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Pacific Southwest, Region 9: Superfund

Serving Arizona, California, Hawaii, Nevada, the Pacific Islands, and Tribal Nations

Casmalia Resources

EPA #: CAD020748125

State: California(CA)

County: Santa Barbara

City: Casmalia

Congressional District: 23rd and 24th

Other Names: Casmalia Resources Hazardous Waste Management Facility

Bulletin Board

On 10/13/17, this website will no longer be updated. Site information will be migrated to the new web page at: http://www.epa.gov/superfund/casmalia .
EPA appreciates your patience through this transition. If you have questions, please contact EPA staff listed below.


Description and History

NPL Listing History

NPL Status: Final

Proposed Date: 06/14/01

Final Date: 09/13/01

Deleted Date:

Site Description

The Casmalia Resources Superfund Site (Site), formerly the Casmalia Resources Hazardous Waste Management Facility, is an approximately 252-acre, inactive commercial hazardous waste treatment, storage, and disposal facility located in Santa Barbara County, California. This Site is located 10 miles southwest of the City of Santa Maria, 1.2 miles north of the Town of Casmalia, and four miles from the Pacific Ocean.

Site History

Between 1973 and 1989, the Site accepted approximately 5.6 billion pounds of waste into 92 waste management or treatment facilities. These facilities included landfills, ponds, shallow wells, disposal trenches, and hazardous waste treatment units. During its operational history, more than 10,000 businesses and government entities sent commercial hazardous waste to the Site. The waste material accepted at the Site included sludges, pesticides, solvents, acids, metals, caustics, cyanide, and nonliquid polychlorinated biphenyls (PCBs). The facility owners and operators were Casmalia Resources, Hunter Resources and Kenneth H. Hunter, Jr.

Facing multiple regulatory enforcement actions, the facility's owners and operators stopped accepting shipments of waste material in 1989. In 1991, the owners and operators abandoned any further efforts to properly close and clean up the Site. At that time, conditions at the Site presented imminent and substantial endangerment to human health and the environment. From 1992 to 1996, the United States Environmental Protection Agency (EPA) used Superfund authorities to take emergency actions to stabilize the various waste management or treatment facilities on the Site. These actions included installing and operating systems for collecting, treating, and disposing of contaminated subsurface liquids, controlling the flow of storm water, and stabilizing the landfills.

Images Documents

Figure 1 - Aerial View Showing Location of Casmalia Resources Disposal Site - JPG
Figure 2 - Aerial View of Site - GIF
Additional Photos Casmalia Site - JPG

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Contaminants and Risks

Contaminated Media
  • Groundwater
  • Surface Water
  • Air
  • Soil and Sludges
  • Environmentally Sensitive Area

The Casmalia Resources Superfund Site has been stabilized and risks are being controlled. Engineering controls have been installed to control on-site risks and ensure that there are no unacceptable off-site risks to human health and the environment. Interim response actions which have been performed to contain and treat waste materials have included construction of engineered capping systems on former landfills, installation of several hundred groundwater monitoring wells and vapor and other environmental monitoring probes, construction of drainage systems, and installation of systems to extract and treat contaminated liquids. Such measures prevent exposure to potentially harmful chemicals in soil, air, surface water, or groundwater.

The remedial investigation (RI) has been completed, and EPA approved the final RI Report on April 26, 2011. The RI includes a risk assessment that finds that there are no unacceptable off-site risks to human health or the environment. Remaining on-site risks, primarily to ecological receptors, will be addressed as part of a final remedial action that will be implemented after completion of the ongoing feasibility study, issuance of a proposed plan for public comment, and formal selection of a final sitewide remedial action in a record of decision (ROD).

Wastes found at the Casmalia Resources Superfund Site have included a wide range of materials with potentially toxic properties. Response actions are being designed to control risks and provide containment. Waste products generated from these interim actions are being contained and treated on-site or shipped off-site for treatment and disposal. Although there were historic releases of contaminants to the air during active commercial landfill operations, these operations have long since been discontinued, and the landfills have been capped or are otherwise being controlled. In addition, older environmental control systems that might have been vulnerable to spills or releases have been upgraded or completely replaced.

On-site groundwater contains a large number of constituents of potential concern (COPCs), many of which exceed drinking water standards (maximum contaminant levels, or MCLs). Groundwater monitoring shows that contamination is being contained through a combination of engineering controls (extraction wells and trenches) and natural degradation of contaminants (natural attenuation).

EPA has been performing or overseeing continuous improvements to site operations, maintenance, and monitoring practices. All site systems are being inspected on an ongoing basis. Any further contaminant releases to the air are unlikely and would be detected quickly by site inspections. Off-site exposure to site–related contaminants is considered negligible due to a lack of complete exposure pathways.

A detailed risk assessment, addressing health and ecological risks, was completed as part of the Remedial Investigation and is included as part of the final RI Report. In conjunction with the RI, the risk assessment shows that on-site risks are being controlled and concludes there are no unacceptable off-site risks and that waste materials are being contained through a combination of engineering controls and natural degradation of contaminants (natural attenuation).

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Who is Involved

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Investigation and Cleanup Activities

In 1997, EPA entered into a judicial settlement (consent decree) with the Casmalia Steering Committee (“CSC”), a group of 54 of the largest generators of waste disposed at the Site. The CSC members generated approximately half of the waste disposed of at the site. The consent decree specifies four phases of work:

• Phase 1 -- Site maintenance, groundwater monitoring, and contaminated liquids management activities for specified periods of time, construction of the pesticides/solvents landfill cap, the planning and design of three additional landfill caps, conducting site investigations, and design of permanent site-wide response actions;
• Phase 2 -- continuation of site maintenance, groundwater monitoring and liquids management activities after Phase 1, construction of the four additional landfill caps, construction of additional permanent site-wide response actions, and five years of operation and maintenance of the permanent responses;
• Phase 3 -- thirty years of Site operation and maintenance and;
• Phase 4 -- the long-term maintenance of the Site once after the 30-year operation and maintenance period is over.

For more details about the site clean-up plans, you may contact one of the EPA’s Remedial Project Manager(s) listed below.

Initial Actions

Response Actions taken at the Site include:

o Capping one landfill in 1999 (with additional corrective construction in 2001);
o Capping a second landfill in 2001;
o Capping two additional landfills in 2002;
o Installing and operating a ground water collection and treatment system;
o Consolidating and managing numerous waste water collection and containment impoundments; and
o Implementing numerous Site improvements such as slope stabilization, minimizing the amounts of infiltrating rainwater, improving contaminated liquids control, and improving access to Site areas.

Site Studies

The Remedial Investigation (RI) Work Plan was approved in June, 2004. RI field activities began during the summer of 2004. More than 2,700 locations were investigated and sampled for more than 600 different chemicals of concern. An Interim Progress Report (IPR) was completed and data gaps were identified as part of a second phase of RI Field sampling. Based on the Remedial Investigation and Feasibility Study (RI/FS) developed from this Work Plan, final response actions will be selected. These response actions may include capping an additional landfill, closing surface water impoundments, removal of pooled DNAPL, capping additional waste disposal areas, and the installation of ground water control and treatment systems.

The CSC submitted a Draft RI Report in May 2008. EPA and the Casmalia interagency committee reviewed the draft and provided comments to the CSC in October 2008. Community representatives from the nearby town of Casmalia and their consultant provided input to the review of the Draft RI Report. The CSC submitted a revised draft RI report at the end of January 2010.  EPA, the interagency committee (IAC), and community representatives reviewed the revised draft and provided extensive comments on June 17, 2010.  EPA and the CSC worked together using an over-the-shoulder review process to develop a revised document. EPA issued its approval of the RI report on April 26, 2011.

Meanwhile, the CSC submitted a draft Feasibility Study (FS) on February 28, 2011. EPA and the interagency committee conducted a detailed technical review and provided comments on the draft. The CSC submitted a revised draft FS Report on October 31, 2011. EPA and the interagency committee reviewed the Revised Draft FS Report and EPA approved the Final FS Report on April 1, 2016.

See Site Description and History above.

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Cleanup Results to Date

Landfill Final Covers Installed

      A landfill cover (also known as a cap) is designed to provide long-term protection for people and the environment from direct exposure to the hazardous waste contained beneath it. The cap also provides a hydraulic barrier to rainfall, preventing it from leaching through buried hazardous waste and generating additional groundwater contamination --thereby reducing long-term site maintenance costs. A multi-layered landfill cover has been installed on three of the four landfills.

      Pesticides/ Solvent Landfill

      During the summer of 1999, the CSC constructed a cover system over the Pesticides/Solvents Landfill and a storm water run-off control system. Following construction, EPA deemed that both the cover system and the run-off control system had construction deficiencies and corrective action was necessary. Corrective action work began during summer 2001 and was completed in January 2002.

      Heavy Metals and Caustic Cyanide Landfills

      In cooperation with EPA and the State of California, the CSC constructed the final cover systems for the Heavy Metals Landfill in 2001 and the Caustic/Cyanide Landfill and Acids Landfill in 2002.

      PCB Landfill

      The PCB Landfill will be used to contain any contaminated soils and sediments from other portions of the Site during the final phase of response activities; therefore, the PCB Landfill will receive its cover following the completion of these activities.

      Surface and Groundwater Monitoring and Treatment Programs Continue

      In early 2001, the CSC issued a report regarding site-wide groundwater contamination. The EPA and CSC are continuing their extensive groundwater monitoring program. The goals of this program are to monitor the extent of groundwater contamination and the progress of the on-going site groundwater extraction and treatment system.

      Approximately 255 wells are checked for water level elevations on a routine basis. In addition, water from 66 groundwater wells and 5 ponds is sampled annually or semi-annually and analyzed in an environmental laboratory for various chemical contaminants. Chemically affected ground water is treated on-site.

      The groundwater treatment system uses granular activated carbon (GAC) to remove organic contaminants from the groundwater collected in the Perimeter Source Control Trenches. Treated water is discharged to an on-site pond for evaporation. Two wells, Gallery Well and Sump 9B, collect contaminated liquids from the Pesticide/Solvent Landfill (PS Landfill). The Gallery Well and Sump 9B liquids are pumped into a holding tank and transferred to a tank truck for transport to an off-site treatment and disposal facility.

      Initiation of Site-Wide Investigation and Study: Remedial Investigation/Feasibility Study

      Ongoing remedial investigative (RI) work in 2006 and 2007 included continued data collection and analysis as well as the development of a groundwater flow computer model for the site. The MODFLOW model used sophisticated computer programs to simulate actual site hydrologic conditions. After proper set-up and calibration were achieved, the model provided valuable information to help characterize current groundwater conditions, assess potential future clean-up alternatives and help design future response actions.

      EPA and the CSC conducted a detailed geophysical investigation to characterize the subsurface structure of the Site, particularly the P/S Landfill. In December 2005, the CSC undertook extensive geophysical fieldwork under EPA oversight. The geophysics field work and follow-up analysis applied a technology called seismic refraction technology with tomographic inversion. Seismic refraction uses sound waves to assess underground geologic features. EPA worked with the CSC to complete the evaluation of the geophysical models and analyses and incorporate the results into the Draft RI Report.

      EPA approved the final RI Report the CSC on April 26, 2011.

      The CSC has submitted two drafts of a feasibility study report that identifies and evaluates remedial alternatives based on the 9 criteria described in CERCLA (CERCLA 9-point criteria). The FS divides the site into areas, and proposes and evaluates numerous cleanup alternatives for each area. EPA evaluated six (6) possible sitewide alternatives, including the No Further Action alternative in the Feasibility Study. EPA is now preparing a Draft Proposed Plan for the future issuance for public review and comment.

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Potentially Responsible Parties

Potentially responsible parties (PRPs) refers to companies that are potentially responsible for generating, transporting, or disposing of the hazardous waste found at the site.

Financing the Cleanup

In 1992 EPA assumed the role of the lead regulatory agency after the facility's owners and operators claimed financial difficulty and abandoned any further efforts to clean up the Site. EPA responded by undertaking emergency response action activities, while concurrently seeking voluntary participation in site work by former customers of the facility. To clean up, close and care for this site, EPA estimates it will cost $284 million (in 1999 dollars). Sources of funding for these response actions include the trust fund established by the former owners and operators, as well as settlements with “potentially responsible parties” (explained below) and government funding.

Potentially Responsible Parties

The term potentially responsible parties (PRPs) refers to people, organizations and companies that are potentially responsible for generating, transporting, or disposing of the hazardous waste found at the site. The PRPs at the Casmalia Site include the former owners and operators and generators and transporters of waste disposed of at the site.

During the years of the Casmalia facility’s operation, the facility accepted waste from thousands of private businesses and government agencies. One of the EPA’s major responsibilities is to create an equitable process to ensure that each of these parties pays its share of total site costs -- both for the expenses that EPA has incurred already, and for future improvements and maintenance at the site. The current estimate of these expenses is $284 million, based on an engineering cost estimate prepared in 1999. EPA expects that the cost estimates will be updated as work progresses towards selection of a final cleanup approach.

EPA is working with PRPs to enter into settlements to help fund ongoing and future cleanup activities the site. To date EPA has settled with over 1,150.Casmalia PRPs. EPA refers to these as "Cashout" settlements, because under the settlement terms the PRPs pay into an account to finance the work. Over 1,000 of these entities are referred to as de minimis contributors because they sent relatively small amounts of waste to the site. The remaining parties include the former owners and operators and customers that are referred to as “major” waste generators. These settlements have generated over $110 million in funding for response actions at the site.


In December of 2001, the EPA negotiated a settlement with the State of California regarding the State's liability for wastes that the various State departments and agencies shipped to Casmalia. The settlement with the State was for $15.9 million.

On July 22, 2003, the U.S. District Court for the Central District of California approved a settlement with a group of 41 major waste generators, and on August 14, 2003, the same court approved settlements with 3 additional major parties. These 44 parties sent a combined total of 10.9% of the waste to the site, and paid a combined total of $31.9 million.

Naturally, the former owners and operators are expected to apply their own resources to the site’s cleanup as well. To that end, in 1997 the United States filed suit in federal district court against Casmalia Resources, Hunter Resources, and Kenneth H. Hunter, Jr., the facility owners and operators. On February 14, 2002, the owner/operators settled with the EPA for $6.9 million, and the court entered the settlement on November 22, 2002. In May of 2005, the EPA negotiated two (2) settlements with trustees for the estates of George and Mario Castagnola's who were Limited Partners of Casmalia Resources. The settlement was for $400,000.

Funds received from these settlements will be applied to Casmalia Resources site related work. Meanwhile, EPA will continue to offer "Cashout" settlements to other PRPs.

Since 2000, EPA has entered into settlements with de minimis generators, who took smaller amounts of waste to the site, to obtain significant settlement funds that will be applied to site response work. The table below summarizes settlement information for de minimis PRPs, including settlement ID, volume of waste, parties, and settlement recoveries.

Summary of De Minimis Settlements
Group ID
No. of Parties
$ - Recoveries
% of Waste
AOC 99-02(a)
AOC 99-02(d)
AOC 99-02(c)
AOC 99-02(c)(supp)
AOC 99-02(e)
AOC 99-02(c)(supp)(2)
AOC 99-02(e)(supp)
AOC 99-02(f)
AOC 99-02(g)
AOC 99-02(h)
AOC 99-02(i)

Anyone who would like documents associated with the settlement process may download a Document Order Form by clicking the link below called Settlement Documents and fax it to Karen Goldberg's attention at (415) 947-3570, or call (415) 369-0559, extension 10 to request copies.

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Documents and Reports

Show details for Administrative RecordsAdministrative Records
Show details for Fact SheetsFact Sheets
Show details for ImagesImages
Show details for Legal DocumentsLegal Documents
Show details for MapsMaps
Show details for Technical DocumentsTechnical Documents

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Community Involvement

Public Meetings: The EPA is committed to having the local community involved in the issues surrounding the Casmalia site.

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Public Information Repositories

The public information repositories for the site are at the following locations:

Documents (from 1992-present) related to Casmalia are available for viewing and copying at this location:

U.S. EPA Superfund Records Center
Third Floor
75 Hawthorne Street
San Francisco, CA 94105
(415) 947-8717

A more limited set of key documents is available at:

Santa Maria Public Library
Reference Department
421 S. McClelland St.
Santa Maria, CA 93454
General No. (805) 925-0994

Davidson Library (MC-19010)
University of California Santa Barbara
(805) 893-2731

The most complete collection of documents is the official EPA site file, maintained at the following location:

Superfund Records Center

Mail Stop SFD-7C

95 Hawthorne Street, Room 403

San Francisco, CA 94105

(415) 820-4700

Enter main lobby of 75 Hawthorne street, go to 4th floor of South Wing Annex.

Additional Links

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EPA Site Manager
Russell Mechem
US EPA Region 9
Mail Code SFD
75 Hawthorne Street
San Francisco, CA 94105
EPA Community Involvement Coordinator
Alejandro Diaz
US EPA Region 9
Mail Code SFD
75 Hawthorne Street
San Francisco, CA 94105
EPA Public Information Center
State Contact
Chris Sherman

Dan Niles

Patty Velez




Department of Toxic Substances Control
Sacramento Field Office

Central Coast Water Board

California Department of Fish and Wildlife
PRP Contact
Corey Bertelsen
Community Contact
Other Contacts
After Hours (Emergency Response)
(800) 424-8802

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