California Department of Toxic Substances Control

COMPREHENSIVE FIELDDATA REVIEW

#1

In 1997, under the Department of ToxicSubstances Control’s (DTSC) oversight, asystematic investigation into contamination atthe Santa Susana Field Laboratory (SSFL)began. This investigation (called a RCRAFacility Investigation) was based oninvestigation workplan reviewed and approvedby DTSC in 1996. The investigation focused onsuspected areas of contamination identified inthe United States Environmental ProtectionAgency’s (US/EPA) SSFL Site Assessment (thefirst step in the RCRA Corrective Process). In1999, following assignment of additionalpersonnel to the project, DTSC staff initiated acomprehensive field data review of theinvestigation data to insure potential data gapswere addressed early. All areas on the facilitywere systematically visited as part of theassessment process, including areas with nosuspected contamination. This reviewincorporated historical aerial photographs of theSSFL dating back to the 1940s, systematicvisiting of all buildings and activity areas, as wellas records of chemical handling activities. As aresult of this systematic review, additional areasof concern have been identified, and asignificant expansion of field sampling and datacollection analysis beyond the original workplanhas been required. During this field effort,DTSC staff specified the type, number, locationof all sample collection areas, and directed thecollection of sample data by Boeing’senvironmental consultants. To date, over 5,000samples have been collected and analyzed.Since 1999, DTSC technical staff have devotedmore than 33,000 hours to oversight ofpermitting and corrective action activities atSSFL.

California Department of Toxic Substances Control

DTSC staff review fault trace and geology mapped by Boeing’senvironmental consultant, Dr. Ross Wagner, in the Coca teststand area.

Photo above shows DTSC staff inspecting exploratorytrench and selecting sampling locations.

Cal/EPA, DTSC, Region 3. Dated: 04/08/2002

In 2000, DTSC approved an investigation intothe fractured bedrock and deep groundwaterat the SSFL. An investigation into fracturedbedrock contamination of this size and scopehas never been attempted before. Severalnew investigation techniques were developedand will be deployed for the first time.


Core drilling rig in Bowl rocket test stand area. Well boringwas drilled to over 400 feet depth.. Over 350 rock subcoreswere collected and analyzed for solvents.

Within minutes after removal from the boring, coresamples are logged by a geologist and prepared foranalyses by a chemist.

The multimillion dollar effort will evaluate thethree dimensional distribution of contamination inthe fractured bedrock, and will assessgroundwater flow through the fractured bedrockbeneath the facility. The first phase of theinvestigation will include the drilling andinstallation of continuously cored boreholes todepths in excess of 500 feet. An estimated 350rock samples will be collected from each boringand analyzed for contamination.

DEEP GROUNDWATERINVESTIGATION OF

FRACTURED BEDROCK#2


Newly installed well borings andapproximately 100 currently existing wells atSSFL will be retrofitted with water samplingdevices. Each well will contain up to 14sampling ports and pressure transducers inorder to study vertical and horizontalgroundwater characteristics in threedimensions to the depth of contamination.


Above graph shows geophysical log of well boring used toevaluate rock properties. Photo below shows retrofitting ofexisting well with multiport sampling device in wells.

Prior to retrofitting, each well boring will begeophysically logged to evaluate rockproperties. Slug tests and cross boringpumping tests will be conducted to evaluatehydraulic conductivity, rock fractureconnectivity, and groundwater flowcharacteristics in the bedrock. Water qualitydata collected from the wells will be used toassess contaminant in the subsurfacebedrock.

DEEP GROUNDWATERINVESTIGATION OF

FRACTURED BEDROCK#3


A comprehensive investigation of shallowgroundwater was conducted at SSFL toidentify and assess the flow, direction, anddistribution of contaminants in shallowgroundwater away from contaminant sourceareas. Field work for this investigationprogram began in October 2000. DTSC staffwere onsite during the field investigation toobserve drilling and well installation, selectborehole depths, and specify the location ofnew wells. A total of 94 single and multisampling groundwater pressure (piezometer)monitoring wells were installed, with 191sampling ports. An additional 23 shallowgroundwater pressure (piezometer)monitoring wells were installed in the fall of2001. Data collection of borehole rock stratawas performed at selected locations tooptimize well design. Water levelmeasurements were monitored daily fromJanuary through June during and followingrain events.


Top photos: Hollow stem auger drilling rig installingshallow piezometers; rock core, and geophysical loggingtool. Below and left photo: Water level data collectedduring winter months; map with piezometric data.

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Precipitation DataPZ-015A Groundwater ElevationPZ-015B Groundwater ElevationPZ-015C Groundwater ElevationPZ-015D Groundwater ElevationPZ-015E Groundwater ElevationPZ-015F Groundwater ElevationPZ-015G Groundwater Elevation

SHALLOW GROUNDWATERINVESTIGATION

#4


Excavation of Polychlorinated biphenyl’s(PCB) and dioxin impacted soils from theFormer Sodium Disposal Facility (FSDF)impoundments and channels was finalized inAugust 2000. Completion of the FSDFcleanup follows nine years of delay andcontroversy. The removal action is asignificant accomplishment, and represents amajor step towards the remediation andprevention of contamination movement downand along the channels below the FSDF.Following removal of the soils, the exposedbedrock surfaces were swept and vacuumedclean, and mapped for fractures and chemicalresidues. As a precautionary measure, aDTSC registered geologist took samples toconfirm that soil and bedrock wereremediated to the required health-basedcleanup levels prior to installation of theengineered backfill.


Top photos: The upper impoundment covered by tarpprior to excavation in 1999; Excavation and removal ofcontaminated soil by hand crews in channels belowimpoundment; Excavation of the upper impoundment.

INTERIM MEASURESSODIUM DISPOSAL FACILITY

#5


Top photo: removal of contaminated soil down tobedrock (upper impoundment).

Installation of a low water permeabilityengineered backfill cover was undertaken atthe Sodium Burn Pit in October 2000. As partof the cover installation, soil moisture probesand water level gauges (pan lysimeters) wereinstalled to monitor performance of the cover.Shallow monitoring wells have been installedin various areas of the cover to evaluatelateral (sideways) infiltration. The moistureprobes record data from predetermined depthswithin the backfill cover 24 hours a day, 365days a year. Data recorded during an above-normal rainfall event between January throughMarch 2001 indicate that water has notpenetrated through the cover.


Top photo: Installation of low permeability backfillcover; Left and bottom photos (left to right): Installationof monitoring drain; final cover grade (upperimpoundment); final cover; data collection station - soilmoisture probes monitor moisture content change. Datais collected 24 hours per day.

INTERIM MEASURESSODIUM DISPOSAL FACILITY

#6



PERCHLORATE INSIMI VALLEY GROUNDWATER

#7


Previous Work Undertaken

In 1995 the City of Simi Valley installed 11 non-potable wells to monitor and de-water portions ofthe valley which routinely experienced floodingproblems caused, in part, by a shallow watertable. Perchlorate was detected at traceconcentrations in one de-watering well onCasarin Avenue. Soon after, the USEnvironmental Protection Agency (EPA) re-sampled the same well and obtained similarresults. The City of Simi Valley and the EPAasked the Department of Toxic SubstancesControl (DTSC) to review the data.

What is Perchlorate?

Perchlorate is commercially produced as solidsalts of ammonium, sodium and potassium.The chemical is used as an oxidizer in solidpropellants for rockets, fireworks, munitions,also used to manufacture matches, and hasreportedly been associated with somefertilizers. Perchlorate is water-soluble andexceedingly mobile in groundwater systems.It can persist for many decades under typicalgroundwater and surface water conditionsbecause of its resistance to react with thesurrounding environment. One of theconcerns about perchlorate is the potentialhealth effects at low levels in drinking water.Currently, the Department of Health Servicesuses an advisory action level of 4 microgramsper liter to protect drinking water consumersfrom adverse health effects. Perchlorate hasnot been detected in any drinking watersupplies in Simi Valley.

Top photo: Model of a perchlorate molecule. Bottom left:Map shows locations of eleven de-watering wells testedin the vicinity of Royal Avenue and Erringer Road.Perchlorate was detected in one well on Caballero Streetat 9.42 micrograms per liter. Ten other wells testedcontained no detectable perchlorate. All of the abovementioned wells are not used for human consumption.


PERCHLORATE INSIMI VALLEY GROUNDWATER

#8


DTSC Investigations IntoPerchlorateAs part of the effort to define the source ofperchlorate detected in Simi Valley, DTSC hascollected and analyzed over 40 groundwaterand surface water samples, researched countyrecords and talked with community membersto identify potential sampling points, andcoordinated resources with the Los AngelesRegional Water Quality Control Board and theCity of Simi Valley. All water samples wereanalyzed by DTSC’s Hazardous MaterialsLaboratory. Results so far indicate perchloratewas detected in groundwater samplescollected from 5 non-potable monitoring wellsat concentrations ranging from 3.38 to 9.42micrograms per liter (ug/L). Four of the wellsare located at a former Thrifty Gas Stationlocated at the corner of Erringer Road andRoyal Avenue. One well is located onCaballero Street. These results promptedDTSC to collect an additional 24 samplesbetween the Rocketdyne Facility and SimiValley in March 2002. Results of the samplingare pending. Two drinking water supply wellsowned by Southern California Water Companyin Simi Valley are routinely sampled forperchlorate and contain no detectableconcentrations. Perchlorate has not beendetected in any drinking water supplies in SimiValley.

Top : Map of Simi Valley, Simi Hills, and Rocketdyne(outlined in red). Blue dots represent recent DTSCgroundwater or surface water locations sampled byDTSC. Photographs show artesian wells and springs onBrandeis Bardine Institute property where recentsamples were collected. Left Photographs: Groundwatersamples from Caballero Street well in Simi Valley.


PUBLIC PARTICIPATIONACTIVITIES

#9

The Department of Toxic Substances Control’s (DTSC) public participation efforts at the SantaSusana Field Laboratory (SSFL) began in 1990. Due to the high level of public scrutiny regardingcleanup activities at the facility, the Department has devoted significant resources in responding tocommunity questions and concerns. Ongoing outreach efforts have included numerous publicmeetings, fact sheets, and public notices.

Over the past year, current activities have focused on reviewing and developing DTSC’s publicparticipation strategy. To date, the following steps have been taken:

• Development of a community profile of residents living within a five-mile radius of the facility. This effort includes:

- Mailing of 96,000 community surveys (3,500 + completed surveys returned) - Documentation of community concerns and comments - Development of a 5,000 + address facility mailing list - Demographic profile within an eight-mile radius of the facility - Community interviews and briefings

Based on the input received from the returned community surveys, the most frequently mentionedconcerns and questions included:

• Protection of public health and the environment• Confusion regarding which agency is responsible for different cleanup activities• Difficulty at understanding the science associated with technical cleanup activities• Frustration at the amount of time being taken to clean up the facility

A high level of mistrust of government agency decision-making exists within the community.DTSC is working to improve this situation by broadening public outreach, improving the circulationand quality of information, and by working with members of the SSFL Workgroup in promoting anenvironment of constructive dialogue and informative decision-making.

DTSC’s Public Participation Program appreciates suggestions and recommendations on how toimprove their outreach efforts. For further information regarding public participation activities, orto make suggestions on improving our approach, please contact Tim Chauvel at 818-551-2829,Fax: 818-551-2850, Email: [email protected].



LIST OF AGENCYCONTACTS

#10

Department of Toxic Substances Control (DTSC): DTSC is the regulatory agency in charge ofinvestigating the release and cleanup of hazardous chemicals at the facility. For furtherinformation, contact: Mr.. Gerard Abrams, Telephone: (916) 255-3600, or Tim Chauvel,Telephone: (818) 551-2829.

Agency for Toxic Substances and Disease Registry (ATSDR): ATSDR has evaluated theSSFL for possible threats to public health from operations at the facility. For further information,contact: Hazardous Substances & Public Health, ATSDR, 1600 Clifton Road, NE, MS E33,Atlanta, GA 30333; telephone (404) 498-0112; fax (404) 498-0061, or their website at:www.atsdr.cdc.gov .

United States Environmental Protection Agency (EPA): The EPA has chaired the SantaSusana Field Laboratory (SSFL) Workgroup meetings formed in 1989. The State of Californiawas authorized by the EPA to implement federal regulations governing cleanup of chemicalcontamination in soil and groundwater at the SSFL. For further information, contact: Mr. JohnBeach, Telephone: (415) 972-3347.

United States Department of Energy (DOE): DOE is the regulatory agency in charge of cleanupof radioactive contamination in Area IV of the Santa Susana Field Laboratory (SSFL). For furtherinformation, contact: Mr. Mike Lopez, Telephone: (510) 637-1633.

California Department of Health Services (DHS): DHS licenses the possession, use, transfer,and disposal of certain radioactive materials at SSFL. For further information, contact: Mr. SteveHsu, Telephone: (916) 322-4797.

Ventura County Air Pollution Control District (VCAPCD): VCAPCD is responsible forregulating emissions of air contaminants at SSFL. VCAPCD has no regulatory authority overradionuclide emissions. For further information contact: Mr. Karl Krause, Telephone: (805) 645-1444.

Ventura County Environmental Health Division (VCEHD): VCEHD is responsible forimplementing a number of environmental programs relating to underground storage tankmanagement, hazardous materials inventory, and spill prevention countermeasures. For furtherinformation, contact the VCEHD front desk, Telephone: (805) 654-2813.

Los Angeles Regional Water Quality Control Board (LARWQCB): LARWQCB overseessurface water discharges from the SSFL. The National Pollutant Discharge Elimination System(NPDES) permit issued to the SSFL requires that discharges to surface waters are monitored andthe resultant data reported to the LARWQCB monthly. For further information contact: Ms.Casandra Owens, Telephone: (213) 576-6750


Documents

California Department of Toxic Substances Control