NUREG/CR-6648 

ORNL/TM-1999/172

Environmental Assessment

San Bernardino National 

Wildlife Refuge Well 10 

Oak Ridge National Laboratory 

U.S. Nuclear Regulatory Commission 

Office of Nuclear Material Safety and Safeguards 

Washington, DC 20555-0001
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NUREG/CR-6648 

ORNL/TM-1999/172 

Environmental Assessment 

San Bernardino National 

Wildlife Refuge Well 10 

Manuscript Completed: September 1999 

Date Published: December 1999 

Prepared by 

J.T. Ensminger, C.E. Easterly, R.H. Ketelle, H. Quarles, M.C. Wade 

Oak Ridge National Laboratory 

Managed by Lockheed Martin Energy Research Corporation 

Oak Ridge, TN 37831-6370 

B. Canico,.NRC Project Manager 

Prepared for 

Division of Industrial and Medical Nuclear Safety 

Office of Nuclear Material Safety and Safeguards 

U.S. Nuclear Regulatory Commission 

Washington, DC 20555-0001 

NRC Job Code J5084
ABSTRACT

The U.S. Geological Survey (USGS), at the request of the U.S. Fish and Wildlife Service, 

evaluated the water production capacity of an artesian well in the San Bernardino National 

Wildlife Refuge, Arizona. Water from the well initially flows into a pond containing three 

federally threatened or endangered fish species, and water from this pond feeds an adjacent 

pond/wetland containing an endangered plant species. USGS received a source license from 

the U.S. Nuclear Regulatory Commission (NRC) for the radioactive (

24 1

Am-Be) source used in a 

neutron emission/detection tool commonly used in well loggings of this type. The source was 

inadvertently lost in the well in 1986; and after several unsuccessful attempts to retrieve the 

source, the USGS has requested that the Am-Be source license be terminated and has 

attempted to seal the source in place with cement as required by NRC license termination 

regulations. Because of uncertainties related to the condition of the stainless steel source 

container, the effectiveness of a cement plug already installed, and concerns about the 

potential for future contamination, NRC decided to prepare this environmental assessment to 

analyze the potential water quality, ecological, and human health impacts of three alternatives 

for final disposition of the Am-Be source: (1) the proposed action, abandonment in place; 

(2) Am-Be source retrieval; and (3) the no-action alternative. The assessment found that the 

proposed action would result in no significant water quality or human health impacts and would 

produce only temporary and minor ecological impacts associated with emplacement of the 

cement plug. The source retrieval alternative-under a worst case scenario-could result in 

adverse impacts (radiation) on the three fish species of concern. The no-action alternative 

would be unlikely to produce significant adverse impacts but would require continued monitoring 

to ensure that unexpected contaminant concentrations do not occur in water or pond sediment.

iii NUREGICR-6648

iii NUREG/CR-6648
CONTENTS 

M .e 

A BSTRA CT ............................................................. iii 

LIST OF FIGURES....................................................... vii 

ACRONYMS AND ABBREVIATIONS ......................................... ix 

S U M M A RY ............................................................. xi 

1. INTRO DUCTIO N ..................................................... 1 

1.1 PURPOSEAND NEED ............................................. 1 

1.2 BACKG RO UND ................................................... 1 

1.3 LOCATION, TOPOGRAPHY, AND CLIMATE ............................. 5 

2. PROPOSED ACTION AND ALTERNATIVES ................................ 7 

2.1 THE PROPOSED ACTION: ABANDONMENT IN PLACE ................... 7 

2.2 SOURCE RETRIEVAL ALTERNATIVE ................................. 8 

2.3 NO-ACTION ALTERNATIVE ........................................ 9 

3. ENVIRONMENTAL EFFECTS .......................................... 11 

3.1 GEOLOGY/HYDROLOGY .......................................... 11 

3.1.1 G eology ................................................... 11 

3.1.2 Hydrology .................................................. 14 

3.1.3 Conceptual Model of Well 10 .................................... 15 

3.1.4 Conceptual Model of Contaminant Release from Well 10 .............. 18 

3.1.4.1 .Near-Field Processes ................................... 18 

3.1.4.2 Local Groundwater Capture and Discharge Processes .......... 18 

3.1.4.3 Partitioning in Pond Water, Sediment ....................... 19 

3.1.4.4 Potential Migration in the Aquifer Away from Well 10 ........... 19 

3.1.5 Assessment of Alternatives ..................................... 20 

3.1.5.1 Proposed Action: Abandonment in Place .................... 20 

3.1.5.2 Source Retrieval Alternative .............................. 20 

3.1.5.3 No-Action Alternative ................................... 21 

3.2 ECOLOGY ..................................................... 21 

3.2.1 Methodology for Evaluating Radiation Effects on Aquatic Biota .......... 22 

3.2.2 Assessment of Alternatives ..................................... 22 

3.2.2.1 Proposed Action: Abandonment in Place .................... 23 

3.2.2.2 Source Retrieval Alternative .............................. 23 

3.2.2.3 No-Action Alternative ................................... 24

V 

NUREGICR-6648

V NUREG/CR-6648
Contents Environmental Assessment for San Bernardino 

3.3 HEALTH AND SAFETY ............ * ................................ 24 

3.3.1 Hum an Population ............................................ 24 

3.3.2 Assessment of Alternatives ..................................... 25 

3.3.2.1 Proposed Action: Abandonment In Place .................... 25 

3.3.2.2 Source Retrieval Alternative .............................. 27 

3.3.2.3 No-Action Alternative ................................... 28 

4. REGULATORY COMPLIANCE ........................................... 29 

5. REFERENC ES ....................................................... 31 

APPENDIX A: METHODOLOGY FOR EVALUATING RADIATION EFFECTS 

ON AQUATIC BIOTA ................................................... A-1 

A.1 METHODOLOGY ................................................... A-1 

A.2 ASSESSMENT OF ALTERNATIVES .................................... A-1 

A.2.1 Proposed Action: Abandonment in Place ............................ A-1 

A.2.2 Source Retrieval Alternative ...................................... A-2 

APPENDIX B: SECTION 7 CONSULTATION LETTERS ........................... B-1 

APPENDIX C: SECTION 106 CONSULTATION LETTERS ......................... C-1

NTJREGICR-6648 

vi

NUREG/CR-6648 vi
LIST OF FIGURES 

1 Location of the San Bernardino National Wildlife Refuge and approximate boundary 

of San Bernardino Valley .................................................. 2 

2 Layout of the San Bernardino National Wildlife Refuge and location of Well 10 ........ 3 

3 Environment of the San Bernardino National Wildlife Refuge and Twin Pond area ...... 6 

4 Geologic features of the San Bernardino Valley ................................ 12 

5 Typical geologic cross section of the San Bernardino National Wildlife Refuge region ... 13 

6 Conceptual model of the San Bernardino National Wildlife Refuge Well 10 and 

contam inant m igration .................................................... 16

vii NUREGICR-6648

Environmental Assessment for San Bernardino Contents

vii NUREG/CR-6648
ACRONYMS AND ABBREVIATIONS

Am americium 

Be beryllium 

Bq becquerel (1 nuclear disintegration per second; 1 Ci = 3.7 x 1010 Bq) 

CFR Code of Federal Regulations 

Ci curie 

cm centimeter 

d day 

DOE U.S. Department of Energy 

EA environmental assessment 

EPA U.S. Environmental Protection Agency 

OF degrees Fahrenheit 

ft foot 

FWS U.S. Fish and Wildlife Service 

g gram 

gal gallon 

gpm gallons per minute 

h hour 

ha hectare 

in. inch 

kd sorption distribution coefficient 

kg kilogram 

km kilometer 

L liter 

Lpm liters per minute 

M mole 

m meter 

m 3 cubic meter 

MeV mega electron-volt 

mGy milligray (used in measurements of absorbed dose of ionizing radiation) 

mil one-thousandth of an inch, or 0.0254 mm 

mm millimeter 

mrem millirem (used in measurements of ionizing radiation received) 

Np neptunium 

NRC U.S. Nuclear Regulatory Commission 

ORISE Oak Ridge Institute for Science and Education 

ORNL Oak Ridge National Laboratory 

pCi picocurie 

rad a unit used in measuring absorbed doses of ionizing radiation (1 rad = 0.01 Gy) 

s second 

SBNWR San Bernardino National Wildlife Refuge 

USGS U.S. Geological Survey 

y year 

yd3 cubic yard

ix NUREGICR-6648

ix NUREG/CR-6648
SUMMARY

The U.S. Geological Survey (USGS) currently holds a license issued by the U.S. Nuclear 

Regulatory Commission (NRC) for a radioactive (

24 'Am-Be) well logging source that has been 

lost in an artesian well (#10) in the San Bernardino National Wildlife Refuge, Arizona, since 

1986. The source, which contains about 2.5 Ci 241

Am, is lodged in the lower aquifer at 

approximately 183 m (600 ft) depth. At this depth the water is essentially stagnant with very little 

lateral flow and very little (if any) interaction with the upper water column of the well. Artesian 

flow enters the well column between the 90 m (300 ft) and 123 m (410 ft) levels. The well feeds 

an area called Twin Pond [0.10 ha (0.25 acres)], which is home to two endangered and one 

threatened fish species and one endangered plant. The USGS has requested that the Am-Be 

source license be terminated, ending their responsibilities related to Well 10, and has attempted 

to seal the source in place with cement as required by NRC license termination regulations. 

Following attempted sealing of the source in the well, USGS performed sampling and analysis 

of groundwater discharging from Well 10. Samples collected during 1989 and 1990 produced 

some indication of traces of 241

Am dissolved in the water. Subsequent sampling in 1990 did not 

indicate the presence of contamination. However, additional samples collected in 1993 again 

suggested low concentrations of 241

Am may have been present. Consequently, uncertainties 

related to the condition of the stainless steel source container, the effectiveness of the cement 

plug installed, and concerns about the potential for future contamination resulted in the decision 

to prepare an environmental assessment (EA). This EA addresses the potential water quality, 

ecological, and human health impacts of three alternatives for final disposition of the Am-Be 

source: (1) the proposed action, abandonment in place; (2) Am-Be source retrieval; and (3) the 

no-action alternative. The key findings for each of the three alternatives are summarized below. 

Proposed action: abandonment in place: Video logging of the well produced no evidence 

that the cement plug previously installed by USGS exists. Therefore, under NRC regulations, 

this alternative would require additional sealing of the Am-Be source to inhibit vertical 

movement of the Am, and emplacement of a permanent plaque at the well head as specified in 

10 CFR Part 39. In the case of a release of Am from the stainless steel container in the lower 

aquifer of the well, the combination of very low groundwater flow and geochemical retardation 

processes would inhibit lateral movement of the Am. The distribution coefficient for Am of 1 04 to 

106 means that 10,000 to 1,000,000 times more of the Am would be adsorbed to the clay, sand, 

and silt found in the geological environment than would remain in solution in the water; Under 

this alternative, no adverse impact is expected to either the water quality of Well 10 or other 

wells in the area. 

Using a U.S. Department of Energy (DOE) methodology for evaluating radiation effects on 

aquatic biota and a conservative concentration of 10 pCi/L 241

Am in water entering Twin Pond, a 

potential dose rate of 0.0035 mGy/h was calculated. This is three orders of magnitude below 

the DOE recommended dose rate limit of 0.4 mGy/h. Thus, no effects would be expected to 

aquatic biota. There would be minor and temporary short-term ecological impacts associated 

with the process of cement plug emplacement. These would result from transportation of 

equipment and personnel to the site and preparation of the site for the set up and operation of 

equipment.

xi NUREG/CR-6648
A highly conservative kd of 1000 was used for assessment of the migration of Am through the 

complex geological/hydrological environment of the region to a location where it might reach an 

off-site well used for drinking or irrigation. This was assumed to be a distance of 1,000 m 

(3,300 ft). Upon failure of the stainless steel Am-Be container, the Am would be dissolved at an 

estimated maximum concentration of 8 x 106 pCi/L in about 290,000 L (75,400 gal) of water. 

Assuming that 1 percent of the contaminated plume annually mixes with faster moving water 

supplying the well, the average conoentration in irrigation wator w ulW .,Q77 pgi(L, If thiM 

concentration entered into the soil-to-plant pathway or into drinking water, the annual dose 

would be less than 0.3 mrem/y. Therefore, essentially no radiation dose would be received and 

no health effects would be expected. At the maximum concentration of 1.36 pCi/L 241

Am that 

has been detected in the lower part of Well 10, consumption of 2 L of water per day on an 

annual basis would result in a dose of 3.6 mrem/y. This is still below the 4 mrem/y EPA dose 

limit and far below the NRC standard for unrestricted use of decommissioned sites of 

25 mrem/y. 

Source retrieval alternative: Under this alternative, Well 10 would be re-drilled to a larger 

diameter and all liquids and solids removed would be contained and disposed of off-site. If the 

source has already been breached, the drill cuttings, particularly those from the deeper part of 

the well, would be expected to be contaminated with Am released from the source. If the source 

has not been breached, the potential exists that it could be breached during the retrieval 

process resulting in Am being dissolved in the drilling fluid and the water. 

An accidental breach of the source container while conducting this alternative would be 

completely or at least partially controlled by the containment procedures that would be 

implemented. However, the potential for an accidental release at or near the ground source is a 

negative factor for this alternative. There would be opportunity for occupational doses and the 

potential for this area to be restricted from public access. 

As a highly conservative, worst case scenario for this assessment, it has been assumed that 

the entire contents of the source are lost directly into Twin Pond. Using the DOE methodology 

for evaluating radiation effects on aquatic biota, a dose rate of 0.610 mGy/h was calculated. 

This is higher than the 0.4 mGy/h DOE dose rate limit; therefore, adverse effects could be 

expected to the three fish species of concern. 

No-action alternative: Under the no-action alternative, the potential would remain for 

discharge of Am contaminated water or particulate material from Well 10 into the adjacent 

ponds and wetlands. In addition, in the future, someone could inadvertently drill into the source 

in an effort to redevelop the well. Estimation of the likely concentrations that would be expected 

to result from this discharge suggests that the discharge would occur at low concentration over 

a long period of time since the Am is expected to adsorb to soil and other particulate materials 

in the ground or in the well. Under this condition, no acute water quality, ecological, and human 

health effects would be expected. However, because the Am-Be source would not be sealed in 

the lower part of the well, continued monitoring would be necessary to ensure that unexpected 

contaminant concentrations do not occur in water or pond sediment. If 241

Am were subsequently 

detected in the water, the well would be plugged with cement as described under the proposed 

action.

NUTREGICR-6648 

xii

Summary Environmental Assessment for San Bernardino

NUREG/CR-6648 xii
1. INTRODUCTION

The U.S. Geological Survey (USGS) currently holds a license for the use of a radioactive 

source composed of americium (

241

Am) and beryllium (Be) for well logging in the San 

Bernardino National Wildlife Refuge (SBNWR) in Arizona (Figure 1). The Refuge is located in 

extreme southeastern Arizona and is managed by the U.S. Fish and Wildlife Service (FWS). 

The radioactive source has been lost at a depth of about 183 m (600 ft) in an artesian water 

well adjacent to Twin Pond within the SBNWR since 1986 (Figure 2). This environmental 

assessment (EA) is being prepared to evaluate the potential impacts of alternatives for final 

disposition of the source and safe termination of the source license. 

1.1 PURPOSE AND NEED 

The radioactive source has been underwater in the well for almost 12 years. During that time, 

intermittent monitoring by USGS has not conclusively indicated whether or not water from the 

well has been contaminated by the source. USGS has requested from the Nuclear Regulatory 

Commission (NRC) permission to cease activities and end USGS responsibilities related to the 

Am-Be source. USGS took action to fulfill its obligation under current NRC regulations by attempting to seal the source in place with cement. However, follow-up visual examination of 

the well with a downhole camera produced no evidence that the cement plug actually formed. 

Termination of the license would require successfully sealing the source in place and placement 

of a permanent plaque at the well head containing information about the source. However, 

because of uncertainties about the condition of the stainless steel source container, the 

effectiveness of the cement covering, and concerns about the potential for future 

contamination, the NRC determined that an EA addressing the impacts of alternatives for final 

disposition of the source is warranted. 

1.2 BACKGROUND 

In 1986 the FWS requested that USGS log an artesian well (Well 10) that feeds Twin Pond 

(Figure 2) within the SBNWR in order to assess the water production capacity of the well. Water 

from the well initially flows into a pond containing three federally threatened or endangered fish 

species-the endangered Yaqui chub (Gila purpurea) and Yaqui topminnow (Poeciliopsis 

occidentalis) and the threatened beautiful shiner (Cyprinella formosa). Water from this pond, in 

turn, feeds an adjacent pond/wetland containing the endangered plant species Huachuca water 

umbel (Lilaeopsis schaffneriana subspecies recurva). Thus, the FWS is interested in ensuring 

an adequate long-term water supply for the ponds. 

The USGS used an NRC-licensed radioactive source to conduct well logging for the purpose of 

quantifying the water production capacity of the artesian well. The source is composed of 241

Am 

(originally 2.53 Ci) and Be compressed into a cylindrical pellet, within a double-walled stainless 

steel container. The radioactive material in the source, 241

Am (half-life of 432 years), emits 

alpha radiation which dislodges neutrons from Be. The Am-Be source is part of a larger 

neutron emission/detection tool commonly used in well logging.

1 NUREG/CR-6648
Introdnction Environmental Assessment for San Bernardino

Base from U.S. Geological survey 1:250,000 

Douglas, 1963

0 5 10 MILES 

I

o 50 100 MILES Dough 

0 50 100 KILOMETERS 

INDEX MAP SHOWING AREA

10 KILOMETERS OF REPORT (SHADED) 

Figure 1. Location of the San Bernardino National Wildlife Refuge and approximate 

boundary of San Bernardino Valley.

I • !

Environmental Assessment for San Bernardino Introduction

NUREG/CR-6648 2
r~~1 

00 S7 .11 w 

/NNATIONAj WILLIFE REFUE\ 

SONORA MEXICO 

N 0 500 1.0oo FEET 

H I r IL 

0 0 100 200 300 METERS EXPLANATION 

(, OPEN WATER 

1-1 1 REFUGE WELL NUMBERS 

Fn STRUCTURE 

UNPAVED ROADS 

Figure 2. Layout of the San Bernardino National Wildlife Refuge and location of Well 10. '
On July 15, 1986, the Am-Be neutron well-logging source was lost by USGS in Well 10. The 

Am-Be tool was torn from the logging cable as it was being returned to the surface during a 

logging run. The logging probe containing the source fell back down the well. A video log made 

immediately after loss of the source did not show its location. The USGS notified the NRC and 

the FWS that the source had been lost in Well 10. 

Three series of attempts were made to recover the source between July 15, 1986, and 

October 21, 1987. During these recovery attempts, the logging probe was damaged and the 

source was separated from the body of the well logging tool. In consultation with the NRC and 

the FWS, USGS declared the source irretrievable on October 20, 1987. After this decision was 

reached, a 0.76 m3 (1 yd3) cement plug was emplaced around and above the source (that was 

presumed to be at the bottom of the well) and an inverted tricone drill bit with a 5-ft drill pipe 

subassembly was placed in the well at the top of the cement to prevent intrusion into the 

source. One cubic yard of cement would fill about 15 m (50 ft) of the well, assuming that the 

borehole diameter below the 152 m (500 ft) depth is about 3.9 cm (10 in.). It is inferred from 

project records that the bottom of the well was tagged at a depth of 162 m (531 ft) after 

placement of the cement and drill bit/subassembly. On March 30, 1988, USGS returned to the 

site to inspect the well and respond to a report that well discharge had been diminished by the 

source abandonment procedure. Although the well was flowing at about 76 Lpm (20 gpm) (the 

same rate as prior to source abandonment), video logging of the well found the bottom of the 

well at a depth of 176 m (577 ft)-some 14 m (46 ft) deeper than the well depth sounded after 

emplacement of the cement and drill bit in 1987. 

The unexpected depth at which the well bottom was located after source abandonment and the 

lack of cement at the depth where it was expected to be encountered might be explained in two 

ways: (1) the fact that the original total drilled depth of the well is unknown and (2) the 

possibility that drill cuttings or collapsed borewall material may have formed a bridge in the well 

at the 178 m (583 ft) depth. If the original depth of the well was significantly deeper than the 

186 m (611 ft) maximum depth sounded, and if a porous debris bridge existed in the well at the 

178 m (583 ft) depth, the source would presumably have come to rest on top of it; but the 

cement, being of relatively low viscosity, could have seeped down through the bridge and come 

to rest in the deeper part of the well. This process may have occurred over a period of several 

hours after emplacement of the cement but prior to the cement hardening. If the inverted drill bit 

and subassembly were resting on the top of the cement mass, they could have gradually settled 

to rest directly on the Am-Be source and debris bridge as the cement filtered down through the 

bridge. Another explanation, considered less plausible, is that the cement dispersed in fractures 

located near the base of the well. Presumably if there were fractures capable of taking a cubic 

yard of cement, there would be water flow in the zone. However, well flowmeter tests indicate 

that there is no groundwater flow in the well below a depth of 152 m (500 ft). 

The USGS has sampled the Well 10 water for 241

Am. The results of the sampling are presented 

in Section 3.1.3. Three samples collected in 1989 and 1990 indicated traces of 241

Am in the well 

water, while the last four samples taken in 1990 did not show the presence of 241

Am. Based on 

the results of sampling for 24'Am in the well, USGS believes that continued monitoring is 

unwarranted and is requesting that the licence for the source be terminated. However, because 

of the uncertainties concerning the condition of the Am-Be source and the ineffectiveness of 

the attempt to seal it in place with cement, there is a need to assess the potential for significant

Environmental Assessment for San Bernardino Introduction

4 NUREG/CR-6648
doses to persons who might use the well for drinking water in the future, or to nearby populations who might use the aquifer for drinking water or agriculture. 

1.3 LOCATION, TOPOGRAPHY, AND CLIMATE 

The SBNWR is located approximately 30 km (19 miles) east of Douglas in southeastern 

Arizona immediately north of the Mexican border (Figure 1). The nearest city in Mexico is Agua Prieta, approximately 35 km (21 miles) to the southeast. The 930-ha (2,300-acre) SBNWR lies 

near the center of the San Bernardino Valley, a surface water drainage basin that straddles the 

U.S.-Mexican border (Figure 1). Land surface elevations north of the international border range from a low of about 1,130 m (3,700 ft) where Black Draw crosses the border, to elevations of 

about 2,440 m (8,000 ft) in the Chiricahua Mountains at the northern end of the San Bernardino 

basin. The valley floor slopes gently to the south along the stream valleys, and the margins of 

the valley rise through rugged terrain to the uplands of the Pedregosa and Perilla Mountains to 

the west, the Chiricahua Mountains to the north, and the Peloncillo Mountains to the east. 

Photographs of the local environs are provided in Figure 3. Although the area is arid, annual 

rainfall in the area surrounding the SBNWR varies in relation to the general area elevation, with 

more precipitation in the mountains than in the valley floor area. In the vicinity of the refuge, annual rainfall is about 33 cm (13 in.), while in the Chiricahua Mountains to the north, rainfall 

increases to about 46 cm (18 in.) at the 1,615 m (5,300 ft) elevation and about 63 cm (25 in.) at 

the 2,135 m (7,000 ft) elevation (USGS 1991). Climatological data for Douglas, elevation 

1,220 m (3,990 ft), indicate that between 1951 and 1980 the mean daily minimum and 

maximum temperatures were 7.5 and 25.4 0C (45.5 and 77.7 0F), and the temperature extremes 

were -20 and 41.7 0C (-4 and 107°F) (NOAA 1985).

5 

NUREGICR-6648

Environmental Assessment for San Bernardino Introduction

5 NUREG/CR-6648
Introduction Environmental Assessment for San Bernardino

Arid Regional Environment

Twin Pond

Twin Pond Vicinity 

Figure 3. Environment of the San Bernardino National Wildlife Refuge and Twin Pond 

area. 

NUREGICR-6648 6

Introduction Environmental Assessment for San Bernardino
2. PROPOSED ACTION AND ALTERNATIVES

This EA evaluates the potential impacts of alternatives for safely terminating activities at the 

well. The proposed action is abandonment of the source in place subsequent to compliance with all NRC requirements for termination of the USGS licence for the source. Two other 

potential alternatives for final disposition of the source are (1) undertaking an additional attempt 

at source retrieval by overdrilling the borehole and overcoring the cement plug and (2) no

action, which would mean that the license would not be terminated and monitoring would 

continue indefinitely. The proposed action and alternatives are described in the following subsections at a level of detail sufficient for assessment of the potential impacts of each in 

Section 3. 

2.1 THE PROPOSED ACTION: ABANDONMENT IN PLACE 

The proposed action is to abandon the radioactive source in place consistent with the 

requirements of 10 CFR Part 39.15. This regulation requires sealing the source in place with a 

cement plug, installing a mechanical device to prevent inadvertent intrusion, and posting a 

permanent sign with detailed descriptions of the source and borehole conditions. Under this 

alternative, abandonment procedures implemented by the licensee would be evaluated with 

respect to the requirements of 10 CFR Part 39.77. If these proposed procedures are found to 

comply with that regulation, NRC may terminate the source license. The regulation requires compliance with the procedures of Part 39 and preparation of a written report of those actions 

to the NRC and other appropriate state and federal agencies. 

Because the initial USGS attempt to plug the well appears to have been unsuccessful, this 

alternative would require placing additional cement to plug the well and installing an appropriate plaque as specified in Part 39. The plaque would be made of a long-lasting material such as 

stainless steel, would be at least 17 cm (7 in.) square, and would be mounted at the well head. 

To install the plaque, a one to two-person work crew would drive to the well and then walk to 

the wellhead and mount the plaque with hand tools. 

The installation of a cement plug in the bottom portion of the well would provide for the positive sealing of the well below a depth of 152 m (500 ft) to ensure isolation of the source from the 

upper part of the well. The plug would prevent future mixing of 241

Am in water at the bottom of 

the well and would further reduce the likelihood of contaminant migration up the well column. 

Pressure grouting of the bottom of the well using low pressure pumps would force cement down 

into the low permeability region of the well, encapsulating the lost Am-Be source, the drilling subassembly and bit (intrusion preventer) previously placed in the well, and filling the wellbore 

to the desired level. Emplacement of this plug would effectively seal the logging source and drill 

bit assembly in place permanently and seal the 241

Am contamination within the inactive 

groundwater flow zone. 

The process of well grouting would entail transporting necessary equipment and personnel to 

the site in the wildlife refuge via existing roadways and upgraded trails. Some access ways to 

the well would require at least temporary improvement to allow the required vehicular access, 

and a work pad would have to be constructed around the well to support a workover rig that

7 NUREG/CR-6648
would be capable of extending piping and a packer down the well to at least 152 m (500 ft). A 

leveled area would be required at a nearby location to support either a vehicle-mounted grout 

mixing plant and pumping equipment or portable mixing and pumping equipment. Grout would 

be delivered to the workover rig and well head via flexible hose. Because the well is 

immediately adjacent to the pond, a water-tight and bermed work area would be constructed 

around the well. To keep displaced water from entering the pond, a liquid containment system 

would be required to collect all water discharged from the well during grouting, and a brief well 

flushing period would be needed after emplacement of the cement plug. The collected water 

would require sampling and analysis prior to disposal because there is a chance that 

particulates entrained in the displaced water may contain 241

Am or may be of high pH from the 

chemical effect of cement grout. It is assumed that water from the well could be used for mixing 

of grout, otherwise water from another nearby well may be used. 

2.2 SOURCE RETRIEVAL ALTERNATIVE 

An alternative to the proposed action is to remove the source from the borehole. Under this 

alternative, aggressive actions to retrieve the source would be undertaken by the licensee. 

Source retrieval, while perhaps difficult and costly, is technically feasible. Activities to implement 

this alternative would involve overdrilling the existing borehole to a larger diameter and to a 

depth just above the existing cement plug. A coring tool of larger diameter than the existing 

borehole would then be used to incrementally overcore the cement plug and retrieve the 

source. 

The process of source retrieval would entail transporting necessary equipment and personnel 

via existing roadways and trails into the wildlife refuge and preparing a site for the drill rig, 

support vehicles, and personnel vehicles. The drill rig would be backed up to the well and made 

level at the pond's edge in preparation for drilling. Because the well is immediately adjacent to 

the pond, a water-tight and bermed drilling work platform would be constructed from the bank, 

extending out over the pond to allow the work crew to perform the drilling. To keep potentially 

contaminated soil, rock chip, and drilling fluid wastes from entering the pond, these materials 

would be delivered in a closed system from the well head to a large truck-mounted container 

through a large diameter flexible hose. When full, the container would be emptied off-site. 

Drilling fluid would be trucked to the site as well. 

If the source is not breached upon retrieval, it would be removed from the site, and a larger 

diameter well would be constructed in the borehole. This would include a well screen, sand 

pack, and riser cemented in place. Because the borehole would be of large diameter and 

therefore require more cement than can be readily prepared by hand or with a small mixer, a 

cement truck would be brought to the site to stabilize the well in place. If the new well were 

properly installed, it could supply more water than at present because of the larger diameter. 

If the source has been breached and contamination is found in the lower zone of the well, it 

would be necessary to plug the lower part of the well as described above in the proposed 

alternative. The newly constructed Well 11, Oasis well, near Twin Pond (Figure 2) could be 

used to maintain water supply to the pond during the source removal process. This could be 

accomplished by simply attaching a hose to the well head and delivering the water to the pond. 

However, prior to use, the well water would be tested to be certain that its chemistry is

Environmental Assessment for San Bernardino Proposed Action and Alternatives

NUREG/CR-6648 8
Environmental Assessment for San Bernardino

adequately similar to that of Well 10. At completion of the drilling process, the site and access 

road would be revegetated as necessary. 

2.3 No-ACTION ALTERNATIVE 

Under this alternative, the USGS license for the Am-Be source would not be terminated. The initial effort by USGS to plug the well was not successful; therefore, the no-action alternative 

would require continued monitoring of the well and USGS would retain the license for the 

Am-Be source indefinitely.

9 

NUREGICR-6648

Proposed Action and Alternatives

9 NUREG/CR-6648
3. ENVIRONMENTAL EFFECTS

The following sections describe the relevant environmental conditions and address the potential long- and short-term environmental impacts of implementing the alternatives described in 

Section 2. 

3.1 GEOLOGY/HYDROLOGY 

This section describes the physical aspects of the SBNWR with respect to geology, groundwater occurrence, and surface water features. A detailed discussion of the history of 

Well 10 is included. Subsequently the short- and long-term water quality impacts of the three 

alternatives are addressed. 

3.1.1 Geology 

Southeastern Arizona lies in the southernmost extent of the Basin and Range Province in the 

United States. The dimensions of the San Bernardino Valley watershed are approximately 48 km (30 miles) north/south by 32 km (20 miles) east/west. The term Basin and Range refers 

to the alternating valleys and mountain ranges that are common through much of the area west 

of the Rocky Mountains and the Colorado Plateau. The Basin and Range landforms were 

formed when movement of bedrock occurred along faults causing uplift of bedrock to form 

mountain ranges and relative subsidence of land between the mountains to form geologic basins. At the time that the faulting, uplifting, and subsidence were in progress, erosion of soil 

and weathered bedrock from the rising mountain blocks provided sediment that partially filled 

the subsiding basins between the mountain ranges (USGS 1991). 

In the San Bernardino Valley area, volcanic activity accompanied the formation of the Basin and 

Range and basalt flows from the local volcanoes interfingered with the sediment mass in the 

basin (Figure 4). At least eight basalt flows have been reported in drilling records in the basin 

(USGS 1991). The upper basin fill was deposited after most of the geologic structures of the 

area formed, thus these deposits are draped over underlying faults and older sediment layers. However, in the San Bernardino Valley several minor faults displace the upper basin fill 

sediments (USGS 1991). 

The sedimentary and layered volcanic basin fill materials are quite heterogeneous in 

composition and texture (Figure 5). In southern Arizona, basin-fill sediments have been 

subdivided into lower and upper units on the basis of structural and stratigraphic characteristics 

(USGS 1991). The lowest part of the basin fill sediment is generally finer grained than the upper unit, presumably because the source of the lower (older) material was the ancient soil that laid 

above the bedrock in areas thatwere rising along the basin margins. These sediments consist 

of mudstone and siltstone that contain 80 percent or more silt and clay and locally include 

disseminated gypsum. Sediments in the upper part of the lower basin fill are somewhat coarser 

than the lowermost fill material and contain 55-80 percent silt and clay and lenses of sand and 

gravel, but no known evaporite minerals (USGS 1991).

11 NUREG/CR-6648
Environmental Assessment for San Bernardino Environmental Effects

ARBITRARY BOUNDARY 

OF GROUND-WATER AREA

R. 29 F. SONORA R.PO3 R.E.L3 R. sL E. 

Base from U.S. Geological Survey 1:250.000 Modified from Wilson and others (1269) 

Douglas. 19SS o MILES 

i 5 KIILMT. 0 5 KILOMETERS

EXPLANATION 

ALLUVIAL SEDIMENTS-Unconsolldated 2 CONSOLIDATED ROCKS-Igneous. 

to highly consolidated sediments of metamorphic. and sedimentary rocks 

Cenozoic age of middle Tertiary to Paleozoic age -- FAULT 

BASALT FLOWS-rOu-lernary to TertiaryF 

ase,

Figure 4. Geologic features of the San Bernardino Valley. Source: USGS 1991. 

NUREG/CR-6648 12

31*2Z30"
Modified from Pool (1985)

EXPLANATION

UPPER BASIN FILL

LOWER BASIN FILL WITH FACIES 

CHANGES GRADING TO FINE. 

GRAINED MATERIAL (MUOSTONE AND EVAPORITES) 

PRE-BASIN AND RANGE DEPOSITS 

BEDROCK

-- ----- WATER TABLE 

---- ? POTENTIOMETRIC SURFACE FOR 

LOWER BASIN FILL-CQueried where uncertain

l, FAULT

Figure 5. Typical geologic cross section of the San Bernardino National Wildlife Refuge region. Source: USGS 1991.

174 

I¢D

C,)

9 

0 

U, 

-I.) 0 

9 

C,' 

9 

C

E31

46
The sedimentary materials near the center of the basin, where the SBNWR is located, are 

generally finer grained in both the lower and upper units than the materials near the basin 

edges because the sediment was derived from the uplifted mountainous blocks surrounding the 

basin. Much of the San Bernardino basin surface is covered by weathered basalt flows less 

than 3 million years old (USGS 1991). 

3.1.2 Hydrology 

The primary water-bearing units in the San Bernardino Valley aquifer system are the basin-fill 

sediments and alluvium in incised stream valleys. The depth to water ranges from less than 6 m 

(20 ft) in the vicinity of Black Draw in the SBNWR to several hundred feet beneath upland areas 

east, west, and north of the SBNWR (Figure 5). Confined zones occur in the basin fill portions 

of the aquifer where dense basalt layers or less permeable sediment layers occur in the basin 

fill sequence. Permeable sediment layers and basalt beds make up the lesser part of the 

aquifer matrix in the valley, and their occurrence is discontinuous. It is possible that preferential 

groundwater flow pathways are present in or around the basalts either as fractures or highly 

porous zones. Such features may be capable of transmitting groundwater and dissolved 

constituents rapidly over long distances. The distribution of permeable sediment lenses and 

basalt beds in the basin fill materials produces a 3-dimensionally complex interfingering of 

permeable, water-bearing zones in a larger mass of relatively less permeable sedimentary 

material (Figure 5). 

SBNWR groundwater occurs under confined conditions deep in the lower basin fill sediment. 

Nine of the ten wells near the refuge wetlands discharged artesian flows in 1985 (USGS 1991). 

Discharges from these flowing wells provide a supply of fresh water to a number of ponds and a 

wetland area. Water-bearing units in the lower basin fill in the refuge area are confined by lower 

permeability sediment layers or basalt beds. Springs occur in several areas in the western part 

of the refuge where basalt flows terminate or are eroded by local stream valleys, exposing 

permeable sediment layers of the upper basin fill. Groundwater discharged from the springs is 

not derived from the deep groundwater aquifer beneath the area. 

The source of groundwater recharge to the aquifer in the San Bernardino area is precipitation 

that falls on the higher elevation portions of the basin and in the adjacent mountains. Less 

rainfall occurs in the valley floor area than in the adjacent highland areas. Although much of the 

precipitation is returned to the atmosphere through evapotranspiration, some water percolates 

through the unsaturated soil zone to reach the water table as recharge. Surface water 

infiltration occurs in the coarse alluvial sediments along the mountain fronts and throughout the 

valley in stream channels when surface flows are present. The absence of extensive alluvial 

deposits along the base of the Peloncillo Mountains at the eastern edge of the valley allows 

recharge of water-bearing units beneath the weathered basalt flows by direct percolation of 

water through the fractured basalt (USGS 1991). 

The general groundwater flow pattern in the San Bernardino Valley is from recharge areas that 

border the valley at the edges of the mountains toward the center of the basin and then 

southward beneath the valley axis toward Mexico. The groundwater flow directions are inferred 

to be generally similar to the drainage pattern of surface water flow in the basin with the 

groundwater flow being restricted to those subsurface zones with sufficient permeability to 

transmit significant flow. Groundwater that discharges to the surface via springs in the refuge

Environmental Effects Environmental Assessment for San Bernardino

NUREG/CR-6648 14
Environmental Assessment for San Bernardino

wetland area is inferred to originate as relatively shallow flow associated with near-surface 

basalt beds. Groundwater that discharges from artesian wells in the refuge or that may be 

pumped from deep wells elsewhere in the basin originates from the regional groundwater 

recharge and flow system. 

Most groundwater withdrawn in the San Bernardino Valley area is used for watering livestock, with lesser amounts used for domestic water supply. Although no groundwater was withdrawn 

for irrigation purposes in the valley at the time of USGS investigations in the area (USGS 1991), it is reported that at least one high capacity irrigation well [15,200 Lpm (4000 gpm)] has been 

developed in Mexico near the U.S.-Mexican border in the southern portion of the San 

Bernardino Valley (Longsworth 1991). 

Groundwater quality is generally acceptable for livestock and domestic uses. The geochemical makeup of the dissolved constituents varies spatially depending on the type of geologic material in which the water has resided during its storage in the aquifer and the duration of storage. Most of the wells sampled by USGS (1991) were of a calcium bicarbonate water type with a 

subordinate fraction showing a sodium bicarbonate water type. 

3.1.3 Conceptual Model of Well 10 

Well Number 10 in the SBNWR was drilled in the early 1900s using the cable tool drilling method. The exact original depth of the well is undocumented although logging and other 

activities in the well during the mid and late 1980s indicate that well depth could have ranged from 178 to 186 m (583 to 611 ft). A schematic diagram of SBNWR Well 10, shown in Figure 6, illustrates the approximate well configuration, zones of groundwater inflow to the well based on 

USGS information (1991), the estimated location of the lost Am-Be source, and potential contaminant migration pathways away from the Am-Be source location. The well contains a metal casing from the ground surface to a depth of 63 m (207 ft). This casing is presumed to be 3.2-cm (8-in.) in diameter based on the minimum well diameter of 3.2 cm (8 in.) reported by USGS (1991). 

The USGS performed various tests that contribute to the conceptual model of the well 

developed in this section. A key test from the standpoint of understanding groundwater behavior in the vicinity of the well is the flowmeter test. USGS flowmeter results indicate that groundwater enters the well in several depth intervals, with about half the artesian flow entering the well near a depth of 149 m (488 ft). Based on the previous descriptions of basin fill materials and aquifer conditions in the San Bernardino basin, it is presumed that intervals of Well 10 where no groundwater inflows occur are low permeability layers that confine the water bearing zones. The flowmeter test also indicates that below a depth of about 152 m (500 ft) the well contains essentially stagnant groundwater as indicated by no flow of water in the wellbore. 

Based on the large inflow of artesian groundwater only a few feet above the top of a stagnant 

zone, the staff infers that a local groundwater capture zone is formed by the continual discharge of water up the wellbore to the ground surface (Figure 6). If Well 10 were completely plugged, it is assumed that this local groundwater capture would cease to occur and groundwater near the bottom of the well would flow slowly to the south toward Mexico along with the bulk of the water 

in the San Bernardino basin.

NUREG/CR-6648

Environmental Effects

15
Consumptive Use 

MgI uomesuic 

0 * . Pond e ands 

Well Casing 

2 207 

M• •O•3Ol 310 inflow •-•"•-•.!:..:..:..... 

340 

38HUH~i~ 4 i.i':~i~lsi.i Basalt flows 

0) 0 488 -10 gp 0 500 

53 Groundwaterl stagnation zone Grudae withrawa 

for Goundwater withdrawal us 

Local Groundwater Capture Zone for agricultural/domestic use 

Minimum pofie - Local capture with discharge up depth of well well to surface 

Potential Lateral Groundwater Migration Source Release Mechanism (AhmclReadto 

- Breached containment - Dilution rj 

- S.S. degradation -Dispersion 

Near-Field Migration -Chemical Retardation 09 

- Dilution 

- Dispersion 9 

Figure 6. Conceptual model of the San Bernardino National Wildlife Refuge Well 10 and contaminant migration. 0
Environmental Assessment for San Bernardino

Following the loss of the logging source and events described in Section 1.2, USGS performed sampling and analysis of the groundwater discharging from Well 10 to determine if 241

Am was being released from the source. Table 1 includes the analytical results for 241

Am in water samples collected from Well 10. The table includes results for samples collected quarterly during 1989 and 1990 as well as final samples collected in 1993. The samples collected during the first three quarterly sampling rounds in 1989 and 1990 showed traces of 241

Am dissolved in the well water. The last of the four quarterly samples collected in 1990 did not show the 

presence of 241

Am. 

Table 1. Results of 241

Am analyses on water samples from Well 10 

241

Am and 2-sigma counting uncertainty (pCi/L) 

Sample date Bottom Other Top 

8-15-89 1.36 ± 0.28 0.59 ± 0.386a 0.085 ± 0.065 

11-30-89 0.187 ± 0 .1 0 2 b 0.081 ± 0.062c 0.053 ± 0.053 

2-28-90 0.037 ± 0 .10 3 b 0.038 ± 0.091c 0.781 ± 0.293 

6-7-90 0.0204 ± 0 .0 15 7b 0.0054 ± 0.0143c 0.0696 ± 0.0304 

8-21-90 0.00065 ± 0 .0 0 8 8 b 0.0115 ± 0.0127c 0.0099 ± 0.016 

10-14-93 0.07 ± 0.04 (MDAd 0.04 ± 0.015 (MDA d 

0.02) 0.27) 

10-14-93 -0.11 ± 0.01 (filtered) 0.08 ± 0.05 (filtered) 

"1.8 m (6 ft) above bottom bBottom early 

"cBottom late 

dMDA = minimum detectable activity 

Sources: Transmittal letter from Robert D. MacNish (District Chief, U.S. Geological Survey Water Resources Division, Tucson, Arizona) to Ms. Beth Riedlinger (U.S. NRC Region 5), July 8, 1993, 'attached to data table containing results of quarterly sample analyses. Transmittal letter-Analysis of USGS Well Water Samples (RFTA #94-01), William L. Beck, Oak Ridge Institute for Science and Education (ORISE), to Jim Montgomery, NRC, Dec. 7,1993. 

Additional samples were collected in 1993 and analyzed at a different laboratory. These final sample results again suggest that low concentrations of 24 1

Am may have been present; however, the sample analyst stated that even though the printed result suggests a low activity of 24

•Am, activity levels so close to the minimum detectable activity may actually represent a 

false positive indication of 24'Am (Beck 1993). 

The detection of 24

"Am at concentrations as much as 10 times its analytical detection limit indicates that some part of the previous attempts to recover the source probably breached the canister containing the source. Recovery of part of the logging tool but not the source suggests serious damage to the device may have occurred.

NUREG/CR-6648

Environmental Effects

17
3.1.4 Conceptual Model of Contaminant Release from Well 10 

As shown on Figure 6, the migration of contamination from the bottom of Well 10 to potential 

receptors involves movement through several physical zones, each of which may have varying 

capabilities to attenuate dissolved 241

Am concentrations. The principal components of the 

contaminant migration model for the Am-Be source in Well 10 include (1) near-field processes 

and conditions related to source release, solubilization, and interaction with borehole geologic 

materials; (2) local groundwater capture and discharge processes as influenced by the 

hydrogeologic conditions of the aquifer materials and the documented flow regime in the well; 

(3) partitioning in surface water and pond sediment/biota following discharge from the well; and 

(4) potential migration in the aquifer away from the well. 

3.1.4.1 Near-Field Processes 

The first step in a release from the source at the time of canister failure is dissolution of the 

AmO 2 powder in the source and geochemical attenuation in the near-field region within the well 

bore. The solubility limit of AmO 2 is approximately 1 x 10-8 M (at the solubility limit there would 

be a concentration of about 8 x 106 pCi/L) (Kowalzyk 1998). Americium hydrolyzes rapidly as 

the source dissolves, forming poorly soluble hydrolysis products that are subject to formation of 

particulates or adsorption to naturally occurring particulates. The range of published sorption 

distribution coefficients (kd) for 241

Am on mineral surfaces such as quartz, feldspars, and clay 

minerals in natural environments is between 104 to 106 (10,000 to 1,000,000 times more 

americium adsorbed to the solid phase than remaining in solution) (PNL 1981) indicative of 

strong adsorption of americium onto sediment or soil particles. The consequence of these high 

kd values on the release and movement of 241

Am away from the Am-Be source in Well 10 is 

strong retention of the americium in the sedimentary materials that form the lower basin fill 

surrounding the well. 

Because the source was lost and possibly partially cemented into the stagnant groundwater 

zone at the base of the well, the americium is expected to adsorb strongly onto the clays, silts, 

and sands of the borehole wall within a short distance of the source. The rate of americium 

movement in the stagnant zone is expected to be very slow with the adsorption to the borehole 

walls further slowing its movement. 

In order to verify the role of contaminant adsorption in limiting americium concentration in Well 

10, the maximum measured americium concentration in the groundwater can be compared to 

the order of magnitude one might expect if the source were breached and americium was 

dissolved into the groundwater stagnation zone. Under this scenario, a theoretical maximum 

dissolved 241

Am concentration would have been on the order of 8 x 106 pCi/L. Reduction of this 

concentration by kd sorption to the well wall materials by a factor of 106 would result in a 

dissolved concentration ranging from 1 to 10 pCi/L. This range includes the 1.36 pCi/L 

concentration measured in water sampled immediately above the well bottom some 3 years 

after abandonment of the source (Table 1). 

3.1.4.2 Local Groundwater Capture and Discharge Processes 

In the conceptual model for migration of americium away from the source, initial dissolution and 

attenuation of americium in the near-field region is followed by capture of dissolved constituents

Environmental Assessment for San Bernardino Environmental Effects

NUREG/CR-6648 18
Environmental Assessment for San Bernardino

near the well bottom in the upwelling artesian groundwater flow in the well. In this part of the 

contaminant transport pathway, dissolved materials undergo mixing and dilution by the water 

flowing into the well. Flowmeter tests performed in Well 10 indicate that about half the total flow 

in the wells enters the wellbore at a depth of 149 m (488 ft), the other half entering in two 

approximately 9 m (30 ft) thick intervals that lie between 90 and 120 m (300 and 400 ft) below 

the ground surface. In this part of the conceptual model, the americium concentration is 

expected to diminish as water flows up the well because of both dilution in the inflowing water 

volume and some further adsorption onto the borehole wall material. No quantitative estimate of 

the amount of water that may rise from the stagnation zone into the basal artesian flow region is 

available. However, for purposes of this assessment it is assumed that 1 percent of the total 

flow from the well originates from the stagnation zone. Further assessment of the human health 

and environmental affects of americium discharge to the surface under this scenario is 

presented in following sections. 

3.1.4.3 Partitioning in Pond Water, Sediment 

Any AmO 2 that dissolved in water would be expected to adsorb onto any clays, silts, and sands 

present in and near the water column, the range of kd being between 104 and 106. For a kd of 

105, for instance, any 241Am in solution which reached Twin Pond (which is fed by Well 10), 

would therefore reach equilibrium at 1:100,000 (i.e., I part 241Am in solution to 100,000 parts 

sorbed to sediments). This value is consistent with that found in a study of the ecological 

behavior of 241Am in a radioactive waste pond on the Hanford Reservation which received 

plutonium and americium wastes over a period of about 30 years (Emery et al. 1975). The 

Emery study stated, "These concentrations of 241Am in pond water were 1.08 pCi/L 

(1 pCi/L - .001 pCi/g) while concentrations in sediments averaged 53 pCi/g (wet)." The 

resulting kd is approximately 105. The Hanford pond is similar to Twin Pond in that it is shallow, 

allowing light penetration to the bottom of the entire pond, and has a simple food web, 

consisting of small fish, rooted aquatic vegetation, algae, detritus, and various insects. 

3.1.4.4 Potential Migration in the Aquifer Away from Well 10 

With the well flowing, the hydrogeology in the immediate vicinity of Well 10 favors capture and 

local surface discharge of any dissolved americium that is not adsorbed to borewall geologic 

materials. Based on the understanding of regional groundwater occurrence and flow in the San 

Bemardino basin (USGS 1991), if Well 10 were completely plugged with cement (from bottom 

to top), groundwater in the vicinity of the well would be expected to flow slowly southward 

toward the Mexican border. Under a scenario in which Well 10 was plugged and abandoned, 

the near-field geochemical retardation processes would be enhanced by forcing any dissolved 

constituents from near the well bottom to migrate through the low permeability sediments that 

surround the well below the 152 m (500 ft) depth. Based on the strong adsorption of americium 

in geologic materials, particularly those containing fine silts and clays, very small amounts of 

americium are expected to ever reach the productive part of the aquifer. If americium reaches a 

flowing zone in the aquifer, the adsorption and dilution processes previously discussed would 

act to slow its movement and reduce its concentration. Under a far-field migration scenario, 

contaminated groundwater from the vicinity of Well 10 would be subjected to a large amount of 

longitudinal dispersion and sorption in the large volume of porous sedimentary material along 

its flowpath.

Environmental Effects

19 NUREG/CR-6648
3.1.5 Assessment of Alternatives 

Taken collectively, the results of analyses from the Well 10 water (Table 1) leave a degree of 

uncertainty with regard to the integrity of the Am-Be source canister. It is possible that attempts 

to recover the source damaged the metal canister, allowing dissolution of the AmO 2 and BeO 

source material. On the other hand, the analytical results are somewhat uncertain since the 

latest, and most reliable, measured 241

Am concentrations in the well water lie in a range of 

potential false positive contaminant detection (Beck 1993). 

3.1.5.1 Proposed Action: Abandonment in Place 

Abandonment of the Am-Be source in place through pressure cementing of the well from the 

152 m (500 ft) depth to the total depth of 183 m (about 600 ft) would encapsulate all materials 

in the borehole below 152 m (500 ft). This action would eliminate the possibility of potential 

mixing of contaminated water at the well bottom with the discharging artesian flow. With 

completion of the cementing of the well base, the contaminant release scenario for the Am-Be 

source would be limited to diffusion of the contaminant upward through approximately 30 m 

(100 ft) of cement grout or through the native silts and clays of the geologic formation 

surrounding the well. If it is assumed that the source has been breached, emplacement of an 

improved cement plug below the 152 m (500 ft) depth, which is the base of active groundwater 

flow in the vicinity of Well 10, would retain 241

Am in the geologic materials at the base of the 

well. The combination of very low groundwater flow in this region and geochemical retardation 

processes would contain the americium beneath the useable aquifer. Under this alternative no 

adverse impact would be expected to either the water quality of Well 10 or other wells in the 

area. After plugging the basal portion of the well, continued discharge of the artesian flow to the 

ponds and wetlands could continue. 

3.1.5.2 Source Retrieval Alternative 

Removal of all materials in Well 10, including the Am-Be source, the drill bit and subassembly, 

and residues of the cement previously placed in the well is technically feasible. The well would 

essentially be re-drilled to a larger diameter and all liquids and solids removed would be 

contained and disposed of off-site (Section 2.2). 

With respect to the release of americium, this alternative could have potential short-term 

impacts during the retrieval operation. If the source has already been breached, the drill 

cuttings from the retrieval operation, particularly those from the deeper part of the well, would 

be expected to be contaminated with the americium released from the source. These cuttings 

would require characterization and some type of processing to prepare them for disposal at an 

approved facility. If the source has not been breached, the potential exists that it could be 

breached during the retrieval process, in which case americium would be expected to dissolve 

in the drilling fluid. In either case, the drilling fluid and cuttings would require containment, 

sampling and analysis prior to disposal, and offsite disposal as dictated by the presence or 

absence of contamination after the retrieval operation. Upon completion of the retrieval 

operation the well could be re-completed to continue providing water to the local ponds and 

wetlands.

NUREGICR-6648 

20

Environmental Effects Environmental Assessment for San Bernardino

NUREG/CR-6648 20
3.1.5.3 No-Action Alternative 

Under the no-action alternative, the potential would remain for discharge of americium

contaminated water or particulate material from Well 10 into the adjacent ponds and wetlands. 

Estimation of the likely concentrations that would be expected to result from this discharge 

suggests that the discharge would occur at low concentrations over a long period of time since 

the americium is expected to adsorb to soil and other particulate materials in the ground or in 

the well. Under this condition, no acute water quality effects would be expected. However, 

because the Am-Be source would not be sealed in the lower part of the well, continued 

monitoring would be necessary to ensure that unexpected contaminant concentrations do not 

occur in water or pond sediment. If 241

Am were subsequently detected in the water, the well 

could be plugged with cement as described under the proposed action. 

Under the no-action alternative it would be possible for the source containment to be 

inadvertently breached by future drilling. If someone should attempt to redevelop the well 

without realizing the presence of the source, they could drill into it, thereby releasing americium. 

The potential impacts of such a scenario would be similar to those discussed in Section 3.1.5.2 

above. 

3.2 ECOLOGY 

The SBNWR was established in 1982 to protect a wetlands habitat for wildlife and several 

species of fish, including the federally endangered Yaqui chub (Gila purpurea), the endangered 

Yaqui topminnow (Poeciliopsis occidentalis sononensis), and the threatened beautiful shiner 

(Cyprinella formosa) (Longsworth 1991; Maes 1995). The refuge covers about 930 ha (2,300 

acres) of the San Bernardino Valley in southeastern Arizona and encompasses a portion of the 

headwaters of the Yaqui River, a major river system which primarily drains western Chihuahua 

and eastern Sonora, Mexico. Marshes, ponds, springs, and flowing wells in the refuge sustain a 

unique ecosystem in southeastern Arizona. Habitat damage from cattle grazing and land 

clearing for farming before acquisition of the area by the FWS resulted in a decline in native fish 

and wildlife [personal communication from K. Cobble, USFWS Manager of San Bernardino 

National Wildlife Refuge, Douglas, Arizona, to H. D. Quarles, Oak Ridge National Laboratory 

(ORNL), Oak Ridge, Tennessee, October 14,1997]. 

Terrestrial vegetation consists of grasses, desert shrubs, cacti, mesquite, and acacia. 

Cottonwood and willow trees grow near the wetlands. Restoration of previously drained 

wetlands using water from flowing wells and springs has promoted growth of vegetation and an 

increase in wildlife and endangered fish populations (Longsworth 1991). The majority of aquatic 

habitats that now exist on the refuge are the result of manmade ponds maintained by clear 

water springs and artesian wells. The ponds are maintained (e.g., by vegetation thinning) to 

offer refugia for Rio Yaqui fishes. The degree of artificiality of aquatic habitats on the refuge is 

of concern, but such refugia are necessary until more secure natural habitats are available 

(Maes 1995). 

Artesian flow from well Number 10 feeds Twin Pond, which is approximately 0.10 ha (0.25 acre) 

in area with an average depth of about I m containing about 1,000,000 L of water (1,000 m3 x 

1,000 Unm3 ). Near the pond are a variety of trees including cottonwoods, willows, and acacias.

Environmental Assessment for San Bernardino Environmental Effects

21 NUREG/CR-6648
Dominant aquatic vegetation includes sedges, cattails, and pondweed. The pond water is clear. 

Fish species present include Yaqui chub (endangered), Yaqui topminnow (endangered), and 

beautiful shiner (threatened). Runoff from the pond flows to the south and feeds a small nearby 

wetland which contains the endangered plant species water umbel (Lilaeposis schaffneriana 

spp. recurva) (personal communication from K. Cobble, USFWS Manager of San Bernardino 

National Wildlife Refuge, Douglas, Arizona, to H. D. Quarles, ORNL, Oak Ridge, Tennessee, 

October 14, 1997). 

3.2.1 Methodology for Evaluating Radiation Effects on Aquatic Biota 

A methodology for evaluating the potential for aquatic biota to incur effects from chronic 

exposure to low-level radiation in the environment has been adapted from several existing 

methods by the U.S. Department of Energy (DOE) (Blaylock et al. 1993). A detailed description 

and application is provided in Appendix A. The methodology considers external exposure from 

radionuclides in water, sediment, and from other biota such as vegetation, as well as internal 

radiation from radionuclides ingested via food and water and, in some cases, from 

radionuclides absorbed through the skin and respiratory organs. The risk is evaluated by 

comparing the calculated radiation dose to biota with the DOE's recommended dose rate of 

0.4 mGy/h (1 rad/d). A lower dose rate to the most sensitive organisms should ensure 

protection of populations of aquatic organisms, based on reviews summarized in the National 

Council on Radiation Protection and Measurements Report No. 109 (NCRP 1991). 

In the event that any 241

Am reaches, or has reached, the biota in Twin Pond, its potential 

distribution, after reaching equilibrium, may be similar to that observed in a pond on the 

Hanford Reservation (Emery et al. 1975). At Hanford the highest concentrations were found in 

algal floc (decomposing algal material) averaging 64 pCi/g (wet). Levels in other biota were in 

all cases lower than concentrations in algal floc, or for organisms feeding on it, and were 

generally below that in sediment [53 pCi/g (wet)]. For instance, goldfish, which feed on algae 

and detritus (algal floc), concentrated relatively small amounts of americium, from 2-4 pCi/g 

(wet). Based on this, the authors concluded, "These low levels of americium concentration in 

goldfish tissue suggest that even years of active feeding on a substrate relatively high in 

americium content will not cause much transfer across the gut wall and into various body 

tissues" (Emery et al. 1975). The concentration in aquatic insects and submerged vegetation 

varied widely, but was generally about 10 pCi/g (wet); watercress, dragonfly larvae, and snails 

had 241Am levels about twice as high, i.e., 20 pCi/g (wet). A single mallard duck collected while 

feeding on the Hanford pond (food preferences are organic debris and algae) had a whole body 

concentration of 0.008 pCi/g (wet) 241

Am, a concentration so low that it was considered by the 

authors not to constitute an environmental hazard or an important transport mechanism (Emery 

and Klopfer 1975). Based on these observations the authors concluded that the potential for 

concentration by food chain transfer does not appear to be great (Emery et al. 1975). 

3.2.2 Assessment of Alternatives 

The ecological impacts associated with the three alternatives described in Section 2 are 

addressed in the following sections. Using the methodology and calculations presented in 

Appendix A, the potential for effects from 24 1

Am to threatened and endangered fish and other 

species in Twin Pond is described.

Environmental Effects Environmental Assessment for San Bernardino

NUREG/CR-6648 22
3.2.2.1 Proposed Action: Abandonment in Place 

Under this alternative, near-term ecological impacts would be minor and temporary, involving only minimal disturbance to the well site. 

Using the DOE methodology (Appendix A) for evaluating radiation effects on aquatic biota for 

an 24'Am concentration of 10 pCi/L in water entering Twin Pond, no effects would be expected. The dose rate (0.0036 mGy/h) is more than three orders of magnitude less than the DOE 

recommended dose limit. Therefore, there is little potential for effects on any of the species of 

fish present in Twin Pond. As the 241

Am in solution sorbs to sediments, the concentration in 

water would become markedly less, and dose to fish would decrease even more. At such low 

levels, effects to other pond biota less sensitive than teleost fish would not be expected. 

3.2.2.2 Source Retrieval Alternative 

The activities required to remove the source from the borehole are discussed in Section 2.2, 

and are similar to, but more extensive than, those of the proposed action. There would be 

short-term site disturbances associated with a larger staging area. Preventive measures would 

be employed to protect the integrity of the pond from entry of drilling materials. To protect the 

pond from drilling activities, a water-tight and bermed drilling platform would be constructed 

from the bank, allowing the work crew to perform drilling without introducing fluids and materials 

into the pond. To keep turbid water and drilling fluid wastes from entering the pond, a closed 

system would deliver these materials from the well head to a large truck-mounted container 

through a large diameter flexible hose. The container materials would be disposed of off-site. 

With these protective measures, impacts to the pond biota, as from introduction of small 

amounts of uncontaminated sediment from the surrounding work area, would be minimal and of 

short duration. If the 241

Am source has been breached, it is possible that contaminated solids 

could be mobilized in the well water. If so, these materials should also be prevented from 

entering the pond. If not, the possibility exists for deleterious effects to pond biota due to 

significant sediment entry. Upon completion of source retrieval, ecological impacts to the site 

and access road would be mitigated by revegetating them as necessary. 

If the source were recovered intact, there would be no impacts to pond biota from 241

Am. The 

possibility exists, however, that the source could be breached during the recovery attempt. As a 

highly conservative, worst case scenario for this assessment, we assumed that the entire 

contents of the source are lost directly into Twin Pond. Using the previously discussed 

methodology for evaluating radiation effects on fish (Appendix A), a dose rate of 0.610 mGy/h 

was calculated. 

A dose rate of 0.610 mGy/h exceeds the DOE recommended dose rate limit of 0.4 mGy/h; therefore, adverse effects to the three fish species of concern in Twin Pond (Yaqui chub, Yaqui topminnow, and beautiful shiner), and possibly other organisms in the food web would be 

possible. Effects of exposure at similar levels to natural populations of fish include greater brood size and embryo mortality for mosquitofish (Gambusia affinis) (Blaylock 1969; Trabalka 

and Allen 1977; Blaylock and Frank 1980) and lower fecundity and delay in spawning for roach 

(Rutilus rutilus) (Voronina et al. 1974; Peshkov et al. 1978).

23 NUREGICR-6648

Environmental Assessment for San Bernardino Environmental Effects

23 NUREG/CR-6648
Potential effects to the endangered plant species water umbel (Lilaeposis schaffneriana spp. 

recurva ), which is present in the nearby small wetland fed by the runoff from Twin Pond, are 

unlikely due to the higher radiation tolerance of plants than animals and the lower 

concentrations of 241

Am that would reach the wetland. 

The potential for effects would lessen as the pond ecosystem approached steady-state. 

Through time 241

Am would be lost from the pond as a result of outflow, contaminated sediments 

would become covered with those which were not contaminated, and radioactive decay of 24 1

Am to less hazardous 237

Np would occur. 

An accidental breach of the Am-Be source containment resulting from activities associated with 

this alternative would be at least partially contained by the procedures described in Section 2.2. 

However, the potential for an accidental release at or near the ground surface is a negative 

factor for this alternative. 

3.2.2.3 No-Action Alternative 

Under the no-action alternative, the potential would remain for discharge of americium 

contaminated water or particulate material from Well 10 into the adjacent ponds and wetlands. 

Estimation of the likely concentrations that would be expected to result from this discharge 

suggests that the discharge would occur at low concentration over a long period of time since 

the americium is expected to adsorb to soil and other particulate materials in the ground or in 

the well. Under this condition, no acute ecological effects would be expected. However, 

because the Am-Be source would not be sealed in the lower part of the well, continued 

monitoring would be necessary to ensure that unexpected contaminant concentrations do not 

occur in water or pond sediment. If 241

Am were subsequently detected in the water, the well 

would be plugged with cement as described under the proposed action. 

Under the no-action alternative it would be possible for the source containment to be 

inadvertently breached by future drilling. If someone should attempt to redevelop the well 

without realizing the presence of the source, they could drill into it, thereby releasing americium. 

The potential impacts of such a scenario would be less than those discussed in Section 3.2.2.2, 

as most of the americium would be confined to the lower aquifer (also see Section 3.1.4.2). 

3.3 HEALTH AND SAFETY 

This section includes a discussion of potential impacts the Am-Be source could have on local 

users of the water from the aquifer, as well as those users in Mexico. The safety of the U.S. and 

Mexican drinking and agricultural water supplies is discussed. The health and safety impacts to 

workers who might be involved in removing the source are addressed, as are the potential 

short- and long-term impacts to human health and safety of the three alternatives. 

3.3.1 Human Population 

Well 10 is located in the SBNWR approximately 30-35 km (19-21 miles) from the nearest 

population centers, Douglas, Arizona, and Agua Prieta, Mexico, respectively. Thus, there is little 

potential for direct contact of significant populations with Well 10 water. Another route of

Environmental Effects Environmental Assessment for San Bernardino

NUREG/CR-6648 24
Environmental Assessment for San Bernardino

exposure to any Well 10 contamination would be through the use of water from wells drilled into the same aquifer for drinking or irrigation. For this assessment, a high capacity well pumping 15,200 Lpm (4,000 gpm) (Section 3.1.2) is considered to be 1,000 m (3,300 ft) distant from the 

well. 

3.3.2 Assessment of Alternatives 

The potential human health effects of the three alternatives described in Section 2 are addressed in the following sections. Scenarios involving breached and unbreached conditions 

of the stainless steel containers are included. 

3.3.2.1 Proposed Action: Abandonment In Place 

Under the proposed action scenario, the source would remain sealed in place with installation of a cement plug. At issue is whether or not the 241

Am would be retained for its effective lifetime (i.e., 5 to 7 half-lives). Several perspectives on human risk are presented to provide a picture of the risk potential. Because the geology and hydrology of the site and nearby region are complex and not thoroughly understood (Section 3.1), the approach that is taken is to identify conservative approaches to estimate risk to humans. These approaches vary according to the alternative under discussion. By conservative, it is meant that the estimates are purposely designed not to underestimate human risk. 

Container not breached at present: The 432 year half-life of 241

Am means that the total quantity of 241

Am will decrease by a factor of 2 every 432 years. The longer the source remains below ground, undisturbed, the lower will be the potential for harm from the parent radionuclide. However, the primary progeny, neptunium (237Np) will grow in as the parent americium decays. This progeny radionuclide has a half-life of about 2.14 x 106 y and its radiotoxicity or hazard level per curie is approximately the same as that of 241

Am. However, the 237

Np has a much slower decay rate than 241

Am so that the hazard is proportionally less. Since hazard depends on radioactive decay, the Np hazard per gram is less than that for Am by the same factor as the ratio of their half-lives (i.e., 2.14 x 106 y + 432 y = 4953 = 5000), so the hazard or Curie quantity potential is reduced by that factor. Thus, given that the source material or, more likely, its 

progeny, is bound to enter the aquifer, it is instructive to examine the potential health impacts down gradient. 

The sum of the inner wall and outer wall thicknesses of the source container is about 3.1 mm (0.123 in.) and the corrosion rate for the Type 304 stainless steel in dilute nitric acid is in the 

range of 2.5 x 10-4 mm/y (10 mils/y). At this rate, the walls would be breached in about 12,000 years. In groundwater, the corrosion rate would be substantially lower. But even if it takes a few million years to breach the container, there is still a hazard because of the ingrowth of the daughter • 24

7Np, but this hazard is about a factor of 5,000 less than that from the parent 1

Am. 

Given the likelihood that the stainless steel container and the proposed cement plug would eventually be breached by corrosion/erosion, migration of the 241

Am and/or 3

7 Np off-site through the aquifer would occur at some time. In this estimate of human hazard potential, the potential sources of exposure to be considered are via a home well in Mexico or an agricultural well in Mexico, both of which would be located approximately 1,000 m (3,300 ft) from the

NUREG/CR-6648

Environmental Effects

25
radioactive source. As discussed in Section 3.1.2, the aquifer is poorly characterized and, as a 

consequence, refined estimates of dilution and retardation between the source and any location 

down gradient are not possible. However, it is possible to make an upper limit estimate of 

radiation dose to people using kd. 

There is substantial uncertainty regarding the kd of 241

Am, with many sources being available 

which provide varying kd values for 241

Am. In Section 3.1.4.1 a source is cited for a kd of 10' to 

106 for americium. However, in order to be very conservative in the assessment of human 

health effects, a different source is used here. The k, between water and sediment has been 

measured for plutonium to be in the range of 10,000 to 100,000 in a variety of settings (Allard 

and Rydberg 1983). In this article, experimental evidence demonstrates that at near neutral pH, 

the kd of Pu is greater than that for Am by an order of magnitude. Thus for the calculation of 

effects on humans, the value of 1,000 is conservatively chosen for the kd because of the 

unspecified environment of silt/sand/basalt at the depth of the source in the case of 241

Am. 

When the container fails and exposes the source material, it will be dissolved at a maximum 

concentration of 8 x 106 pCi/L requiring about 290,000 L (75,400 gal) of water to dissolve the 

2.5 Ci (Kowalzyk .1998). At this point the water containing the 24 1

Am would interact with the 

sediment/soil particles surrounding the well. Once the contaminated water interacts with the 

sediment and/or soil particles, the kd of 1,000 means that the concentration of 241

Am in the 

water would be reduced by a factor of 1,000 to 8 x 103 pCi/L. Eventually, as fresh water moves 

into the contaminated sediment/soil, it would become contaminated with 241

Am, but slightly less 

than 8 x 103 pCi/L. As the water moves farther down gradient, it would also interact with 

additional sediment and/or soil and become more diluted. But, in this conservative estimate, we 

will not take advantage of further hold-up in the sediment/soil. After many years, the plume of 

water at the concentration of 8 x 103 pCi/L would reach a hypothetical agricultural well about 

1,000 m (3,300 ft) from the original contaminated source. If this well were to be used for 

irrigating 40 ha (100 acres), using 30 acre in. of irrigation per year, it would need to pump about 

3 x 108 L (78 x 106 gal) during the growing season. This pumping rate would be seen by the 

deeper stagnant contaminated water as a type of "pressure relief" and there would be a slow 

migration of this contaminated water toward the agricultural well. If 1 percent annually of the 

290,000-L (75,400-gal) contaminated plume from the deep, slowly migrating water (containing 

8 x 103 pCi 24 1

Am), were mixed with the faster moving water in the aquifer supplying the bulk of 

the agricultural water, the average concentration in the irrigation water would be 0.077 pCi/L. If 

this concentration entered into the soil-to-plant pathway or into drinking water, the approximate 

annual dose would be less than 0.3 mrem/yr, well below any regulatory limit of concern. 

A home well is shallow by comparison with an agricultural well because it is also only as deep 

as needed for supply rates of a few hundred gallons per day and the provisions of potable 

water. Home use pumping rates would not provide the "pressure relief" considered with the 

agricultural well, and essentially no water from the deep, slowly moving water would be taken 

up in the home well. Therefore, essentially no radiation dose would be received for the case of 

a home well in Mexico. 

Container breached at present: Under the assumption that the container is breached, we 

must consider (1) the possibility of contaminated water coming to the surface and 

(2) contaminated water migrating off-site and down gradient into Mexico and used as 

(a) irrigation water or (b) small home well.

Environmental Assessment for San Bernardino Environmental Effects

NUREG/CR-6648 26
Environmental Assessment for San Bernardino

A series of measurements was made after the source was lost in the well. These data indicated roughly that 241

Am may have been present at a maximum level of 1.36 pCi/L early after the accident. Since June 1990, the presence of 241

Am has not been unambiguously indicated in water samples. The maximum value of 1.36 pCi/L was taken from the lower part of the well, probably in the stagnant zone. One would expect some dilution before the radionuclide could reach the surface. However, to make a bounding calculation of potential radiation dose it is assumed that a person could use Well 10 for drinking water and that the water was always at the maximum recorded concentration of 1.36 pCi/L. With the consumption of 2 L/d, on an annual basis, this would result in a dose of 3.6 mrem. This is to be compared with the 4 mrem/y dose limit promulgated by the U.S. Environmental Protection Agency (EPA), and the NRC standard for unrestricted use of decommissioned contaminated sites of 25 mrem/y (10 CFR 

Part 20). 

(a) Migration of the 241

Am and its 237

Np daughter off-site through the aquifer is a possibility. Based on the discussion above, use of water from an agricultural well might result in a dose of less than 0.3 mrem/y. 

(b) As discussed in Section 3.3.1.1, essentially no radiation dose would be received for the case of a home well in Mexico. 

3.3.2.2 Source Retrieval Alternative 

Retrieval of the source would present the potential for occupational doses and for the San 

Bernardino Wildlife Refuge to be restricted from public access. 

Container breached at present: If the container is breached, it is possible that a substantial amount of the 241

Am is very close to the breached container. This would mean that, during the course of overdrilling and coring to retrieve the source, some volume of Am-contaminated soil would be encountered at the surface. Unless stringent and expensive precautions are maintained, contaminated material would spread to the ponds, possibly restricting their use. In the upper limit, all of the nearly 2.5 Ci could be brought up. In the case of the contaminated material entering the pond, a large amount of contaminated soil would have to be collected and disposed of. If the drilling spoils were carefully collected, only a small amount of contaminated material would require disposal at an approved site. The maximum potential concentration of contaminated water would be 2.5 Ci divided by the volume of the pond, 106 L = 2.5 ACi/L. 

Health physics procedures and measurement techniques are sufficiently developed to minimize the adverse impacts to workers. For example, occupational exposures to contamination could be precluded by preventing the contaminated drilling residue from becoming airborne during any of the processes. Americium decays by emitting an alpha particle; consequently, the major concern is inhalation, since gloves or clothing would adequately shield the body from the alphas. The use of respirators would preclude inhalation exposures. Regardless of the precautions used, the drilling equipment would become contaminated; thus decontamination would be required before the rig could be moved to another location. The major trade-off to minimize occupational exposures to contamination in a situation like the current scenario is 

cost. 

27 NUREG/CR-6648
Container not breached: If the container is not breached, two possibilities exist. The first is 

that it can be retrieved without incident. The second is that it is breached in the retrieval 

attempt. In the latter case, the above discussion in Section 3.3.2.1 would apply, thus adverse 

effects on human health would not be anticipated. 

3.3.2.3 No-Action Alternative 

Under the no-action alternative, the potential would remain for discharge of americium 

contaminated water or particulate material from Well 10. Estimation of the likely concentrations 

that would be expected to result from this discharge suggests that the discharge would occur at 

low concentration over a long period of time since the americium is expected to adsorb to soil 

and other particulate materials in the ground or in the well. Under this condition, no human 

health effects would be expected. However, because the Am-Be source would not be sealed in 

the lower part of the well, continued monitoring would be necessary to ensure that unexpected 

contaminant concentrations do not occur in water. If 241

Am were subsequently detected in the 

water, the well would be plugged with cement as described under the proposed action. 

There is a possibility, under the no-action alternative, that future inadvertent drilling could 

penetrate the source, thereby releasing americium. The potential impacts of such a scenario on 

human health would be less than those discussed in Section 3.3.2.2, as most of the americium 

would be confined to the lower aquifer. The potential environmental impacts of this scenario 

would be similar to those discussed in Section 3.3.2.1.

NUREG/CR-6648 28

Environmental Assessment for San Bernardino Environmental Effects
4. REGULATORY COMPLIANCE

All appropriate regulations that apply to this project will be identified. In the case of the source 

removal alternative, special permits may be required from the FWS and the state of Arizona to 

disturb areas in or close to the ponds. 

Actions undertaken as part of the proposed abandonment of the well at the SBNWR would 

comply with a number of federal statutes and regulations including the following: the Atomic 

Energy Act; National Environmental Policy Act along with the Council on Environmental 

Quality's implementing regulations (40 CFR Parts 1500-1508), and NRC's implementing 

regulations (10 CFR Part 51); Clean Water Act; the Endangered Species Act; EPA drinking 

water standards; the Occupational Safety and Health Act and its implementing regulations 

(29 CFR 1910, Subparts G, Occupational Health and Environmental Controls; I, Personal 

Protective Equipment, and J, General Environmental Controls; and 29 CFR Part 1926, Safety 

and Health Standards for Construction); NRC's regulations in 10 CFR Part 20, Standards for 

Protection against Radiation; and NRC's regulations concerning abandonment and termination 

of the source license would comply with regulations in 10 Part 39. 

The staff initiated consultation of the proposed action with the FWS to comply with Section 7 of 

the Endangered Species Act of 1973 on June 15, 1999. On June 30, 1999, the FWS provided a 

letter on the project. During a follow-up call, the FWS stated that the project was in compliance 

with Section 7 of the Endangered Species Act and the FWS would not require additional action 

(personal communication from Bruce Palmer, Ecological Services Field Office, U.S. Fish and 

Wildlife Service, Phoenix, Arizona, to Murray Wade, ORNL, Oak Ridge, Tennessee, August 2, 

1999). Correspondence concerning the consultation can be found in Appendix B. 

On June 15, 1999, the staff initiated consultation with the State Historic Preservation Officer 

(SHPO) for the State of Arizona to comply with Section 106 of the National Historic 

Preservation Act. In a July 23, 1999 letter, the SHPO concurred that the project as proposed 

would not have an effect on cultural resources. Correspondence concerning cultural resources 

is included in Appendix C.

29 NUREGICR-6648 29 NUREG/CR-6648
5. REFERENCES

Allard, B. and J. Rydberg 1983. "Behavior of Plutonium in Natural Waters," Ch. 19, 

pp. 275-293, in Plutonium Chemistry, ed. C. Carnall and G. Choppin, American Chemical 

Society. 

Blaylock, B. G. 1969. "The Fecundity of a Gambusia affinis affinis Population Exposed to 

Chronic Environmental Radiation." Radiat. Res. 37:108-117. 

Blaylock, B. G. and M. L. Frank 1980. "Effects of Chronic Low-level Irradiation on Gambusia 

affinis," pp. 81-91 in N. Egami (ed.), Radiation Effects on Aquatic Organisms. University Park 

Press, Baltimore, Md. 

Blaylock, B. G., M. L. Frank and B. R. O'Neal 1993. Methodology for Estimating Radiation Dose 

Rates to Freshwater Biota Exposed to Radionuclides in the Environment, ES/ER/TM-78, Oak 

Ridge National Laboratory, Oak Ridge, Tenn. 

Emery, R. M., D. C. Klopfer, T. R. Garland, and W. C. Weimer 1975. Ecological Behavior of Plutonium and Americium in a Freshwater Pond," BNWL-SA-5346, Pacific Northwest 

Laboratory, Richland, Wash. 

Emery, R. M. and D. C. Klopfer 1975. "The Distributions of Transuranic Elements in a 

Freshwater Pond Ecosystem," prepared for Eighth Rochester International Conference on 

Environmental Toxicology: Radioisotopes in the Aquatic Environment, Models and Mechanisms. 

Kowalzyk, C. L. 1998. Letter report to Clay Easterly, Oak Ridge National Laboratory, Oak 

Ridge, Tenn., from C. L. Kowalczyk, Los Alamos National Laboratory, NMT-2:FY98-150. 

Longsworth, S. A. 1991. "Geohydrology and Chemical Quality of Ground Water, San 

Bernardino National Wildlife Refuge, Arizona," U.S. Geological Survey, Water-Resources 

Investigations 

Report 90-4190. 

Maes, R. A. 1995. "Habitat Use by Fishes of the San Bernardino National Wildlife Refuge," Thesis submitted to the School of Renewable Natural Resources, University of Arizona. 

NOAA (National Oceanic and Atmospheric Administration) 1985. Narrative Summaries, Table, 

and Maps for Each State with Overview of State Climatologist Programs, 31 ed., vol. 1, Gale 

Research Company, Detroit, Mich. 

NCRP (National Council of Radiation Protection and Measurements) 1991. Effects of Ionizing 

Radiation on Aquatic Organisms," NCRP Report No. 109, National Council on Radiation 

Protection and Measurements, Bethesda, Md. 

Peshkov, S. P., I. A. Shekhanova, G. N. Romanov, B. S. Prister and G. P. Sheyin 1978. 

"Biological Characteristics of Roach (Rutilis rutilis lacustris Pall.) After Living in Water 

Containing 90

Sr and 1

37

Cs," in Radioecological Problems of Atomic Power Plant Cooling31 NUREG/CR-6648
Reservoirs, Urals Scientific Center, Academy of Sciences of the USSR, Sverdlovsk. (In 

Russian). 

PNL (Pacific Northwest Laboratory) 1981. Critical Review: Radionuclide Transport, Sediment 

Transport, and Water Quality Mathematical Modeling; and Radionuclide Adsorption/Desorption 

Mechanisms, NUREG/CR-1322, Richland, Wash. 

Trabalka, J. R. and C. P. Allen 1977. "Aspects of Fitness of a Mosquitofish Gambusia affinis 

Exposed to Chronic Low-level Environmental Radiation." Radiat. Res. 70:198-211. 

Voronina, E. A., S. P. Peshkov and I. A. Shekhanova 1974. "The Rate of Growth and Fecundity 

of Fish Living in a Medium with a Raised Level of Irradiation," Trudy Vses. Nauchno-Issled. Inst. 

Morsk. Rybn. Khoz. Okeanogr. 100:74-79. (In Russian).

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32

References Environmental Assessment for San Bernardino

NUREGICR-6648 32
APPENDIX A

METHODOLOGY FOR EVALUATING RADIATION 

EFFECTS ON AQUATIC BIOTA 

A.1 METHODOLOGY 

The U.S. Department of Energy (DOE) methodology uses indicator species and combines and 

simplifies three approaches for calculation of radiation doses to aquatic organisms, taking into 

account the organism's size, mass, and geometry. For alpha radiation, the internal dose rate for 

small fish or a mollusk, Da, is calculated as 

Da = 5.76 x 10-4 EanaCo /,uGy/h 

where 

Ea is the energy of the alpha particle (MeV); 

(for 241

Am E. = 5.57 E + 00), 

na is the proportion of transitions producing an alpha particle of energy Ea(MeV) (dimensionless); (for 241

Am na = 1), and 

CO is the concentration of the radionuclide in the organism (Bq/kg wet weight). 

It is assumed that external alpha radiation from water and sediment is insignificant (due to the 

low penetrating power of alpha radiation) for aquatic organisms. Biological concentration factors 

for freshwater fish have been derived to estimate the concentration of a radioisotope in the fish 

to that in the surrounding water at steady-state conditions. For 241

Am, the biological concentration factor, as determined from the findings of Emery et al. (1975) (see Section 3.1.4.4), is approximately 3,000 (3 pCi/g fish/0.001 pCi/g water). This factor is used in 

the calculation of Co (i.e., C. = concentration in water x biological concentration factor). 

A.2 ASSESSMENT OF ALTERNATIVES 

The ecological impacts associated with the three alternatives described in Section 2 are 

addressed in the following sections. 

A.2.1 Proposed Action: Abandonment in Place 

If the 241

Am source has been or becomes breached, then near-field processes, such as 

precipitate formation and sorption by sedimentary materials (see Section 3.1.4) would cause 

strong retention of 241

Am in the materials that form the lower basin fill surrounding the well. If 

the source were breached at the bottom of the well and released its contents suddenly, as 

could have happened during attempted recovery or sealing operations, then reduction of the

A-1 NUREG/CR-6648
24.Am concentration because of the near-field processes would result in a dissolved 

concentration on the order of 1-10 pCi/L (the EPA drinking water standard is 15 pCi/L) in water 

entering Twin Pond (see Section 3.1.4). This represents a worst case scenario for the 

abandonment in place alternative. Any future breach of the source would likely result from 

corrosion of the stainless steel container and would probably release 241

Am more slowly with 

corresponding lower 241

Am concentrations in water reaching Twin Pond. 

Using the previously discussed methodology for evaluating radiation effects on aquatic biota for 

a concentration of 24 1

Am of 10 pCi/L in water entering Twin Pond, no effects would be expected. 

The dose rate to a small fish living in the undiluted stream of well water would be 

Ea = 5.57 

na 1 

C. = (10 pCi/L)(.037 Bq/pCi)(1 kg/L)(3000) = 1,110 Bq/kg; 

therefore, 

Da= (5.76 x 10-4)(5.57)(1)(1,110) = 3.6aGy/h 

Da = 0.0036 mGy/h < 0.4 mGy/h (DOE recommended dose rate limit) 

The dose rate is more than 3 orders of magnitude less than the DOE recommended dose limit. 

Therefore, there is little potential for effects on any of the species of fish present in Twin Pond. 

As the 241

Am in solution sorbs to sediments the concentration in water would become markedly 

less, and dose to fish would decrease even more. At such low levels effects to other pond biota 

less sensitive than teleost fish would not be expected. 

Placement of an additional cement plug, as discussed in Section 2.1, would further reduce the 

likelihood of contaminant migration up the well. There would be minor and temporary short-term 

ecological impacts associated with the process of cement plug emplacement, which would 

entail transporting equipment and personnel on existing roadways and trails into the refuge and 

preparing the site for the drill rig, support vehicles, and personnel vehicles. 

A.2.2 Source Retrieval Alternative 

The volume of Twin Pond is 1,000,000 L, and the entire 2.5 Ci of 24

"Am is assumed to be lost in 

the pond and go into solution with the pond water. Since the pond ecosystem would not be at 

steady-state, all initial exposure would be due to an organism's water consumption and gill 

throughput (typically several times the body weight of the fish each hour), and not from initially 

uncontaminated sediments or detritus. Assuming the resultant concentration in an organism is 

only twice that of the concentration in water, the dose rate to a small fish would be as follows: 

Ea = 5.57 

na = I 

Co = (2.5 Ci) (3.7 x 1010 Bq/Ci) (2) / (1 x 106 L) (1 kg/L) 

Co = 9.25 x 104;

NUREG/CR-6648 

A-2

Environmental Assessment for San Bernardino Appendix A

NUREG/CR-6648 A-2
Environmental Assessment for San Bernardino Appendix A 

therefore, 

Da = (5.76 x 10-4) (5.57) (2) (9.25 x 104) 4Gy/h Da = 610 lzGy/h or 0.610 mGy/h. 

A dose rate of 0.610 mGy/h exceeds the DOE recommended dose rate limit of 0.4 mGy/h; therefore, adverse effects to the three fish species of concern in Twin Pond [Yaqui chub (endangered), Yaqui topminnow (endangered), and beautiful shiner (threatened)], and possibly other organisms in the food web would be possible. Effects of exposure at similar levels to natural populations of fish are greater brood size and embryo mortality for mosquitofish (Gambusia affinis) (Blaylock 1969; Trabalka and Allen 1977; Blaylock and Frank 1980) and lower fecundity and delay in spawning for roach (Rutilus rutilus) (Voronina et al. 1974; Peshkov 

et al. 1978). 

Potential effects to the endangered plant species water umbel (Lilaeposis schaffneriana spp. recurva ), which is present in the nearby small wetland fed by the runoff from Twin Pond, are unlikely due to the higher radiation tolerance of plants than animals and the lower 

concentrations of 241

Am that would reach the wetland. 

Immediately upon dissolution of the 241

Am in the pond, the 241

Am in solution would begin to sorb 

to particulates and the pond bottom substrate, thereby lowering the concentration in water and increasing the concentration in sediments. There would also be loss of americium from the pond as contaminated water flowed out and was replaced by clean water. 241

Am associated with surface sediment particles is tightly bound and less than about 1 percent could be available to the food web in soluble form (Emery et al. 1975). However, under this very conservative scenario, the resulting concentrations in pond surface substrate could initially be high enough to 

expose snails at dose rates exceeding the DOE recommended limit. Predators feeding on pond organisms, or other species dependent this water resource, would be at less risk due to low 

potential for food chain transfer (Emery et al. 1975).

A-3 NUREGICR-6648 A-3 NUREG/CR-6648
APPENDIX B 

SECTION 7 CONSULTATION LETTERS

B-I 

NUREGICR-6648 B-1 NUREG/CR-6648
Environmental Assessment for San Bernardino Appendix B 

OAK RIDGE NATIONAL LABORATORY 

MANAGED BY LOCKHEED MARTIN ENERGY RESEARCH CORPORATION PHONE_ (423),574-832 FOR THE U.S. DEPARTMENT OF ENERGY 

FAXP (423) 5748682 

POST OFFICE BOX 2006 OAK RIDGE TN 37831a-e5 INTERNET: wn"VoLgov 

June 15, 1999 

Mr. David Harlow. Field Supervisor Fish and Wildlife Service 

Ecological Services Field Office 

2321 W. Royale Palm Road 

Suite 103 

Phoenix, Arizona 85021 

Dear Mr. Harlow. 

Re: 

National 

Informal 

Wildlife 

Section 7 consultation for the draft Environmental Assessment, San Bernardino Refuge, Well 10, Arizona 

The 

composed 

U.S. Geological 

of americium 

Service (USGS) currently holds a license for the use of a radioactive Am-Be source (

241

Wildlife Refuge (SBNWR) 

Am) and beryllium (Be) for well logging in the San Bernardino National 

Arizona and is managed 

in Arizona (see Figure 1). The Refuge is located in extreme southeastern by the U.S. Fish and Wildlife Service (FWS). The radioactive source has been lost 

SBNWR 

at a depth 

since 

of 

1986 

approximately 

(see Figure 

600 ft in an artesian water well adjacent to Twin Ponds within the 2). The Nuclear Regulatory Commission Oak Ridge National Laboratory (NRC), with the assistance of (ORNL), is preparing an Environmental Assessment the potential impacts (EA) that evaluates 

Environmental Policy 

for 

Act 

safely terminating activities at the well In accordance with the National (NEPA) and the NRC's regulations implementing NEPA. The proposed action is to abandon the source in place subsequent to compliance with all NRC requirements USGS for termination. of license for the source. 

Act 

In order 

(ESA), 

to coordinate 

please provide 

NEPA 

me 

implementation 

with 

with that required by Section 7 of the Endangered Species 

of any information andlor concerns you might have regarding the effects 

have 

this 

any 

proposed 

questions 

action 

concerning 

on listed, proposed, and candidate threatened and endangered species. if you 

at 

this project, please contact me at (423) 574-8632 or Mr. Tim Ensminger (423) 574-5657. Thank you for your assistance. 

Sincerely, 

Murray Wade, 9RNL Staff Member 

MCW:mh 

Enclosures 

cc: Bruce Carrico, NRC 

J. T. Ensminger, ORNL 

Lance McCold, ORNL 

H. Quarles, ORNL 

Oral Jirnqjm9 c5cience Jo (&/e

B-3 NUREG/CR-6648
rnVironmeuiai Assessment Ior •an Bsernardino Appendix B 

United States Department of the Interior 

U.S. Fish and Wildlife Service 

2321 W. Royal Palm Road, Suite 103 

Phoenix, Arizona 85021-4951 

(602)640-2720 FAX (602)640-2730 

In Reply Refer To: 

AESO/SE 

2-21-99-I-255 June 30, 1999 

Mr. Murray Wade 

Oak Ridge National Laboratory 

P.O. Box 2008 

Oak Ridge, Tennessee 37831-6206 

RE: Draft EA, San Bernardino National Wildlife Refuge, Well 10, Arizona 

Dear Mr. Wade: 

This letter responds to your June 15, 1999, request for an inventory of threatened or endangered species, or those that are proposed to be listed as such under the Endangered Species Act of 

1973, as amended (Act), which may potentially occur in your project area (Cochise County). The enclosed list may include candidate species as well. We hope the enclosed county list of 

species will be helpful. In future communications regarding this project, please refer to 

consultation number 2-21-99-1-255. 

The enclosed list of the endangered, threatened, proposed, and candidate species includes all 

those potentially occurring anywhere in the county, or counties, where your project occurs. 

Please note that your project area may not necessarily include all or any of these species. The 

information provided includes general descriptions, habitat requirements, and other information 

for each species on the list. Also on the enclosed list is the Code of Federal Regulations (CFR) citation for each listed or proposed species. Additional information can be found in the CFR 

and is available at most public libraries. This information should assist you in determining which species may or may uot occur within your project area. Site-specific surveys could also 

be helpful and may be needed to verify the presence or absence of a species or its habitat as 

required for the evaluation of proposed project-related impacts. 

Endangered and threatened species are protected by Federal law and must be considered prior 

to project development. If the action agency determines that listed species or critical habitat may be adversely affected by a federally funded, permitted, or authorized activity, the action agency 

must request formal consultation with the Service. If the action agency determines that the 

planned action may jeopardize a proposed species or destroy or adversely modify proposed critical habitat, the action agency must enter into a section 7 conference with the Service. 

Candidate species are those which are being considered for addition to the list of threatened or 

endangered species. Candidate species are those for which there is sufficient information to 

support a proposal for listing. Although candidate species have no legal protection under the

B-5 

NUREGICR-6648

B-5 NUREG/CR-6648
Appendix B Environmental Assessment for San Bernardino

2 

Act, we recommend that they be considered in the planning process in the event that they 

become listed or proposed for listing prior to project completion. 

If any proposed action occurs in or near areas with trees and shrubs growing along watercourses, 

known as riparian habitat, the Service recommends the protection of these areas. Riparian areas 

are critical to biological community diversity and provide linear corridors important to migratory 

species. In addition, if the project will result in the deposition of dredged or fill materials into 

waterways or excavation in waterways, we recommend you contact the Army Corps of 

Engineers which regulates these activities under Section 404 of the Clean Water Act. 

The State of Arizona protects some plant and animal species not protected by Federal law. We 

recommend you contact the Arizona Game and Fish Department and the Arizona Department 

of Agriculture for State-listed or sensitive species in your project area. 

The Service appreciates your efforts to identify and avoid impacts to listed and sensitive species 

in your project area. If we may be of further assistance, please feel free to contact Tom Gatz 

(x240). 

Sincerely, 

f6!DavidSL. Harlow 

Field Supervisor 

Enclosure

NUREG/CR-6648 

B-6

Environmental Assessment for San Bernardino Appendix B

NUREG/CR-6648 B-6
Environmental Assessment for San Bernardino

USTED. PROPOSED, AND CANDIDATE SPECIES FOR THE FOLLOWING COUNTY: 

031251M999 

I)LISTED

COCHISE 

TOTAL= 21

NAME: CANELO HILLS LADIES' TRESSES SPIRANTHES DEUTESCENS 

STATUS: ENDANGERED CRITICAL HAB No RECOVERY PLAN: No CFR: 62 FR 665,01-06-97 

DESCRIPTION: SLENDER ERECT MEMBER OF THE ORCHID FAMILY (ORCHIDACEAE). 

FLOWER: STALK 50 CM TALL. MAY CONTAIN 40 WHITE FLOWERS 

SPIRALLY ARRANGED ON THE FLOWERING STALK. ELEVATION 

RANGE: about 5000 FT. 

COUNTIES: COCHISE. SANTA CRUZ 

HABITAT: FINELY GRAINED, HIGHLY ORGANIC. SATURATED SOILS OF CIENEGAS 

POTENTIAL HABITAT OCCURS IN SONORA. MEXICO. BUT NO POPULATIONS HAVE BEEN FOUND.

NAME: COCHISE PINCUSHION CACTUS CORYPHANTHA ROBBINSORUM 

STATUS: THREATENED CRITICAL HAB No RECOVERY PLAN: Yes CFR: 51 FR 952, 1-9-1986 

DESCRIPTION: A SMALL UNBRANCHED CACTUS WITH NO CENTRAL SPINES AND 11-17 

WHITE RADIAL SPINES. THE BELL-SHAPED FLOWERS ARE BORNE ON 

THE ENDS OF TUSERCULES (Protrusions). FLOWERS: BELL SHAPED, ELEVATION 

PALE YELLOW-GREEN. FRUITS: ORANGE-RED TO RED RANGE: >4200 FT. 

COUNTIES:COCHISE AND SONORA. MEXICO 

HABITAT: SEMIDESERT GRASSLAND WITH SMALL SHRUBS, AGAVE, OTHER CACTI, AND GRAMA GRASS. 

GROWS ON GRAY LIMESTONE HILLS.

NAME: HUACHUCA WATER UMBEL ULAEOPSIS SCHAFFNERIAALA ssp RECURVA 

STATUS: ENDANGERED CRITICAL HA Yes RECOVERY PLAN: No CFR: 62 FR 665. 01-06-97 

DESCRIPTION: HERBACEOUS. SEMI-AQUATIC PERENNIAL IN THE PARSLEY FAMILY 

(UMBELLIFERAE) WITH SLENDER ERECT. HOLLOW. LEAVES THAT GROW 

FROM THE NODES OF CREEPING RHIZOMES. FLOWER: 3 TO 10 ELEVATION 

FLOWERED UMBELS ARISE FROM ROOT NODES. RANGE. 350046500 FT. 

COUNTIES: PIMA, SANTA CRUZ. COCHISE 

HABITAT: CIENEGAS. PERENNIAL LOW GRADIENT STREAMS. WETLANDS 

AND IN ADJACENT SONORA. MEXICO. WEST OF THE CONTINENTAL DIVIDE. POPULATIONS ALSO ON FORT 

HUACHUCA MILITARY RESERVATION. PROPOSED CRITICAL HABITAT IN COCHISE AND SANTA CRUZ COUNTIES (63 

FR 71838)

I

B-7 NTJREGICR-6648

Appendix B

B-7 NUREG/CR-6648
Appendix B Environmental Assessment for San Bernardino 

LISTED, PROPOSED, AND CANDIDATE SPECIES FOR THE FOLLOWING COUNTY: COCHISE 

03/25/1999 

NAME: NEW MEXICAN RIDGE-NOSED RATTLESNAKE CROTALUS WILLARDI OBSCURUS 

STATUS: THREATENED CRITICAL HAB Yes RECOVERY PLAN: Yes CFR: 43 FR 34479, 04-04-1978 

DESCRIPTION: SMALL 12-24 INCHES. SECRETIVE GRAYISH-BROWN WITH DISTINCT 

RIDGE ON THE END OF THE SNOUT. THE DORSAL SURFACE HAS 

OBSCURE, IRREGULARLY SPACED WHITE CROSSBARS EDGED WITH ELEVATION 

BROWN (NOT A BOLD PATTERN). RANGE: 5600-9000 FT. 

COUNTIES:COCHISE 

HABITAT: PRESUMABLY CANYON BOTTOMS IN PINE-OAK & PINE-FIR COMMUNITIES WITH ALDER. MAPLE, OAK. & 

BOX ELDER 

THE SUBSPECIES HAS NOT BEEN DOCUMENTED IN ARIZONA. HOWEVER, IT HAS BEEN OBSERVED NEAR THE 

ARIZONA BORDER IN THE PELONCILLO MOUNTAINS AND LIKELY OCCURS IN THE ARIZONA PORTION OF THAT 

RANGE AS WELL. ANOTHER SUBSPECIES, (CROTALUS WILLARDI WILLARDI). IS AN ARIZONA STATE CANDIDATE. 

NAME: JAGUAR, UNITED STATES POPULATION PANTHERA ONCA 

STATUS: ENDANGERED CRITICAL HAB No RECOVERY PLAN: No CFR: 62 FR 39147,7-22-97 

DESCRIPTION: MUSCULAR CAT WITH RELATIVELY SHORT. MASSIVE LIMBS AND A DEEP

CHESTED BODY. CINNAMON-BUFF IN COLOR WITH BLACK SPOTS. ELEVATION 

RANGE: <8000 FT. 

COUNTIES: COCHISE, PIMA 

HABITAT: IN ARIZONA. RANGED WIDELY THROUGHOUT A VARIETY OF HABITATS FROM SONORAN DESERT TO 

CONIFER FORESTS 

MOST RECORDS ARE FROM THE MADREAN EVERGREEN-WOODLAND, SHRUB-INVADED SEMI-DESERT GRASSLAND, 

AND ALONG RIVERS. HISTORIC RANGE IS CONSIDERED TO HAVE EXTENDED BEYOND THE COUNTIES LISTED 

ABOVE. REPORTS OF INDIVIDUALS IN THE SOUTHERN PART OF THE STATE CONTINUE TO BE RECEIVED. THE 

MOST RECENT RECORDS OF A JAGUAR IN THE U.S. ARE FROM THE NEW MEXICO/ARIZONA BORDER AREA AND IN 

SOUTHCENTRAL ARIZONA, BOTH IN 1996, AND CONFIRMED THROUGH PHOTOGRAPHS. UNCONFIRMED SIGHTINGS 

AND TRACKS CONTINUE TO BE REPORTED. THIS SPECIES HAS A SIGNED CONSERVATION AGREEMENT IN PLACE. 

BUT THE DEVELOPMENT OF THE AGREEMENT WAS NOT SUFFICIENT TO REMOVE THE NEED TO LIST THIS SPECIES 

NAME: JAGUARUNDI HERPAILURUS (=FELIS) YAGOUAROUNDI TOLTECA 

STATUS: ENDANGERED CRICAL HAB No RECOVERY PLAN: No CFR. 41 FR 24064; 06-14-76 

DESCRIPTION: SMALL CAT WITH SHORT LEGS: SLENDERELONGATE BODY; AND LONG 

TAIL HEAD SMALL & FLATTENED WITH SHORT ROUNDED EARS. 

REDDISH-YELLOW OR BLACKISH TO BROWN-GRAY IN COLOR AND ELEVATION 

WITHOUT SPOTS. RANGE: 3500-6000 FT. 

COUNTIES: SANTA CRUZ, PIMA, COCHISE 

HABITAT: CAN BE FOUND IN A VARIETY OF HABITATS (SEE BELOW) 

SEMI-ARID THORNY FORESTS, DECIDOUS FORESTS, HUMID PRE-MONTANE FORESTS, UPLAND DRY SAVANNAHS, 

SWAMPY GRASSLANDS, RIPARIAN AREAS, AND DENSE BRUSH. UNCONFIRMED REPORTS OF INDIVIDUALS IN THE 

SOUTHERN PART OF THE STATE CONTINUE TO BE RECEIVED. NO SPECIMENS HAVE BEEN COLLECTED IN 

ARIZONA. 

2

NIJREG/CR-6648 

B.-8

NUREG/CR-6648 B-8
Environmental Assessment for San Bernardino Appendix B 

LISTED, PROPOSED, AND CANDIDATE SPECIES FOR THE FOLLOWING COUNTY: COCHISE 

0312511999 

NAME: LESSER LONG-NOSED BAT LEPTONYCTERIS CURASOAE YERBABUENAE 

STATUS: ENDANGERED CRITICAL HAB No RECOVERY PLAN: Yes CFR: 53 FR 38456, 09-30-88 

DESCRIPTION: ELONGATED MUZZLE, SMALL LEAF NOSE, AND LONG TONGUE. 

YELLOWISH BROWN OR GRAY ABOVE AND CINNAMON BROWN BELOW. 

TAIL MINUTE AND APPEARS TO BE LACKING. EASILY DISTURBED. ELEVATION 

RANGE: <6000 FT. 

COUNTIES: COCHISE, PIMA. SANTA CRUZ, GRAHAM, PINAL. MARICOPA 

HABITAT: DESERT SCRUB HABITAT WITH AGAVE AND COLUNMNAR CACTI PRESENT AS FOOD PLANTS 

DAY ROOSTS IN CAVES AND ABANDONED TUNNELS. FORAGES AT NIGHT ON NECTAR. POLLEN. AND FRUIT OF 

PANICULATE AGAVES AND COLUMNAR CACTI. THIS SPECIES IS MIGRATORY AND IS PRESENT IN ARIZONA, 

USUALLY FROM APRIL TO SEPTMBER AND SOUTH OF THE BORDER THE REMAINDER OF THE YEAR. 

NAME: MEXICAN GRAY WOLF CANIS LUPUS BAILEYI 

STATUS: ENDANGERED CRITICAL HAB No RECOVERY PLAN: Yes CFR: 32 FR 4001, 03-11-67; 43 

DESCRIPTION: LARGE DOG-LIKE CARNIVORE WITH VARYING COLOR, BUT USUALLY A FR 1912, 03-09-78 

SHADE OF GRAY. DISTINCT WHITE UP MNE AROUND MOUTH. WEIGH 60

90 POUNDS. ELEVATION 

RANGE: 4.000-12,00,FT. 

COUNTIES:APACHE, COCHISE, GREENLEE. PIMA. SANTA CRUZ 

HABITAT: CHAPPARAL, WOODLAND, AND FORESTED AREAS. MAY CROSS DESERT AREAS. 

HISTORIC RANGE IS CONSIDERED TO BE LARGER THAN THE COUNTIES LISTED ABOVE. UNCONFIRMED REPORTS 

OF INDIVIDUALS IN THE SOUTHERN PART OF THE STATE (COCHISE, PIMA. SANTA CRUZ) CONTINUE TO BE 

RECEIVED. INDMDUALS MAY STILL PERSIST IN MEXICO. EXPERIMENTAL NONESSENTIAL POPULATION 

INTRODUCED IN THE BLUE PRIMITIVE AREA OF GREENLEE AND APACHE COUNTIES. 

NAME: OCELOT LEOPARDUS (=FELIS) PARDALIS 

STATUS: ENDANGERED CRITICAL HAB No RECOVERY PLAN: Yes CFR: 47 FR 31670; 07-21-82 

DESCRIPTION: MEDIUM-SIZED SPOiTED CAT WHOSE TAIL IS ABOUT 112 THE LENGTH 

OF HEAD AND BODY. YELLOWISH WITH BLACK STREAKS AND STRIPES 

RUNNING FROM FRONT TO BACK TAIL IS SPOTTED AND FACE IS LESS ELEVATION 

HEAVILY STREAKED THAN THE BACK AND SIDES. RANGE: <8000 FT. 

COUNTIES: SANTA CRUZ, PIMA. COCHISE 

HABITAT: HUMID TROPICAL & SUB-TROPICAL FORESTS, SAVANNAHS. AND SEMI-ARID THORNSCRUB. 

MAY PERSIST IN PARTLY-CLEARED FORESTS. SECOND-GROWTH WOODLAND. AND ABANDONED CULTIVATION 

REVERTED TO BRUSH. UNIVERSAL COMPONENT IS PRESENCE OF DENSE COVER. UNCONFIRMED REPORTS OF 

INDMIDUALS IN THE SOUTHERN PART OF THE STATE CONTINUE TO BE RECEIVED. 

3

B-9 NUREGICR-6648

B-9 NUREG/CR-6648
Appendix B Environmental Assessment for San Bernardino

LISTED, PROPOSED, AND CANDIDATE SPECIES FOR THE FOLLOWING COUNTY: COCHISE 

0312511999 

NAME: BEAUTIFUL SHINER CYPRINELLA FORMOSA 

STATUS: THREATENED CRITICAL HAB Yes RECOVERY PLAN: Yes CFR: 49 FR 34490, 831-1984 

DESCRIPTION: SMALL (2.5 INCHES) SHINY MINNOW AND VERY SIMILAR TO RED SHINER. 

MALES COLORFUL DURING BREEDING (YELLOW-ORANGE OR ORANGE 

ON CAUDAL AND LOWER FINS AND BLUISH BODY. ELEVATION 

RANGE: <4500 FT. 

COUNTIES: COCHISE 

HABITAT: SMALL TO MEDIUM SIZED STREAMS AND PONDS WITH SAND, GRAVEL, AND ROCK BOTTOMS. 

VIRTUALLY EXTIRPATED IN THE UNITED STATES, WITH THE EXCEPTION OF A FEW ISOLATED POPULATIONS ON 

NATIONAL WILDLIFE REFUGES AND IN MEXICO. SAME CRITICAL HABITAT AS YAQUI CHUB AND CATFISH (SEE 49 FR 

34490, 08-31-1984). 

NAME: YAQUI CATFISH ICTALURUS PRICEI 

STATUS: THREATENED CRITICALHAB Yes RECOVERY PLAN: Yes CFR: 49 FR 34490.08-31-1984 

DESCRIPTION: SIMILAR TO CHANNEL CATFISH (Ictalurus punctatus) EXCEPT ANAL FIN 

BASE IS SHORTER AND THE DISTAL MARGIN OF THE ANAL FIN IS 

BROADLY ROUNDED WITH 23-25 SOFT RAYS. BODY USUALLY ELEVATION 

PROFUSELY SPECKLED. RANGE: 4000-5000 FT. 

COUNTIES: COCHISE 

HABITAT: MODERATE TO LARGE STREAMS WITH SLOW CURRENT OVER SAND AND ROCK BOTTOMS 

CRITICAL HABITAT ALLAQUATIC HABITATS IN THE MAIN PORTION OF SAN BERNADINO NATIONAL WILDLIFE 

REFUGE 

NAME: YAQUI CHUB GILA PURPUREA 

STATUS: ENDANGERED CRITICAL HAB yes RECOVERY PLAN: Yes CFR: 49 FR 34490. 08-31-1984 

DESCRIPTION: MEDIUM SIZED MINNOW (<6 INCHES) DARK COLORED, LIGHTER BELOW. 

DARK TRIANGULAR CAUDAL SPOT 

ELEVATION 

RANGE: 4000-6000 FT. 

COUNTIES: COCHISE (AZ), MEXICO 

HABITAT: DEEP POOLS OF SMALL STREAMS, POOLS, OR PONDS NEAR UNDERCUT BANKS. 

CRITICAL HABITAT INCLUDES ALL AQUATIC HABITATS OF THE MAIN PORTION SAN BERNADINO NATIONAL WILDLIFE 

REFUGE. 

4

NUREGICR-6648 

B-i 0

NUREG/CR-6648 B-1I0
Environmental Assessment for San Bernardino Appendix B 

LSTED, PROPOSED. AND CANDIDATE SPECIES FOR THE FOLLOWING COUNTY: COCHISE 

0312511999 

NAME: YAQUI TOPMINNOW POECILIOPSIS OCCIDENTALIS SONORIENSIS 

STATUS: ENDANGERED CRITICA. HAS No RECOVERY PLAN: Yes CFR: 32 FR 4001. 03-11.1967 

DESCRIPTION: SMALL (2 INCHES) TOPMINNOW GUPPY-LKE, LIVE BEARING, LACKING 

DARK SPOTS. BREEDING MALES JET BLACK WITH YELLOW FINS. 

ELEVATION 

RANGE: <4500 FT. 

COUNTIES:COCHISE 

HABITAT: SMALL TO MODERATE SIZED STREAMS, SPRINGS, & CIENEGAS GENERALLY IN SHALLOWS 

NAME: AMERICAN PEREGRINE FALCON FALCO PEREGRINUSANATUM 

STATUS: ENDANGERED CRITICAL HAS No RECOVERY PLAN: Yes CFR: 35 FR 16047,10-13-70; 35 

DESCRIPTION: A RECLUSIVE, CROW-SIZED FALCON SLATY BLUE ABOVE WHITISH FR 8495, 06-02-70 

BELOW WITH FINE DARK BARRING. THE HEAD IS BLACK AND APPEARS 

TO BE MASKED OR HELMETED. WINGS LONG AND POINTED. LOUD ELEVATION 

WAIIJNG CALLS ARE GIVEN DURING BREEDING PERIOD. RANGE: 3500-9000 FT. 

COUNTIES: MOHAVE COCONINO NAVAJO APACHE SANTA CRUZ MARICOPA COCHISE YAVAPAI GILA PINAL PIMA 

GREENLEE GRAHAM YUMA 

HABITAT: CLIFFS AND STEEP TERRAIN USUALLY NEAR WATER OR WOODLANDS WITH ABUNDANT PREY 

THIS IS AWIDE-RANGING MIGRATORY BIRD THAT USES A VARIETY OF HABITATS. BREEDING BIRDS ARE YEAR

ROUND RESIDENTS. OTHER BIRDS WINTER AND MIGRATE THROUGH ARIZONA. SPECIES IS ENDANGERED FROM 

REPRODUCTIVE FAILURE FROM PESTICIDES. SPECIES HAS BEEN PROPOSED FOR DEUSTING (63 FR 45446) BUT 

STILL RECEIVES FULL PROTECTION UNDER ESA 

NAME: BALD EAGLE HALIAEETUS LEUCOCEPHALUS 

STATUS: THREATENED CRITICAL HAB No RECOVERY PLAN: Yes CFR: 60 FR 35999.07-12.95 

DESCRIPTION: LARGE. ADULTS HAVE WHITE HEAD AND TAIL HEIGHT 28- 3r. 

WINGSPAN 66- 6. 1-4 YRS DARK WITH VARYING DEGREES OF 

MOTTLED BROWN PLUMAGE. FEET BARE OF FEATHERS. ELEVATION 

RANGE: VARIES FT. 

COUNTIES:YUMA, LA PAZ, MOHAVE. YAVAPAI, MARICOPA, PINAL, COCONINO, NAVAJO. APACHE, SANTA CRUZ. PIMA. 

GILA. GRAHAM. COCHISE 

HABITAT: LARGE TREES OR CLIFFS NEAR WATER (RESERVOIRS. RIVERS AND STREAMS) WITH ABUNDANT PREY 

SOME BIRDS ARE NESTING RESIDENTS WHILE A LARGER NUMBER WINTERS ALONG RIVERS AND RESERVOIRS. 

AN ESTIMATED 200 TO 300 BIRDS WINTER IN ARIZONA. ONCE ENDANGERED (32 FR 4001, 03-11-1967:43 FR 6233,02

14-78) BECAUSE OF REPRODUCTIVE FAILURES FROM PESTICIDE POISONING AND LOSS OF HABITAT. THIS 

SPECIES WAS DOWN LISTED TO THREATENED ON AUGUST 11, 1995. ILLEGAL SHOOTING, DISTURBANCE, LOSS OF 

HABITAT CONTINUES TO BE A PROBLEM. 

5

B-I I NUREGICR-6648

B-1 1 NUR.EG/CR-6648
Appendix B Environmental Assessment for San Bernardino 

LISTED, PROPOSED, AND CANDIDATE SPECIES FOR THE FOLLOWING COUNTY: COCHISE 

03/251999 

NAME: CACTUS FERRUGINOUS PYGMY-OWL GLAUCIDIUM BRASILIANUM CACTORUM 

STATUS: ENDANGERED CRITICAL NAB Yes RECOVERY PLAN: No CFR: 62 FR 10730, 3-10-97 

DESCRIPTION: SMALL (APPROX. 7"). DIURNAL OWL REDDISH BROWN OVERALL WITH 

CREAM-COLORED BELLY STREAKED WITH REDDISH BROWN. SOME 

INDIVIDUALS ARE GRAYISH BROWN ELEVATION 

RANGE: <4000 FT. 

COUNTIES: MARICOPA, YUMA. SANTA CRUZ, GRAHAM, GREENLEE, PIMA, PINAL, GILA. COCHISE 

HABITAT: MATURE COTTONWOODNVILLOW, MESQUITE BOSQUES, AND SONORAN DESERTSCRUB 

RANGE LIMIT IN ARIZONA IS FROM NEW RIVER (NORTH) TO GILA BOX (EAST) TO CABEZA PRIETA MOUNTAINS 

(WEST). ONLY A FEW DOCUMENTED SITES WHERE THIS SPECIES PERSISTS ARE KNOWN, ADDITIONAL SURVEYS 

ARE NEEDED. LISTING EFFECTIVE APRIL 9. 1997. PROPOSED CRITICAL HABITAT IN PIMA, COCHISE, PINAL, AND 

MARICOPA COUNTIES (64 FR 71821). 

NAME: MEXICAN SPOTTED OWL STRIX OCCIDENTALIS LUCIDA 

STATUS: THREATENED CRITICAL HAB No RECOVERY PLAN: Yes CFR: 56 FR 14678, 04-11-91 

DESCRIPTION: MEDIUM SIZED WITH DARK EYES AND NO EAR TUFTS. BROWNISH AND 

HEAVILY SPOTTED WITH WHITE OR BEIGE. 

ELEVATION RANGE: 4100-9000 FT. 

COUNTIES: MOHAVE, COCONINO, NAVAJO, APACHE, YAVAPAI, GRAHAM, GREENLEE. COCHISE. SANTA CRUZ, PIMA, 

PINAL. GILA, MARICOPA 

HABITAT: NESTS IN CANYONS AND DENSE FORESTS WITH MULTI-LAYERED FOLIAGE STRUCTURE 

GENERALLY NESTS IN OLDER FORESTS OF MIXED CONIFER OR PONDERSA PINEJGAMBEL OAK TYPE. IN 

CANYONS, AND USE VARIETY OF HABITATS FOR FORAGING. SITES WITH COOL MICROCLIMATES APPEAR TO BE 

OF IMPORTANCE OR ARE PREFERED. 

NAME: NORTHERN APLOMADO FALCON FALCO FEMORALIS SEPTENTRIONAULS 

STATUS: ENDANGERED CRITICAL HAB No RECOVERY PLAN: Yes CFR: 51 FR 6686, 01-25486 

DESCRIPTION: RUFOUS UNDERPARTS, GRAY BACK. LONG BANDED TAIL, AND A 

DISTINCT BLACK AND WHITE FACIAL PATTERN. SMALLER THAN 

PEREGRINE LARGER THAN KESTREL. BREEDS BETWEEN MARCH- JUNE ELEVATION RANGE: 3500-9000 FT. 

COUNTIES: COCHISE, SANTA CRUZ 

HABITAT: GRASSLAND AND SAVANNAH 

SPECIES FORMERLY NESTED IN SOUTHWESTERN US. NOW OCCURS AS AN ACCIDENTAL. GOOD HABITAT HAS 

LOW GROUND COVER AND MESQUITE OR YUCCA FOR NESTING PLATFORMS. CONTINUED USE OF PESTICIDES IN 

MEXICO ENDANGERS THIS SPECIES. NO RECENT CONFIRMED REPORTS FOR ARIZONAL 

6

NUREGICR-6648 

B-I 2

NUREG/CR-6648 B-1 2
Environmental Assessment for San Bernardino Appendix B

LISTED, PROPOSED. AND CANDIDATE SPECIES FOR THE FOLLOWING COUNTY: 

0312511999

COCHISE

NAME: SOUTHWESTERN WILLOW FLYCATCHER EMPIDONAX TRAILL1! EXTIMUS 

STATUS: ENDANGERED CRITICAL HAB Yes RECOVERY PLAN: No CFR:60 FR 10694,02-27-95 

DESCRIPTION: SMALL PASSERINE (ABOUT 6") GRAYISH-GREEN BACK AND WINGS, WHITISH THROAT, LIGHT OLIVE-GRAY BREAST AND PALE YELLOWISH 

BELLY. TWO WINGBARS VISIBLE. EYE-RING FAINT OR ABSENT. ELEVATION 

RANGE: <8500 FT. 

COUNTIES: YAVAPAI, GILA, MARICOPA, MOHAVE, COCONINO. NAVAJO. APACHE, PINAL, LA PAZ. GREENLEE, GRAHAM, YUMA. PIMA. COCHISE. SANTA CRUZ 

HABITAT: COTTONWOODNWILLOW & TAMARISK VEGETATION COMMUNITIES ALONG RIVERS & STREAMS 

MIGRATORY RIPARIAN OBLIGATE SPECIES THAT OCCUPIES BREEDING HABITAT FROM LATE APRIL TO 

SEPTEMBER. DISTRIBUTION WITHIN ITS RANGE IS RESTRICTED TO RIPARLAN CORRIDORS. DIFFICULT TO DISTINGUISH FROM OTHER MEMBERS OF THE EMPIDONAX COMPLEX BY SIGHT ALONE. TRAINING SEMINAR 

REQUIRED FOR THOSE CONDUCTING FLYCATCHER SURVEYS. CRITICAL HABITAT ON PORTIONS OF THE 100-YEAR FLOODPLAIN ON SAN PEDRO AND VERDE RIVERS; WET BEAVER AND WEST CLEAR CREEKS, INCLUDING TAVASCI 

MARSH AND ISTER FLAT, THE COLORADO RIVER. THE LITILE COLORADO RIVER, AND THE WEST, EAST, AND 

SOUTH FORKS OFTHE LITTLE COLORADO RIVER. REFERENCE 60 CFR:62 FR 39129. 7/22/97. 

NAME: WHOOPING CRANE GRUS AMERICANA 

STATUS: ENDANGERED CRITICAL HAS Yes RECOVERY PLAN: Yes CFR: 32 FR 4001. 03-11-1967; 43 

DESCRIPTION: TALLESTAMERICAN BIRD (UP TO 5 FEET) SNOWY WHITE. LONG NECK FR 20938, 05-15-78 

AND LEGS, BLACK WING TIPS. RED CROWN. AND BLACK WEDGE 

SHAPED PATCH OF FETHERS BEHIND ITS EYE. ELEVATION 

RANGE: 4500 FT. 

COUNTIES: COCHISE 

HABITAT: MARSHES. PRAIRIES, RIVER BOTTOMS 

BIRDS IN THE ROCKY MOUNTAIN POPULATION ARE OCCASIONAL VISITORS IN ARIZONA DURING MIGRATION. 

USUALLY NEAR WILCOX PLAYA.

NAME: SONORA TIGER SALAMANDER AMBYSTOMA TIGRINUM STEBBINSI 

STATUS: ENDANGERED CRmCAL HAS No RECOVERY PLAN: No CF-R 62 FR 665. 01-06-97 

DESCRIPTION: 2-6 TO 4.9 SNOUT-VENT LENGTH WITH LIGHT-COLORED BANDS ON A 

DARK BACKGROUND. AQUATIC LARVAE ARE UNIFORM DARK COLOR 

WITH PLUME-LIKE GILLS AND TAIN FINS. ELEVATION 

RANGE: 4000-6300 FT. 

COUNTIES: SANTA CRUZ, COCHISE 

HABITAT: STOCK TANKS AND IMPOUNDED CIENEGAS IN SAN RAFAEL VALLEY. HUACHUCA MOUNTAINS 

ALSO OCCURS IN THE FOOTHILLS OF THE EAST SLOPE OF THE PATAGONIA AND HUACHUCA MOUNTAINS. 

POPULATIONS ALSO ON FORT HUACHUCA.

7

B-I 3 NUREGICR-6648 B-1 3 NUREG/CR-6648
Appendix B Environmental Assessment for San Bernardino

LISTED, PROPOSED, AND CANDIDATE SPECIES FOR THE FOLLOWING COUNTY: COCHISE 

0312511999 

2) PROPOSED TOTAL= 2 

NAME: BLUMERS DOCK (CHIRICAHUA] RUMEX ORTHONEURUS 

STATUS: PROPOSED CRITICAL HAB No RECOVERY PLAN: No CFR: 

DESCRIPTION: LARGE LONG-LIVED PERENNIAL PLANT IN THE BUCKWHEAT FAMILY 

THAT CAN REACH 1.2-2.0 METERS. LARGE BROAD, OVAL SEMI

SUCCULENT LEAVES ARE BRIGHT GREEN. CONSPICOUS SECONDARY ELEVATION 

VEINS AT RIGHT ANGLES TO THE MIDVEIN RANGE: 6500-9000 FT. 

COUNTIES:APACHE, COCHISE, GILA, GRAHAM. NAVAJO 

HABITAT: MID TO HIGH ELEVATION SPRINGS. STREAMS, & WETLANDS WITH MOIST ORGANIC SOILS OR SHADED 

CANYONS 

SPECIES FOUND IN CHIRICAHUA, PINALENO, HUACHUCA. SIERRA ANCHA. AND WHITE MOUNTAINS. SPECIES 

FOUND ON CORONADO, A-S, TONTO, SOME ON AND COCONINO. SPECIES ALSO FOUND IN WESTERN AND 

NORTHERN NEW MEXICO (GILA, SANTA FE, AND CARSON NF). 

NAME: MOUNTAIN PLOVER CHARADR/US MONTANUS 

STATUS: PROPOSED THREATENED CRITICAL HAB No RECOVERY PLAN: No CFR: 64 FR 7587; 02-16-1999 

DESCRIPTION: WADING BIRD; COMPACTLY BUILT: IN BREEDING SEASON WITH WHITE 

FOREHEAD AND LINE OVER THE EYE: CONTRASTING WITH DARK 

CROWN; NONDESCRIPT IN WINTER. VOICE IS LOW. VARIABLE WHISTLE. ELEVATION 

RANGE: VARIABLE FT. 

COUNTIES:YUMA, SANTA CRUZ, PIMA. COCHISE, PINAL. APACHE 

HABITAT: OPEN ARID PLAINS, SHORT-GRASS PRAIRIES, AND SCATTERED CACTUS. 

AZ PROVIDES WINTERING HABITAT ONLY. SPECIES PRIMARILY FOUND IN ROCKY MOUNTAIN STATES FROM 

CANADA TO MEXICO; SERVICE ACCEPTING COMMENTS ON PROPOSED RULE UNTIL APRIL 19, 1999; R6 HAS LEAD 

8

NIJREGICR-6648 

B-14

NUREG/CR-6648 B-14
Environmental Assessment for San Bernardino Appendix B

LISTED, PROPOSED, AND CANDIDATE SPECIES FOR THE FOLLOWING COUNTY: COCHISE 

0312511999 

3) CANDIDATE TOTAL= 4 

NAME: LEMMON FLEABANE ERIGERON LEMMONII 

STATUS: CANDIDATE CRmICAL HAB No RECOVERY PLAN: No CFR: 

DESCRIPTION: A PROSTRATE PERENNIAL IN THE SUNFLOWER FAMILY. STEMS AND 

LEAVES ARE DENSELY HAIRY. FLOWERS LOOK LIKE SMALL DELICATE 

DAISIES, WITH WHITE TO LIGHT PURPLE OUTER PETALS AND YELLOW ELEVATION 

INNER PETALS. RANGE: 1500.6000 FT. 

COUNTIES: COCHISE 

HABITAT: GROWS IN DENSE CLUMPS IN CREVICES, LEDGES. AND BOULDERS IN CANYON BOTTOMS IN PINE-OAK 

WOODLAND 

ONE SITE ON FORT HUACHUCA MILITARY RESERVATION 

NAME: GILA CHUB GILA INTERMEDIA 

STATUS: CANDIDATE CRITICAL HAB No RECOVERY PLAN: No CFR: 

DESCRIPTION: DEEP COMPRESSED BODY. FLAT HEAD. DARK OLIVE-GRAY COLOR 

ABOVE. SILVER SIDES. ENDEMIC TO GILA RIVER BASIN. 

ELEVATION 

RANGE: 2000- 3500 FT. 

COUNTIES: SANTA CRUZ. GILA, GREENLEE, PIMA, COCHISE. GRAHAM, YAVAPAI 

HABITAT: POOLS, SPRINGS. CIENEGAS, AND STREAMS 

MULTIPLE PRIVATE LANDOWERS. INCLUDING THE NATURE CONSERVANCY. THE AUDUBON SOCIETY, AND 

OTHERS. ALSO FT. HUACHUCA. SPECIES ALSO FOUND IN SONORA MEXICO. 

NAME: HUACHUCA SPRINGSNAIL PYRGULOPSIS THOMPSONI 

STATUS: CANDIDATE CRITICAL HAB No RECOVERY PLAN: No CFR: 

DESCRIPTION: VERY SMALL (1.7-3.2mm) CONICAL SHELL IDENTIFICATION MUST BE 

VERIFIED BY CHARARCTERISTICS OF REPRODUCTIVE ORGANS. 

ELEVATION 

RANGE: 4500-6000 FT. 

COUNTIES:COCHISE. SANTA CRUZ 

HABITAT: AQUATIC AREAS, SMALL SPRINGS WITH VEGETATION SLOW TO MODERATE FLOW. 

INDMDUALS FOUND ON FIRM SUBSTANCES (ROOTS. WOOD. AND ROCKS) OTHER POPULATIONS FOUND ON FORT 

HUACHUCA MILITARY PROPERTY 

9

B-15 NUREGICR-6648

B-15 NUREG/CR-6648
Appendix B Environmental Assessment for San Bernardino 

LISTED, PROPOSED, AND CANDIDATE SPECIES FOR THE FOLLOWING COUNTY: COCHISE 

0312511999 

NAME: CHIRICAHUA LEOPARD FROG RANA CHIRICAHUENSIS 

STATUS: CANDIDATE CRITICAL HAB No RECOVERY PLAN: No CFR: 

DESCRIPTION: CREAM COLORED TUBERCULES (spots)ON A DARK BACKGROUND ON 

THE REAR OF THE THIGH, DORSOLATERAL FOLDS THAT ARE 

INTERRUPTED AND DEFLECTED MEDIALLY, AND A CALL GIVEN OUT OF ELEVATION 

WATER DISTINGUISH THIS SPOTTED FROG FROM OTHER LEOPRD RANGE: 3000-8300 FT. 

COUNTIES:SANTA CRUZ, APACHE. GILA, PIMA, COCHISE, GREENLEE. GRAHAM, YAVAPAI, COCONINO. NAVAJO 

HABITAT: STREAMS, RIVERS, BACKWATERS. PONDS, AND STOCK TANKS THAT ARE FREE FROM INTRODUCED FISH 

AND BULLFROGS 

REQUIRE PERMANENT OR NEARLY PERMANENT WATER SOURCES. POPULATIONS NORTH OF THE GILA RIVER ARE 

THOUGHT TO BE CLOSELY-RELATED, BUT DISTINCT, UNDESCRIBED SPECIES. SPECIES ALSO FOUND ON FORT 

HUACHUCA 

10

NIJREGICR-6648 

8-16

NUREG/CR-6648 B-1 6
Environmental Assessment for San Bernardino Appendix B

LISTED. PROPOSED, AND CANDIDATE SPECIES FOR THE FOLLOWING COUNTY: COCHISE 

0312511999 

CONSERVATION AGREEMENT TOTAL= I 

NAME: RAMSEY CANYON LEOPARD FROG RAAIA SUBAQUAVOCALIS 

STATUS: NONE CRITICAL HAB No RECOVERY PLAN: No CFR: 

DESCRIPTION: BROWN OR GREEN FROG, 2.5 TO 4 INCHES LONG; SPOTS ROUNDED 

WITH LIGHT BORDERS; DORSOLATERAL FOLDS ARE INTERRUPTED 

POSTERIORLY AND DEFLECTED MEDIALLY; YELLOWISH PIGMENTATION ELEVATION 

ON THE GROIN WHICH MAY EXTEND INTO THE POSTERIOR VENTER RANGE: 5.000 FT FT. 

COUNTIES: COCHISE 

HABITAT: STTREAM AND PONDED AQUATIC HABITATS 

CONSERVATION AGREEMENT BETWEEN THE SERVICE. ARIZONA GAME AND FISH DEPARTMENT. THE NATURE 

CONSERVANCY. BUREAU OF LAND MANAGEMENT. CORONADO NATIONAL FOREST, THE US ARMY INTELLIGENCE 

CENTER AND FORT HUACHUCA, AND A PRIVATE LANDOWNER WAS FINALIZED JULY 1996 

11

B-I 7 NUREGICR-6648 B-17 NUREG/CR-6648
APPENDIX C 

SECTION 106 CONSULTATION LETTERS

c-I NUREGICR-6648

C-1 NUREG/CR-6648
OAK RIDGE NATIONAL LABORATORY MANAGED BY LOCKHEED MARTIN ENERGY RESEARCH CORPORATION PHONE: (423) 574-8632 FOR THE U.S. DEPARTMENT OF ENERGY FAX: (423) 578-8661 

POST OFFICE BOX 2W8 INTERNET: wmN*onl.gov 

OAK RIDGE. TN 37831-206 

June 15, 1999 

Ms. Jo Anne Miller 

State Historic Preservation Office 

Arizona State Parks 

1300 W. Washington 

Phoenix, Arizona 85007 

Dear Ms. Miller 

The Nuclear Regulatory Commission (NRC) has requested the assistance of Oak Ridge National 

Laboratory (ORNL) in preparing an Environmental Assessment that evaluates the potential impacts for 

safely terminating activities at a well near Douglas, Arizona. This activity is in accordance with the 

National Environmental Policy Act (NEPA) and the NRC's regulations implementing NEPA. 

The U.S. Geological Service (USGS) currently holds a license for the use of a radioactive Am-Be source composed of americium (

241

Am) and beryllium (Be) for well logging in the San Bernardino National 

Wildlife Refuge (SBNWR) in Arizona (see Figure 1). The Refuge is located in extreme southeastern 

Arizona and is managed by the U.S. Fish and Wildlife Service (FWS). The radioactive source has been 

lost at a depth of approximately 600 ft in an artesian water well adjacent to Twin Ponds within the 

SBNWR since 1986 (see Figure 2). The proposed action is to abandon the source in place subsequent 

to compliance with all NRC requirements for termination of the USGS license for the source. 

As part of the agency coordination and consultation responsibilities, in compliance with NEPA and 

Section 106 of the National Historic Preservation Act of 1966, as amended, federal agencies are required to consider the effects of their actions on historic properties. Based on the available information, 

the NRC has determined that no significant effect on historic properties will occur from the proposed well 

abandonment We appreciate your written concurrence and/or comments on our determination. Should 

you require additional information, please call me at (423) 574-8632 or Tim Ensminger at 

(423) 574-5657. Thank you for your anticipated assistance. 

Sincerely, 

Murray WadeRNL Staff Member 

MCW:mh 

Enclosures 

cc: B. Carrico, NRC 

J. T. Ensminger, ORNL 

L McCold, ORNL 

O rfi - 73

1rin yin c5cience Ia

C-3 NUREGICR-6648

Environmental Assessment for San Bernardino Appendix C

C-3 NUREG/CR-6648
Appendix C Environmental Assessment for San Bernardino

OAK RIDGE NATIONAL LABORATORY MANAGED BY LOCKHEED MARTIN ENERGY RESEARCH CORPORATION 

FOR THE U.S. DEPARTMENT OF ENERGY 

POST OFFICE BOX 2C06 

OAK RIDGE, TN 37831.-Oe 

June 15, 1999 

Ms. Jo Anne Miller 

State Historic Preservation Office 

Arizona State Parks 

1300 W. Washington 

Phoenix, Arizona 85007

PHONE: (423) 574-8832 FAX (423) 576-8861 

INTERNET: wnvom'.9gov 

JUN lo 

ARIZONA STATEPARKS BOARD 

7/ 77

Dear Ms. Miller: 

The ýuclear RegulatoCommission as requested the assistance of Oak Ridge National 

Laboratory (ORNL) in preparing an Environmental Assessment that evaluates the potential impacts for 

safely terminating activities at a well near Douglas, Arizona. This activity is in accordance with the 

National Environmental Policy Act (NEPA) and the NRC's regulations implementing NEPA. 

The U.S. Geological Service (USGS) currently holds a license for the use of a radioactive Am-Be source u 

composed of americium (4IAm) and beryllium (Be) for well logging in the San Bernardino National d, W-Je r 

Wildlife Refuge (SBNWR) in Arizona (see Figure 1). The Refuge is located in extreme southeastern 

Arizona and is managed by the U.S. Fish and Wildlife Service (FWS). The radioactive source has been w•/,. 

lost at a depth of approximately 600 ft in an artesian water well adjacent to Twin Ponds within the - hian C' 

SBNWR since 1986 (see Figure 2). The proposed action is to abandon the source in place subsequent 

to compliance with all NRC requirements for termination of the USGS license for the source. 

As part of the agency coordination and consultation responsibilities, in compliance with NEPA and 

Section 106 of the National Historic Preservation Act of 1966, as amended, federal agencies are 

required to consider the effects of their actions on historic properties. Based on the available information, 

the NRC has determined that no significant effect on historic properties will occur from the proposed well 

abandonment. We appreciate your written concurrence andlor comments on our determination. Should 

you require additional information, please call me at (423) 574-8632 or Tim Ensminger at 

(423) 574-5657. Thank you for your anticipated assistance. 

Sincerely,

Murray WadeWRINL Staff Member 

MCW:mh 

Enclosures 

cc: B. Carrico, NRC 

J. T. Ensminger, ORNL 

L. McCold, ORNL

0CUR 

ARIONA STATE PARS 80-W 

QP0Ar 'ý- J.ThH

0 i - i. io

NUREG/CR-6648 

0-4

Appendix C Environmental Assessment for San Bernardino

NUREGICR-6648 C-4
NRC FORM 336 U.s. NUCLEAR REGULATORY COMMISSION 1. REPORT NUMBER (2-89) (Assigned by NRC, Add Vol., Supp., Rev., NRCM 1102, 

2 BIBUOGRAPHIC SETand Addendum Numbers, If any.) DATA SHEET 

(See inshcbons on the reverse) NUREG/CR-6648 

2. TITLE AND SUBTITLE ORNIJTM-1999/1972 

Environmental Assessment 

3. DATE REPORT PUBLISHED 

San Bernardino National Wildlife Refuge Well 10 MONTH YEAR 

December 1999 

4. FIN OR GRANT NUMBER 

J5084 

5. AUTHOR(S) 6. TYPE OF REPORT 

J.T. Ensminger, C.E. Easterly, R.H. Ketelle, H. Quarles, M.C. Wade Environmental Assessment 

7. PERIOD COVERED (inclusive Dates) 

8. PERFORMING ORGANIZATION - NAME AND ADDRESS (If NRC, provide Division, O or Region, U.S. Nuclear Regulatory Commission and mailing address, if conbrac., 

provide neme and marling eddress.) 

Oak Ridge National Laboratory 

P.O. Box 2008 

Oak Ridge, TN 37831-6370

V. SPONuSRING UORANIZATION - NAME AND ADDRESS (If NRC, type "Same as above; if confractor, provide NRC Division, Office orRegion, U.S. Nucleer Regulatory Commission. and mailing address.)

Division of Industrial and Medical Nuclear Safety 

Office of Nuclear Material Safety and Safeguards 

U.S. Nuclear Regulatory Commission 

Washington, DC 20555-0001

In mi IODI LeskrrAav ,Jvre

11. ABSTRACT (210 woars oriess) 

The U.S. Geological Survey (USGS) currently holds a license issued by NRC for-a radioactive (Am-241-Be) well logging source that has been lost in an artesian well (#10) in the San Bernardino National Wildlife Refuge, Arizona, since 1986. The USGS has requested that the Am-Be source license be terminated and has attempted to seal the source in place with cement as required by NRC license termination regulations. This environmental assessment addresses the potential water quality, ecological, and human health impacts of three alternatives for final disposition of source: (1) the proposed action, abandonment in place; (2) source retrieval; and (3) the no-action aftemative. 

The proposed action would require additional sealing of the Am-Be source and emplacement of a permanent plaque at the well head. No impacts to water quality, aquatic biotia, or human-health would be expected. For the source retrieval alternative, the potential for an accidental release at or near the ground source is a negative factor for this altemative; and impacts to aquatic biota are possible for a worst-case scenario. Under the no-action alternative, no acute water quality, ecological, and human health effects would be expected. However, because the Am-Be source would not be sealed in the lower part of the well, continued 

monitoring would be necessary to ensure that unexpected contaminant concentrations do not occur.

12. KEY WORDS/DESCRIPTORS (List words or p1s that wil aessist resechrws inoasteng the rep.rt) 13. AVAILABILITY STATEMENT 

ecology unlimited environmental assessment 14. SECURITY CLASSIFICATION San Bernardino National Wildlife Refuge (Ti ',) well logging unclassified 

(This Report) 

unclassified 

15. NUMBER OF PAGES 

16. PRICE

This form was eleclonincally produced by Eite Federal Forms, Inc.

1

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NUREG/CR-6648 ENVIRONMENTAL ASSESSMENT: SAN BERNARDINO NATIONAL WILDLIFE REFUGE WELL 10 DECEMBER 1999

UNITED STATES 

NUCLEAR REGULATORY COMMISSION 

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