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The site, a former petroleum refinery, encompasses approximately 440 acres and is locatedapproximately 2 miles north of Cushing, Oklahoma in Payne County. The Cushing area oncehad been a center of extensive petroleum production and refining; petroleum production,storage, and pipeline activities continue in the general area. The refinery, for a time, alsoprocessed nuclear materials for Atomic Energy Commission use in some of its buildings alongDeep Rock Road. Kerr-McGee, the last operator of the refinery, has conducted extensivecontamination investigations at the site and some substantive removals. More such activities arebeing planned. Kerr-McGee has entered into an agreement with the State of Oklahoma toremediate the site, and theresidual impacts from the nuclear activities are being addressed undera new license with the Nuclear Regulatory Commission.

A large tract of land east of Linwood Avenue (designated Property A for this assessment andknown locally as the Rafferty property) had been used for petroleum refining and storage, andonce was thought by agencies to have been part of Kerr-McGee's operations. More recently, ithas been determined that that Property A was never associated with the Kerr-McGee site. Another corporation will conduct detailed investigations of Property A and will initiateappropriate follow up activities. The Oklahoma Department of Environmental Quality recentlynamed the property the Sinclair Topping Plant. The limited early information available aboutProperty A has been addressed in this public health assessment because of it's proximity to theKerr-McGee site and the associated community population of interest.

The Kerr-McGee site does not currently present a health hazard to the public. However if Kerr-McGee does not complete planned remedial activities, and the property is laterdeveloped forresidential use, residents could be exposed in the future to contaminants andradioactivematerials that might harm their health.

Property A, which is not associated with the Kerr-McGee site, is an indeterminate publichealthhazard because sufficient chemical and radiological data are not currently available to adequatelyevaluate environmental media. Lead contaminated soil and sediment were found on theproperty; the extent of such contamination, which is not known at this time, will determinewhether or not those media are a public health threat.


The Kerr-McGee Cushing Refinery site was proposed by the U.S. Environmental ProtectionAgency (EPA) for addition (Update No. 10) to the NationalPriorities List (NPL) in October of1989. EPA subsequently deleted the site (Update 11). In May 1990, Kerr-McGee entered into aConsent Order with the Oklahoma State Department of Health (OSDH) that addresses investigation and remediation. In 1993, the site was put under new Nuclear RegulatoryCommission (NRC) license for the purpose of addressing and remediating the residualradiological impacts. The background information that follows focuses on issues that theAgency for Toxic Substances and Disease Registry (ATSDR) believes are the most pertinent toevaluating public health significance.

A. Site Description and History

General Background

    Kerr-McGee Site

The site, a former petroleum refinery, encompasses approximately 440 acres and is locatedapproximately 2 miles north of Cushing, Oklahoma in Payne County (Figure 1, Appendix A: onPage 33). The Cushing area once had been a center of extensive petroleum production andrefining; petroleum production, storage, and pipeline activities continue in the general area.

The Kerr-McGee site is west of Linwood Avenue, and is divided by Deep Rock Road, whichruns east-west. Several different owners had operated a refinery on the property starting about1915. Kerr-McGee purchased the refinery in 1956 and operated it until 1972; they thendismantled refining facilities and many of the storage tanks. Most of the refining structures werelocated south of Deep Rock Road, on the eastern part of the site. NGC Inc. has an agreementwith Kerr-McGee under which they continue to operate a few petroleum storage tanks on theproperty and a pipeline (1). Between 1963 and 1966, Kerr-McGee also processed nuclearmaterials in some refinery buildings located along the south side of Deep Rock Road; portions ofthose facilities have been dismantled (2) .

Kerr-McGee once sold parts of the site, and, more recently, has repurchased properties. Kerr-McGee advised ATSDR that as of early 1996 there were three small parcels within the siteboundary that Kerr-McGee does not own--a parcel of about 1 acre on the southern edge of DeepRock Road that has two active cement silos, about 1 acre on the northern edge of Deep RockRoad that has an inactive oil reclaiming facility, and about 1 acre in the southeast corner of thesite that has a small inactive tank. About 1990, four residences were removed from the property(one was located along Deep Rock Road and three were along Linwood Ave, immediately southof Skull Creek). The site now is enclosed by a three-to-four strand wire fence and posted. Kerr-McGee staff report that recreational activities are not permitted on the property.

Kerr-McGee has conducted extensive contamination investigations at the site and someremovals. More such activities are being planned. ATSDR has considered key elements ofthose activities in this public health assessment.

    Property A (locally known as Rafferty property)

When proposing the Kerr-McGee site for the NPL, EPA believed a large tract of land east ofLinwood Avenue that once had been used for petroleum refining and storage also had been partof Kerr-McGee's operations--see Property A on Figure 1. More recently, it has been determinedthat Property A was never associated with the Kerr-McGee site. The limited early informationavailable about Property A has been addressed in this public health assessment because of it'sproximity to the Kerr-McGee site and the community population of interest.

Records indicate that refinery operations stopped prior to 1956 (3). Oklahoma DepartmentofEnvironmental Quality (ODEQ) staff report to ATSDR that another corporation will conductdetailed investigations of Property A and will initiate whatever follow up activities are deemedappropriate. The ODEQ recently named the property the Sinclair Topping Plant. Only a fewsamples have been taken of environmental media on Property A to date. ATSDR has used thelimited early investigation data to qualitatively evaluate Property A and develop generalrecommendations that may influence investigations of that property.

Former Site Operations and Waste Disposal

    Petroleum Facilities

Petroleum refining, storage, and transport activities have been conducted at the site bymultipleowner companies. Refining processes changed as technology advanced. Prior to 1951, asulfuric acid treating unit was used to process lubricating oil. That unit produced wastediatomaceous earth and clay filtering materials containing entrained sulfuric acid andhydrocarbons (4). Those wastes (sludges, etc.) were deposited in five unlined pits (Pit 1 through5) on the property. Pits 1 through 4 are located north of Deep Rock Road, while Pit 5 is locatedsouth of the road, near Skull Creek. The waste volume has been estimated to be 300,000 cubicyards, half of which is contained in Pit 5 (1,5). After 1951, a different treatment unit wasinstalled, and production of acid wastes stopped (1). Other estimates place the amount at nearly400,000 cubic yards. Kerr-McGee reported that Pits 1, 2, 3, and 5 were full when theypurchased the refinery in 1956, and, therefore, were not used in their refinery operations. Pit 4was used by Kerr-McGee to dispose of desalter refinery waste and waxy residues (1). The pitsare surrounded by chain link fencing. In 1994, 21 additional small waste deposits containingpetroleum sludge were identified and evaluated (6).

    Nuclear Facilities

Uranium and thorium processing occurred between 1963 and 1966. The Atomic EnergyCommission (AEC) issued Kerr-McGee a source material license (SMB-664) on November 7,1962 and a special nuclear material license (SNM-695) on April 23, 1963 (7). Uraniumprocessing wastes included carbon crucibles, high efficiency particulate air (HEPA) filters,magnesium fluoride, and calcium fluoride. Disposal methods for the carbon crucibles andHEPA filters are uncertain. Magnesium fluoride, a byproduct of the processing activities,disposal also is uncertain, but it may have been returned to the AEC because it contained traceuranium impurities. Calcium fluoride was transported to Kerr-McGee's Cimarron Facility inCrescent, Oklahoma for processing to recover the remaining chemically enriched uranium. Forthorium processing, wash water and nitric acid pickling solution were the only known wastes. Wash water that did not meet unrestricted release criteria was discharged on a hill at thenortheast corner of the Kerr-McGee property and allowed to percolate into the soil or to flowoverland to Pit 4. The pickling solution was recycled (4).

Post Operations Investigations, Removals, Disposal, and Improvements Thru1995

A new fence has been placed around the entire Kerr-McGee property, and additional chainlinkfencing with barbed wire on top has been erected around the pits. Kerr-McGee is furtherrestricting access to the area by refusing to grant permission for recreational use of the property,and by clearing brushy areas that would inhibit visual observation of trespassers in remote areas(8). Kerr-McGee has advised ATSDR that dust control measures have been an integral part ofremediation activities.

    Oil Refinery-Related Materials

Several site investigations have been performed since 1986 by EPA, Kerr-McGee--or theirassociated contractors, and state and local agencies to evaluate whether chemical contaminationis present. Those investigations have focused on groundwater and conditions around the fivedisposal pits, drainage courses associated with the pits, and Skull Creek. Samples have beenobtained on site of waste hydrocarbon sludges and tars, soils, sediments, groundwater, andsurface water. Off-site, less extensive sampling has been undertaken of soils, public well water,private well water, pond water, and creek water and sediments.

When operations ceased, refinery facilities and many of the tanks on the site were demolished. Much material that was reusable was removed from the site. The remainder was buried andcovered at numerous locations on the property. Several more recent (1990 to present) remedialactivities have been conducted specifically to limit access to, or transport of, potentiallyhazardous contaminants. These activities include rerouting Skull Creek away from Pit 5 andinstalling underground collection systems on both sides of the creek to intercept and remove oilyand acidic seepage. Berms and ditches around Pits 1, 2, 3, and 5 have been renovated, and pitrunoff is held and neutralized before discharge. Asbestos wastes have been buried (9). Kerr-McGee reported to ATSDR staff that the former spray and oil trap ponds near Pit 5 alsohavebeen remediated in accordance with state oversight and authorization. Contaminated soils andsludges found at those ponds were deposited in Pit 5; other soils encountered were spread andtilled into natural soils at four different areas of the site.

    Radiological-Related Materials

Several investigations have been performed since 1966 principally by Kerr-McGee--or theirassociated contractors to evaluate the locations and levels of radioactivity. The investigationshave focused on the Kerr-McGee property; some off-site media also have been surveyed.

In 1966, Kerr-McGee requested termination of its Atomic Energy Commission (AEC)licenses,and clean-up and decontamination were conducted in accordance with then-existing guidelines. Some of the waste generated during the decommissioning was shipped to the Cimarron Facilityfor storage. Low-level radioactive waste was buried in trenches north of Deep Rock Road. TheAEC surveyed the uranium/thorium processing buildings for radioactivity, found the resultssatisfactory for unrestricted use of the property, and formally terminated Kerr-McGee'suranium/thorium licenses on July 25, 1966 (7).

In 1972, Kerr-McGee resurveyed the site for radioactivity. Additional clean-up anddecontamination were initiated as a result of the survey. Some low-level wastes were buried inPit 4, and covered with 4 feet of soil. Further clean-up of the former uranium/thoriumprocessing plant and some other parts of the property occurred from 1979 through 1982. Contaminated soil and other wastes, depending on radioactivity levels, either were shipped toapproved commercial low-level disposal sites; buried on site in trenches; or managed on siteusing land farming techniques (i.e., spreading a thin layer of contaminated material overnoncontaminated soil and deep plowing the zones together) (7).

In 1989, Kerr-McGee conducted an additional survey in the vicinity of the former nuclearprocessing facilities to determine whether radiation levels met then current regulatory guidelines. Surface areas, soils, and sediments were evaluated using alpha and gamma radiation-detectinginstruments. Kerr-McGee reviewed the survey results and identified some clean-up actions (10). Those activities resulted in relicencing the facility under NRC jurisdiction for purposes ofcompleting the remediation under a formal NRC newly instituted program.

A site-wide radiological characterization in 1990 included a gamma survey on a 10-meter gridfollowed by analysis of discrete samples taken at locations where gamma levels exceededbackground (exceeded 15 microRoentgens per hour--µR/hour). Thatcharacterization disclosedthat only a small portion of the overall property--mostly north of Deep Rock Road--containssubstantive residual process-related radioactivity. There, deposits of elevated radiologicalcontaminants were found within several small to large areas including Pit 4, the trash dump,several tank berms, and a pipe storage area. South of Deep Rock Road, elevated levels wereprimarily in the vicinity of the former nuclear processing buildings and near a segment of SkullCreek running adjacent to the buildings.(11). In 1994, further characterization was undertakenwithin four large areas (total about 200 acres) not expected to have been affected by licensedradioactive materials (12). The survey proved negative in those areas.

In the early 1990s, additional removals and partial decontaminations were conducted at theformer nuclear processing facilities. Some small deposits were also remedied near the eastboundary of Pit 5. Some of the removed materials have been drummed and shipped to aradioactive waste disposal site, and some have been temporarily stored on-site awaiting off-sitelicensed disposal (2).

Current Remediation, Decommissioning, Future Use Issues

In May 1990, Kerr-McGee entered into a Consent Order (with the then-named OklahomaState Department of Health (OSDH)) that addressed investigation and remediation. The ConsentOrder divided the site work into non-radiological (i.e., chemical) and radiological activities. Remediation activities include dust control measures and monitoring to confirm that themeasures are effective.

The agreement calls for non-radiological remediation planning and implementation to beperformed in a manner similar to the federal Superfund remedialinvestigation and feasibilitystudy process. The ODEQ issued a Record of Decision (ROD) for the five large acidic sludgepits that outlines waste neutralization, excavation, and placement in an on-site engineereddisposal cell. Kerr-McGee staff recently advised that the cell is being constructed and sludgeremediation has begun. Dust control measures are being implemented. All activities are to beconducted under terms of a health and safety plan designed to minimize occupational and publicexposures and includeon-site and property-line air monitoring (13). Hydrocarbon removals thateither include radiological components or are to be conducted within the limits of definedradiologic waste areas will be coordinated with the general radiologic waste removal program. The 21 smaller hydrocarbon waste deposits identified are being addressed under planning andapprovals now in place. Plans call for Phase II investigations for chemical contaminationextending to areas beyond those already examined. Removal and residual contamination criteriawill be developed at a later time.

Current and future radiological cleanup is being addressed under terms of a new licence and a site decommissioning plan that was submitted to the NRC for approval in 1994 and modified in1996. These changes involve shipping of licenced, buried material to an off-site, licenceddisposal facility; whereas, the 1994 plan intended construction of an on-site disposal cell toreceive most of the radiological contaminants at the site. The plan includes a health physicsprogram designed to minimize occupational and public exposures and also provides for a finalsite radiological survey. Soil and debris with low levels of activity satisfying Branch TechnicalPosition (BTP) Option 1 (see Appendix B, Page 35) is to be left in place or used to fillexcavations. Soil and debris containing radionuclides in excess of BTP Option 1 criteria are to beexcavated, placed in containers, and shipped to a licensed disposal site.

Equipment and buildings intact and left in place will meet NRC's Guidelines forDecontamination of Facilities and Equipment Prior to Unrestricted Use or Termination ofLicenses for Byproduct, Source, or Special Nuclear Materials. Cleanup candidates include Pit 4, some refinery tank berms, trash dump, burial trenches, the abandoned and filled segment of the rerouted part of Skull Creek, additional parts of process buildings and adjacent land, somelocalized deposits of soil, rubble, and NORM (2) .

Kerr-McGee staff advised ATSDR representatives that it would ultimately like to release thesitewithout restriction for any combination of residential and industrial, commercial, or recreationaldevelopment. More likely, the site will be divided into portions sustaining specific future uses. Those uses consider the following:

  • Residential--people living on the property,
  • Industrial/commercial--business operating on the property with workers occupying theproperty 40 hours per week,
  • Caretaker status--Kerr-McGee keeping and maintaining the property, with caretakerpresent one day per week, and
  • Trespasser status--Kerr-McGee keeping the land; people periodically might trespass.

Investigations will be conducted to provide additional information needed for making future usedecisions.

Kerr-McGee expects that the NRC will release the site for unrestricted use and developmentafter further radiological decommissioning activities have been completed. Kerr-McGee alsowill evaluate different portions of the site with respect to State-approved Remedial ActionObjectives (being developed--will address both chemical and radiological toxicity and anyassociated human health issues) and will identify which areas can be efficiently cleaned to meetspecific future use scenarios.

B. Site Visit

Representatives from ATSDR, Kerr-McGee and ODEQ met in March 1996 to discuss siteissuesand to tour the property. A similar visit was made in 1990. Pertinent information obtained fromthose visits is included in appropriate sections of this document.

C. Demographics, Land Use, and Natural Resources


Cushing, Oklahoma, the second largest city in Payne County, is located about 2 miles south ofthe site and has a population of approximately 7,200 residents (14). Outlying residential areashave expanded toward the site. Much of the expansion has been along Highway 18 west of thesite and along Granstaff Road south of the site. ATSDR staff observed the greatestconcentration ofnearby residences to be in the North Drake subdivision, which is south of DeepRock Road and extends from Highway 18 eastward and northward toward the site boundaries. The nearest residence there is close to Deep Rock Road and is about 100 feet from the siteboundary; the next closest is about 400 feet away. Granstaff road, about 1,200 feet south of thesouthernmost site boundary, has about 3 dozen homes along the road and in a small subdivisionnorth of the road. On the east side of the site, there are about a dozen residences across LinwoodAvenue. Several are within 200 feet of the property. Linwood Avenue to the north and south ofthe site also has a few residences; the closest is about 200 feet north of the property. Kerr-McGee staff report that in recent times four residences had been located on the propertynowunder their ownership. These were removed about 1990. One of them was on Deep Rock Roadnear the nuclear reprocessing facilities; the others were along Linwood Avenue, a short distancesouth of Deep Rock Road.

Deep Rock Elementary School is located on the east side of Linwood Avenue. Thesuperintendent of Cushing Schools reported that about 130 students in grades one through fiveattend the school. Most of these children ride school buses (15).

The total number of workers employed by the various oil companies that operated on the siteare not known.

Land Use

ATSDR noted that the immediate site vicinity is largely rural; properties adjacent to the siteprimarily are grassland, or are used for crops and livestock, or are grown over with vegetation. Residential and school land uses are described under the preceding Demographics section. Thedeveloped areas surrounding the site are zoned industrial and residential (1). The area hasscattered oil wells and oil fields in all directions from the site. Property A, east of the site, oncehad a refinery.

Natural Resource Use


Groundwater beneath the site and vicinity lies in three sequential zones; the overburden, theVanoss Group, and the underlying Vamoosa-Ada aquifer. The Vamoosa-Ada aquifer providesthe primary water source for the area.

The shallowest water occurs within the relatively thin zone of overburden (loose silt, sand,andgravel) that overlies bedrock (16)(17). The overburden ranges from 0 to 25 feet in depth and ischaracteristically saturated within 3 to 5 feet above the bedrock (18). Groundwater in that zoneflows laterally along the underlying bedrock surface and discharges into nearby drainage systems(1). Little water is expected to penetrate the underlying bedrock.

Rocks comprising the Vanoss Group underly the overburden zone. The shales and mudstonein this formation are expected to have low permeability that should retard downward movement ofwater from the overlying overburden aquifer. However, the permeability of the Vanoss Groupbeneath the site has not been determined. The formation includes permeable sandstone zonesthrough which groundwater can migrate. Sandstone zones have been noted to occur at depths asshallow as 10 to 65 feet below the ground surface. Monitoring wells extending into thesandstone zones indicate that groundwater there is under confined conditions (1) (i.e., the zone isconfined between two less permeable zones) (18). Data are not available to establish rate ordirection of ground-water flow within the Vanoss Group (1).

The deeper Vamoosa-Ada aquifer is the municipal groundwater source for the area. Waterfromthis aquifer sometimes is withdrawn via wells to supplement the Cushing city water system. Theoverlying Vanoss Group should prevent shallow groundwater from migrating downward andrecharging the deeper Vamoosa-Ada aquifer. At the site, the Vamoosa-Ada aquifer is about 200feet below the surface. Aquifer recharge occurs where the aquifer rises to, or near, the groundsurface (1) (i.e.,about 2½ miles east of the site, where the zone may be covered only by thinsurficial deposits, such as alluvium) (17). No hydraulic connection is known to exist betweenSkull Creek and the Vamoosa-Ada aquifer. Therefore, the deeper ground-water system thatserves as a key water source in the area appears to be protected from surface water and shallowground-water infiltration (1).

Water quality data for municipal wells and for the few private wells that have been sampled in the site vicinity do not show evidence of contamination from site releases.

    Municipal Water

Cushing's principal water source is Cushing Municipal Lake on Big Creek Watershed, locatedabout 6 miles southwest of the property. However, during dry weather that source issupplemented from 9 municipal wells located about 1½ to 3 miles to the south and southeastof the site. These wells extend into the Vamoosa-Ada aquifer, and casings are slotted to withdrawwater from multiple permeable zones. Water is withdrawn from as shallow as 160 feet (19). Public water users in the site area are serviced either by the Cushing system or by the RuralWater and Sewer District No. 4. Discussion with a representative of District No. 4 indicates thatthey obtain water from a well in Cushing and purchase water from another system that has itssource in Pawnee County.

ATSDR met with representatives of the water systems to clarify their service connections. Allwater users along Highway 18 and Granstaff Road in the site vicinity obtain their potablesupplies from a public water system. Businesses and residents on Deep Rock Road, betweenHighway 18 and Linwood Avenue, also are connected to a public system. Along LinwoodAvenue, the Deep Rock School and businesses use public water, and all but a few residents areconnected.

    Private Well Water

The history and current status of private well use in the site area are not clearly established. ATSDR staff toured the area with water system personnel and discussed their serviceconnections. Those discussions and the results of well sampling activities indicate that1) essentially all residences and businesses in the vicinity are connected to the publicsystem, 2)a few of those connected also have a private well (which is most likely used for irrigation), and3) a few have only a private well.

Water company representatives showed that all residences and businesses within at least¾ mileof the site southward (in the direction of Granstaff Road) and westward (toward Highway 18)receive potable water from a public supply system. Northward, along an east-west trendingunnamed road ½ mile from the site, one or two residences get their potable supply fromprivatewells. Eastward, along Linwood Avenue, the Deep Rock School and all residences except twoare connected to a public water system. One residence at the intersection of Linwood Avenueand Deep Rock Road gets potable water from a well, as does a residence on Property A. Abusiness that may operate on Property A also is assumed to use well water. There once was awell at a former on-site home (one of the four removed about 1990 along Linwood Avenue,south of Deep Rock Road). That resident was contacted by ODEQ staff and reported she didn'trecall ever using the well.

Farther away, between about ¾ mile and 3 miles from the site, ODEQ has found severalotherwells. ODEQ staff recently reported to ATSDR that their telephone calls to those well ownersshowed most are being used for potable purposes. A few of the property owners could not becontacted in that survey.

    Surface Water

Skull Creek, which flows across the site in a northerly/northeasterly direction, has itsheadwatersin Cushing and discharges into the Cimarron River about 5 stream miles down gradient of thesite. The city of Cushing once discharged treated effluent from their sewage treatment plant intothe creek but terminated that practice in 1985. Site runoff and some discharge from on-sitewaste pits has also flowed into the creek (20). A few pools in the creek support fish year round,and fishing and swimming occur where the creek discharges to the Cimarron River (21). Thecreek is not used for irrigation (but is classified for use in agriculture) or as a public watersupply. Livestock might use the creek for a water source. The Cimarron River has poor waterquality and is not used as a public water supply source. Due to the high total dissolved solids theCimarron River has been classified by the State Water Quality Standards Department asunsuitable for agricultural uses (22). Keystone Lake, into which the Cimarron River dischargesabout 32 miles downstream, is a public water source (1).


During a site visit, ATSDR learned that the site area supports many types of animals,includingdeer, rabbits, raccoons, and game birds. Hunting once had been permitted onsite.

D. Health Outcome Data

ATSDR decided to evaluate cancer mortality (deaths) in the area because of citizens' concernabout cancer. The Oklahoma Department of Health maintains the cancer registry (23). Theregistry was analyzed for the years 1976 to 1990. The results of the analysis are given in thePublic Health Implication section (subsection C., Health Outcome Data Evaluation, on Page 20).


During our investigations, we received information about several citizens' concerns (24,25):

  1. Are the numbers and types of cancers in the area attributable to the Kerr-McGee site?
  2. Are the private and municipal drinking water supplies contaminated?
  3. Are people being exposed to contaminants that might bioaccumulate in humans?
  4. Is it safe to swim in or to water livestock from area ponds?
  5. Are the numbers of illnesses and deaths in area neighborhoods attributable to the site?
  6. Should citizens monitor their radiation doses with radiation badges?

Our response to these questions is provided in the Community Health Concerns Evaluationsubsection (beginning on Page 20)

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