Spiro Mine Tunnel Reconstruction

3Kings Water Treatment Plant Construction

Mobilizing Construction Crews 

• Shuttling of construction crews to and from the project site is underway. 

Construction Hours

• Crews will be working Monday-Saturday, 7 a.m. to 7 p.m.

Construction Mitigation 

• Construction mitigation (fencing, erosion protection, mud track off pads, etc.) are in place and will remain for the duration of the project. 
• Road sweeping efforts will continue to be adjusted to address changing conditions.

Site Construction

• Excavation for structures continues. Piles of soil will remain in place until mid-summer when back-filling can be performed. Precautions are underway to prevent dust as a result of the material stockpiles.
• Installation of formwork and rebar for below-grade concrete basin walls continues. 
• Several large concrete pours are being scheduled. We will continue to assess traffic impacts in the neighborhood from the concrete placements and material deliveries and will provide advance notifications as appropriate. 
• A temporary building for the treatment of drinking water from the Thiriot Spring was installed. This building, located along Three Kings Drive at the northwest corner of the site, will be removed as the 3KWTP work is completed.

Roadway Utility Work 

• Initial utility work within Three Kings Drive is complete, however, additional work will still be required as the treatment plant work moves forward. The impact on the neighborhood is being considered in the scheduling of the remaining work. The use of flaggers is anticipated for this work, rather than the previously used one-way signals. Advance notice for any work within the roadway will be provided. 

Golf Course Work 

• Work within the Golf Course area of play was completed in advance of the course opening.
• Design and scheduling for dredging of the golf course ponds are progressing and we are continuing to coordinate closely with the Park City Golf Course staff. As more information is developed, we will provide updates.

The following key construction mitigation items are contained in Park City’s Conditional Use Permit and Building Permits. Park City Water is committed to meeting these items.

• Working hours 7:00 a.m. to 7:00 p.m.
• No staging, unloading, or deliveries within Three Kings Drive or adjacent streets
• No parking on Three Kings Drive or adjacent streets
• Installation of a pedestrian walkway on the west side of the Three Kings Drive along the Project frontage
• Construction worker parking off-site and shuttled in and out daily
• Noise Mitigation
• Lighting Mitigation
• Park City will monitor pavement condition of Thaynes Canyon Drive and Three Kings Drive and Three Kings Drive. Pavement maintenance to be performed on an as needed basis. Final paving will be performed following project completion.
• Additionally, Public Information notices will be sent out in advance of significant work impacting the adjacent City streets occurring    (i.e. large concrete pours involving a significant number of concrete trucks on the road, large equipment deliveries, or necessary water shutdowns)

The construction manager has developed a detailed critical path for the Project. The following milestones have been identified, however, the schedule is dynamic due to work production and issues such as weather and materials availability/deliveries.

What is Mining-Influenced-Water?  

During the mining period in Park City’s history, drainage tunnels were constructed at the lower elevations of the mine works to keep water within the mountain from interfering with the mining operations.  These drainage tunnels, which contain trace metals from the natural soils and mining operations, discharged directly to the environment.  Over the course of Park City’s history, these waters have been used for various purposes such as drinking water, irrigation, and snowmaking.  The water which exits existing mine tunnel entrances (portals) are referred to as Mining-Influenced-Water (MIW).

Why Treat Mining Influenced Water?

Metals in waste streams don't naturally degrade and are toxic to aquatic life, even at low concentrations.  As part of the EPA’s Clean Water Act, it has established that cleanup of mining-influenced-waters, such as those being discharged from the tunnels, is a significant environmental benefit.  In 2014 the Utah Division of Water Quality (DWQ) and Park City entered into a Stipulated Compliance Order (SCO) which contained major milestones for treatment compliance and requirements on pollutant loadings related to the water discharges from the Judge and Spiro mine tunnels.  Non-compliance with the terms of the SCO can lead to:

• fines and operations interference from the State of Utah Division of Water Quality and the EPA:

• continued stream degradation

Characteristics of MIW Treatment Design

Water treatment design is a process in which the raw water is analyzed and, based on the receiving water characteristics (stream designation by the DWQ) and the discharge requirements for the treated effluent (water to be discharged from the plant), the treatment process is established. The design is highly site specific and focuses on treatment efficiency, reliability, cost-effectiveness, and minimalizing such items as energy use, traffic impacts, maintenance, and personnel.

Characteristics of the tunnel water must be taken into consideration in terms of physical, chemical and biological characteristic. Sizing of the M-I-W treatment plant depends upon the flows collected within each drainage tunnel. Tunnel flows change from year to year and vary significantly from season to season.  The new water treatment plant process has been developed through substantial studies, which included a year-long pilot-scale study to establish the treatment process and prove its effectiveness in removing metals in the tunnel raw water and a thorough evaluation of life-cycle cost and benefit.

The selected process is considered a multi-barrier approach and includes pre-oxidation, rapid mix/flocculation/ sedimentation (to remove specific particulate metals though precipitation), granular media filtration (to further remove iron and manganese from the water which may cause aesthetic water quality problems such as reddish and/or blackish staining of sinks/bathtubs or laundry), post-filter adsorption (where specific medias are used to remove targeted dissolved metals), and disinfection (for drinking water use).