2021-12-07_REVISION - M2012032 ‎(29)‎

• Permit No: M2012032
• IBM Index Class Name: Revision
• Doc Date: 12/7/2021
• Doc Name Note: Exhibit Q: Proof of Mailing Notices to County Commissioners and Soil Conservation District
• Doc Name: Proposed Revision Materials
• From: Ouray Silver Mines, Inc
• To: DRMS
• Type & Sequence: AM2
• Email Name: LJW
• Email Name: THM
• Media Type: D
• Archive: No

Technical Revision 08 (TR-08)
In May of 2016, TR-08 was submitted to permit construction of a bioreactive bed and infiltration
line to create an integrated passive treatment system in which mine portal discharge would pass
from the mine water pond through a bioreactive bed in sediment pond #2 before infiltrating to
groundwater through adjacent waste rock using an infiltration line. These changes were designed
to practically eliminate the flow at Outfa11001, improve mine discharge water quality, and allow
for infiltration of mine discharge water to groundwater. This revision included supporting
documents and updates to Maps G-13, 14, and 15. TR-08 was approved in July of 2016.
Technical Revision 09 (TR-09)
TR-09 was submitted in February 2017. Updates to the permit with this revision included the
following:
• Add and upgrade buildings on site to ease winter operations and maintenance and to
provide offices for staff.
• Permit mill discharge, which will be treated prior to comingling with mine discharge in
the mine water management system.
• Update water quality monitoring requirements.
• Permit the sale of blended tailings and waste rock, provided the blend passes applicable
leachate standards.
TR-09 was approved by DRMS in March of 2017.
Technical Review 10 (TR-10)
TR-10, submitted in August of 2018, included the following updates:
• Construct the five-stage passive mine water treatment system with surface water
discharge at a new industrial wastewater outfall (Outfall 002A) as permitted by the Water
Quality Control Division under Permit No. CO-0000003.
• Construct a new monitoring well (GW-4)to monitor the passive treatment system.
• Relocate a diesel tank to a less congested area of the mine site.
The five-stage passive treatment system with Sneffels Creek discharge via second outfall was
approved as Modification 4 to Colorado Discharge Permit System (CDPS)permit CO-0000003
on July 31, 2018, effective August 31, 2018.
TR-10 was approved in September of 2018.
Revenue Mine December 2021 3