Image: Harshaw, AZ. Area – www.commons.wikimedia.org
INTRODUCTION
Mining first began on the Hermosa Property in the Patagonia Mountains, situated in Coronado National Forest in South Eastern Arizona in 1878 which last produced in 1950. Arizona Mining Inc., also known as Wildcat Silver, owned mining explorations on their private land holdings for the Hermosa project intermittently from 2006 to 2018 when they sold to Australia based, South32. Hermosa Mine is located in Santa Cruz County, AZ at an elevation of 5400’. South 32 spent the first year remediating the historical environmental damage from old mine tailings left in the 1960s when former owner, ASARCO, stopped their mining production. Currently there are two distinct deposits. The Taylor Deposit is comprised of a zinc (and zinc replacement)-lead-silver sulfide deposit; and Clark Deposit, a zinc, manganese, and silver oxide resource, South32 said, adding that the Hermosa project also included a “highly prospective land package with potential for discovery of polymetallic and copper mineralization.” (NogalesInternational.com).
Controversy has surrounded this project for decades as it has the potential to threaten private wells, local water supplies and surrounding environment habitats. “The mine is proposed within the Coronado National Forest, and therefore subject to the 1872 Mining Law. Federal land managers interpret the 1872 Mining Law to require them to permit mines, no matter if the land is better used for other purposes – like protecting a town’s drinking water supply watershed.” (www.patagoniaalliance.org – 2014).
On April 28, 2021, ADEQ extended the comment period until May 30, 2021 based on this letter from the Patagonia Area Resource Alliance dated April 26, 2021.
ADEQ Extends APP Comment Deadline to May 30, 2021
STAY TUNNED
Response to Comments provided by ADEQ on the Preliminary Decision to Issue a Significant Amendment to the Individual Aquifer Protection Permit for the Hermosa Project Property; Santa Cruz County, Arizona
Comment:
1) Consider including an Appendix listing Acronyms that are identified at the first mention and
then abbreviated globally thereafter.
ADEQ NOTE: The commenter provided a list of suggested acronyms that is not included in
this document.
ADEQ Response: Thank you for your comment. ADEQ will consider your comment in future
revisions to the APP Framework. ADEQ has added a list of acronyms used in this document in
Table 2.
Comment:
2) There could be a Table of Contents, I have seen permits with and without them, is there a
criterion that determines this?
ADEQ Response: Thank you for your comment. A Table of Content has been added to the APP.
Comment:
3) Consider detailing the location of the POCs on the site detail that correspond to the
LAT/LONGs, once they are determined.
ADEQ Response: Please refer to Section 2.4 of the permit which describes the location of each
POC.
Comment:
4) It would be helpful to have a detailed map showing the discharge points at Alum Gulch and
Harshaw Creek or include them in the site detail.
ADEQ Response: A map of the PMA and the DIA showing the location of proposed POCs will
be attached to the executive summary.
Comment:
5) Section 2.2.1.3, page 6, paragraph 3 – Consider including the AZPDES permit number
(AZ0026387) as mentioned on page 2 and carry throughout permit, since it is a concurrent
active permit.
ADEQ Response: ADEQ acknowledges your comment and has made the change in Sections
2.2.1.3 and 2.2.1.4.
Comment:
6) Section 2.2.2 – Are there any site-specific characteristics that could be mentioned here? Soil,
washes, ephemeral streams, vegetation, or habitat characteristics?
ADEQ Response: The TSF and the UCP were designed using Prescriptive BADCT and
therefore, no site-specific characteristics were used in the design. Site-specific characteristics of
Harshaw Creek were also considered when evaluating the DIA and PMA. For example, AMI
conducted infiltration testing, cross-section surveys, and grain size analysis of stream sediments
to characterize the stream morphology.
Comment:
7) 6.1 Section 2.2.3, page 6, sentence 2 – consider changing submitting to submitted.
ADEQ Response: ADEQ acknowledges your comment. Section 2.2.3 Pre-operational
Requirements has been revised to indicate it is “not applicable”.
Comment:
8) Section 2.6.3.3, page 14, #3 – Is there a material characterization plan to determine the type and source of the material, if it is not an intended material as described in section 2.3 - Discharge
Limitations
ADEQ Response: There is no “material characterization plan”. Since Section 2.6.3.3 is related
to inflow of unknown and unexpected materials, characterization is expected to be conducted
based on the knowledge of the material that was spilled.
Comment:
9) Are there any training requirements for staff performing the material characterization?
(Characterize the unexpected material and contents of the affected impoundment and evaluate
the volume and concentration of the material to determine if it is compatible with the surface
impoundment liner).
ADEQ Response: It would be the responsibility of the emergency response coordinator at the
facility to conduct an investigation and collect samples based on the knowledge of the incident.
Comment:
10) Section 2.6.3.3, page 14, #4 – Is the Permittee (AMI) to report to the Groundwater Protection Value Stream as all other reporting instances are directed, or to ADEQ. It seems like ADEQ (director) reviews the report and responds to the report with possible permit amendments or other actions. (See 2.7.3 requirements before including this comment). Or are the Groundwater Protection Value Stream and ADEQ interchangeable? If that is the case, it should be reflected in the permit, to avoid confusion.
ADEQ Response: The Groundwater Protection Value Stream is a program within ADEQ. The
two terms are interchangeable in the permit.
Comment:
11) Section 2.6.3.5, page 15, #2 – If the TSF or the UCP becomes unstable to the point of failure and results in a discharge, notify the ADEQ WQCS within 24 hours. Please define WQCS as it is only mentioned once throughout the permit.
ADEQ Response: ADEQ appreciates the comment. The term “WQCS” has been replaced with
“Groundwater Protection Value Stream”.
Comment:
12) When a failure occurs, or there has been discharge of hazardous or nonhazardous material it
might be helpful to have photo documentation for your records and/or for ADEQ. This could be
in the form of photolog with the date the photo was taken, all discharging units, related pollution
control devices, the site location (parcel number/Hermosa Mine Property – Parcel # XXX-XX,
Santa Cruz County, Arizona), north arrow and any other information you might feel useful to
accompany the report.
ADEQ Response: Attachment of a photo log is a normal expectation for the types of reports
discussed in your comment.
Comment:
13) After completion of berm or BADCT failure repair, include photos the repair from the same
vantage point as the original failure photos. This makes a nice compliance follow up for ADEQ.
ADEQ Response: Attachment of a photo log at the time of an incident and following completion
of repairs is a normal expectation.
Comment:
14) Section 2.6.3.5, page 15, #6 – Would the assessment of the groundwater include the
sampling list in table 4.3.1?
ADEQ Response: Yes, any contingency groundwater sampling conducted would include the parameters listed in Table 4.3.1.
Comment:
15) Section 2.6.5.2, page 16, - Along with notifying the Groundwater Protection Value Stream
which has been required throughout the permit, now there is a requirement to notify the
Southern Regional Office (SRO). Is the Groundwater Protection Value Stream in the Phoenix
office or the SRO? Whatever the case maybe it should be consistent throughout the permit to
avoid confusion when reporting anything to ADEQ. Or is reporting to the SRO only required
for emergency response and contingency requirements?
ADEQ Response: All references to the Southern Regional Office have been removed.
Comment:
16) Section 2.6.6, page 16, #4 – If cleanup of any part of the aquifer is required, is there a plan on how that is to be accomplished? Is there a way to get the affected water to the Patagonia
Water/Wastewater Treatment Plant?
ADEQ Response: The permittee is required to maintain an updated version of the contingency
plan at the facility, and follow the actions laid out in the plan if there is a discharge that results
in a violation of the permit. A contingency plan for the existing APP facilities can be found in
Attachment B of the APP application submitted in June 2017, and an updated Contingency Plan
is due within 30 days of permit issuance as per compliance schedule item No. 7 in Section 3 of
the draft APP. If groundwater impact is detected as a result of a release of pollutants from the
mine operation, ADEQ may require corrective action (i.e., cleanup). The cleanup plan will be
based on the volume and nature of pollutants present in the groundwater.
Comment:
17) Section 2.7.1, page 17, #4 – Alert Level (AL), Aquifer Quality Limit (AQL) and Discharge
Limit (DL) have already been abbreviated prior to this mention, therefor it is not necessary to
list them out again, and they could be listed in an appendix of acronyms.
ADEQ Response: Item #4 in Section 2.7.1 has been deleted to match the current version of the
APP Framework.
Comment:
18) Section 2.7.2, sentence 1 could been shortened to read - A signed copy of this permit and A
Logbook (paper copies, forms, or electronic data) of the inspections and measurements shall be
maintained at all times at the location where day-to-day decisions regarding the operation of the
facility are made.
ADEQ Response: ADEQ acknowledges your comment and will consider it during future revisions to the APP Framework.
Comment:
19) Section 2.8, page 18 - Temporary Cessation in the Arizona Revised Statute sites [49-
243(K)(8)] which is for any other measures the director deems necessary. Could it be [A.R.S.
49-243(K)(6)], which is regarding closure?
ADEQ Response: Section 2.8 is pertaining to Temporary Cessation of operations for a given
facility or the whole facility and the citation is appropriate.
Comment:
20) Section 2.8, page 19 – Is there a time limit on Temporary Cessation, or can operations be
temporarily ceased indefinitely, and continue to report triennially?
ADEQ Response: The permittee is required to submit a plan for ADEQ approval. Different
conditions require different timeframes for temporary cessation. If the approved period of
temporary cessation comes due, the permittee is required to submit a revised plan and provide
rationale for ADEQ’s approval of the extended period.
Comment:
21) Section 6.8, page 31 – This section is regarding inspection and entry, however ARS § 49-
1009 Tank Performance Standards is referenced. Should it be ARS 49-1011 Right to inspect
records, tanks, and equipment?
ADEQ Response: The typographical error has been corrected to reflect the correct statute, i.e.
ARS. §§ 41-1009.
Comment:
22) Section 6.9, page 32 – This section is the Duty to Modify and is referencing ARS § 49-
248(K)(8) Such other terms and conditions as the director deems necessary to ensure
compliance with this article which is in Section 7.0. Should it be 49-203. Powers and duties of
the director and department?
ADEQ Response: It appears that the commenter may have misquoted the statute as ARS § 49-
248(K)(8), and probably meant to cite ARS. § 49-243(K)(8). ARS. § 243(K)(8) allows the
director to insert conditions necessary to ensure compliance with the permit. A permittee that
does not modify his permit before changing operations is not compliant with the permit.
Comment:
23) Has this been modified, or is 1.6 BILLION gallons/year for 4 years still the projected water
use? Once the water is removed the aquifer will compact, eventually causing subsidence, and
will never be a water bearing zone again. I am familiar with mining methods and Freeport has devised a method that does not dewater to this extent.
ADEQ Response: The planned discharge from mine dewatering is 4,500 gpm or 1.97 billion
gallons per year. The hydrogeology of the Patagonia Mountains is not conducive to aquifer compaction and subsidence due to the consolidated nature of the carbonate strata, volcanic and intrusive rocks beneath the site. Consequently, no significant compaction or subsidence is anticipated as a result of dewatering activities. Areas of known subsidence in Arizona occur within the basin fill deposits, which are characterized by extensive thickness of unconsolidated materials (sands, gravels, and clays). Land subsidence in the basins of Arizona is generally due to compaction of alluvium caused by lowering of the water table from groundwater pumping. Note that ADWR is currently monitoring land subsidence through the utilization of surveying techniques such as Global Positioning System (GPS) surveying and Interferometric Synthetic Aperture Radar (InSAR). ADRW has developed an extensive catalogue of land subsidence maps using these techniques (https://new.azwater.gov/hydrology/field-services/land-subsidence-arizona). None of these areas of subsidence has occurred within or adjacent to the Patagonia Mountains.
Comment:
22.1) Is this going to be an open pit mine? And if not, what methods are they using? This use of
groundwater is excessive, especially in the desert southwest.
ADEQ Response: ADEQ has not received any plans for the future mine operations.
Comment:
24) Is there anything being done to protect our groundwater from excessive mining and exploration?
ADEQ Response: The Aquifer Protection Program, as designed by state law, protects groundwater by regulating discharges of pollutants to groundwater. The permittee is required to install control systems to prevent the discharge of pollutants as well as monitor to ensure pollutants are not discharged above allowable limits.
Comment:
25) Section 1.0, page 1 - Authorization for the Significant Amendment Draft Permit #P-512235; LTF: 83040 has been given by ADEQ to Arizona Minerals Inc., however, Arizona Mineral Inc., sold to South32 in 2018. I’m confused as to who the responsible party is now.
ADEQ Response: Arizona Minerals, Inc. (AMI), is a Nevada corporation doing business in Arizona, and is an independent company whose ultimate parent company is South32, a mining
company organized under Australian law. In 2018, South32 purchased AMI and established AMI as a wholly owned subsidiary licensed to conduct business in the United States and Arizona. AMI is the legal entity conducting business associated with the permit.
Image: Arizona Mining Arizona mining hermosa - Bing images
COMMENT LETTERS
April 30, 2021
ADEQ
Vimal Chauhan
Groundwater Protection
1110 W. Washington St., MC5415B-3
Phoenix, AZ 85007
Email Comments to: This email address is being protected from spambots. You need JavaScript enabled to view it.
Dear Mr. Chauhan,
Environmental Review, Inc. has reviewed the Preliminary Decision to Issue a Significant Amendment to the Individual Aquifer Protection Permit No. P-512235; LTF: 83040 for the Hermosa Project Property in Santa Cruz County and has the following comments:
Draft Permit:
1) Consider including an Appendix listing Acronyms that are identified at the first mention and then abbreviated globally thereafter.
a. A.A.C – Arizona Administrative Code
b. Acre Feet – ac. ft. or AF
c. ADEQ – Arizona Department of Environmental Quality also referred to as The Department
d. ADHS – Arizona Department of Health Services
e. ADWR – Arizona Department of Water Resources
f. AL, AL#1 or AL1 –Choose how to notate Alert Level 1 as either AL#1 or AL1
g. AL, AL#2 or AL2 – Choose how to notate Alert Level 2 as either AL#2 or AL2
h. AMBGM - Arizona Mining BADCT Guidance Manual
i. AMI – Arizona Minerals Inc. also referred to as The Permittee
j. AMSL – Above Mean Sea Level
k. APP – Aquifer Protection Permit
l. AQL - Aquifer Quality Limits
m. A.R.S – Arizona Revised Statute
n. ASTM - formerly known as American Society for Testing and Materials -stands for Quality and Technical Excellence.
o. AZPDES – Arizona Pollution Discharge Elimination System
p. BADCT - Best Available Demonstrated Control Technology
q. BMP – Best Management Practice
r. COC – Chain of Custody
s. Cubic Yard – yd3
t. Director – ADEQ Director?
u. DL – Detection Limit
v. EPA – Environmental Protection Agency
w. ERP – Emergency Response Plan
x. Feet - ft
y. GCL - Geosynthetic Clay Liner
z. GPVS – Groundwater Protection Value Stream could be abbreviated as it is used 39 times
aa. HDPE - High Density Polyethylene
bb. Inch – in
cc. LCRS - Leak Collection and Removal System
dd. LPSL - Low Permeability Soil Layer
ee. Million Gallons – MG
ff. Million Gallons per day - MGD
gg. PAG - Potential Acid Generating
hh. PL – Performance Level
ii. POC – Point of Compliance
jj. QA/QC - Quality Control and Quality Assurance
kk. SMRF – Self Monitoring Report Form
ll. Square Feet – ft2
mm. Southern Regional Office - SRO
nn. TSF – Tailings Storage Facility
oo. TSS – Total Suspended Solids
pp. UPC – Underground Collection Pond
qq. WQCS -
rr. WTP1, WTP2 – Water Treatment/Wastewater Treatment Plant
2) There could be a Table of Contents, I have seen permits with and without them, is there a criterion that determines this?
3) Consider detailing the location of the POCs on the site detail that correspond to the LAT/LONGs, once they are determined.
4) It would be helpful to have a detailed map showing the discharge points at Alum Gulch and Harshaw Creek or include them in the site detail.
5) Section 2.2.1.3, page 6, paragraph 3 – Consider including the AZPDES permit number (AZ0026387) as mentioned on page 2 and carry throughout permit, since it is a concurrent active permit.
6) Section 2.2.2 – Are there any site-specific characteristics that could be mentioned here? Soil, washes, ephemeral streams, vegetation, or habitat characteristics?
7) Section 2.2.3, page 6, sentence 2 – consider changing submitting to submitted.
8) Section 2.6.3.3, page 14, #3 – Is there a material characterization plan to determine the type and source of the material, if it is not an intended material as described in section 2.3 - Discharge Limitations
9) Are there any training requirements for staff performing the material characterization? (Characterize the unexpected material and contents of the affected impoundment and evaluate the volume and concentration of the material to determine if it is compatible with the surface impoundment liner).
10) Section 2.6.3.3, page 14, #4 – Is the Permittee (AMI) to report to the Groundwater Protection Value Stream as all other reporting instances are directed, or to ADEQ. It seems like ADEQ (director) reviews the report and responds to the report with possible permit amendments or other actions. (see 2.7.3 requirements before including this comment). Or are the Groundwater Protection Value Stream and ADEQ interchangeable? If that is the case, it should be reflected in the permit, to avoid confusion.
11) Section 2.6.3.5, page 15, #2 – If the TSF or the UCP becomes unstable to the point of failure and results in a discharge, notify the ADEQ WQCS within 24 hours. Please define WQCS as it is only mentioned once throughout the permit.
12) When a failure occurs, or there has been discharge of hazardous or nonhazardous material it might be helpful to have photo documentation for your records and/or for ADEQ. This could be in the form of photolog with the date the photo was taken, all discharging units, related pollution control devices, the site location (parcel number/Hermosa Mine Property – Parcel # XXX-XX, Santa Cruz County, Arizona), north arrow and any other information you might feel useful to accompany the report.
13) After completion of berm or BADCT failure repair, include photos the repair from the same vantage point as the original failure photos. This makes a nice compliance follow up for ADEQ.
14) Section 2.6.3.5, page 15, #6 – Would the assessment of the groundwater include the sampling list in table 4.3.1?
15) Section 2.6.5.2, page 16, - Along with notifying the Groundwater Protection Value Stream which has been required throughout the permit, now there is a requirement to notify the Southern Regional Office (SRO). Is the Groundwater Protection Value Stream in the Phoenix office or the SRO? Whatever the case maybe it should be consistent throughout the permit to avoid confusion when reporting anything to ADEQ. Or is reporting to the SRO only required for emergency response and contingency requirements?
16) Section 2.6.6, page 16, #4 – If cleanup of any part of the aquifer is required, is there a plan on how that is to be accomplished? Is there a way to get the affected water to the Patagonia Water/Wastewater Treatment Plant?
17) Section 2.7.1, page 17, #4 – Alert Level (AL), Aquifer Quality Limit (AQL) and Discharge Limit (DL) have already been abbreviated prior to this mention, therefor it is not necessary to list them out again, and they could be listed in an appendix of acronyms.
18) Section 2.7.2, sentence 1 could been shortened to read - A signed copy of this permit and A Logbook (paper copies, forms, or electronic data) of the inspections and measurements shall be maintained at all times at the location where day-to-day decisions regarding the operation of the facility are made.
19) Section 2.8, page 18 - Temporary Cessation in the Arizona Revised Statute sites [49-243(K)(8)] which is for any other measures the director deems necessary. Could it be [A.R.S. 49-243(K)(6)], which is regarding closure?
20) Section 2.8, page 19 – Is there a time limit on Temporary Cessation, or can operations be temporarily ceased indefinitely, and continue to report triennially?
21) Section 6.8, page 31 – This section is regarding inspection and entry, however ARS § 49-1009 Tank Performance Standards, is referenced. Should it be ARS 49-1011 Right to inspect records, tanks and equipment?
22) Section 6.9, page 32 – This section is the Duty to Modify and is referencing ARS § 49-248(K)(8) Such other terms and conditions as the director deems necessary to ensure compliance with this article which is in Section 7.0. Should it be 49-203 - Powers and duties of the director and department?
The following comments were sent to Mr. Chauhan via email on 4/28/2021 as a supplement to the above comments.
Dear Mr. Chauhan,
This is an extension of the comments I just submitted to you today.
I was just reading the Home | Patagonia Area Resource Alliance (patagoniaalliance.org) newsletter, and ran across this update.
7/2020: South32 announces their massive dewatering plans, which will draw down an estimated 1.6 billion gallons of water per year for four years in order to help them reach their target minerals.
1. Has this been modified, or is 1.6 BILLION gallons/year for 4 years still the projected water use? Once the water is removed the aquifer will compact, eventually causing subsidence, and will never be a water bearing zone again.
I am familiar with mining methods and Freeport has devised a method that does not dewater to this extent.
2. Is this going to be an open pit mine? And if not, what methods are they using? This use of groundwater is excessive, especially in the desert southwest.
3. Is there anything being done to protect our groundwater from excessive mining and exploration?
4. Section 1.0 – Authorization, page 1 - ADEQ is Authorizing Arizona Minerals Inc. to operate, however, Arizona Minerals sold to South32 in 2018.
Please direct your response and comments to: This email address is being protected from spambots. You need JavaScript enabled to view it.
Sincerely,
Laura Macklin, Associate in Arizona
Senior Reviewer
Environmental Review, Inc., a 501(c)(3) Nonprofit Public Benefit Corporation
1792 Rogers Avenue, San Jose, CA 95112, http://www.envreview.org/
References and Document Links:
South32 | Patagonia Area Resource Alliance (patagoniaalliance.org)
The full Hermosa Mine Proposal can be found here: Hermosa Mine Proposal: Potential impacts to Patagonia’s water supply (patagoniaalliance.org)
Arizona Mining Says New PEA Gives Taylor a US$2-billion NPV | INN (investingnews.com)
Major Mines & Projects | Hermosa Project (miningdataonline.com)
Hermosa Silver Mine Near Patagonia, Arizona | The Diggings™