Image:  Harshaw, AZ.  Area –



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.” (  

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.” ( – 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




                      Image:  Arizona Mining  Arizona mining hermosa - Bing images    




April 30, 2021



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, 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, 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, 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, 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, page 15, #6 – Would the assessment of the groundwater include the sampling list in table 4.3.1?

15) Section, 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 ( 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.






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,


References and Document Links:


PUBLIC NOTICE & PUBLIC HEARING | Preliminary Decision to Issue a Significant Amendment to an APP for the Hermosa Project Property in Santa Cruz County | ADEQ Arizona Department of Environmental Quality (


South32 | Patagonia Area Resource Alliance (


The full Hermosa Mine Proposal can be found here:  Hermosa Mine Proposal: Potential impacts to Patagonia’s water supply (


Arizona Mining Says New PEA Gives Taylor a US$2-billion NPV | INN (


Mineral deposit to be renamed for former mining executive | Local News Stories |


Hermosa (


Major Mines & Projects | Hermosa Project (



Hermosa Silver Mine Near Patagonia, Arizona | The Diggings™