REP50689

• Permit No: C1980003
• IBM Index Class Name: Report
• Doc Date: 3/11/2003
• Doc Name: 2002 Annual Hydrology and Reclamation Report
• From: MWH
• To: DMG
• Annual Report Year: 2002
• Permit Index Doc Type: Hydrology Report
• Media Type: D
• Archive: No

February 2003 Hayden Gukh Mine 2002 Annual Reclamation and Hydrology Repor! 1 Page 4
3.0 HYDROLOGIC MONITORING
3.7 SURFACE WATER MONITORING
As indicated in Section 1.0, the CDMG approved Hayden Gulch Mine's request to discontinue
hydrologic monitoring in a letter dated June 29, 1999. A copy of the letter is found in Exhibit 2.
As part of the1999 mid-term review, CDMG requested that the hydrologic monitoring plan be
updated. The request was made to assure compliance with Section 2.05.6(3)(iv). In the response to
CDMG's request, HGCC (the previous operator) indicated that a hydrologic monitoring program is
no longer needed at the Hayden Gulch Mine. The technical basis for the cessation of the monitoring
program is as follows.
"The Division stated in the permanent impoundment determination that the monitoring data
indicate a trend in quality that will be suitable for livestock and wildlife use, and will tamely with NPDES
limitations, CWQCC barn surface water standards and CIPiQCC in-stream standards. In addition, the
Division concluded that discharge from impoundments will not cause material damage to existing or future
water users downstream... The Division also concluded that Sedimentation Ponds 003 and HG-
8 are no longer part of a mine sediment tontml plan, but are watering ponds far wildlife and livestock"
Finally, the Division concluded as part of the bond release fmdings that HGCC no longer
needs to conduct water monitoring activities at the Hayden Gulch Mine because runoff from
the mine has not resulted in an adverse impact to the hydrologic balance, will not impact
existing or future downstream users, and HGCC has successfully met all requirements of the
Act and regulations.
These findings were used as the basis to petition the CDPHE that there was no longer a need to
conduct CDPS monitoring at the two permanent ponds. The CDPHE approved HGCC's request de-
activating the CDPS permit in a letter dated October 29, 1999. A copy of CDPHE's approval to de-
activate the CDPS permit is included as Exhibit 3.
Because both the CDMG and the CDPHE relieved the operator of all surface water monitoring
requirements at the Hayden Gulch Mine, there was no hydrologic monitoring at the mine during
calendaz year 2002.
3.2 GROUNDWATER MONITORING
As part of the Phase II/Phase III bond release application, HCGG requested that groundwater
monitoring at the Hayden Gulch Mine be discontinued and all monitoring wells abandoned. In the
Bond Release Inspection Report dated July 8, 1998, the CDMG indicated that the groundwater
monitoring program could be discontinued and monitoring wells at the site could be abandoned. In
accordance with the CDMG's direction, the nine site monitoring wells were abandoned during
October 1998. The well abandonment reports were transmitted to the CDMG on October 16, 1998.
Consequently, there are no groundwater monitoring activities at the Hayden Gulch Mine.
3.3 SEDIMENT POND MONITORING
As indicated above in Section 3.1, the CDMG approved cessation of sampling the sedimentation
ponds. Patt of their technical basis was, "that Sedimentation Ponds 003 and HG-8 are no Jonger part of a
mine sediment control plan, but are watering ponds for wildlife and livestock."
MWH * P.O. Box 774018 * Steamboat Springs, Cokrado 80477 * [phone]
PiPRH%6 G.4b TU./R~ie1e/i~AnMNift
oAOnol®