Finding of No Significant Impact Proposed Remedial Action at Two Uranium Processing Sites Near Slick Rock, CO

DEPARTMENT OF ENERGY

Finding of No Significant Impact Proposed Remedial Action at Two

Uranium Processing Sites Near Slick Rock, CO

AGENCY: Department of Energy.

ACTION: Finding of no significant impact.

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SUMMARY: The U.S. Department of Energy (DOE) has prepared an

environmental assessment (EA) (DOE/EA-0339) of the proposed remedial

action at two uranium processing sites near Slick Rock in San Miguel

County, Colorado. These sites contain radioactively contaminated

materials that would be removed and stabilized at a remote location.

Based on the information and analyses in the EA, the DOE has determined

that the proposed action does not constitute a major Federal action

significantly affecting the quality of the human environment within the

meaning of the National Environmental Policy Act (NEPA) of 1969 (42

U.S.C. 4321 et seq.), as amended. Therefore, preparation of an

environmental impact statement is not required, and the DOE is issuing

this Finding of No Significant Impact (FONSI).

ADDRESSES: Single copies of the ea are available from: Charles Cormier,

Uranium Mill Tailings Remedial Action Acting Project Manager, U.S.

Department of Energy, Uranium Mill Tailings Remedial Action Project

Office, 2155 Louisiana NE, Suite 4000, Albuquerque, New Mexico 87110

(505) 845-4628.

FOR FURTHER INFORMATION ON THE NEPA PROCESS, CONTACT: Carol M.

Borgstrom, Director, Office of NEPA Oversight, EH-25 U.S. Department of

Energy, 1000 Independence Avenue, SW., Washington, D.C. 20585 (202)

586-4600 or 1-800-472-2756.

SUPPLEMENTARY INFORMATION:

Background

The Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978,

Public Law (PL) 95-604, authorized the DOE to perform remedial action

at two uranium processing sites near Slick Rock, Colorado, to reduce

the potential health effects from the radioactive materials at the

sites and at vicinity properties associated with the processing sites.

The U.S. Environmental Protection Agency (EPA) promulgated standards

for the UMTRCA in Title 40, Code of Federal Regulations, Part 192 (40

CFR Part 192). These standards contain measures to control the

contaminated materials and to protect groundwater quality. Remedial

action at the Slick Rock sites must be performed in accordance with

these standards and with the concurrence of the U.S. Nuclear Regulatory

Commission (NRC) and the state of Colorado.

Site Descriptions

The Slick Rock uranium processing sites consist of the Union

Carbide and North Continent sites. The Union Carbide processing site is

approximately 2 road miles northwest of the unincorporated town of

Slick Rock in San Miguel County, Colorado. The North Continent

processing site is approximately 1 road mile east of the Union Carbide

site. Both sites are on the west bank of the Dolores River in the

floodplain, and the nearest residence to either site is approximately

0.3 air mile. Both the Union Carbide and North Continent sites are

privately owned. Almost all the land surrounding the processing sites

is administered by the Bureau of Land Management (BLM) and is used for

livestock grazing. County Roads S8, S9, and 10R traverse the area of

the processing sites and connect with State Highway 141 approximately

0.75 road mile south of the North Continent site.

Contaminated materials at the Union Carbide and North Continent

processing sites cover approximately 55 and 12 acres, respectively.

There are also 17 acres of contaminated materials across the Dolores

River from the Union Carbide site. The contaminated materials consist

of the uranium mill tailings from the uranium ore processing

operations, soils beneath the tailings, and windblown and waterborne

contamination from the tailings. The total volume of contaminated

materials at both processing sites is estimated to be 618,300 cubic

yards. In addition, approximately 2500 cubic yards of contaminated

materials at four nearby properties (vicinity properties) are

associated with the processing sites.

The proposed Burro Canyon disposal site is approximately 5 road

miles east of the Slick Rock processing sites via County Roads S8 and

10R and State Highway 141. The site is above the 1000-year floodplain

of the Dolores River. The disposal site is on land administered by the

BLM and used primarily for livestock grazing. The town of Slick Rock is

approximately 2 air miles southwest of the disposal site.

Proposed Action

The proposed remedial action is relocation of the contaminated

materials from the Slick Rock processing sites to the Burro Canyon

disposal site. At the disposal site, the contaminated materials would

be stabilized in a partially below grade disposal cell and covered with

approximately 5 feet of earth and rock. The disposal cell would cover

approximately 12 acres and the final disposal site would cover

approximately 57 acres. The final disposal site would be permanently

transferred from the BLM to the DOE, and any future use of the disposal

site would be precluded. Approximately 178 acres at the Burro Canyon

site would be used for the disposal cell, final disposal site, and

temporary construction facilities. Soil excavated at the disposal site

would be used to construct the disposal cell; any remaining soil would

be left at the disposal site, graded, and reseeded. Ground water at the

disposal site would be protected by the claystones and mudstones in the

geological formations below the disposal site. These natural foundation

materials would inhibit any downward migration of contaminated water

from the contaminated materials. The disposal cell cover system would

inhibit infiltration of rainfall and runoff through the disposal cell.

After remedial action, the Slick Rock processing sites would be

backfilled with clean fill material, recontoured to promote surface

drainage, and revegetated. The processing sites would then be released

for any uses consistent with existing land use controls. The DOE will

evaluate the need for ground water compliance at the processing sites

during the Uranium Mill Tailings Remedial Action (UMTRA) Ground Water

Project.

The proposed remedial action includes the application of

supplemental standards to approximately 17 acres of BLM-administered

land across the Dolores River from the Union Carbide processing site.

This area contains riparian habitat, and there is no access

[[Page 10070]] to the area. Cleaning up this area would result in the

destruction of riparian habitat and would be very costly because it

would be necessary to construct a temporary bridge across the Dolores

River. Furthermore, without the cleanup, the long-term health impacts

to individuals and the general public residing in the vicinity of the

area would be negligible. If this application of supplemental standards

were approved by the NRC and the state of Colorado, the contamination

in this area would not be cleaned up.

The remedial action would require the use of earthen and rock

materials. Earthen materials would be obtained from the Disappointment

Valley borrow site on BLM-administered land that is used primarily for

livestock grazing. This borrow site is approximately 7 road miles east

of the Slick Rock processing sites and 4.4 road miles southeast of the

Burro Canyon disposal site. Approximately 65 acres would be temporarily

disturbed at the Disappointment Valley borrow site, and the borrow site

would be restored in accordance with the Free Use Permit issued by the

BLM. Rock materials would be obtained from the Dolores River borrow

site, which is on privately owned land that is used for pasture and

growing hay. This borrow site is just north of the Dolores River,

midway between the Slick Rock processing sites. Approximately 25 acres

would be temporarily disturbed at the Dolores River borrow site and

would be restored in accordance with the land use agreement negotiated

between the DOE and the land owner.

The contaminated materials and borrow materials would be

transported by truck between the processing, disposal, and borrow sites

along County Roads S8 and 10R, State Highway 141, and a new 0.5-mile

haul road from State Highway 141 to the Burro Canyon disposal site.

Approximately 0.25 mile of County Road S8 crosses the southern portion

of the Union Carbide processing site and would be temporarily relocated

approximately 400 feet south, to allow cleanup of the processing site.

Most of the land crossed by County Roads S8, S9, and 10R and the new

haul road is administered by the BLM, and the use of these roads for

the proposed remedial action would be authorized by rights-of-way

issued by the BLM.

Remedial action is scheduled to take 19 months with two winter

shutdown periods of 5 months each (mid-November to mid-April). It is

estimated that the remedial action would require an average work force

of 100 workers and would cost $7.5 million.

Environmental Impacts

The EA for the Slick Rock UMTRA Project sites assesses the

environmental impacts that may result from the proposed remedial action

and proposes mitigative measures that would reduce the severity of the

impacts. This FONSI is based on the information and analyses in the EA,

which are summarized below.

Supplemental Standards

The proposed remedial action includes the application of

supplemental standards to one area east of the Dolores River opposite

the Union Carbide processing site. If this application of supplemental

standards were approved by the NRC and state of Colorado, this area

would not be cleaned up. Additional areas at and adjacent to the Slick

Rock processing sites may be considered for the application of

supplemental standards.

Air Quality

The proposed action would have temporary minimal impacts to air

quality. None of the impacts are expected to violate air quality

regulations. The most important air pollutant created by the remedial

action would be uncontrolled fugitive dust. Much of the fugitive dust

would be produced along County Roads S8, S9, and 10R and the haul road

to the Burro Canyon disposal site. An Air Pollution Emissions Notice

and Emission Permit would be obtained from the state of Colorado prior

to the beginning of the remedial action.

This permit would require the implementation of a dust control plan

that would include measures such as covering haul trucks, treating haul

roads and disturbed areas with water or chemical additives, limiting

speeds on unpaved haul roads, and stopping work during windy periods. A

monitoring plan to ensure that air quality standards are not exceeded

would be developed by the remedial action contractor and must be

approved by the state of Colorado and San Miguel County before any

ground-disturbing activities are initiated.

Health Effects Related to Radiation

The proposed action would have a long-term positive impact on

health by controlling and stabilizing the source of radiation. It is

estimated that the proposed 19-month remedial action would result in

0.0004 total excess health effects for the general public. No action at

the processing sites would result in an estimated total of 0.0001

excess health effects for the general public during the same 19 months;

however, the increased risk of excess health effects would continue for

thousands of years without remedial action. It is estimated that 5

years of no action at the processing sites would result in 0.0003

excess health effects for the general public. In addition, continued

dispersion or unauthorized removal and use of the contaminated

materials could result in greater excess health effects than those

estimated for no action. The 19 months of remedial action would result

in a calculated total of 0.0015 excess health effects for remedial

action workers. Environmental monitoring would be performed at the

processing and disposal sites and radiological control measures would

be implemented to ensure that the public health is adequately and

appropriately protected in accordance with DOE Order 5400.5,

Radiological Protection of the Public and the Environment. Radiological

exposures of remedial action workers would be controlled in accordance

with DOE Order 5480.11, Radiation Protection for Occupational Workers.

Operational measures that include wetting the work area, covering haul

trucks, or temporarily stopping work during high winds would be

implemented to reduce airborne radioactive particulate matter

concentrations to below harmful levels.

Surface Water

No adverse impacts to surface water quality would occur. Cleanup of

contaminated materials at the Slick Rock processing sites would result

in surface disturbance; surface water runoff from disturbed areas could

be contaminated. In addition, contaminated wastewater would be

generated by activities such as equipment washing. The remedial action

design includes the construction of drainage and erosion controls,

including lined wastewater retention ponds and silt fences or berms, to

prevent the discharge of contaminated water from the sites. Appropriate

drainage and erosion controls would also be used at the disposal and

borrow sites to prevent or minimize erosion and any associated surface

water impacts. Excavation of the North Continent site would be

scheduled for the dry summer months to reduce the impact caused by

precipitation and runoff. The DOE would comply with all applicable

state of Colorado storm water regulations. After remedial action,

surface water runoff would not cause erosion of the disposal cell and

transport contaminants into local surface waters because erosion-

control features such as limiting the topslope of the disposal cell and

the placement of rock erosion [[Page 10071]] protection are designed to

withstand long-term erosive forces. Disturbed areas would be graded to

promote drainage and would be revegetated when remedial actions are

complete.

Ground Water

The proposed action would have a positive effect on ground water

below the processing site by removing the source of contaminants. No

impacts are expected to ground water below the disposal cell. The

disposal cell at the Burro Canyon site is designed to control

radioactive and nonradioactive contaminants in compliance with the

EPA's proposed ground water protection standards. The protection of

human health and the environment at the Burro Canyon disposal site

would be ensured by a combination of design features and advantageous

hydrogeologic conditions. There is no existing or potential use of

ground water in the uppermost aquifer in the immediate vicinity of the

Burro Canyon site because sustainable amounts of ground water are not

available from the aquifer. The cleanup and/or control of existing

ground water contamination at the Union Carbide and North Continent

processing sites will be evaluated during the ground water compliance

phase of the UMTRA Project.

Flora and Fauna

Flora and fauna would be affected directly and indirectly by the

proposed remedial action. Direct effects would include the loss of

habitat, loss of less-mobile wildlife species, and displacement of

other wildlife species. Indirect effects would arise from increased

fugitive dust, noise levels, and human activity. The duration of the

direct effects would depend on the restoration of disturbed areas.

Indirect effects would continue for the duration of the remedial action

or less.

Mitigative measures to protect bighorn sheep that could be killed

accidentally by haul trucks would be speed limits and driver education.

Removal of water from the Dolores River would be limited to amounts

that would be protective of fish and wildlife that require an adequate

flow in the river.

Mineral Resources and Soils

No impacts to mineral resources would occur. Temporary impacts to

soils would occur during the proposed action. Disturbed soils would

undergo restoration after remedial activities are complete. Topsoils

would be excavated, stored, and then replaced during restoration. A

loss of mining claims on the proposed Burro Canyon disposal site would

occur. The DOE would compensate valid claim holders to the extent

required by law.

Threatened and Endangered Species

Impacts to fish and their critical habitat would occur as a result

of the proposed action. The use of water from the Dolores River for

remedial action would cause a net depletion of approximately 150 acre-

feet of water in the upper Colorado River basin. This has resulted in a

``may affect'' determination for the endangered Colorado squawfish,

humpback chub, bonytail chub, and razorback sucker and their critical

habitat. These determinations required formal consultation with the

FWS, which resulted in the identification of mitigation consisting of a

one-time payment of $11.98 per acre-foot of water based on an average

annual use. The funds would be used to improve conditions for

endangered fish species.

The southwestern willow flycatcher has been proposed as threatened

and endangered. This bird species was not present in the area of the

Slick Rock processing sites in 1990, 1991, and 1994, but potential

habitat for this species does occur at the sites. A survey for this

species would be conducted prior to the remedial action. If it is

determined that the southwestern willow flycatcher nests at or near

areas that may be disturbed by the remedial action, formal

consultations with the FWS would be initiated and a mitigation plan

would be prepared. Similarly, surveys were conducted at the proposed

disposal site for black-footed ferrets; none were found.

Floodplains and Wetlands

During the proposed remedial action at the Slick Rock processing

sites, contaminated materials would be removed from the 100-year

floodplain of the Dolores River. Approximately 28 and 13 acres would be

disturbed within the 100-year floodplain at the Union Carbide and North

Continent sites, respectively. After the remedial action, the disturbed

areas would be backfilled with clean fill material to approximate the

original 100-year floodplain. However, the man-made ground elevations

of the tailings pile at the Union Carbide site would not be

reestablished, which would increase the area of the 100-year floodplain

at the site by approximately 7 acres. Remedial action at the North

Continent site would not increase the size of the 100-year floodplain.

Flooding is not a hazard at the Burro Canyon disposal site. The

site is above the 100-year floodplain of the Dolores River and is 60

feet higher in elevation than the closest intermittent drainage area.

Remedial action activities at the Dolores River borrow site probably

would occur within the 100-year floodplain of the Dolores River. Upon

completion of the remedial action, the disturbed area at the Dolores

River borrow site would be restored, but the area of the 100-year

floodplain at the borrow site would be slightly increased. Remedial

action activities at the Disappointment Valley borrow site would not

occur within a 100-year floodplain.

The proposed remedial action would disturb riparian plant

communities along the Dolores River. Approximately 42 acres of riparian

plant communities would be disturbed at the Union Carbide and North

Continent processing sites. It was determined that 10 acres of these

riparian plant communities meet the USACE definition of a wetland.

These wetlands are regulated by the USACE through its Section 404

Permit process, and the DOE would mitigate remedial action impacts to

wetlands as determined by this process. Approximately 17 acres of

riparian plant communities across the Dolores River from the Union

Carbide site are contaminated but are not proposed for cleanup during

the remedial action by the application of supplemental standards. The

application of supplemental standards to the other 42 acres of riparian

plant communities at the Union Carbide and North Continent sites would

not be feasible due to the relatively high levels of contamination in

these areas.

The no action alternative would leave the contaminated materials in

the floodplain and wetland areas of the Dolores River and continue to

adversely impact the floodplains and wetlands by not controlling the

source of contamination. The proposed action involves action within the

floodplain and wetland areas. Based on the Floodplain/Wetlands

Assessment, the DOE has determined that there is no practical

alternative to the proposed activities in the floodplain and wetlands

areas and that the proposed remedial action has been designed to

minimize potential harm to or within the floodplain and wetland areas.

The Floodplain/Wetlands Assessment in the EA and this Floodplain

Statement of Findings were prepared pursuant to Executive Orders 11988,

Floodplain Management, and 11990, Protection of Wetlands, and 10 CFR

Part 1022, Compliance With Floodplain/Wetlands Environmental Review

Requirements. Mitigation measures to reduce impacts to floodplain

disturbance would be to backfill disturbed areas with clean fill

[[Page 10072]] material to approximate the original 100-year

floodplain. However, the man-made ground elevations of the tailings

pile at the Union Carbide site would not be reestablished, which would

increase the area of the 100-year floodplain at the processing site by

approximately 7 acres. Remedial action at the North Continent site

would not increase the size of the 100-year floodplain.

Historical and Cultural Resources

Two cultural resource sites, one near the Union Carbide processing

site and the other near the Burro Canyon disposal site, are not

expected to be affected by remedial action activities. Both of these

cultural resource sites would be fenced and avoided during remedial

action, and the site near the Union Carbide processing site would be

further protected by a barrier to shield against dust, rocks, and

exhaust fumes. If any additional cultural resources are identified

during the remedial action (e.g., subsurface resources), work would

stop in the area of the cultural resources, and the appropriate state

and Federal agencies would be consulted to determine the significance

of and protection for the resources. The Ute Mountain, Southern, and

Northern Ute Tribes were also consulted to determine whether the

proposed remedial action would impact any tribal cultural use areas. No

impacts were identified.

Land Use

The remedial action would result in the temporary and permanent

disturbance of approximately 335 acres of land. This would result in

the temporary and permanent loss of grazing forage at the Slick Rock

processing sites, Burro Canyon disposal site, and Dolores River and

Disappointment Valley borrow sites. The DOE would mitigate the

temporary and permanent loss of grazing forage in accordance with land-

use agreements negotiated with affected grazing lessees and private

landowners.

The final restricted Burro Canyon disposal site would encompass

approximately 57 acres, and any future use of this area would be

precluded. After remedial action, the Slick Rock processing sites would

be released for any use consistent with existing land-use controls.

Six unpatented mining claims exist within the proposed permanent

withdrawal area. The DOE would compensate valid claim holders to the

extent required by law.

Socioeconomics

The remedial action impacts on employment, housing, community

services, and the economy would be minimal due to the short duration of

the remedial action and the relatively small number of workers

required. These impacts would be expected to be distributed among

numerous nearby and more distant communities; consequently, no single

community would be affected substantially by the remedial action. The

wages and salaries paid to remedial action workers and expenditures for

equipment, materials, and supplies would have direct, positive impacts

on the economies of San Miguel, Dolores, and Montezuma Counties. The

local economies also would benefit indirectly as these wages, salaries,

and expenditures are respent locally on other goods and services.

Direct and indirect expenditures would generate tax revenues that would

be available to local and state government use.

Transportation

The remedial action would increase the traffic volume on County

Roads S8, T11 and State Highway 141. A portion of County Road S8 would

be relocated to allow cleanup of the Union Carbide processing site.

These roads and highway would be improved as necessary, and other

mitigative measures (e.g., trained flag persons and temporary warning

signs) would be implemented as required to mitigate the potential

traffic hazards. After remedial action, these roads and highway would

be returned to their original locations and conditions. The public

would be restricted from access to County Roads S9 and 10R and a

private disposal site access road off T11 during remedial action, which

is expected to last 19 months.

Alternative to the Proposed Action

No Action Alternative

The no action alternative would consist of leaving the contaminated

materials in their present conditions and locations at the Slick Rock

processing sites. The contaminated materials would continue to be

exposed to erosion, and eventual erosion of the contaminated materials

would result in the transport of contaminants into the Dolores River.

The processing sites and adjacent areas would remain unusable. The

contaminated materials would also be susceptible to unauthorized

removal and use by humans, which could cause more widespread

contamination and increased public health hazards. The no action

alternative is not a legal alternative for the DOE and would not

satisfy the requirements of the UMTRCA (PL 95-604).

Alternatives Considered and Rejected

The DOE's analysis of disposal site alternatives encompassed

technical, environmental, and cost factors, as well as the risks

associated with each alternative. Alternatives evaluated but rejected

were 1) stabilization of the mill tailings in place at the processing

sites, 2) stabilization of the mill tailings at other locations near

the processing sites, and 3) colocating the mill tailings at other

uranium mill tailings sites. The first alternative was rejected because

the major portion of the tailings would be stabilized in the flood

plain of the Dolores River and water resources protection would be

inadequate. The second was rejected due to the other sites' proximity

to ground water. The third was rejected because the cost of disposal

would result in significant increases in cost by a factor of two and

six, respectively, over the cost of disposal at Burro Canyon.

Determination

Based on the information and analyses in the EA, the DOE has

determined that the proposed remedial action does not constitute a

major Federal action significantly affecting the quality of the human

environment within the meaning of the NEPA. Therefore, the preparation

of an environmental impact statement is not required.

Signed in Albuquerque, New Mexico, this 27th day of January,

1995.

Bruce G. Twining,

Manager.

[FR Doc. 95-4428 Filed 2-22-95; 8:45 am]

BILLING CODE 6450-01-P