Sixth Five Year Review Report for Former Cimarron Mining Corporation Superfund Site Lincoln County New Mexico


SIXTH FIVE-YEAR REVIEW REPORT FOR
FORMER CIMARRON MINING CORPORATION SUPERFUND SITE
LINCOLN COUNTY, NEW MEXICO

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Prepared by

U.S. Environmental Protection Agency
Region 6
Dallas, Texas 75270

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SIXTH FIVE-YEAR REVIEW REPORT
FORMER CIMARRON MINING CORPORATION SUPERFUND SITE
CARRIZOZO, LINCOLN COUNTY, NEW MEXICO
EPA ID#: NMD980749378

This memorandum documents the U.S. Environmental Protection Agency's (EPA's) performance, determinations,
and approval of the former Cimarron Mining Corporation Superfund Site (Site) sixth Five-Year Review (FYR)
under Section 121(c) of the Comprehensive Environmental Response, Compensation, and Liability Act, 42 U.S.
Code Section 9621(c), as provided in the attached Sixth Five-Year Review Report.

Summary of the Sixth Five-Year Review Report

The Site was placed on the National Priorities List (NPL) of Superfund sites in 1989. The Site consisted of two
operable units (OUs). Operable Unit 1 (OU-1) addressed cyanide contamination in groundwater at the former
Cimarron Mining Corporation (Cimarron) mill site, a 10.6 acre milling facility used to recover iron and precious
metals from ores. Operable Unit 2 (OU-2) addressed lead contamination in soil, sediment, and waste rock at the
former Sierra Blanca mill site, a 7.5-acre site also used to recover a variety of metals from ore.

EPA issued a record of decision (ROD) for OU-1 in 1990, requiring extraction of shallow groundwater
contaminated with cyanide at concentrations above 0.2 milligrams per liter (mg/L) and discharge to the Town of
Carrizozo Publicly Owned Treatment Works (POTW). The EPA issued the OU-2 ROD in 1991 requiring the
solidification and stabilization of contaminated surface soil, sediment, and waste rock exceeding 500 milligrams
per kilogram (mg/kg) of lead and on-site disposal at the former Sierra Blanca mill site. Other components of the
OU-1 and OU-2 remedies included: 1) the plugging of an abandoned water supply well, 2) filling in of cinder
block trenches and a discharge pit, 3) the removal of chemical drums and the decontamination of tanks and
associated piping, and 4) institutional controls (ICs) to prevent future exposure to contaminated groundwater, as
well as to ensure the integrity of the remedy.

A partial NPL Site deletion was completed for OU-1 (surface soil only) on August 31, 2000 (65 FR 52947). The
OU-1 groundwater extraction system operated for nine years (1993-2001) before it was shut down due to
diminished extraction rates. Groundwater monitoring conducted at OU-1 in 2017, to support the fifth FYR,
showed total cyanide concentrations were below the remediation goal of 0.2 mg/L for cyanide in all samples.
Isoconcentration contour maps and time-series plots of cyanide concentrations from 2017 showed significant
decreases in cyanide concentrations both spatially and temporally. Five recovery wells used for groundwater
monitoring went dry and were properly plugged in 2014. A Final Closeout Report for OU-1 was signed by EPA
on June 23, 2020, and a full Final NPL Site Deletion for OU-1 (groundwater) was published in the Federal
Register on September 20, 2020 (83 FR 61610). On May 11, 2021, the plugging and abandonment of monitoring
wells MW-01 through MW-08, MW-10, MW-12, and RW-07, at OU-1, was completed. There are no hazardous
substances remaining at OU-1 above levels that allow for unlimited use/unrestricted exposure (UU/UE);
therefore, OU1 will not be included in this or future FYRs.

The OU-2 cleanup of soil, sediment, and waste rock included the consolidation/stabilization of approximately 900
cubic yards of such materials and their placement into two on-site repositories at the former Sierra Blanca mill
site. This work was completed in 1997. The repositories were capped with a low-permeability soil cover and
revegetated. Operable Unit 2 was fully deleted from the NPL on August 31, 2000 (65 FR 52947) and is currently
in post-closure inspection and monitoring.

The inspection of OU-2 for this sixth FYR was performed in January 2023. The two soil repositories at OU-2 are
in good condition and intact, with no evidence of surface erosion, digging, burrowing, or excavation. January
2023 groundwater monitoring, in the vicinity of the OU-2 repositories, showed no detections of dissolved metals
above federal or State of New Mexico (State) drinking water standards or State groundwater standards, except for
iron and manganese. Similar iron concentrations have occasionally been detected in these wells during prior
groundwater sampling events at OU-2. Background manganese concentrations in groundwater in the Carrizozo

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area are similar to Site manganese concentrations; therefore, it is uncertain whether the high concentrations are
sourced from the Site or reflect natural background water quality. Periodic groundwater monitoring (once every 4-
5 years) will continue at OU-2.

Environmental Indicators

Human Exposure Status: Current human exposure is controlled, and a protective remedy is in place.

Site-Wide Ready for Reuse: A Site-wide Ready for Anticipated Use (SWRAU) determination was made on
September 20, 2007. All remediation goals set forth in the RODs have been achieved for all media that may affect
current and reasonably anticipated future uses of the Site so that there are no unacceptable risks. All necessary ICs
specified in the RODs are in place and effective at protecting the remedy.

The protectiveness of the remedy is anticipated to not be affected by climate change.

Potential for environmental justice concern per national and/or state averages based on EPA's Environmental
Justice Screening and Mapping Tool (EJScreen) does exist. The EJScreen reports for OU-2 indicates that the
population within one mile of OU-2 meets or exceeds the 80th percentile when compared to state, EPA region, or
national averages for the following environmental indicators: lead, ozone, Superfund proximity, unemployment
rate and over age 64.

Actions Needed

There are no actions needed for the remedy to be protective.

Determination

I have determined that the remedy for the former Cimarron Mining Corporation Superfund Site is currently
protective.

Digitally signed by LISA

I I^A PRICFPRICE

LU'* r ni\_l_ Date: 2023.07.06 15:28:16
-05'00'

Lisa Price, Acting Director

Superfund and Emergency Management Division

U.S. Environmental Protection Agency Region 6

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ISSUES/RECOMMENDATIONS

SIXTH FIVE-YEAR REVIEW REPORT
FORMER CIMARRON MINING CORPORATION SUPERFUND SITE
CARRIZOZO, LINCOLN COUNTY, NEW MEXICO
EPA ID#: NMD980749378

Issues/Recommendations

Ol (s) without Issucs/kecomiiKMuhttioiis IdcntiTicd in (ho l ivc-Yc;ir Review:

OU-1: No Issues/Recommendations

OU-2: No Issues/Recommendations

4

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Table of Contents

LIST 01 ABBREVIATIONS & ACRONYMS	6

I.	INTRODUCTION	7

FIVE-YEAR REVIEW SUMMARY FORM	8

II.	RESPONSE ACTION SUMMARY	8

Basis for Taking Action	9

Response Actions	9

Status of Implementation	10

IC Summary Table	12

Systems Operations/Operation & Maintenance	12

III.	PROGRESS SINCE THE LAST REVIEW	13

IV.	FIVE-YEAR REVIEW PROCESS	14

Community Notification, Involvement & Site Interviews	14

Data Review	14

Site Inspection	14

V.	TECHNICAL ASSESSMENT	15

QUESTION A: Is the remedy functioning as intended by the decision documents?	15

QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action

objectives (RAOs) used at the time of the remedy selection still valid?	15

QUESTION C: Has any other information come to light that could call into question the
protectiveness of the remedy?	16

VI.	ISSUES/RECOMMENDATIONS	16

OTHER FINDINGS	16

VII.	PROTECTIVNESS STATEMENT	17

VIII.	NEXT RE VIEW	17

APPENDIX A - REFERENCE LIST

APPENDIX B - FIGURES AND TABLES

APPENDIX C - SITE CHRONOLOGY

APPENDIX D - INTERVIEW RECORDS

APPENDIX E - SITE INSPECTION CHECKLIST

APPENDIX F - SITE PHOTOGRAPHS

APPENDIX G - EJSCREEN REPORT (OU-2)

5

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LIST OF ABBREVIATIONS & ACRONYMS

ARAR

Applicable or Relevant and Appropriate Requirement

CERCLA

Comprehensive Environmental Response, Compensation, and Liability Act

CFR

Code of Federal Regulations

COC

Contaminant of Concern

EA

Endangerment Assessment

EPA

U.S. Environmental Protection Agency

ESD

Explanation of Significant Difference

FS

Feasibility Study

FR

Federal Register

FYR

Five-Year Review

gpm

gallons per minute

HRS

Hazard Ranking System

HQ

Hazard Quotient

ICs

Institutional Controls

MCL

Maximum Contaminant Level

NCP

National Oil and Hazardous Substances Pollution Contingency Plan

NM

New Mexico

NMED

New Mexico Environment Department

NMEID

New Mexico Environmental Improvement Division

NM OSE

New Mexico Office of the State Engineer

NMWQCC

New Mexico Water Quality Control Commission

NPDWR

National Primary Drinking Water Regulations

NPL

National Priorities List

mg/kg

milligrams per kilograms

mg/L

milligrams per Liter

O&M

Operation and Maintenance

OSWER

Office of Solid Waste and Emergency Response

OU

Operable Unit

POTW

Publicly Owned Treatment Works

ppm

parts per million

PRP

Potentially Responsible Party

RA

Remedial Action

RAO

Remedial Action Objective

RD

Remedial Design

RI

Remedial Investigation

ROD

Record of Decision

RPM

Remedial Project Manager

RSL

Regional Screening Level

SAP

Sampling and Analysis Plan

SDWA

Safe Drinking Water Act

SWRAU

Site-Wide Ready for Anticipated Use

TBC

To be considered

TR

Total risk

USACE

U.S. Army Corps of Engineers

USGS

U.S. Geological Survey

UU/EU

Unlimited Use/Unrestricted Exposure

6

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I. INTRODUCTION

The purpose of a Five-Year Review (FYR) is to evaluate the implementation and performance of a remedy to
determine if the remedy is and will continue to be protective of human health and the environment. The methods,
findings, and conclusions of reviews are documented in five-year review reports such as this one. In addition,
FYR reports identify issues found during the review, if any, and document recommendations to address them.

The U.S. Environmental Protection Agency (EPA) is preparing this FYR pursuant to the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA) Section 121, consistent with the National
Contingency Plan (NCP) (40 CFR Section 300.430(f)(4)(h)) and considering EPA policy.

This is the sixth FYR for the former Cimarron Mining Corporation Superfund Site (hereinafter the "Site"). The
triggering action for this statutory review is the signature date of the previous FYR. The FYR has been prepared
because hazardous substances, pollutants, or contaminants remain at the Site above levels that allow for unlimited
use and unrestricted exposure (UU/UE). The references used for the FYR are included in Appendix A.

The Site consisted of two operable units (OU)s. Operable Unit 1 (OU-1) addressed cyanide contamination
in groundwater at the former Cimarron Mining Corporation (Cimarron) mill site. Operable Unit 2 (OU-2)
addressed lead contamination in soil at the former Sierra Blanca mill site. The excavated soil from OU-2 was
stabilized and solidified with cement and placed in two repositories at the former Sierra Blanca mill site. Both Site
OUs have been deleted from the National Priorities List (NPL) of Superfund sites. A NPL Partial Site Deletion
was completed for OU-1 (surface soil only) and OU-2 on August 31, 2000. Full NPL Site Deletion for OU-1
(groundwater) was completed on September 20, 2020. Operable Unit 2 is currently in post-closure inspection and
monitoring.

The sixth FYR was led by Mr. Mark Purcell, the EPA Region 6 Remedial Project Manager (RPM), with support
from Mr. Anthony McGlown of the New Mexico Environment Department (NMED). Participants included
NMED project managers Mr. Bill Pearson and Mr. Joshua Faulconer, OU-1 property owner Mr. Tim Means, and
town of Carrizozo Clerk Ms. Leann Weihbrecht. The town of Carrizozo is the current property owner at OU-2.
The public was notified of the initiation of the sixth FYR by a public notice published in a local newspaper on
August 19, 2022.

Site Background

The Site is in the town of Carrizozo, Lincoln County, New Mexico, and is approximately 100 miles south-
southeast of Albuquerque (Figure 1, Appendix B). Operable Unit 1 encompassed approximately 10.6 acres and
was located on the north side of Highway 380. Operable Unit 2 encompassed 7.5 acres and was located east of
U.S. Highway 54.

The historic land use at both mill sites involved mineral and precious metal ore milling activities. The mill sites
operated from 1960 to July 1982, with some suspensions. Both sites are currently inactive. The land use at OU-1
is currently an auto repair shop and salvage yard. The owner of the auto repair shop and property has resided on
site since 2000. The once impacted shallow groundwater aquifer at OU-1 is currently not used for any purpose.
The groundwater flow direction at OU-1 is to the northwest. The OU-2 former Sierra Blanca mill site is fenced
with two-strand smooth wire. The former mill site is not being used for residential or commercial purposes.
Analytical results for groundwater samples collected at OU-2 indicate that groundwater has not been impacted by
former milling activities and the presence of contaminated-soil repositories onsite.

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FIVE-YEAR REVIEW SUMMARY FORM

SITE IDENTIFICATION

Site Name:

Former Cimarron Mining Corporation Superfund Site, Operable Units 1 and 2

EPA ID:

NMD980749378

| Region: 6

State: NM City/County: Cimarron/Lincoln County |

SITE STATUS

NPL Status: Final

Multiple OUs?

Yes

Has the site achieved construction completion?

Yes

Lead agency: EPA

[If "Other Federal Agency", enter Agency name]:

Author name (Federal or State Project Manager): Mark Purcell

Author affiliation: Remedial Project Manager, EPA Region 6

Review period: 8/19/2022 - 7/6/2023
Date of site inspection: 1/26/2023
Type of review: Statutory
Review number: 6
Triggering action date: 9/13/2018

Due date (fiveyears after triggering action date): 9/13/2023

II. RESPONSE ACTION SUMMARY

The Site was placed on the NPL on October 4, 1989, due to shallow groundwater contamination at the Cimarron
mill site. The primary contaminant of concern (COC) in groundwater was cyanide. Based on the findings of the
OU-1 remedial investigation (RI), the major sources of groundwater contamination were cinder block trenches
and a discharge pit where cyanide solution recycling and disposal operations were performed. The OU-1 risk
assessment identified ingestion of contaminated groundwater (as a drinking water source) to be a potential
exposure pathway. Other potential exposure pathways were incidental ingestion of soil and inhalation of fugitive
dust.

The potential for migration of shallow contaminated groundwater (at a depth of approximately 55 feet) to deeper
productive aquifers was a concern. EPA, in consultation with the New Mexico Environment Improvement
Division (NMEID), the predecessor to NMED, determined that remediation of shallow groundwater in the source
area was appropriate to control potential contaminant migration from the shallow groundwater to underlying
drinking water aquifers. The contamination in soil at OU-1, however, was at a concentration below health-based
screening levels and did not warrant remediation.

8

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Remedial investigation (RI) activities were conducted at OU-2 from May 1990 to June 1991. Surface soils, tank
sediments, and waste rock piles were found to be contaminated with metals (primarily lead) above health-based
screening levels. Based on the RI findings, EPA determined that approximately 570 cubic yards of surface soils,
tank sediments, and waste rock piles were contaminated. Historical analytical results for groundwater samples
collected from OU-2 monitoring wells indicated that groundwater at OU-2 was not impacted. A chronology of
site-related events is included in Appendix C.

Basis for Taking Action

OU-1, Basis for Taking Action

The Record of Decision (ROD) for OU-1 was signed on September 21, 1990. The ROD established that the
Remedial Action Objectives (RAOs) for OU-1 were to 1) remediate source area groundwater to control potential
impacts of migration from the contaminated shallow groundwater zone to potential underlying drinking water
aquifers and restore the groundwater to its potential future beneficial use, and 2) remove cyanide-contaminated
source area materials to prevent additional contamination of the shallow aquifer. The major sources of the cyanide
contamination at OU-1 were the cinder block trench sediment piles and, to a lesser degree, the unlined discharge
pit. Some cyanide contamination did occur below the tailings and waste rock piles, but the piles were not found to
be significant sources. Most of the groundwater contamination occurred during milling operations, when soils
were saturated with the cyanide solution and percolated downward to shallow groundwater.

OU-2, Basis for Taking Action

The ROD for OU-2 was signed on September 6, 1991. The ROD established that the RAOs for OU-2 were to 1)
reduce the mobility of lead in soil, sediment, and waste pile materials and its potential for contaminating
groundwater by stabilizing the soil, sediment, and waste pile materials exceeding 500 parts per million (ppm)
lead, and 2) removal of lead-contaminated source area materials to prevent additional migration of contamination
to site soils. Lead contamination in soil and waste pile material was found to represent the most significant threat
to human health at OU-2. Other heavy metals, including arsenic, were found at elevated concentrations; however,
they were not found to pose an unacceptable risk. Testing conducted during the RI on the waste pile material
showed the potential for lead contamination from the pile to migrate via leaching from the tank sediments and
several ore waste rock piles.

Response Actions

OU-1, Response Actions

EPA selected the remedy for OU-1 in the September 21, 1990, ROD. The selected remedy was to restore the
groundwater to its potential future beneficial use as a drinking water aquifer, and thus established 0.2 milligrams
per liter (mg/L) of cyanide as the remediation goal.

The major components of the selected remedy included pumping and extraction of shallow groundwater with
discharge to the town of Carrizozo POTW and groundwater monitoring.

In addition to the groundwater remedy, the selected remedy included the following:

• Removal of chemical drums and decontamination of tanks and associated piping;

• Filling-in of the cinder block trenches and a discharge pit;

• Plugging an abandoned water supply well; and

• Inspection and maintenance of the existing fence.

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The selected remedy specified a three-well concentric configuration for groundwater pumping. During the
Remedial Design (RD) process, NMED requested a revised recovery well configuration utilizing a seven-well
linear placement. This change was implemented through an Explanation of Significant Difference (ESD) to the
ROD, dated September 22, 1993.

OU-2, Response Actions

The ROD for OU-2 was signed by the EPA on September 6, 1991. The selected remedy addressed the
remediation of soil, sediment, and waste rock pile contamination at OU-2. The major components of the
selected remedy included the following:

•	Cement solidification/stabilization of contaminated soil, sediment, and waste rock exceeding 500
micrograms per kilogram (mg/kg) of lead for on-site disposal;

•	Installation of a low-permeability soil cover/cap for the repository areas; and

•	Groundwater monitoring, including the installation of two groundwater monitoring wells.

In addition to the remedy for the contaminated soil, sediment, and waste rock piles, the selected remedy
included the following:

•	Removal of chemical drums, and decontamination of tanks and associated piping;

•	Filling-in discharge pits and cinder block trench with on-site soils and covering with clean fill;
and

•	Inspection and maintenance of the existing fence.

Status of Implementation

OU-l, Groundwater Remedial Actions

Construction of the groundwater remedy was completed in January 1993. The groundwater extraction system
consisted of seven extraction/recovery wells located directly adjacent to the primary sources of groundwater
contamination, the former cinder block trenches. In addition, 13 monitoring wells were installed onsite and four
monitoring wells (one up-gradient and three down-gradient) were installed off site (Figure 2, Appendix B).

In April 1993, after initial pumping of groundwater during construction and three months of testing, the remedy
was determined to be operational and functional. The Site achieved construction completion status when the
Interim Close-out Report was completed in September 1993.

The groundwater extraction system operated for approximately nine years and was shut down in December 2001
for a performance assessment due to diminished extraction rates. During the operational period, the groundwater
extraction rates from the recovery wells declined from about 2.0 gallons per minute (gpm) during the early stages
of operation to about 0.5 gpm during late 1998 and continued to decline to approximately 0.2 gpm at the time of
shutdown in December 2001. The low water yields from recovery wells were due, at least in part, to low initial
water levels that further declined with pumping.

Several optimization activities were performed during system operations. They included the following:

•	Auto Dialer alert systems were improved in response to nuisance shutdowns;

•	Potential biofouling of extraction wells was investigated, and well re-development was performed;

•	Jack pumps were found to be worn and were replaced with flow-controlled submersible electric pumps;

•	Based on higher flow rates, the number of operating extraction wells was reduced from six to three (RW-
1, RW-5, and RW-7); and

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• Micro-purge sampling devices were installed in 12 monitoring wells to provide more representative
groundwater samples.

Although operational efficiencies were achieved, none of the optimization efforts resulted in improved overall
extraction rates or cyanide removal rates. During system operations, there were several periods of extended
downtime, which had the effect of re-saturating the portions of the aquifer that had been dewatered during
pumping. This type of "pulse pumping" improved the flushing of contaminants from the de-watered zones.
Overall, cyanide concentrations in groundwater had been reduced significantly by the time the groundwater
extraction ceased; however, two monitoring wells (MW-04 and MW-06) and three extraction wells (RW-02, RW-
03, and RW-06) continued to show cyanide concentrations above the remediation goal. A total cyanide mass of
approximately 1.8 pounds was removed and approximately 1.8 million gallons of extracted groundwater were
discharged to the Carrizozo POTW during the operational period of nine years (from September 1992 through
December 2001). In consultation with NMED, EPA determined that all appropriate response actions required at
OU-1 had been met, and a partial deletion of OU-1 (soils only) from the NPL was completed in August 2000.

In 2017, groundwater monitoring was conducted at OU-1 to support the fifth FYR. The analytical results showed
total cyanide concentrations were below the remediation goal of 0.2 mg/L for cyanide in all samples.
Isoconcentration contour maps and time-series plots of cyanide concentrations, from 2017, showed significant
decreases in cyanide concentrations both spatially and temporally. Five recovery wells used for groundwater
monitoring went dry and were properly plugged in 2014. A Final Closeout Report for OU-1 was signed by EPA
on June 23, 2020, and a full Final NPL Site Deletion for OU-1 (groundwater) was published in the Federal
Register on September 20, 2020 (83 FR 61610). On May 11, 2021, the plugging and abandonment of monitoring
wells MW-01 through MW-08, MW-10, MW-12, and RW-07 at OU-1 was completed.

OU-2, Surface Soil Remedial Actions

Site remediation at OU-2 was performed by the Department of Interior's Bureau of Reclamation under
interagency agreement #DW14412401 with EPA. The remedial activities were completed, and a preliminary
close-out report was signed on September 24, 1992.

A total of approximately 570 cubic yards of lead-contaminated soil, sediment, and waste rock pile materials were
consolidated into an on-site repository, and two monitoring wells were installed by September 1992. Based on
follow-up investigations by NMED, concentrations of lead exceeding 500 mg/kg were observed in surface soils at
two locations onsite. Consequently, in August 1997, an additional 332 cubic yards of contaminated soils were
excavated, stabilized with cement, and placed in a second on-site repository. Both repository areas were covered
with a low-permeability cap and re-vegetated. In consultation with NMED, EPA determined that all appropriate
response actions required at OU-2 had been met, and a full deletion of OU-2 from the NPL was completed in
August 2000.

Groundwater monitoring has been conducted at the Site since remedial actions were completed because onsite
repositories with hazardous waste were left in place and require continued monitoring to ensure protectiveness of
the remedy (Figure 2, Appendix B). Periodic groundwater monitoring (once every 4-5 years) will continue at OU-
2.

Institutional Controls

In addition to the initial remedies specified in the RODs, institutional controls (ICs) have been established. The
ICs are a "Prohibition Against Disturbance" for OU-1 and OU-2, and a "Restrictive Covenant" for OU-1, signed
by the respective property owners in 2006. These ICs were established by EPA and are included as attachments to
the access and remediation agreement between NMED and the property owner at OU-1, dated June 18, 2009. A
summary of the ICs is presented in Table 1, below.

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IC Summary Table

Table 1: Summary of Planned and/or Implemented Institutional Controls

Modiii. eniiineeivd



ICsCiillcd





Tide of IC

controls. ;iihI ;uv;is 1 hill do

ICs

lor in (lie

Impiiclcd

IC

Instrument

mil support I I /I 1. bused

Needed

Decision

I'iircolls)

OI>.jcc(i\c

Implemented iind

on curron 1 conditions



Documents





Dale (or planned)









No breach or











disturbance of the



Shallow groundwater
(less than 100 feet below

ground surface);
monitoring well network

Yes

No

OU-1

monitoring wells in
place
onsite; and no
drilling and installation
of any new wells onsite
to withdraw shallow
groundwater (i.e., less
than 100 feet below
ground surface), except

for the purpose of
remediation, as needed.

Prohibition

Against
Disturbance
signed on April
25, 2006, and
Restrictive
Covenant signed
on July 10, 2006









No breach or











disturbance of the











monitoring wells in











place



Two soil repository







onsite; and no

Prohibition

covers







excavation is to occur

Against

on top of

Yes

No

OU-2

within 10 feet of the

Disturbance

solidified/stabilized







soil repository areas, or

signed on April

repository waste cells







in any manner that
could potentially
breach or disturb the
solidified/stabilized
repository cells.

25, 2006

Systems Operations/Operation & Maintenance

Operation and maintenance (O&M) inspections and groundwater monitoring were conducted in accordance with
the O&M plans that were developed by NMED for OU-1 (2008) and OU-2 (2007). Currently, there are no
remedial systems operating onsite. Therefore, the O&M objectives consist of site inspections and groundwater
monitoring to 1) ensure that activities are not occurring that could mobilize any residual contaminants in the
vadose zone and impact groundwater, and 2) confirm that groundwater conditions remain below the Site cleanup
standards specified in the ROD.

During this FYR period, NMED conducted O&M inspections at OU-1 (May 2021) and OU-2 (May 2021 and
January 2023). During the inspections, NMED contacted the property owners and discussed any activities or
issues that may potentially impact the remedies at the Site. NMED officials conducted a "walk around" of the
properties to inspect monitoring wells, fencing, general housekeeping, and any evidence of activities or events
that would create the potential for water ponding and infiltration.

All monitoring wells at OU-1 were properly plugged and abandoned in May 2021. NMED is no longer
performing routine O&M inspections at OU-1 following the full deletion of OU-1 from the NPL in September
2020.

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During the O&M inspections at OU-2, NMED determined that the two monitoring wells and the inactive supply
wells were in good condition. The inspections at OU-2 indicated there has been no new construction debris or
dumping activity at the Site. NMED installed fencing and signage around the repository areas at OU-2 in May
2021. The two soil repository covers were in good condition and intact with no evidence of surface erosion,
digging, burrowing, or excavation. NMED collected groundwater samples from the monitoring wells for analysis
in January 2023.

III. PROGRESS SINCE THE LAST REVIEW

This section includes the protectiveness determinations and statements from the 2018 FYR as well as the
recommendations and the status of those recommendations from the 2018 FYR. The information is shown on
Table 2, below.

Table 2: Protectiveness Determinations/Statements from the 2018 Five-Year Review

(>l #

I'rotectiveness
Determination

Protectiveness Statement

Protective

The remedy at OU-1 is protective of human health and
the environment.

Exposure pathways to contaminated groundwater have

been controlled by the remedy. Institutional

controls prohibiting disturbance of existing monitoring

wells and restricting drilling and installation of

any new wells to withdraw shallow groundwater (i.e.,

less than 100 feet deep) onsite were established to ensure

that the remedy at OU-1 remains protective of human

health and the environment into the

future.

Protective

The remedy at OU-2 is protective of human health and
the environment.

Exposure pathways to contaminated soil have been
controlled by the remedy. Institutional controls
prohibiting disturbance of the two onsite soil repositories
are established to ensure that the remedy at
OU-2 remains protective of human health and the
environment into the future.

Sitewide

Protective

Remedial actions at both OUs are currently protective of
human health and the environment. There is
no known human exposure for the groundwater exposure
pathway at OU-1. In addition, there is no
known human exposure for the contaminated soil
exposure pathway at OU-2 and the established
institutional controls prohibit the disturbance of the
onsite soil repositories. Therefore, the Site-wide
remedy is protective.

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IV. FIVE-YEAR REVIEW PROCESS

Community Notification, Involvement & Site Interviews

A public notice was posted on August 19, 2022, in the Ruidoso News stating that EPA was conducting the sixth
FYR of the remedy, with the results of the review to be presented in a FYR report. The public notice also invited
the public to submit any comments to the EPA and stated the report would be made available at the following Site
information repository:

Carrizozo Community Public Library and Archive
406 Central Ave
Carrizozo, NM 88301

During the FYR process, interviews were conducted to document any perceived problems or successes to date
with the remedy that has been implemented. Interview records are included in Appendix D. The
results of these interviews are summarized below.

An interview was conducted on January 26, 2023, with Mr. Tim Means, the property owner and resident at OU-1.
Mr. Means indicated an overall positive impression of the Site's activities and progress and complimented EPA
and NMED on a job well done.

Ms. Leanne Weihbrecht, Town Clerk for the town of Carrizozo, was also interviewed following the FYR
inspection of OU-2 on January 26, 2023. Ms. Weihbrecht indicated that the Site has been well maintained by
NMED and that the overall impression of the project is good. Ms. Weihbrecht was not aware of any incidents or
problems at the Site and stated that she felt well informed about site activities.

Data Review

OU-2, Groundwater Monitoring

Groundwater samples were not collected from downgradient monitoring well MW-08 during the January 2023
sampling event, because the well has been dry since 2008. Groundwater samples from monitoring well MW-07
and inactive supply well 6AG showed no detections of dissolved metals above federal or State drinking water
standards or State groundwater standards, except for iron (4.2 mg/L in MW-07 to 4.4 mg/L in 6AG) and
manganese (0.50 mg/L in MW-07). Similar iron concentrations have occasionally been detected in these wells
during prior groundwater sampling events at OU-2. Background manganese concentrations in groundwater in the
Carrizozo area are similar to Site manganese concentrations; therefore, it is uncertain whether the detected
concentrations are sourced from the Site or reflect natural background water quality. Periodic groundwater
monitoring (once every 4-5 years) will continue at OU-2. The groundwater analytical results are presented in a
table in Appendix B.

Site Inspection

The inspection of the Site (OU-2) was conducted on 1/26/2023. In attendance were Mr. Anthony McGlown, Mr.
Bill Pearson and Mr. Joshua Faulconer of NMED. The purpose of the inspection was to assess the protectiveness
of the remedy at OU-2. A Site Inspection Checklist is included in Appendix E. Site photographs are included in
Appendix F.

The current owner of OU-2 is the town of Carrizozo which, along with Lincoln County, uses the property for the
disposal of construction/demolition refuse. As noted in the previous FYR, construction debris has been piled close
to the westernmost soil repository but does not cover it. Following a recommendation by the town of Carrizozo
during the previous FYR, NMED installed fencing and signage around the repository area in May 2021. During

-------
the inspection, the repository cover, fencing, and signage were observed to remain in place and in good condition.
The 6-inch diameter steel casing for well 6AG needs to be properly secured and locked to restrict access by
unauthorized personnel; however, this is the responsibility of the current property owner (i.e., town of Carrizozo).
The two monitoring wells located onsite were in good condition. Site access is through the adjacent town of
Carrizozo property and is controlled by a gate on the west side of the property.

V. TECHNICAL ASSESSMENT

QUESTION A: Is the remedy functioning as intended by the decision documents?

Question A Summary:

In consultation with NMED, EPA determined that all appropriate response actions required at OU-1 had been
met, and a partial deletion of OU-1 (soils only) from the NPL was completed in August 2000, with a full deletion
of OU-1 (groundwater) from the NPL in September 2020.

The data review completed at OU-2 indicates the completed remedy, which consisted of excavation, stabilization,
and on-site burial of the lead-contaminated soils, is functioning as intended. Cleanup criteria (i.e., To-Be-
Considered criteria [TBCs]) for soil contamination cited in the ROD were met when the remedy was completed.
Since hazardous waste is left onsite, site inspections and groundwater monitoring will continue to ensure the on-
going protection of human health and environment.

During the previous FYR, the location of the two capped repositories at OU-2 were found to be inadequately
marked on property owned by the town of Carrizozo. The existing corner rebar posts were only a few inches high
and had been covered by vegetation. To address this, five-foot long metal fence posts were staked at the corners
of the repositories by EPA and NMED during the inspection. NMED returned to install fencing and signage
around the repository areas in May 2021. The fencing and signage were observed to be in good condition during
the January 2023 FYR inspection.

The ICs established by EPA, along with fencing and signage installed by NMED in May 2021, have been
effective in prohibiting the disturbance of the OU-2 repositories. Based on the current FYR, there is no other
information that would question the protectiveness of the remedy at OU-2.

QUESTION B: Are the exposure assumptions, toxicity data, cleanup levels, and remedial action objectives
(RAOs) used at the time of the remedy selection still valid?

Question B Summary:

The exposure assumptions, toxicity data, cleanup levels, and RAOs used at the time of the remedy remain valid.
The federal and State drinking water standards and groundwater standards have not changed during this FYR
period. The TBC criteria identified for lead, the COC identified in the ROD for OU-2, have not changed during
this FYR period. A more stringent TBC criterion for lead in soil was established by both NMED and EPA, since
the RODs were issued. NMED established a 400 mg/kg lead criterion in a 2012 Risk Assessment Guidance for
Site Investigations and Remediation, updated in November 2022. EPA Region 6 established the same 400 mg/kg
lead criterion in the 2017 Human Health Medium-Specific Regional Screening Levels (RSLs) for residential soil.
Although the cleanup level for lead in surface soils and sediments was 500 mg/kg, confirmation soil sampling
results showed the maximum lead concentration at the Site to be 370 mg/kg in surface soils, which is below the
400 mg/kg TBC criterion for lead and supports the protectiveness of the completed remedy.

-------
Table 3: Surface Soils, Sediments, and Waste Rock Remediation To-Be-Considered Criteria for
OU-2

C (>(

Media

C lea 11 up Level

TIK's
(m»/k»)



Source

Lead

Surface Soils,

500

Previous

500-1000

Interim Guidance on

(Pb)

Sediments and
Waste Rock



(ROD)



Establishing Soil Cleanup
Levels at Superfund Sites
(OSWER Directive
#93355.4-02, EPA, 1989)







Recent

400

EPA Regional Screening
Level (RSL) Resident
Soil Table (TR=lE-06,
HQ=1)







Recent

400

NMED Risk Assessment
Guidance for Site
Investigations and
Remediation February 2012
(updated November 2022)

QUESTION C : Has any other information come to light that could call into question the protectiveness of the
remedy?

There have been no changes in physical conditions at the Site that would affect the protectiveness of the
remedy into the future. Following the FYR process, no additional information was identified that would
question the protectiveness of the remedies at either operable unit.

EPA is considering lowering the RSL for lead in residential soil. If EPA establishes a lower RSL for lead, it will
likely affect the protectiveness of the remedy and require additional response actions at the Site to ensure
protectiveness.

VI. ISSUES/RECOMMENDATIONS

Issues/Recommendations

()l (s) without Issues/Recommendations Identified in the l-'ive-Year Review:

OU-1 No Issues/Recommendations
OU-2 No Issues/Recommendations

OTHER FINDINGS

An evaluation of potential future impacts to the Site from climate change was performed as part of this FYR. The
protectiveness of the remedy is anticipated to not be affected by climate change.

16

-------
An evaluation of potential environmental justice1 (EJ) concerns for the Site was performed as part of this FYR.
The potential for EJ concerns per national and/or state averages, based on EPA's Environmental Justice Screening
and Mapping Tool (EJScreen) does exist. The EJScreen report for OU-2 indicates that the population within one
mile of OU-2 meets or exceeds the 80th percentile when compared to state, EPA region, or national averages for
the following environmental indicators: lead, ozone, Superfund proximity, unemployment rate and over age 64.
The EJScreen report is included in Appendix G.

VII. PROTECTIVNESS STATEMENT

Protectiveness Statement(s)

Operable Unit: Protectiveness Determination:

1 Protective

Protectiveness Statement: The remedy at OU-1 is protective of human health and the environment.

Protectiveness Statement(s)

Operable Unit: Protectiveness Determination:

2 Protective

Protectiveness Statement: The remedy at OU-2 is protective of human health and the environment.

Sitewide Protectiveness Statement

Protectiveness Determination:

Protective

Protectiveness Statement: Remedial actions at both OUs are protective of human health and the
environment.

VIII. NEXT REVIEW

The next five-year review report for the former Cimarron Mining Corporation Superfund Site is required five
years from the completion date of this review.

1 EPA defines Environmental Justice as the fair treatment and meaningful involvement of all people regardless of race, color,
national origin, or income, with respect to the development, implementation, and enforcement of environmental laws,
regulations, and policies.

-------
APPENDIX A - REFERENCE LIST

-------
Documents Reviewed

D. B. Stephens and Associates (DBS&A), 2008. "Supplemental Site Investigation and
Evaluation of Remedial Alternatives, Cimarron Mining Corporation Mill Site, Carrizozo, New
Mexico. " February 1, 2008.

EA Engineering, 2021. "Well Plugging and Abandonment Summary Report, Cimarron Mining
Company Superfund Site, Operable Unit 1, Carrizozo, New Mexico. " June 14, 2021.

New Mexico Environment Department (NMED), 2022. Table A-l, NMED Soil Screening
Levels, Risk Assessment Guidance for Site Investigations and Remediation. June 2022.

U. S. Army Corps of Engineers, 2003. "Performance Monitoring Report for Ground Water
Remediation, Cimarron Abandoned Mining Site, Carrizozo, New Mexico, " prepared by AYM
Environmental Services, Inc., Grants, New Mexico and Applied Hydrology Associates, Inc.,
March 3, 2003.

U.S. Bureau of Reclamation, 1991. "Field Operations Plan for Remediation of Operable Unit
1 of the Cimarron Mining Corporation Site, Carrizozo, New Mexico. " August 27, 1991.

U.S. Bureau of Reclamation, 1997. "Contaminated Soil Remediation Report, Sierra Blanca
Unit, Cimarron Mining Corporation Superfund Site, Carrizozo, New Mexico. " August 1997.

U.S. Environmental Protection Agency (EPA), Region 6, 1990. "EPA Superfund Record of
Decision, Cimarron Mining Corp., EPA ID: NMD980749378, OU 01, Carrizozo, NM. "
EPA/ROD/R06-90/060. September 12, 1990.

U.S. EPA, Region 6, 1991. "EPA Superfund Record of Decision, Cimarron Mining Corp., EPA
ID: NMD980749378, OU 02, Carrizozo, NM." EPA/ROD/R06-91/067. September 6, 1991.

U.S. EPA, Region 6, 2018. "Fifth Five-Year Review Report for the Cimarron Mining
Corporation Superfund Site Operable Unit 1 and 2, Carrizozo, Lincoln County, New Mexico. "
Document No. 691625. September 2018.

U.S. EPA, 2017. "EPA Regional Screening Level (RSL) Resident Soil Table (TR=lE-06,
HQ=1). November 2022.

U. S. Department of the Interior, U.S. Geological Survey, 2012. "Geochemistry of Water
Samples in the United States from the National Uranium Resource Evaluation -
Hydrogeochemical and Stream Sediment Reconnaissance (NURE-HSSR) Program Database. "
Sixty-six records were downloaded using a Geographic Information System (GIS) interface
with Google Earth, December 20, 2012.

-------
APPENDIX B - FIGURES AND TABLES

-------
Figure 1: Cimarron Mining Corporation Superfund Site Location Map

-------
Figure 2: Site Layout and Wells at Sierra Blanca Mill Site, 01-2

1997" Reposftory"

MW-8 (downgradient)

6|AG (inactive)

1992 Repository

J,	,.!>

MW-7 (upgradient)

2021 Fencing Installed bv NMED

TT

v

lm»ge © 2013 GeoEye
1^,2013 Goosle

Site Layout and Wells
Sierra Blanca Mill Site, OU-2

New Mexico Environment Department
Cimarron Mining Corporation Superfund Site
Carrizozo, Lincoln County, New Mexico

-------
Summary of Groundwater Sampling Results - January 2023

Well ID

Sample
Date

Depth to

Water
(ft-bTOC)

Sample
Intake
Depth
(ft-bTOC)

Purge
Volume

Field
PH

Temp
(°C)

Conductivity
(jjS/cm)

Total
Dissolved
Solids 1
(mg/L)

Fe
(mg/L)

Mn
(mg/L)

Pb (mg/L)

NM WQCC









6-9





1000

1.0a

0.2a

0.15

Sierra Blanca Mill Site (OU-2) Wells

MW-07
(OU2)

1/26/2023

XX.XX

Bail

1 gal

7.76

15.6

1238

829.46

4.2

0.50

0.007

6AG
(OU-2)

1/26/2023

63.74

Bail

5 gal

7.74

16.3

1327

889.09

4.4

0.19

<0.001

6AG-Dup
(OU-2)

1/26/2023

63.74

Bail

5 gal

7.74

16.3

1327

889.09

3.1

0.19

<0.001

Notes:

1 Total Dissolved Solids estimated by multiplying conductivity values by a factor of 0.67 fhttpV/www.stevenswater.com/water quality sensors/conductivity info.html)
a NMWQCC "Other Standards for Domestic Water Supply"

Dissolved metals were analyzed by EPA Method 200.8 using field-filtered samples (0.45|i filter).

NM WQCC = New Mexico Water Quality Control Commission

OU = Operable Unit

Fe = iron

Mn = manganese

Pb = lead

Ft-bTOC = feet below top of casing

mg/L = milligrams per liter

(.iS/cm = microSiemen per centimeter

ID = Identification

Dup = Duplicate sample

°C = degrees Centigrade

gal = gallon

XX.XX = no water encountered in well

Nine dissolved metals (arsenic-As, barium-Ba, beryllium-Be, cadmium-Cd, cobalt-Co, chromium-Cr, nickel-Ni, vanadium-V, and zinc-Zn) were analyzed and not detected or were detected at
concentrations below EPA MCLs and NMWQCC water quality standards (if applicable).

"<" denotes not detected at concentrations above the specified laboratory reporting limit.

-------
APPENDIX C - SITE CHRONOLOGY

-------
Chronology of Events for the Former Cimarron Mining Corporation Superfund Site

Date

Event

1960 - 1982

Iron and precious metal milling activities conducted at the Cimarron Mining
Corporation mill site (OU-1)

February 1980

NMEID performs field inspections of the Site

1982

Precious metal milling operations resumes at Sierra Blanca mill site (OU-2)

June 1982

NMEID identifies presence of cyanide and elevated metals in shallow
ground water

June 22, 1982

NMEID sends a notice of violation to Cimarron Mining Corporation for
discharge into unpermitted discharge pit.

April, May-June 1984

NMEID performs Site Inspections at Cimarron Mining Corporation mill site
and Sierra Blanca mill site

February 1985

NMEID issues Site inspection report

January to October,
1987

EPA performs Expanded Site Inspection (ESI) for HRS process at OU-1

March 1989

RI/FS begins at OU-1

October 4, 1989

EPA places Cimarron Mining Corporation Site (OU-1 and OU-2) on NPL

June 15, 1990

RI/FS completed at OU-1

July 1990

EPA issues Proposed Plan of Remedial Action for OU-1

September 21, 1990

EPA issues ROD for OU-1

June 1991

RI/FS completed at OU-2

June 1991

EPA issues Proposed Plan of Remedial Action for OU-2

September 6, 1991

EPA issues ROD for OU-2

December 1991

RD/RA is performed at OU-2

September 24, 1992

Remedial Action Completion and Preliminary Close-out Report for OU-2

September 22, 1993

EPA issues ESD for modifying recovery well configuration (from three
wells to seven wells) at OU-1

January 1993

Groundwater remedy construction completed at OU-1

April 1993

Groundwater remedy Operational and Functional Period complete at OU-1

September 1993

Interim Closeout Report and construction activities completion for OU-1
and OU-2

July 1996

Additional soil contaminated with lead identified at OU-2

August 1996 - July
1997

Additional lead-contaminated soil areas remediated

March - May 1998

General cleanup, disposal area capping and re-vegetation, and monitoring
well abandonment performed at OU-2

July 1998

EPA completes first Five-Year Review

August 31, 2001

Partial deletion of OU-2 (former Sierra Blanca mill site) is performed by
EPA

-------
Chronology of Events for the Former Cimarron Mining Corporation Superfund Site

Date

Event

December 18, 2001

Groundwater pumping is suspended, and Performance Assessment
Monitoring implemented at OU-1

August 2002

Performance Assessment Monitoring is completed at OU-1

March 2003

Performance Assessment Monitoring Report is issued for OU-1

July 2003

EPA completes second Five-Year Review

August 12, 2005

EPA issues Final Close-out Report for OU-1

September 2005

Site management responsibility transferred from EPA to NMED

April 26, 2006

Prohibition Against Disturbance - Institutional Control is established for
OUs 1 and 2

July 10, 2006

Restrictive Covenant - Institutional Control is established for OU-1

December 2007

Supplemental Site investigation and valuation of remedial alternatives
performed by NMED at OU-1

December 2007

Operation & Maintenance Plan prepared by NMED for OU-2

April 2008

Operation & Maintenance Plan prepared by NMED for OU-1

July 2008

EPA completes third Five-Year Review

June 2009

Regrading Activities at OU-1 performed by NMED

February 2011

Annual Monitoring Reports for 2008-2009 and 2010 prepared by NMED

September 2013

2011 Annual Monitoring Report prepared by NMED

September 2013

EPA completes fourth Five-Year Review

January 2014

2012 Annual Monitoring Report prepared by NMED

May 2014

Plugging and abandonment of recovery wells at OU-1 performed by NMED

June 2014

Drilling and soil sampling of the vadose zone at OU-1 performed by NMED

March 2015

2013-2014 Annual Monitoring Report prepared by NMED

June 2015

Plugging and abandonment of monitor wells at OU-1 performed by NMED

March 2016

2013-2015 Groundwater Monitoring Report prepared by NMED

September 2018

EPA completes fifth Five-Year Review

September 2020

Full deletion of OU-1 from the NPL is completed by EPA

May 2021

Remaining OU-1 monitoring wells are plugged and abandoned; NMED
installs fencing and signage around OU-2 repositories

January 2023

NMED conducts inspection and groundwater sampling at OU-2 for sixth
Five-Year Review

-------
APPENDIX D - INTERVIEW RECORDS

-------
INTERVIEW RECORD

Site Name: Cimarron Mining Corporation Superfund Site

EPA ID#: NMD980749378

Subject: Sixth Five-Year Review

Time:

12:00 pm

Date:
1/26/2023

Type: In-person interview
Location of Visit: On-site, OU-1

Contact Made By:

Name: Mr. Anthony McGlown

Title: Project Manager

Organization: NMED

Individual Contacted:

Name: Time Means

Title: Property
owner/resident

Organization:

Telephone No:
Fax No:

E-Mail Address:

Street Address: 6589 Hwy 380, Carrizozo,
NM

Summary Of Conversation

Question 1: What is your overall impression of the project? (general sentiment)

No complaints, good impression.

Question 2: What effects have the site operations had on the surrounding community?

None noted.

Question 3: Are you aware of any community concerns regarding the site or its operation and
administration? If so, please give details.

Has not heard anything.

-------
Five-Year Review Interview Form
Page 2

Question 4: Are you aware of any complaints, incidents or activities at the Site such as
vandalism, trespassing, or emergency response from local authorities? If so, please provide
details.

Not aware of any complaints, incidents or other such activities.

Question 5: Do you feel well informed about the Site's activities and progress?

Yes, NMED has kept him informed.

Question 6: Do you have any comments, questions, or recommendations regarding the Site's
management or operation?

Mr. Means complimented the regulatory agencies on a job well done.

-------
INTERVIEW RECORD

Site Name: Cimarron Mining Corporation Superfund Site

EPA ID#: NMD980749378

Subject: Sixth Five-Year Review

Time:

2:30 pm

Date:
1/26/2023

Type: In-person interview
Location of Visit: City Hall

Contact Made By:

Name: Mr. Anthony McGlown

Title: Project Manager

Organization: NMED

Individual Contacted:

Name: Leann Weihbrecht

Title: Town
Clerk/Treasurer

Organization: Town of
Carrizozo

Telephone No: 575-648-2371
Fax No:

E-Mail Address:

Street Address: 400 9th St, Carrizozo, NM

Summary Of Conversation

Question 1: What is your overall impression of the project? (general sentiment)

The site has been kept up on the New Mexico Environment Department's end. Overall good
impression.

Question 2: What effects have the site operations had on the surrounding community?

None.

Question 3: Are you aware of any community concerns regarding the site or its operation and
administration? If so, please give details.

None.

-------
Five-Year Review Interview Form
Page 2

Question 4: Are you aware of any complaints, incidents or activities at the Site such as
vandalism, trespassing, or emergency response from local authorities? If so, please provide
details.

Not aware of any complaints, incidents or other such activities.

Question 5: Do you feel well informed about the Site's activities and progress?

Yes.

Question 6: Do you have any comments, questions, or recommendations regarding the Site's
management or operation?

No questions, comments, or recommendations.

-------
APPENDIX E - SITE INSPECTION CHECKLIST

-------
OSWER No. 9355.7-03B-P

Five-Year Review Site Inspection Checklist (Template)

(Working document for site inspection. Information may be completed by hand and attached to
the Five-Year Review report as supporting documentation of site status. "N/A" refers to "not
applicable.")

I. SITE INFORMATION

Site name: Cimarron Mining Corporation
Superfund Site, Operable Unit (OU) - 2

Date of inspection: January 26, 2023

Location and Region: Carrizozo, NM, Region 6

EPA ID: NMD980749378

Agency, office, or company leading the five-year
review: New Mexico Environment Department

Weather/temperature: Mostly clear, 40-45°F

Remedy Includes: (Check all that apply)

~	Landfill cover/containment
X Access controls

X Institutional controls

~	Groundwater pump and treatment

~	Surface water collection and treatment

~	Monitored natural attenuation

~	Groundwater containment

~	Vertical barrier walls

X Other	Two lead-contaminated soil repositories with soil/vegetation cover_

Attachments: ~ Inspection team roster attached

~ Site map attached

II. INTERVIEWS (Check all that apply)

1. O&M site manager	Anthony McGlown	

Name

Interviewed x at site ~ at office ~ by phone Phone no.
Problems, suggestions; ~ Report attached	

	Project Manager_

Title

_l/26/2023_
Date

2 O&M staff

Name	Title

Interviewed ~ at site ~ at office ~ by phone Phone no. 	

Problems, suggestions; ~ Report attached	

Date

D-l

-------
OSWER No. 9355.7-03B-P

Local regulatory authorities and response agencies (i.e., State and Tribal offices, emergency response
office, police department, office of public health or environmental health, zoning office, recorder of
deeds, or other city and county offices, etc.) Fill in all that apply.

Agency: Town of Carrizozo
Contact: Leanne Weihbrecht

Name

Problems; suggestions; x Report attached

Town Clerk
Title

1/26/2023

575-648-2371

Date

Phone no.

Agency	

Contact	

Name

Problems; suggestions; ~ Report attached

Title

Date Phone no.

Agency	

Contact	

Name

Problems; suggestions; ~ Report attached

Title

Date Phone no.

Agency	

Contact	

Name

Problems; suggestions; ~ Report attached

Title

Date Phone no.

Other interviews (optional) ~ Report attached.

D-2

-------
OSWER No. 9355.7-03B-P

in. ON-SITE DOCUMENTS & RECORDS VERIFIED (Check all that apply)

1.

O&M Documents

O&M manual x Readily available ~ Up to date ~ N/A
As-built drawings ~ Readily available ~ Up to date x N/A
Maintenance logs ~ Readily available ~ Up to date x N/A
Remarks An O&M Plan for OU-2 was developed bv NMED in December 2007 and was most recently



updated in October 2019. O&M activities during this FYR period included a site inspection and



groundwater monitoring event in January 2023.





2.

Site-Specific Health and Safety Plan x Readily available x Up to date ~ N/A
Contingency plan/emergency response plan ~ Readily available ~ Up to date x N/A
Remarks Site-Specific Health and Safety Plan (SSHASP) has been developed bv NMED for ground



water monitoring activities. Emergency contacts are included in the SSHASP











3.

O&M and OSHA Training Records x Readily available
Remarks NMED maintains OSHA training records for all staff.

~ Up to date

~ N/A

4.

Permits and Service Agreements

Air discharge permit ~ Readily available
Effluent discharge ~ Readily available
Waste disposal, POTW ~ Readily available
Other permits ~ Readily available
Remarks

~	Up to date

~	Up to date

~	Up to date

~	Up to date

xN/A
xN/A
xN/A
xN/A

5.

Gas Generation Records ~ Readily available ~ Up to date x N/A
Remarks











6.

Settlement Monument Records ~ Readily available
Remarks

~ Up to date

xN/A









7.

Groundwater Monitoring Records x Readily available ~ Up to date ~ N/A
Remarks Groundwater monitoring records are maintained bv NMED. Sampling results from this FYR



period will be included in the FYR Report.





8.

Leachate Extraction Records ~ Readily available
Remarks

~ Up to date

xN/A









9.

Discharge Compliance Records

Air ~ Readily available
Water (effluent) ~ Readily available
Remarks

~	Up to date

~	Up to date

xN/A
xN/A

10.

Daily Access/Security Logs ~ Readily available
Remarks

~ Up to date

xN/A

















D-3

-------
OSWER No. 9355.7-03B-P

IV. O&M COSTS

O&M Organization

x State in-house

~ PRP in-house

~ Federal Facility in-house

~ Other

~ Contractor for State

~ Contractor for PRP

~ Contractor for Federal Facility

O&M Cost Records

x Readily available x Up to date
x Funding mechanism/agreement in place
Original O&M cost estimate

Total annual cost by year for review period if available

From September 2018

September 2019

$2,500

Annual NMED labor

Date

Total cost

From September 2019

September 2020

$2,500

Annual NMED labor

Date

Total cost

From September 2020

September 2021

_$20,000

OU-1 MW P&A, OU-2 fencing

Date

Total cost

and signage, NMED labor

From September 2021

September 2022

$2,500

Annual NMED labor

Date

Total cost

From September 2022

September 2023

$2,500

Annual NMED labor

Date

Total cost

Unanticipated or Unusually High O&M Costs During Review Period

Describe costs and reasons:

V. ACCESS AND INSTITUTIONAL CONTROLS ~ Applicable DN/A

A. Fencing

1. Fencing damaged ~ Location shown on site map x Gates secured DN/A

Remarks: Fencing and gates are intact. Site is located on Town of Carrizozo property. Access is
controlled through a locked gate on the west side of the property.

B. Other Access Restrictions

Signs and other security measures x Location shown on site map ~ N/A

Remarks: NMED installed fencing and signage around OU-2 repository area in May 2021.

D-4

-------
OSWER No. 9355.7-03B-P

C. Institutional Controls (ICs)

1.	Implementation and enforcement

Site conditions imply ICs not properly implemented	~ Yes x No ~ N/A

Site conditions imply ICs not being fully enforced	DYes x No DN/A

Type of monitoring (e.g., self-reporting, drive by)	Site inspections	

Frequency 	Annual	

Responsible party/agency NMED	

Contact	Anthony McGlown		Project Manager	_l/26/2023_ 505-660-8121

Name

Title



Date



Phone no.

Reporting is up-to-date



~

Yes

~ No

xN/A

Reports are verified by the lead agency

~

Yes

~ No

xN/A

Specific requirements in deed or

decision documents have been met

~

Yes

~ No

xN/A

Violations have been reported



~

Yes

~ No

xN/A

Other problems or suggestions:

~ Report attached









2.	Adequacy	x ICs are adequate	~ ICs are inadequate	[UN/A

Remarks: On April 25. 2006. a "Prohibition Against Disturbance" was signed bv the Mavor of
Carrizozo and registered with the Lincoln County Clerk requiring that no excavation is to occur in the
soil repository areas or in any manner that could potentially breach or disturb the repository cells.

D. General

1.	Vandalism/trespassing ~ Location shown on site map x No vandalism evident

Remarks

2.	Land use changes on site x N/A

Remarks

3.	Land use changes off site x N/A

Remarks

VI. GENERAL SITE CONDITIONS
A. Roads	~ Applicable x N/A

1.	Roads damaged	~ Location shown on site map ~ Roads adequate	x N/A

Remarks

D-5

-------
OSWER No. 9355.7-03B-P

B.

Other Site Conditions





Remarks: Debris piles that contain mostly demolition refuse remain onsite. The debris piles are located



close to the westernmost repository, but the cover remains intact.



























VII.

LANDFILL COVERS x Applicable ~ N/A

A.

Landfill Surface



1.

Settlement (Low spots)
Areal extent
Remarks

~ Location shown on site map x Settlement not evident
Depth







2.

Cracks

Lengths

~ Location shown on site map x Cracking not evident
Widths Depths



Remarks









3.

Erosion

Areal extent
Remarks

~ Location shown on site map x Erosion not evident
Depth







4.

Holes

Areal extent
Remarks

~ Location shown on site map x Holes not evident
Depth







5.

Vegetative Cover ~ Grass x Cover properly established IHNo signs of stress
~ Trees/Shrubs (indicate size and locations on a diagram)

Remarks: Grass and shrub vegetation on soil covers has made the repository boundaries not noticeably



different from the surrounding area onsite.

6.

Alternative Cover (armored rock, concrete, etc.) x N/A

Remarks







7.

Bulges

Areal extent
Remarks

~ Location shown on site map x Bulges not evident
Height













D-6

-------
OSWER No. 9355.7-03B-P

Wet Areas/Water Damage

xWet areas/water damage not evident

~ Wet areas

~ Location shown on site map Areal extent

~ Ponding

~ Location shown on site map Areal extent

~ Seeps

~ Location shown on site map Areal extent

~ Soft subgrade

~ Location shown on site map Areal extent

Remarks

Slope Instability ~ Slides

~ Location shown on site map x No evidence of slope instability

Areal extent

Remarks

Benches ~ Applicable

xN/A

(Horizontally constructed mounds of earth placed across a steep landfill side slope to interrupt the slope

in order to slow down the velocity of surface runoff and intercept and convey the runoff to a lined

channel.)

Flows Bypass Bench

~ Location shown on site map x N/A or okay

Remarks

Bench Breached

~ Location shown on site map x N/A or okay

Remarks

Bench Overtopped

~ Location shown on site map x N/A or okay

Remarks

Letdown Channels ~ Applicable

xN/A

(Channel lined with erosion control mats, riprap, grout bags, or gabions that descend down the steep side

slope of the cover and will allow the runoff water collected by the benches to move off of the landfill

cover without creating erosion gullies.)

Settlement ~ Location shown on site map x No evidence of settlement

Areal extent

Depth

Remarks

Material Degradation ~ Location shown on site map x No evidence of degradation

Material type

Areal extent

Remarks

Erosion ~ Location shown on site map x No evidence of erosion

Areal extent

Depth

Remarks

D-7

-------
OSWER No. 9355.7-03B-P

4.

Undercutting ~ Location shown on site map x No evidence of undercutting



Areal extent Depth





Remarks









5.

Obstructions Type

x No obstructions



~ Location shown on site map

Areal extent



Size





Remarks









6.

Excessive Vegetative Growth

x No evidence of excessive growth

Type



~ Vegetation in channels does not obstruct flow



~ Location shown on site map

Areal extent



Remarks









D.

Cover Penetrations ~ Applicable x N/A



1.

Gas Vents ~ ActiveX Passive



~ Properly secured/locked ~ Functioning

~ Routinely sampled ~ Good condition



~ Evidence of leakage at penetration

~ Needs Maintenance



xN/A





Remarks









2.

Gas Monitoring Probes





~ Properly secured/locked ~ Functioning

~ Routinely sampled ~ Good condition



~ Evidence of leakage at penetration

~ Needs Maintenance x N/A



Remarks









3.

Monitoring Wells (within surface area of landfill)



~ Properly secured/locked ~Functioning

~ Routinely sampled ~ Good condition



~ Evidence of leakage at penetration

~ Needs Maintenance x N/A



Remarks









4.

Leachate Extraction Wells





~ Properly secured/locked ~Functioning

~ Routinely sampled ~ Good condition



~ Evidence of leakage at penetration

~ Needs Maintenance x N/A



Remarks









5.

Settlement Monuments ~ Located ~ Routinely surveyed x N/A



Remarks









D-8

-------
OSWER No. 9355.7-03B-P

E.

Gas Collection and Treatment ~ Applicable x N/A

1.

Gas Treatment Facilities

~	Flaring ~ Thermal destruction ~ Collection for reuse

~	Good condition^ Needs Maintenance
Remarks

2.

Gas Collection Wells, Manifolds and Piping

~ Good condition^ Needs Maintenance
Remarks

3.

Gas Monitoring Facilities (e.g., gas monitoring of adjacent homes or buildings)

~ Good condition^ Needs Maintenance x N/A

Remarks

F.

Cover Drainage Layer ~ Applicable x N/A

1.

Outlet Pipes Inspected ~Functioning DN/A
Remarks

2.

Outlet Rock Inspected ~Functioning ~ N/A
Remarks

G.

Detention/Sedimentation Ponds ~ Applicable x N/A

1.

Siltation Areal extent Depth QN/A

~ Siltation not evident

Remarks

2.

Erosion Areal extent Depth
~ Erosion not evident
Remarks

3.

Outlet Works ~Functioning ON/A
Remarks

4.

Dam ~Functioning DN/A
Remarks

D-9

-------
OSWER No. 9355.7-03B-P

H. Retaining Walls ~ Applicable x N/A

1. Deformations ~ Location shown on site map

~ Deformation not evident

Horizontal displacement Vertical displacement

Rotational displacement



Remarks





2. Degradation ~ Location shown on site map

~ Degradation not evident

Remarks





I. Perimeter Ditches/Off-Site Discharge ~ Applicable

xN/A

1. Siltation ~ Location shown on site map ~ Siltation not evident

Areal extent Depth



Remarks





2. Vegetative Growth ~ Location shown on site map

~ N/A

~ Vegetation does not impede flow



Areal extent Type



Remarks





3. Erosion ~ Location shown on site map

~ Erosion not evident

Areal extent Depth



Remarks





4. Discharge Structure ~ Functioning DN/A



Remarks





VIH. VERTICAL BARRIER WALLS

~ Applicable x N/A

1. Settlement ~ Location shown on site map

~ Settlement not evident

Areal extent Depth



Remarks





2. Performance Monitoring Type of monitoring



~ Performance not monitored



Frequency ~ Evidence of breaching

Head differential



Remarks





D-10

-------
OSWER No. 9355.7-03B-P

IX. GROUNDWATER/SURFACE WATER REMEDIES ~ Applicable x N/A
A. Groundwater Extraction Wells, Pumps, and Pipelines	~ Applicable ~ N/A

1.	Pumps, Wellhead Plumbing, and Electrical

~ Good condition^ All required wells properly operating ~ Needs Maintenance ~ N/A
Remarks

2.	Extraction System Pipelines, Valves, Valve Boxes, and Other Appurtenances

~ Good condition^ Needs Maintenance
Remarks

3. Spare Parts and Equipment

~ Readily available	~ Good condition^ Requires upgrade	~ Needs to be provided

Remarks

B. Surface Water Collection Structures, Pumps, and Pipelines ~ Applicable x N/A

1.	Collection Structures, Pumps, and Electrical

~ Good condition^ Needs Maintenance
Remarks

2.	Surface Water Collection System Pipelines, Valves, Valve Boxes, and Other Appurtenances

~ Good condition^ Needs Maintenance
Remarks

3. Spare Parts and Equipment

~ Readily available	~ Good condition^ Requires upgrade	~ Needs to be provided

Remarks

D-ll

-------
OSWER No. 9355.7-03B-P

C. Treatment System	~ Applicable x N/A

1.	Treatment Train (Check components that apply)

~	Metals removal	~ Oil/water separation ~ Bioremediation

~	Air stripping	~ Carbon adsorbers

~	Filters	

~	Additive (e.g., chelation agent, flocculent)	

~	Others	

~	Good condition	~ Needs Maintenance

~	Sampling ports properly marked and functional

~	Sampling/maintenance log displayed and up to date

~	Equipment properly identified

~	Quantity of groundwater treated annually	

~	Quantity of surface water treated annually	

Remarks

2.	Electrical Enclosures and Panels (properly rated and functional)

~ N/A	~ Good condition^ Needs Maintenance

Remarks

3. Tanks, Vaults, Storage Vessels

~ N/A	~ Good condition^ Proper secondary containment ~ Needs Maintenance

Remarks

4.	Discharge Structure and Appurtenances

~ N/A	~ Good condition^ Needs Maintenance

Remarks

5. Treatment Building(s)

~	N/A	~ Good condition (esp. roof and doorways)	~ Needs repair

~	Chemicals and equipment properly stored
Remarks

6.	Monitoring Wells (pump and treatment remedy)

~	Properly secured/locked ~ Functioning ~ Routinely sampled ~ Good condition

~	All required wells located	~ Needs Maintenance	~ N/A
Remarks

D. Monitoring Data

1.	Monitoring Data

x Is routinely submitted on time	x Is of acceptable quality

2.	Monitoring data suggests:

~ Groundwater plume is effectively contained ~ Contaminant concentrations are declining

D-12

-------
OSWER No. 9355.7-03B-P

D. Monitored Natural Attenuation

1. Monitoring Wells (natural attenuation remedy)

x Properly secured/locked ~Functioning x Routinely sampled x Good condition

x All required wells located ~ Needs Maintenance ~ N/A

Remarks: Monitoring well (MW-8) located northward and down-gradient of the soil repository areas
had already gone dry as of 2008.

X. OTHER REMEDIES

If there are remedies applied at the site which are not covered above, attach an inspection sheet describing
the physical nature and condition of any facility associated with the remedy. An example would be soil
vapor extraction.

XI. OVERALL OBSERVATIONS

A. Implementation of the Remedy

Describe issues and observations relating to whether the remedy is effective and functioning as designed.
Begin with a brief statement of what the remedy is to accomplish (i.e., to contain contaminant plume,
minimize infiltration and gas emission, etc.).

Remedial activities at OU-2 included excavation, stabilization, and onsite disposal of surface
soils, sediments, and waste rock. The disposal areas were capped with clean fill and vegetated.
On April 25. 2006. a "Prohibition Against Disturbance" was signed by the Mayor of Carrizozo
and registered with the Lincoln County Clerk requiring that no excavation is to occur in the soil
repository areas or in any manner that could potentially breach or disturb the repository cells.
However, this IC does not preclude the construction of facilities or improvements above the
repositories, as long as the repositories themselves are not disturbed.

B. Adequacy of O&M

Describe issues and observations related to the implementation and scope of O&M procedures. In
particular, discuss their relationship to the current and long-term protectiveness of the remedy.
Although the nearest downgradient monitoring well (MW-8) has gone dry, inactive
agricultural/ irrigation well (6AG) serves to identify contamination to the shallow aquifer,
where the nearest resident/private well is located approximately 350 feet southeast of the soil
repositories. Based on future water level measurements, if there is sufficient ground water
recharge to the shallow aquifer system and monitoring well (MW-8) is not dry, it will be
sampled during future inspections to determine whether any contaminant release from the
repositories to ground water has occurred.

D-13

-------
OSWER No. 9355.7-03B-P

Early Indicators of Potential Remedy Problems

Describe issues and observations such as unexpected changes in the cost or scope of O&M or a high
frequency of unscheduled repairs, that suggest that the protectiveness of the remedy may be
compromised in the future.

D. Opportunities for Optimization

Describe possible opportunities for optimization in monitoring tasks or the operation of the remedy.

D-14

-------
APPENDIX F - SITE PHOTOGRAPHS

Photograph 1: OU-2, Northeast view. NMED staff gauging water level in downgradient monitoring well

MW-08 (OU-2).





mm

J CAUTION j

REPOSITORY CELL
DO NOT DIG OR TRENCH
FOR INFORMATION CAIL
I 505648-2371 I

MS'f

Photograph 2: OU-2, North view. 2021 fencing and signage along southern boundary of repository area

; north fence boundary marked with red arrow).

-------
W.im

mm

CAUTION

REPOSITORY CELL
DO NOT DIG OR TRENCH
IFOR INFORMATION CALL
L (505)648—2371 I

' "S wk



mm
mm

wsM

Photograph 3: OU-2, North view. Detail view of signage installed along with new fencing around

repository area in May 2021.

-------
APPENDIX G - EJSCREEN REPORT (OU-2)

-------


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EJ Indexes

State Percentile Regional Percentile | USA Percentile

This report shows the values for environmental and demographic indicators and EJSCREEN indexes. It shows environmental and demographic raw data (e.g., the
estimated concentration of ozone in the air), and also shows what percentile each raw data value represents. These percentiles provide perspective on how the
selected block group or buffer area compares to the entire state, EPA region, or nation. For example, if a given iocation is at the 95th percentile nationwide, this
means that only 5 percent of the US population has a higher block group value than the average person in the location being analyzed. The years for which the
data are available, and the methods used, vary across these indicators. Important caveats and uncertainties apply to this screening-level information, so it is
essential to understand the limitations on appropriate interpretations and applications of these indicators. Please see EJSCREEN documentation for discussion of
these issues before using reports.

September 06, 2022	1/3

-------
PA Environmental Protection	EJScreen Report (Version 2.0)

r^. Agency

1 mile Ring Centered at 33.629951,-105.872662, NEW MEXICO, EPA Region 6

Approximate Population: 369
Input Area (sq. miles): 3.14
Cimarron OU-2

Search Result (point)

Rs-. r.-mT.irry M.ips C..-/-I-U.II?',\	$JMe lImvBr? Iv.

Texas Parte 5, Wildlife. © Oper.SfeetMap. Microsoft, Est, HERE,
Garmin, SafeGrap!i. GeoTechnol&jies, Inc, METI.NASA, USGS,
Buieau ot Larwl Management, EPA, NPS, US Census Bureau, USDA

Sites reporting to EPA

Superfund NPL

0

Hazardous Waste Treatment, Storage, and Disposal Facilities (TSDF)

0

September 06, 2022

2/3

-------
United States	__ _	__	_

Environmental protection	EJScreen Report (Version 2.0)

1 mile Ring Centered at 33.629951,-105.872662, NEW MEXICO, EPA Region 6
Approximate Population: 369
Input Area (sq. miles): 3.14
Cimarron OU-2

Selected Variables

Value

State
Avg.

%ile in
State

EPA
Region
Avg.

%ile in

EPA
Region

USA
Avg.

%ile in
USA

Pollution and Sources

Particulate Matter 2.5 (ng/m3)

4.43

5.58

9

9.32

0

8.74

0

Ozone (ppb)

54.1

56.2

11

41.1

94

42.6

90

2017 Diesel Particulate Matter* (ng/m3)

0.0227

0.208

7

0.219

<50th

0.295

<50th

2017 Air Toxics Cancer Risk* (lifetime risk per million)

10

20

21

32

<50th

29

<50th

2017 Air Toxics Respiratory HI*

0.1

0.24

16

0.37

<50th

0.36

<50th

Traffic Proximity (daily traffic count/distance to road)

28

480

13

470

15

710

16

Lead Paint (% Pre-1960 Housing)

0.53

0.18

91

0.16

91

0.28

79

Superfund Proximity (site count/km distance)

0.69

0.13

96

0.08

98

0.13

96

RMP Facility Proximity (facility count/km distance)

0.011

0.25

1

0.83

0

0.75

0

Hazardous Waste Proximity (facility count/km distance)

0.011

0.82

3

0.8

0

2.2

0

Underground Storage Tanks (count/km2)

0.013

2.5

30

2

12

3.9

17

Wastewater Discharge (toxicity-weighted concentration/m distance)

N/A

4.6

N/A

0.5

N/A

12

N/A

Socioeconomic Indicators

Demographic Index

55%

52%

57

44%

67

36%

78

People of Color

51%

63%

32

52%

51

40%

66

Low Income

60%

41%

79

36%

84

31%

88

Unemployment Rate

20%

7%

95

5%

97

5%

97

Linguistically Isolated

0%

5%

30

6%

37

5%

45

Less Than High School Education

12%

14%

49

15%

49

12%

61

Under Age 5

4%

6%

29

7%

21

6%

27

Over Age 64

22%

17%

74

13%

85

16%

79

* Diesel particular matter, air toxics cancer risk, arid air toxics respiratory hazard index are from the EPA's 2017 Air Toxics Data Update, which is the Agency's
ongoing, comprehensive evaluation of air toxics in the United States. This effort aims to prioritize air toxics, emission sources, and locations of interest for
further study. It is important to remember that the air toxics data presented here provide broad estimates of health risks over geographic areas of the country,
not definitive risks to specific individuals or locations. Cancer risks and hazard indices from the Air Toxics Data Update are reported to one significant figure and
any additional significant figures here are due to rounding. More information on the Air Toxics Data Update can be found at: https://www.epa.gov/haps/air-
toxics-data-update.

For additional information, see: www.epa.ROv/environmentaljustice

EJScreen is a screening tool for pre-decisional use only. It can help identify areas that may warrant additional consideration, analysis, or outreach. It does not
provide a basis for decision-making, but it may help identify potential areas of EJ concern. Users should keep in mind that screening tools are subject to substantial
uncertainty in their demographic and environmental data, particularly when looking at small geographic areas. Important caveats and uncertainties apply to this
screening-level information, so it is essential to understand the limitations on appropriate interpretations and applications of these indicators. Please see
EJScreen documentation for discussion of these issues before using reports. This screening tool does not provide data on every environmental impact and
demographic factor that may be relevant to a particular location. EJScreen outputs should be supplemented with additional information and local knowledge
before taking any action to address potential EJ concerns.

September 06, 2022	3/3

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