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Implementation Schedule: The interim plan for operating the Arequa Gulch pumpback system to minimize the potential for an exceedance of the limits established for Outfall OOIA in the revised Cresson Project Permit consists of the following elements. • Operating the pumpback system as necessary during spring snowmelt until an adequate number of samples are collected and analyzed for the indicator pazameter cyanide. • Operating the pumpback system as necessary after intense or extended precipitation events until an adequate number of samples are collected and analyzed for the indicator pazameter cyanide. • Operating the pumpback system at such other times as deemed appropriate, or as necessary to achieve the limits established for Outfa11001A in the revised Cresson Project Permit. • Periodic testing of the pipes, pumps, and associated electrical and instrumentation systems will be conducted during those periods when the pumpback system may be operational (i.e., spring, summer, or fall) and an adequate volume of water is available for transfer to the VLF or ESP. • Winterizing the pumpback system after flows have traditionally ceased in the fall to protect the pipes, pumps, valves, electrical, instrumentation, and other components from the effects of freezing and thawing. • Periodically inspecting the NUD, SUD, SP, experimental ponds (e.g., concrete overflow pond and Arequa limestone pond), treatment works (e.g., sedimentation pond), and Arequa Gulch during those periods when flow has traditionally ceased in the event conditions change unexpectedly and the pumpback system needs to be activated. It is anticipated that the interim operating plan will guide the operation of the pumpback system through at least 2005, when activities to extend the VLF are anticipated to be completed. CC&V will continue to evaluate data collected from the NUD, SUD, SP, and Arequa Gulch and modify as necessary this interim operating plan as and when information becomes available to define a reasonable relationship between flow and water quality for the NUD, SUD, SP, and Arequa Gulch. Flow Routine: The NiJD, SUD, and SP presently capture shallow ground water beneath the VLF and route those flows to where they would naturally flow in Arequa Gulch. CC&V has installed immediately downgradient of the terminus of the NiJD, SUD, and SP and upgradient of Outfall OOlA of the revised Cresson Project Permit the Arequa Gulch pumpback collection sump, as shown on Figure 1. Flows from each of the individual pipes for the NI7D, SUD, and SP have been (and when flow occurs are being) monitored, sampled, and tracked separately. This enables the unique attributes of the NilD, SUD, and SP to be examined separately before merging together. 6/6/2003