.02 and 0.07, respectively.
The values used in the DTSC Preliminary Guidance Manual (7/29/93) were
0.20 and 0.14, respectively.
d. In Table 1-13, the PRG for lead was indicated as 500 mg/kg.
Presently acceptable levels are 130 ppm.
Response: EPA thanks the State for their comments to the Feasibility Study. In response to part (d), EPA refers to the Region IX PRGs for Fourth Quarter 1993 (November 1, 1993), which still identifies the PRG for lead, based on the Uptake Biokinetic Model, as 500 mg/kg for a residential soil exposure.
5. Section 1.6, 1st paragraph. Typo. The Groundwater Elevation Map is
shown in Figure 1-4 and not in Figure 1-5 as stated in the text.
Response: The comment is correct; the figure was misidentified in the text.
3.3 Water Replenishment District of Southern California
1. The August 1993 EPA proposed plan announcement indicates that the
majority of the non-disposal reservoir contaminated soils occur within
5 to 15 feet below ground surface. However, the "Preliminary Risk
Assessment" prepared by the EPA contractor, Ebasco (December 1989)
indicated that "The majority of subsoil contamination was detected at
depths ranging from 10 to 20 feet" (Ebasco, 1989, p2-35). In addition,
a review of soil sample analytical summary tables presented in the
"Final Remedial Investigation Report" (Ebasco, November 1989) indicates
that certain metals, volatile organic compounds, semivolatile organic
compounds, pesticides, and polychlorinated biphenyls occur at
potentially elevated concentrations to maximum depths of 50, 60, 60,
35, and 35 feet, respectively. We are therefore concerned that the
depth of soils excavation may not be adequate to prevent further leaching of contaminants into the ground water,
particularly, if these areas remain undeveloped and are exposed to
rainfall or landscape irrigation infiltration. The installation and
periodic maintenance of an asphalt cap on the excavated area may limit,
albeit not eliminate, this potential problem.
Response: The comment is correct that contamination exists deeper than 5-15 feet deep. EPA was trying to convey that there was little chance for exposure to surface contamination, and that most of the contamination was located at least 5-15 feet deep below the ground surface. Unfortunately, that was not how the Proposed Plan read.
2. We are concerned that certain contaminants in the existing former
disposal reservoir may continue to migrate downward to the groundwater
owing to the potentially high liquids content of some of the sludges
that were deposited in the reservoir. The installation and periodic
monitoring of a soil moisture lysimeter network adjacent to and beneath
the disposal reservoir (the latter via angled borings) may alleviate
Response: EPA appreciates the commenter's concern regarding potential leaching of contaminants into the groundwater from the disposal reservoir. EPA has been monitoring the groundwater beneath the site, and will continue to monitor the groundwater until a groundwater remedy is selected. Since the site has been inactive for almost 30 years, EPA feels that once the infiltration of surface water is eliminated, the likelihood that any contaminant leaching will occur is small.
3. We are concerned that the ground water quality monitoring to be
implemented as part of the proposed soil remedy is not to be considered
as the final ground water remedy. To this end we intent to take an
active role in reviewing and commenting upon data generated from the
proposed ground water monitoring program and to work with EPA to
develop groundwater protection strategies that will ensure groundwater
quality in a cost-effective manner.
Response: Since EPA has not been able to determine that the WDI site is the source of contaminated shallow groundwater, EPA postponed the decision on a groundwater remedy until more data could be collected. The requirement for sampling as part of this remedy is to ensure that the selected remedy is not adversely impacting groundwater quality; it will also provide information for future groundwater actions. Also, since wastes will be left in place, sampling is a closure requirement, and is necessary for conducting five year reviews.
3.4 Department of Toxic Substances Control Comments to WDI Proposed Plan
1. Regardless of the alternative selected as the final remedy, it is
expected that some contaminated soils will be left in place at the
reservoir area and some surrounding areas at the site. Up to the
present, no deed restrictions have been imposed on any parcel.
However, the Department would require a voluntary deed restriction be
recorded to limit the use of these areas.
Health and Safety Code Section 2522.1 authorizes a landowner to agree
voluntarily to a deed restriction on the property. However, if a
landowner refuses to agree to a deed restriction, EPA or the State
should require the landowner to clean up the contaminated areas and
restore them to residential land use.
Response: Institutional controls are part of EPA's selected remedy. During the design of the remedy, EPA hopes to negotiate appropriate restrictions for each parcel of the site. If we cannot reach an agreement on voluntary restrictions for each parcel, the State has the authority under [Para]25220 et seq. of the Health and Safety Code to make a determination that a particular property should be designated as "hazardous waste property" or "border zone property", with subsequent restrictions imposed on those properties.
2. The Department has determined that the design of the RCRA equivalent
cap for Alternative 3C as illustrated in Figure 3 of the Proposed Plan
is inadequate. Potential problems that have been identified and/or
improvements that can be made are presented below:
a. The location of the consolidated excavated soils in the cap is
too shallow and does not allow any buffer zone or safety factor in
the event of accidental or intentional penetration; and/or
cracking/breaking of the asphalt cap and flexible membrane liner.
As you know, some of the proposed excavated soils are contaminated
and exposure could result in health risks.
b. To minimize the exposure to the consolidated soils, it is
suggested that the consolidated soil be buried as close as
possible to the waste material by first removing some of the
current 5-10 feet soil covering.
c. Laying the asphalt directly over the flexible membrane liner
is not advisable for the following reasons:
(1) There is a possibility for the flexible membrane liner
to tear should the asphalt crack or break which could
occur during a major earthquake or as a result of
(2) The flexible membrane liner may be damaged during
installation by the heavy equipment rolling over the
surface and from sharp stones lying next to the
membrane liner. Generally, a layer of fine soil or
sand is placed on the top and bottom of the membrane
liner for protection. The soil layer also serves as a
drainage layer and gas vent layer.
Response: EPA has included your recommendations in the description of the selected remedy. EPA will require that the excavated soil be placed under clean fill already located on the site. The clean surface fill will be scraped back in order to provide room for the excavated material. However, it is not advisable to expose the contaminated soil any more than necessary, so the excavated contaminated soil will be placed at least two feet below the ground surface, but will probably still remain above the unexcavated contaminated soil.
In response to the construction of the cap, EPA has decided to call out only a performance standard for the impermeable cap, so that issues like those brought up by the State will be addressed during the design of the cap. EPA recognizes that these issues are best addressed at that time.
3. DTSC does not object to a different type of cap other than that
proposed in Alternative 3C, provided the remedial response objectives
are maintained, i.e. "...to protect against and minimize the release of
hazardous pollutants, or contaminants so that they do not migrate and
cause substantial danger to present and future public health and
welfare or the environment."
Response: EPA agrees that any remedy must be protective, and EPA's selected remedy will meet the remedial response objectives and be protective.
3.5 Bear, Kotob, Ruby & Gross, on behalf of Dr. Adeline Bennett
Dr. Bennett "would like to see a higher degree of environmentally friendly
landscaping techniques employed in conjunction with the asphalt cap." She
is also concerned about the degree of pollutants that may become airborne in
any excavation of the perimeter properties.... At this time, Dr. Bennett
objects to the transportation of such contaminates into a centralized
collection area, as proposed. Dr. Adeline Bennett does not wish to waive
any rights at this time, but stands ready to cooperate and entertain any
proposal the EPA may propose.
Response: EPA intends for any landscaping that is done on the site to be environmentally sound, which will include low water consumption. We share Dr. Bennett's concern that airborne contaminants may be released during the excavation, and will take precautions to minimize any release and the impact of the excavation to local air quality.
Dr. Bennett has stated that she objects to the consolidation of the
contaminated soils in the central property. The comment does not offer a
specific basis for that objection. To the extent that the objection is
based on a theory that the consolidation would constitute a taking under the
Fifth Amendment, EPA reiterates and incorporates by reference the response
it provided above to the comment made by the Pitts Grandchildren's Trust on
this issue (See Section 3.1 B). While EPA recognizes that the current
property owners may object to the consolidation of contaminated properties
onto the central portion of the site, that option is considered the most
cost effective, and will remove contaminated soil from other parcels they
own, as well as from other parties, in order to make the excavated parcels
potentially useful for future development. An alternative that would leave
all contaminated soils in place with a cap over the property would
significantly impair the future usefulness of the various properties.
3.6 State of California Department of Health Services
1. Ensure that the cap, whether it is the proposed RCRA-equivalent cap or
a clay/green cap, adequately covers the waste so that casual physical
disturbance of the cap can not occur.
Response: EPA will ensure that the cap is protective and adequately prevents physical contact with the underlying contamination.
2. Ensure that the cap, whether it is the proposed RCRA-equivalent cap or
a clay/green cap, adequately covers the waste so that water may not
penetrate into the waste material.
Response: EPA will require that the cap meet an impermeable definition of 10[-7] centimeters/second.
3. Ensure that the integrity of the cap can adequately withstand the
strong seismic activity that has occurred in southern California and is
predicted for the future.
Response: EPA has added seismic ARARs called out in the California Hazardous Waste Control Act, Title 22 CCR, [Para]66264.25(b), Seismic Design Standards.
4. Adequately maintain the fence in order to prevent public access to
site, especially during future site disturbances when waste material is
Consider building a taller sound barrier-type fence along the side of
the site adjacent to the school.
Response: During site activities, the site will be secured. In addition, a supplemental wall will be considered during design of the remedy, at which time the EPA can discuss the options with the City of Santa Fe Springs, the community, and St. Paul High School.
5. Conduct real-time air monitoring and air sampling before and during
site disturbances, especially during the proposed soil excavations.
Monitor and sample the air that is within the human breathing zone as
well as on rooftops. Monitor for volatile organic compounds and
particulate-associated compounds. Take samples during the site
activities separate from samples taken during the time when no site
activities are occurring. Include in the remedial design workplan a
worker health and safety plan and a residential contingency plan that
require certain health protective steps be taken based on the levels
detected in the air monitoring and air sampling.
Response: EPA will conduct air sampling during site activities as suggested.
6. Ensure that the remedial action will involve collection and treatment
of subsurface gases. The microbial production of gases other than
methane may pose a long-term health concern to the employees working in
the on-site buildings. Even if there is not enough methane to light a
flare, another method of treatment may need to be considered.
Response: Consideration of treatment other than flaring is included in this decision, if a treatment option is required.
7. Address in the remedial design the following concern: although the
waste material has not yet migrated laterally through the soil column,
the addition of a cap may provide an additional force that would
encourage lateral migration. If not taken into the account, the waste
may surprisingly appear in the school's athletic fields or ooze through
holes or cracks in the foundations of the on-site buildings.
Response: EPA will take these concerns into account during the design of the remedy to ensure that the remedy does not encourage migration of contaminated soil from under the capped area.
8. Require adequate institutional controls to ensure that there will be no
penetration of the cap for development purposes. Deed restrictions
that prevent digging or excavation of subsurface soils rather than a
simple notice on the deed should be included as a part of the
Response: EPA will negotiate institutional controls with property owners that will be protective for any anticipated actions. Please refer to Section 10.8 of the ROD for a full description of the anticipated restrictions.
9. Require adequate institutional controls that prevent current owners or
future owners for those commercial parcels with underlying waste
material from carrying out activities which entails penetrating the
subsurface soil and disturbing the waste material.
Response: EPA will negotiate institutional controls with property owners that will be protective for any anticipated actions. Please refer to Section 10.8 of the ROD for a full description of the anticipated restrictions.
10. Inspect the cap and surrounding area on a regular basis to ensure that
the cap is intact, there is no spread of the waste material, and the
institutional controls are working.
Response: EPA's selected remedy requires annual sampling and inspections.
11. Circulate the remedial design plan (including the worker health and
safety plan and the residential contingency plan) to CDHS for public
Response: EPA looks forward to working with CDHS in the future, and will provide material for their review, and endeavor to include them in any future community discussions.
3.7 City of Santa Fe Springs
1. The City's preferred alternative is to have the site completely free of
contaminated soil. Implementation could be accomplished by excavating
the soil and hauling it off-site for proper disposal or remediation.
This solution would then allow unrestricted development of the site,
and would totally alleviate any potential problems of human exposure to
the contaminated soil.
Response: As explained during the Public Meeting, this alternative was evaluated by EPA and determined to be very costly for a subsequent small reduction in the long-term risks posed by the site, while increasing the short-term risks. Since the volume of contaminated materials is very large, the risks posed by them fairly low (almost within what EPA considers safe for residential use), and the estimated cost $120 million, complete removal is not considered a feasible option.
2. If the above excavate/haul alternative is deemed cost-prohibitive, then
in-situ bio-remediation of the organic and hydrocarbon constituents of
the waste should be accomplished, and the remaining metal constituents be
immobilized through chemical fixation. This solution would
significantly reduce potential human exposure, and the site would have
less prohibitive restrictions on development.
Response: As explained during the Public Meeting, the main risk posed by this site is due to the presence of arsenic, a naturally occurring metal in California soils. Arsenic poses a cancer risk, and can be toxic or have non-cancer health effects at high levels. For soil micro-organisms, arsenic can be toxic, and will kill them when they come into contact with the contaminant. For this reason, bio-remediation is impractical for this site.
As for chemically fixing the arsenic and other metals found in the soils at the site, this process involves mixing the contaminated soil with materials to basically "cement" the metals so that they cannot leach out. The mixture that is used to "fix" the soil must be carefully determined, so treatability studies must be done to formulate the chemical mix. The fixation process cannot be done while any bio-remediation is taking place, so the treatment would have to wait until the bio-remediation is complete. The soils would be treated on-site, but would probably require excavation (unless the treatment process could be performed in-situ) and replacement once treatment was completed. Since the volume of contaminated soils is estimated at 750,000 yds, and at a minimum, the cost of treating the soils is estimated at $100/yd (from EPA technical staff estimates), the cost of this remedy would be approximately $75 million. This process would prevent the metals from leaching into the groundwater, but would still require restrictions on future use. This same result can be achieved by EPA's selected remedy at a much lower cost.
3. With regard to the peripheral contaminated properties, the
City-preferred alternative is to bio-remediate the contaminated soils
or excavate these soils and haul off-site for remediation. This action
would alleviate the need of transferring the contaminated soil to the
reservoir grounds, and consequently would allow the site to maintain
its present topographical appearance.
Response: See above comment for a discussion of bio-remediation. As for hauling excavated soils off-site, this option was evaluated, but was discarded because it raises the cost of the remedy significantly without providing appreciable, additional risk reduction. Since the area proposed for consolidation is already contaminated and includes the reservoir, the consolidation would not greatly increase the risk posed by the reservoir area. During consolidation and site grading, EPA will endeavor to maintain the site's current topographical profile, since the site is not smooth and flat at present.
4. In some places the depth of clean uncontaminated cover soil is reported
to be at least 15 feet. Upon completion of remediation the site should
be regraded to lower the overall height of the mound as much as
Response: The current site mound height is mainly due to the presence of the old concrete reservoir, and the clean fill covering it. It would not be desirable to remove this soil cover, which would expose the disposed material in the reservoir, in order to flatten the site topography. However, every opportunity will be taken to fill in holes, and minimize the slopes on the site. But since the concrete reservoir is above the level of the street, the site will retain a higher profile than the surrounding properties.
5. Prior to the issuance of the Record of Decision the City requests that
EPA establish the topographical profile of the site before and after
completion of remediation. Knowing the final physical appearance of
the site will assist the City in commenting on the plan as regards
future development opportunities on the site.
Response: Current site profiles are available in the Final Groundwater Characterization Report of May 1989, Figures 2-7 through 2-9. A topographic map of the site can also be found, in Figure 3-2. Expected topographic profiles for the remedy can be included in the design work.
6. Prior to the issuance of the Record of Decision the City requests that
EPA reveal the nature of the deed restrictions at the site upon
completion of remediation and to which properties the restrictions will
be applied. Knowing this will assist the City in commenting on the
restrictions and perhaps recommending alternatives.
Response: As explained in Section 10.6 of this ROD, deed restrictions will be negotiated with site property owners. Specifics of the restrictions will be made at that time, but in general, will follow the outline in Section 10.8.
7. After the site is remediated we recommend that the current fencing
along the northern boundary of the site (particularly along the St.
Paul's High School property) be replaced with a concrete block
retaining wall of sufficient height to restrict the view of the site
from anywhere on the school's property, and of sufficient height to
discourage students or others from climbing the wall. Furthermore, the
school should be generally consulted in this matter so as to express
its concerns regarding the wall's appearance and any landscaping that
may be done.
Response: We have included the design option of a block wall or fence as part of the selected remedy. The exact configuration of any fence will be determined during the design phase of this project, and will include public discussion of the issue. It may not be necessary to construct a fence, depending on the final configuration of the cap, if current trees remain after construction of the remedy.
8. EPA should place a gravel trench adjacent to St. Paul High School to
act as a barrier to migration of methane gas. This is a precaution
which has been required elsewhere in the City adjacent to landfills.
Response: This suggestion has been included as a design option of the remedy decision. The exact configuration and function of the trench, if any, will be determined during design.
9. In those areas where the asphalt cap is not applied and where
development cannot take place (e.g., along the slope of the mound), the
City requires some sort of low maintenance landscaping to reduce the
possibility of unsightly weed growth.
Response: Areas that will be capped with vegetation will be landscaped to be low-maintenance. However, slopes may be paved with asphalt if that is the desired configuration of the cap. It is possible to pave on grades up to 50%.
10. EPA should better define and prepare a plan showing where and how
surface water run-off from the site will be collected and disposed.
Response: The final design for the surface of the site will include uniform run-off. Surface water run-off will be directed to the storm sewers. Since the run-off will not be in contact with contaminated material, it will not be necessary to collect and dispose of it.
11. When weed abatement is permitted by EPA at the site prior to
remediation, the City should be advised in advance of the work, and
dust suppression should be used during the work.
Response: This has in the past been the usual operating procedure. However, EPA was not notified prior to the last weed abatement work that was performed at the request of the Fire Department of the City of Santa Fe Springs. The Los Angeles County Weed Abatement Program Project Manager was out of town when the request was received, so the work was begun without EPA notification. There should probably be only one more weed abatement prior to the implementation of the selected remedy. However, for any future weed abatement activities, better communication within the City's departments as well as with EPA will prevent further misunderstandings. As for dust suppression being used during any weed abatement, though not necessary, may be possible, and will be discussed with the LA County Project Manager before the next abatement is begun.
12. There are numerous unmarked and unsealed barrels containing unknown
substances on the site. The presence of these unmanaged barrels pose a
potential fire and safety hazard, as well as a public nuisance. EPA
should address the management of these barrels immediately, and not
wait until remediation is under way.
Response: These containers were addressed in a letter to the City of Santa Fe Springs dated November 4, 1993. The containers were evaluated by EPA during the removal action taken in March 1988. The containers were determined to contain non-hazardous waste material that did not qualify for action under EPA removal authority. These containers will be addressed by EPA's selected remedy.
3.8 Albert L. Sharp, Mayor Pro Tem, City of Santa Fe Springs
"... Environmentally Safe Products Corporation (ESP) has contacted my office
and made me aware of the option of using biodegradable products to promote
degradation of contaminates. ESP also believes that they have
environmentally safe products which could be used to fixate, in place, the
non-biodegradable contaminates and to seal the surface of the site.... In
assessing the alternatives and before selecting the final WDI clean up
strategy, EPA should give further consideration to the new technologies
which may be available in the marketplace. ESP represents the type of
approach which may provide EPA, The City of Santa Fe Springs, and a
surrounding property owners with a more cost effective and minimal risk
Response: Please see the response to the City of Santa Fe Springs comment on bio-remediation and chemical fixation. EPA contacted Environmentally Safe Products Corporation to investigate their proposal for remediating this site. The materials we received are included in this Responsiveness Summary. EPA feels that the proposal received by ESP was inadequate, and could not use it to determine the effectiveness of the proposed processes. EPA did not receive any information concerning past successes with the ESP processes, nor any participation by a regulatory agency, EPA or state. In addition, the materials EPA did receive (mainly the Material Safety Data Sheet for the soil sealer) show that the material is 100% water soluble, which would not be desired to keep water from infiltrating the soil. Since the proposal required the use of unproven technologies, its selection would require extensive treatability studies and evaluation, during which no other remedy would be implemented. EPA feels that its selected remedy is the most cost effective, protective measure currently available.
3.9 Phil Campbell
"... I am very supportive of your Number 3C proposal. I would hope that
this proposal will be decided upon and initiated within a short time! ... I
would appreciate it if you could give me a time frame as to when we could
expect to have the contamination removed and what those specific plans are!"
Response: EPA hopes that work on the design will begin in early 1994. Once the design is underway, EPA will conduct additional public meetings to discuss the schedule and progress of the project.
4.0 Public Meeting Comments
During the Public Meeting of September 1, 1993, a court reporter was present to provide a transcript of the meeting. EPA received several questions and comments on the Proposed Plan and general site conditions. Many of these comments have already been addressed in Section 2.0 of this Responsiveness Summary, Major Issues and Concerns. EPA feels that the following comments received during the Public Meeting (page numbers are those of the transcript) warrant a specific response.
4.1 Page 24, line 3, Mr. Sharp
"...why would not the fence be moved back to the green area (capped area on
overhead) so all the white area, which had been excavated and the impurities
removed from the soil, be able to be open for development?"
Response: The area that will be capped, and the area to be excavated, are both private properties. EPA's selected remedy requires that the cap be put in place to prevent direct exposure to the contamination and prevent rainwater infiltration. The restrictions on the property require that site activity be compatible with the cap design and that cap integrity be maintained. If the owners of the properties feel that this can be met with a fence, a fence can be placed around the entire cap. However, if the property owners wish all their property fenced, that is also their option. While the excavated properties will be free from development restrictions imposed by EPA, it does not necessarily follow that the properties will actually be developed.
4.2 Page 41, Father Gallagher, Principal, St. Paul High School
"... it does strike me as a little bit strange that we already have a city
government empowered to make decisions for the people within the City, but
that the EPA would come in and become more restrictive than you feel that
the City of Santa Fe Springs would be with our already elected officials,
and you would put something--you would force the city to comply beyond just the normal level of concern that
the people who live right here in the City would already have about what is
going on in the City... The second thing is -- it has to do with the whole
idea about the word contamination is that, you know, there's a lot of
parents here who have children who go to St. Paul, and when people think
contamination, I think that a lot of times they're thinking about nuclear
contamination, the threat of what is airborne, what is soil-born, and I was
led to understand in our conversations that actually that whatever
contamination there is really a metallic contamination from a very minor
kind of a normal industry output like oil, sludge that was a part of what
was going on here, and actually that will not ooze from one piece of
property to the next piece of property without any kind of a major
Response: EPA's authority to respond to actual or potential environmental health risks was granted by the United States Congress under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, also known as Superfund. This law was amended in 1986 by the Superfund Amendments and Reauthorization Act (SARA). These laws give EPA authorities not granted to local governments to address environmental issues.
Concerning the word "contamination", it is an accurate term for the substances found at the WDI site. Though the materials are not nuclear in origin or pose a radiological hazard, the site is not without risk. While some of the contamination comes from a "normal industry" like the oil industry, this does not reduce the hazard to human health. Some of the contaminants found at the site are potential or known human carcinogens, while others have non-cancer health effects. We do not want to minimize the potential dangers of the substances found at the site, nor do we wish to unduly alarm people. Although current risks are small, eliminating exposure to these hazardous substances (the "contamination") will further reduce the risks posed by the site.
Lastly, EPA believes that the selected remedy will adequately contain the contamination, and that migration of the contaminated materials will not be a problem. We will monitor the site annually and evaluate the effectiveness of the chosen remedy to ensure that the selected remedy is performing to EPA expectations.
4.3 Page 48, line 22, Father Gallagher
"...I think there would be some liability on the part of the government for
... putting in something where we would be concerned about -- I would always
be concerned about well, what's happening over there which we have no
control over? I would have control over who was on our property, but I
wouldn't have control over who is standing on the piece of property above us looking down
at the students who are unprotected. So, you know, it's simply a question
or a comment, but I do think that there'd (be) some governmental liability
if something were to occur."
Response: EPA, under CERCLA, has the responsibility to protect human health and the environmental from potential and actual releases of hazardous substances. With the implementation and proper operation and maintenance of the remedy, this responsibility will be met. Since the site is located on privately owned property, any activities occurring on the site that St. Paul High School jeopardizes the safety of their students are the responsibility of the property owners. If the integrity of the remedy is compromised, the situation would warrant EPA attention. However, EPA does not assume any liability for actions taken by private parties on private property.
4.4 Page 50, line 6, Mr. Sharp
"Why wasn't bioremediation put in there as one of the alternatives? It's a
method we've used successfully of cleaning up some of the oil properties in
the City the City wanted to redevelop during the redevelopment agency. I
don't see that listed as any type of alternative, yet it's probably the most
successful method currently used throughout the world."
Response: Please refer to the previous discussions on the lack of bio-remediation options for arsenic contamination in Section 3-7, page 3-16. It was screened during the Feasibility Study and discarded due to the inability to reduce the main risk at the site.
4.5 Page 54, line 5, Mr. Cabral
"I've worked on the one (methane flare) in Rose Hills, and that makes a lot
Response: The amount of noise will be considered when the design of any flare is undertaken. However, with the limited amount of methane that is anticipated, any noise generated at the site should be minimal.
4.5 Page 62, line 4, Ms. Aguilar
"My comment is that...we have children playing out there every day hard,
breathing hard, breathing that gas you're going to put up in the air hard
right next to it. I'm talking a few feet from there. Why can't they just
clean it? Clean it."
Response: As stated in the Public Meeting, no gases were detected at the surface of the site other than typical ambient (local) air. We are concerned that any site contaminants not impact the students, however, and will investigate treating gases that are generated at the site, if necessary. However, if the amount and types of gases that are generated are below acceptable risk standards, the gases will be emitted into the atmosphere. Any emissions will have to meet both health standards and California air quality regulations. As previously explained, the cost of removing the contaminated materials is too high for the limited amount of risk reduction ultimately achieved. Also, complete excavation of the site would increase the short-term risks to the surrounding residents and students, even while meeting all emissions standards. The additional emissions just from the trucks would be significant. At present, there aren't any known technologies that can "clean up" the site.
4.6 Page 66, Father Gallagher
"I would like to say that we are very appreciative of the work of the
EPA...If in conjunction with the City of Santa Fe Springs, who we believe
are responsible individuals elected by the members of the City, that
something should be decided to be done on that property, that we would
prefer that nothing would be above the level of the property in terms of
business where we would have to be concerned about the safety of the
students at some future date based on a decision of somebody other than us
about who is going to own that property or use that property or we would
want something, for example, a wall or the government to provide some kind
of protection so that we would not have to be concerned about the safety of
our students, so if we had a comment to make I would think that it would be
that we would prefer that it not be asphalt, that it would remain exactly
the way it is, and if there is absolutely no problem right now and if I
could build a house there that I could live on for 70 years with no problem,
well, then I would just as soon see that things be left as they are right at
Response: EPA has taken your comment into account regarding public discussion of future uses of the site, as well as having a design option for a wall or enhanced barrier between the site and St. Paul High School. As for the safety of the students being jeopardized by any activities on the site in the future, EPA cannot at present envision any such activity that would be allowed and also protect the integrity of the cap. Also, the final configuration of the cap will be decided during the design phase, and the public will be able to comment and contribute their opinions to the final appearance of the site.
4.7 Page 67, line 6, Mr. Sharp
"Along with Father Gallagher, I as a City Councilman in this City have no
desire to see anything happen on that site as far as a storage yard or
anything. I think every member of the EPA in this room knows how I feel
about putting asphalt down. I don't want to see a black or a green
mountain. As far as I'm concerned, if there's nothing wrong with the soil,
why don't we just plant wild flowers over it, make it as aesthetically
pleasing to the community as we possible can and let that sleeping dog lie
if there's no -- all we're doing is just covering it so someone can come in
and set some tractors and trucks and travel trailers and whatever else on
it. No, I'm not in favor of that."
Response: As previously discussed, the final use of the property will be decided upon by EPA, the City of Santa Fe Springs, and the property owners, along with contributions by the general public. The possibility of a "green" cap has been evaluated, and the limitations of this type of cap, mainly the ease with which it can be pierced, was also presented at the Public Meeting. The final configuration for the surface of the cap will be decided upon during design, with community involvement throughout the process, and can include some "green" cover.
4.8 Page 68, line 20, Ms. Calderone
"... my comment and concern basically goes back to seismic activity. I have
children that go to St. Paul. If we have a major catastrophe -- it could be
today, tomorrow, ten years from now -- my kids have to go out there on that
field. Is there any warning signs, bells or something to say that, you
know, there is toxic waste going out in the air, methane gas? Are they
going to be exposed and harmed by this if they're out there in the field? I
mean what is the limits to where they would be exposed?"
Response: EPA has included seismic requirements into the selected remedy. In the unlikely event that there is a major exposure of the contaminated materials at the site, the risks would still prove fairly small, since the highest risk from the site was long-term, direct exposure to the contamination for residents on the site. Since there are no residents living on the site, the risks are less for the students attending St. Paul High School next door.
4.9 Page 70, line 12, Mr. Calderone
"You're talking about putting the daisies and everything. Is there any way
that you can put a nicer looking fence instead of barbed wire or a higher
Response: Once the remedy construction is completed, there will be no requirement for fencing the site, unless it is determined that a fence is needed to protect the cap. Otherwise, any fencing would be at the discretion of the property owners. EPA has included a block retaining wall as a design option for the remedy that may be placed between the site and St. Paul High School.
4.10 Page 72, line 4, Mr. Moreno
"And there have been reports of odors. I don't know how many people have
gotten sick. There's been -- there have been those reports."
Response: EPA has had only anecdotal evidence of any odors emitted from the site in recent history (since the site was closed and covered with soil). We have also not received any notice that anyone has been made ill from the site. Since no emissions were detected at the site, we can only conclude that the site is not currently the cause of illness or source of odors. The reports referred to reports of a "gas cloud" observed after an earthquake. However, this observation was disputed by the principal of St. Paul High School as having originated at another site, upwind of WDI and the high school.
4.11 Page 74, line 1, Mr. Lazaretto
"Some work beforehand should be done to make representation of how -how
the site will look given the fact that more earth is going to be placed on
top so that there's some good idea so people can make, I think, an informed
decision of how it's going to look ultimately."
Response: A representation of the final appearance of the site will be made during the design phase of this project. Various options should be presented at that time for public evaluation and comment.
4.12 Page 77, line 11, Father Gallagher
"I think that some people have indicated here this evening that they're
confused. If you will not take away everything that is on the property
right now, why would you ever accept that we would want you to dig in some
of the area that you consider contaminated and put that contaminated soil on
top of five feet of soils that is not contaminated and then guarantee us
that that is going to be protected by whatever you do with it when you're
using the argument that it would be safer for us to not -- not to touch --
not to move it from that area at all? So that's why I think that there has
to be a clarification about the word contamination because I have been led
to believe that we're using the word contamination, and there is
probably a possibility of contamination on that piece of property that might
not be any different than the back yard of somebody in Santa Fe Springs in
some areas of contamination."
Response: EPA's selected remedy proposes moving some of the contaminated material that is more readily accessible and consolidating the contamination into a smaller area. This excavation and consolidation will be performed under carefully controlled operations to limit contact with the contaminated soils, so the workers will be exposed to minimal risks. Dust suppression will be used to protect non-workers as well. In order to provide more protection, the surface soil in the consolidation area will be partially removed in order to provide a thicker protective barrier between contaminated soils and the surface.
Although some of the contaminants found at WDI are also found in the background soils in the Santa Fe Springs area, they are found at the site at greater levels than is considered healthy. They are also found at levels higher than background, so in that respect are not like backyard soils. There are also contaminants that are not found in the background, and are present as a result of previous industrial activity at the site. The excavation will be performed to remove the contaminated soils of the sumps to the protective levels established in the Section 10.1 of the ROD.
4.13 Page 81, line 13, Brother Dennis
"My concern is that's a fairly ugly looking thing, and I obviously would be
more -- the green field is obviously more pleasing to look at."
Response: Thank you for your comment. We will consider aesthetics during the design phase of this project.
4.14 Page 86, line 7, Father Gallagher
"One comment, and it would be a very brief one, is that I'd like to
reiterate that the position of the school is that we'd be very reluctant to
have any business up above the level of the school yard where we would have
to be concerned about the safety of the students and always be wondering
well, who was going to be looking down on them since -- since the field is
used for a lot of different activities, so this is a different safety, so I
would hope that the EPA would also allow for that if they're going to be
making some kind of improvements in the area."
Response: As previously stated, final uses for the site will be determined during the design phase of this project; we will try to address concerns similar to those stated in the comment at that time.