Farr West began working on preliminary studies, engineering reports, and designs for this project in 2009. An engineering design and environmental assessment was completed in 2012 and submitted to NDEP and USDA for approval. Multiple funding agencies were approached to finance the construction of Phase 1 and resulted in a USDA funding package that best met the county’s needs.
The Virginia City and Gold Hill Wastewater Improvement Project included the design of a 200,000 gpd wastewater treatment plant, over 12 miles of 8” sewer main, 1.25 miles of 4” sewer laterals, and more than 300 sewer manholes throughout Virginia City, Storey County, Nevada. Over 95% of the installation was by the excavation method, with the average trench depth being 7 feet and some exceeding 20 feet in depth. The project was strategically phased in order to provide continuing service during construction of new infrastructure. Farr West also worked with the county and BLM to obtain easements for all city streets.
Given the historic and cultural environment in the Virginia City area, it was important to reduce the area of disturbance which was accomplished by consolidating sewer mains wherever possible. A successful design required a blend of engineering judgment, knowledge of construction methods, and environmental awareness. Because of the age of the system, locations of existing utilities were mostly unknown as very few as-builts or original design drawings exist. Through interviews and multiple site investigations, Farr West was able to build a quality map of existing utility infrastructure and developed a complete GIS database of all utility assets.
After securing funding, Storey County decided to move forward with replacing the wastewater treatment plant, a $5 million project. This project was one of 43 projects across 32 states that USDA funded in honor of Earth Day in 2014. The funding allowed the county to replace a 1970s system with a larger, more efficient plant. One of the key benefits of this project was the elimination of the threat of pollution to the Six Mile Canyon watershed.
Following the successful completion of the WWTP project, Farr West assisted the county in the acquisition of more than $13 million in project funds for the replacement of the entire collection system in Virginia City and Gold Hill. Services provided as part of this project included engineering design, bidding assistance, construction management, resident observation, and archaeological monitoring for more than 15 months.
Contribution to the Well-Being of People and Communities
The Virginia City and Gold Hill Wastewater Improvement Project has improved the community’s environmental conditions. The project also provided the necessary infrastructure to support current and future economic development and successfully balanced the preservation of historical landmarks with new technology. Finally, more than five archaeological discoveries occurred during the construction of the rehabilitation project in addition to cataloging of numerous cultural materials. The result of these activities was a comprehensive report available to the public, and submission of artifacts to the Nevada State Archives.
Resourcefulness in Planning and Solving Design Challenges
The Virginia City design and construction team continuously researched ways to incorporate innovative design measures while keeping costs low and preserving the natural heritage of the area. Securing such a significant amount of funding from USDA was no small feat, and the team worked diligently to accomplish this.
Pioneering in Use of Materials and Methods
Because Virginia City is a National Historic Landmark listed on the National Register of Historic Places, any ground disturbance is required to be kept to a minimum. Installation of new sewer collection interceptors was made using pipe bursting technology wherever feasible. The facility also contained soils contaminated with arsenic and petroleum products, which were mitigated under the oversight of the Bureau of Corrective Actions, a division of the Nevada Division of Environmental Protection.
Innovations in Construction
The Virginia City project utilized multiple bypass pumping and influent storage solutions to maintain wastewater treatment capabilities throughout the construction of the project. Existing treatment facilities were kept in service for the first phase of construction and were pumped into the new treatment facility in order to “seed” the new plant.
Minimization of Impact on Physical Environment
Because of the historic and cultural sensitivity in the Virginia City area, this project required sewer main consolidation wherever possible. The team was successful in incorporating a blend of sound engineering practices with environmental awareness.