PUBLIC HEALTH ASSESSMENT
KERR-MCGEE REFINERY SITE
CUSHING, PAYNE COUNTY, OKLAHOMA
The site, a former petroleum refinery, encompasses approximately 440 acres and is located approximately 2 miles north of Cushing, Oklahoma in Payne County. The Cushing area once had 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, also processed nuclear materials for Atomic Energy Commission use in some of its buildings along Deep Rock Road. Kerr-McGee, the last operator of the refinery, has conducted extensive contamination investigations at the site and some substantive removals. More such activities are being planned. Kerr-McGee has entered into an agreement with the State of Oklahoma to remediate the site, and the residual impacts from the nuclear activities are being addressed under a new license with the Nuclear Regulatory Commission.
A large tract of land east of Linwood Avenue (designated Property A for this assessment and known locally as the Rafferty property) had been used for petroleum refining and storage, and once was thought by agencies to have been part of Kerr-McGee's operations. More recently, it has 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 initiate appropriate follow up activities. The Oklahoma Department of Environmental Quality recently named the property the Sinclair Topping Plant. The limited early information available about Property A has been addressed in this public health assessment because of it's proximity to the Kerr-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 later developed for residential use, residents could be exposed in the future to contaminants and radioactive materials that might harm their health.
Property A, which is not associated with the Kerr-McGee site, is an indeterminate public health hazard because sufficient chemical and radiological data are not currently available to adequately evaluate environmental media. Lead contaminated soil and sediment were found on the property; the extent of such contamination, which is not known at this time, will determine whether or not those media are a public health threat.
The Kerr-McGee Cushing Refinery site was proposed by the U.S. Environmental Protection Agency (EPA) for addition (Update No. 10) to the National Priorities List (NPL) in October of 1989. EPA subsequently deleted the site (Update 11). In May 1990, Kerr-McGee entered into a Consent Order with the Oklahoma State Department of Health (OSDH) that addresses investigation and remediation. In 1993, the site was put under new Nuclear Regulatory Commission (NRC) license for the purpose of addressing and remediating the residual radiological impacts. The background information that follows focuses on issues that the Agency for Toxic Substances and Disease Registry (ATSDR) believes are the most pertinent to evaluating public health significance.
A. Site Description and History
General Background
The site, a former petroleum refinery, encompasses approximately 440 acres and is located approximately 2 miles north of Cushing, Oklahoma in Payne County (Figure 1, Appendix A: on Page 33). The Cushing area once had been a center of extensive petroleum production and refining; 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, which runs east-west. Several different owners had operated a refinery on the property starting about 1915. Kerr-McGee purchased the refinery in 1956 and operated it until 1972; they then dismantled refining facilities and many of the storage tanks. Most of the refining structures were located south of Deep Rock Road, on the eastern part of the site. NGC Inc. has an agreement with Kerr-McGee under which they continue to operate a few petroleum storage tanks on the property and a pipeline (1). Between 1963 and 1966, Kerr-McGee also processed nuclear materials in some refinery buildings located along the south side of Deep Rock Road; portions of those 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 site boundary that Kerr-McGee does not own--a parcel of about 1 acre on the southern edge of Deep Rock Road that has two active cement silos, about 1 acre on the northern edge of Deep Rock Road that has an inactive oil reclaiming facility, and about 1 acre in the southeast corner of the site 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 south of 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 some removals. More such activities are being planned. ATSDR has considered key elements of those activities in this public health assessment.
When proposing the Kerr-McGee site for the NPL, EPA believed a large tract of land east of Linwood Avenue that once had been used for petroleum refining and storage also had been part of Kerr-McGee's operations--see Property A on Figure 1. More recently, it has been determined that Property A was never associated with the Kerr-McGee site. The limited early information available about Property A has been addressed in this public health assessment because of it's proximity to the Kerr-McGee site and the community population of interest.
Records indicate that refinery operations stopped prior to 1956 (3). Oklahoma Department of Environmental Quality (ODEQ) staff report to ATSDR that another corporation will conduct detailed investigations of Property A and will initiate whatever follow up activities are deemed appropriate. The ODEQ recently named the property the Sinclair Topping Plant. Only a few samples have been taken of environmental media on Property A to date. ATSDR has used the limited early investigation data to qualitatively evaluate Property A and develop general recommendations that may influence investigations of that property.
Former Site Operations and Waste Disposal
Petroleum refining, storage, and transport activities have been conducted at the site by multiple owner companies. Refining processes changed as technology advanced. Prior to 1951, a sulfuric acid treating unit was used to process lubricating oil. That unit produced waste diatomaceous earth and clay filtering materials containing entrained sulfuric acid and hydrocarbons (4). Those wastes (sludges, etc.) were deposited in five unlined pits (Pit 1 through 5) on the property. Pits 1 through 4 are located north of Deep Rock Road, while Pit 5 is located south of the road, near Skull Creek. The waste volume has been estimated to be 300,000 cubic yards, half of which is contained in Pit 5 (1,5). After 1951, a different treatment unit was installed, and production of acid wastes stopped (1). Other estimates place the amount at nearly 400,000 cubic yards. Kerr-McGee reported that Pits 1, 2, 3, and 5 were full when they purchased the refinery in 1956, and, therefore, were not used in their refinery operations. Pit 4 was used by Kerr-McGee to dispose of desalter refinery waste and waxy residues (1). The pits are surrounded by chain link fencing. In 1994, 21 additional small waste deposits containing petroleum sludge were identified and evaluated (6).
Uranium and thorium processing occurred between 1963 and 1966. The Atomic Energy Commission (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). Uranium processing wastes included carbon crucibles, high efficiency particulate air (HEPA) filters, magnesium fluoride, and calcium fluoride. Disposal methods for the carbon crucibles and HEPA 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 trace uranium impurities. Calcium fluoride was transported to Kerr-McGee's Cimarron Facility in Crescent, Oklahoma for processing to recover the remaining chemically enriched uranium. For thorium 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 the northeast corner of the Kerr-McGee property and allowed to percolate into the soil or to flow overland to Pit 4. The pickling solution was recycled (4).
Post Operations Investigations, Removals, Disposal, and Improvements Thru 1995
A new fence has been placed around the entire Kerr-McGee property, and additional chain link fencing with barbed wire on top has been erected around the pits. Kerr-McGee is further restricting 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 of remediation activities.
Several site investigations have been performed since 1986 by EPA, Kerr-McGee--or their associated contractors, and state and local agencies to evaluate whether chemical contamination is present. Those investigations have focused on groundwater and conditions around the five disposal pits, drainage courses associated with the pits, and Skull Creek. Samples have been obtained on site of waste hydrocarbon sludges and tars, soils, sediments, groundwater, and surface 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 and covered at numerous locations on the property. Several more recent (1990 to present) remedial activities have been conducted specifically to limit access to, or transport of, potentially hazardous contaminants. These activities include rerouting Skull Creek away from Pit 5 and installing underground collection systems on both sides of the creek to intercept and remove oily and acidic seepage. Berms and ditches around Pits 1, 2, 3, and 5 have been renovated, and pit runoff 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 also have been remediated in accordance with state oversight and authorization. Contaminated soils and sludges found at those ponds were deposited in Pit 5; other soils encountered were spread and tilled into natural soils at four different areas of the site.
Several investigations have been performed since 1966 principally by Kerr-McGee--or their associated contractors to evaluate the locations and levels of radioactivity. The investigations have 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 Facility for storage. Low-level radioactive waste was buried in trenches north of Deep Rock Road. The AEC surveyed the uranium/thorium processing buildings for radioactivity, found the results satisfactory for unrestricted use of the property, and formally terminated Kerr-McGee's uranium/thorium licenses on July 25, 1966 (7).
In 1972, Kerr-McGee resurveyed the site for radioactivity. Additional clean-up and decontamination were initiated as a result of the survey. Some low-level wastes were buried in Pit 4, and covered with 4 feet of soil. Further clean-up of the former uranium/thorium processing 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 to approved commercial low-level disposal sites; buried on site in trenches; or managed on site using land farming techniques (i.e., spreading a thin layer of contaminated material over noncontaminated soil and deep plowing the zones together) (7).
In 1989, Kerr-McGee conducted an additional survey in the vicinity of the former nuclear processing facilities to determine whether radiation levels met then current regulatory guidelines. Surface areas, soils, and sediments were evaluated using alpha and gamma radiation-detecting instruments. 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 of completing the remediation under a formal NRC newly instituted program.
A site-wide radiological characterization in 1990 included a gamma survey on a 10-meter grid followed by analysis of discrete samples taken at locations where gamma levels exceeded background (exceeded 15 microRoentgens per hour--µR/hour). That characterization disclosed that only a small portion of the overall property--mostly north of Deep Rock Road--contains substantive residual process-related radioactivity. There, deposits of elevated radiological contaminants 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 were primarily in the vicinity of the former nuclear processing buildings and near a segment of Skull Creek running adjacent to the buildings.(11). In 1994, further characterization was undertaken within four large areas (total about 200 acres) not expected to have been affected by licensed radioactive materials (12). The survey proved negative in those areas.
In the early 1990s, additional removals and partial decontaminations were conducted at the former nuclear processing facilities. Some small deposits were also remedied near the east boundary of Pit 5. Some of the removed materials have been drummed and shipped to a radioactive waste disposal site, and some have been temporarily stored on-site awaiting off-site licensed disposal (2).
Current Remediation, Decommissioning, Future Use Issues
In May 1990, Kerr-McGee entered into a Consent Order (with the then-named Oklahoma State Department of Health (OSDH)) that addressed investigation and remediation. The Consent Order divided the site work into non-radiological (i.e., chemical) and radiological activities. Remediation activities include dust control measures and monitoring to confirm that the measures are effective.
The agreement calls for non-radiological remediation planning and implementation to be performed in a manner similar to the federal Superfund remedial investigation and feasibility study process. The ODEQ issued a Record of Decision (ROD) for the five large acidic sludge pits that outlines waste neutralization, excavation, and placement in an on-site engineered disposal cell. Kerr-McGee staff recently advised that the cell is being constructed and sludge remediation has begun. Dust control measures are being implemented. All activities are to be conducted under terms of a health and safety plan designed to minimize occupational and public exposures and include on-site and property-line air monitoring (13). Hydrocarbon removals that either include radiological components or are to be conducted within the limits of defined radiologic waste areas will be coordinated with the general radiologic waste removal program. The 21 smaller hydrocarbon waste deposits identified are being addressed under planning and approvals now in place. Plans call for Phase II investigations for chemical contamination extending to areas beyond those already examined. Removal and residual contamination criteria will 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 in 1996. These changes involve shipping of licenced, buried material to an off-site, licenced disposal facility; whereas, the 1994 plan intended construction of an on-site disposal cell to receive most of the radiological contaminants at the site. The plan includes a health physics program designed to minimize occupational and public exposures and also provides for a final site radiological survey. Soil and debris with low levels of activity satisfying Branch Technical Position (BTP) Option 1 (see Appendix B, Page 35) is to be left in place or used to fill excavations. Soil and debris containing radionuclides in excess of BTP Option 1 criteria are to be excavated, placed in containers, and shipped to a licensed disposal site.
Equipment and buildings intact and left in place will meet NRC's Guidelines for Decontamination of Facilities and Equipment Prior to Unrestricted Use or Termination of Licenses 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, some localized deposits of soil, rubble, and NORM (2) .
Kerr-McGee staff advised ATSDR representatives that it would ultimately like to release the site without restriction for any combination of residential and industrial, commercial, or recreational development. More likely, the site will be divided into portions sustaining specific future uses. Those uses consider the following:
Kerr-McGee expects that the NRC will release the site for unrestricted use and development after further radiological decommissioning activities have been completed. Kerr-McGee also will evaluate different portions of the site with respect to State-approved Remedial Action Objectives (being developed--will address both chemical and radiological toxicity and any associated human health issues) and will identify which areas can be efficiently cleaned to meet specific future use scenarios.
Representatives from ATSDR, Kerr-McGee and ODEQ met in March 1996 to discuss site issues and to tour the property. A similar visit was made in 1990. Pertinent information obtained from those visits is included in appropriate sections of this document.
C. Demographics, Land Use, and Natural Resources
Demographics
Cushing, Oklahoma, the second largest city in Payne County, is located about 2 miles south of the site and has a population of approximately 7,200 residents (14). Outlying residential areas have expanded toward the site. Much of the expansion has been along Highway 18 west of the site and along Granstaff Road south of the site. ATSDR staff observed the greatest concentration of nearby residences to be in the North Drake subdivision, which is south of Deep Rock 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 site boundary; the next closest is about 400 feet away. Granstaff road, about 1,200 feet south of the southernmost site boundary, has about 3 dozen homes along the road and in a small subdivision north of the road. On the east side of the site, there are about a dozen residences across Linwood Avenue. Several are within 200 feet of the property. Linwood Avenue to the north and south of the 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 property now under their ownership. These were removed about 1990. One of them was on Deep Rock Road near the nuclear reprocessing facilities; the others were along Linwood Avenue, a short distance south of Deep Rock Road.
Deep Rock Elementary School is located on the east side of Linwood Avenue. The superintendent of Cushing Schools reported that about 130 students in grades one through five attend 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 site are not known.
Land Use
ATSDR noted that the immediate site vicinity is largely rural; properties adjacent to the site primarily 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. The developed areas surrounding the site are zoned industrial and residential (1). The area has scattered oil wells and oil fields in all directions from the site. Property A, east of the site, once had a refinery.
Natural Resource Use
Groundwater beneath the site and vicinity lies in three sequential zones; the overburden, the Vanoss Group, and the underlying Vamoosa-Ada aquifer. The Vamoosa-Ada aquifer provides the primary water source for the area.
The shallowest water occurs within the relatively thin zone of overburden (loose silt, sand, and gravel) that overlies bedrock (16)(17). The overburden ranges from 0 to 25 feet in depth and is characteristically saturated within 3 to 5 feet above the bedrock (18). Groundwater in that zone flows 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 mudstone in this formation are expected to have low permeability that should retard downward movement of water from the overlying overburden aquifer. However, the permeability of the Vanoss Group beneath the site has not been determined. The formation includes permeable sandstone zones through which groundwater can migrate. Sandstone zones have been noted to occur at depths as shallow as 10 to 65 feet below the ground surface. Monitoring wells extending into the sandstone zones indicate that groundwater there is under confined conditions (1) (i.e., the zone is confined between two less permeable zones) (18). Data are not available to establish rate or direction of ground-water flow within the Vanoss Group (1).
The deeper Vamoosa-Ada aquifer is the municipal groundwater source for the area. Water from this aquifer sometimes is withdrawn via wells to supplement the Cushing city water system. The overlying Vanoss Group should prevent shallow groundwater from migrating downward and recharging the deeper Vamoosa-Ada aquifer. At the site, the Vamoosa-Ada aquifer is about 200 feet below the surface. Aquifer recharge occurs where the aquifer rises to, or near, the ground surface (1) (i.e.,about 2½ miles east of the site, where the zone may be covered only by thin surficial deposits, such as alluvium) (17). No hydraulic connection is known to exist between Skull Creek and the Vamoosa-Ada aquifer. Therefore, the deeper ground-water system that serves as a key water source in the area appears to be protected from surface water and shallow ground-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.
Cushing's principal water source is Cushing Municipal Lake on Big Creek Watershed, located about 6 miles southwest of the property. However, during dry weather that source is supplemented from 9 municipal wells located about 1½ to 3 miles to the south and southeast of the site. These wells extend into the Vamoosa-Ada aquifer, and casings are slotted to withdraw water 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 Rural Water and Sewer District No. 4. Discussion with a representative of District No. 4 indicates that they obtain water from a well in Cushing and purchase water from another system that has its source in Pawnee County.
ATSDR met with representatives of the water systems to clarify their service connections. All water users along Highway 18 and Granstaff Road in the site vicinity obtain their potable supplies from a public water system. Businesses and residents on Deep Rock Road, between Highway 18 and Linwood Avenue, also are connected to a public system. Along Linwood Avenue, the Deep Rock School and businesses use public water, and all but a few residents are connected.
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 service connections. Those discussions and the results of well sampling activities indicate that 1) essentially all residences and businesses in the vicinity are connected to the public system, 2) a few of those connected also have a private well (which is most likely used for irrigation), and 3) a few have only a private well.
Water company representatives showed that all residences and businesses within at least ¾ mile of 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 trending unnamed road ½ mile from the site, one or two residences get their potable supply from private wells. Eastward, along Linwood Avenue, the Deep Rock School and all residences except two are connected to a public water system. One residence at the intersection of Linwood Avenue and Deep Rock Road gets potable water from a well, as does a residence on Property A. A business that may operate on Property A also is assumed to use well water. There once was a well 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't recall ever using the well.
Farther away, between about ¾ mile and 3 miles from the site, ODEQ has found several other wells. ODEQ staff recently reported to ATSDR that their telephone calls to those well owners showed most are being used for potable purposes. A few of the property owners could not be contacted in that survey.
Skull Creek, which flows across the site in a northerly/northeasterly direction, has its headwaters in Cushing and discharges into the Cimarron River about 5 stream miles down gradient of the site. The city of Cushing once discharged treated effluent from their sewage treatment plant into the creek but terminated that practice in 1985. Site runoff and some discharge from on-site waste 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). The creek is not used for irrigation (but is classified for use in agriculture) or as a public water supply. Livestock might use the creek for a water source. The Cimarron River has poor water quality and is not used as a public water supply source. Due to the high total dissolved solids the Cimarron River has been classified by the State Water Quality Standards Department as unsuitable for agricultural uses (22). Keystone Lake, into which the Cimarron River discharges about 32 miles downstream, is a public water source (1).
During a site visit, ATSDR learned that the site area supports many types of animals, including deer, rabbits, raccoons, and game birds. Hunting once had been permitted onsite.
ATSDR decided to evaluate cancer mortality (deaths) in the area because of citizens' concern about cancer. The Oklahoma Department of Health maintains the cancer registry (23). The registry was analyzed for the years 1976 to 1990. The results of the analysis are given in the Public Health Implication section (subsection C., Health Outcome Data Evaluation, on Page 20).
During our investigations, we received information about several citizens' concerns (24,25):
Our response to these questions is provided in the Community Health Concerns Evaluation subsection (beginning on Page 20)
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