The Effluent Storage Tank Project (CIP project # 2599SS2010) provides for operational and emergency storage for up to 2 million gallons of treated effluent produced by the District’s sewage-treatment plant – otherwise known as the Wastewater Resource Recovery Facility (WRRF).

Watch a video about this project:

 

Q: What is the Effluent Storage Tank and why do we need it?

A: Prior to construction of the new Effluent Storage Tank, the WRRF contained two unlined effluent storage ponds that were originally designed as the discharge point for the treated effluent from the WRRF. These ponds were used prior to enactment of federal regulations requiring all treated effluent be discharged outside of the Tahoe Basin, incorporated as part of the Porter-Cologne Act in the late 1960s.

Since that time, the Mill Creek ponds remained to provide emergency effluent storage in the event where the capacity of the existing 500,000-gallon effluent storage tank was exceeded – for example, if there was a leak in the Effluent Export Pipeline and pipeline operations needed to be shut down temporarily to fix the leak.

The WRRF operates under a discharge permit that is issued and monitored by the Nevada Department of Environmental Protection (NDEP). In order to best protect the Tahoe Basin environment, the recent and current NDEP discharge permits contain strict conditions that prevent the use of the emergency ponds unless they have been lined with an impermeable liner.

Initially, the IVGID Public Works Department investigated the cost and feasibility of lining the existing effluent storage ponds on the site to comply with NDEP standards; however, the Nevada Department of Water Resources (DWR) Dam Safety Department would not permit modifications to the existing Mill Creak dam(s) on the storage ponds without modernizing the entire dam to present day construction standards, which would have drastically increased the cost associated with installing pond linings.

Once those requirements were determined, the Public Works Department pivoted to building a new 2-million-gallon freestanding Effluent Storage Tank next to the WRRF facility on the site of Mill Creek Pond 1. This new Effluent Storage Tank has enough storage capacity to handle an average day’s output of the WRRF without slowing or shutting down the facility.

Q: What does the tank look like?

A: Take a look at our Effluent Storage Tank Project video to see the tank site, get a sense of the scale of the project, and see a timelapse video of the tank being built. 

Q: How long did the project take?

A: The District began discussions about the Effluent Pond Lining Project in conjunction with the Effluent Export Pipeline Project back in July 2020 and pivoted to the current Effluent Storage Tank solution in 2022. Construction of the tank began in May 2024 with earthwork to remove the dam and construction of a new access road to facilitate tank construction.

While grading activities on site were underway, the lower Diamond Peak parking lot was utilized as a satellite yard to precast the reinforced concrete panels used to construct the tank walls and dome panels. These panels were then trucked to the tank site and erected in August 2024 with a series of on-site concrete pours to tie all the precast panels together.

The Effluent Storage Tank is expected to be operational and in service in late October 2024. However, the cool autumn temperatures are expected to delay final painting of the tank into the spring/summer of 2025.

Q: Who is the contractor and how were they selected?

A: Granite Construction is the contractor for the Effluent Storage Tank Project, and they are working on the project in a collaborative contract structure known as “Construction Manager at Risk” or CMAR contract. (Find more information about the CMAR process in the update on the Effluent Export Pipeline Replacement Project.)

Project status updates

At the November 9, 2022 Board of Trustees meeting, staff provided an update on the project (PDF).

At the January 28, 2021 Board of Trustees Meeting, Trustees approved a Construction Manager-At-Risk (CMAR) pre-construction contract to Granite Construction. Granite Construction’s completed their review of background material, a Findings Memorandum, and participated in selection of the Design Engineer. The team of Granite, Jacobs and IVGID staff continued to work on the design specifics of the project.

    Project information: