TMWRF was constructed between October 1964 and February 1967 to combine the existing two wastewater plants, one belonging to the City of Reno, one belonging to the City of Sparks that were constructed in the early 1930's.
The City of Reno plant, a combined storm/sewer plant, was constructed in 1930 and placed into service on July 10th, 1931. This had an original capacity of 8 million gallons per day (MGD) for $149,000. This plant included a venturi flume flow meter influent channel, bar screen, grit tank, two primary clarifiers, and a 300 pound per day chlorinator with one digester and six sludge drying beds for solids handling. This plant was expanded up to 16.5 MGD capacity in 1950 for $620,000. This expansion added two comminutors, one primary clarifier, two trickling filters, a secondary clarifier, and expanded capacity of chlorination to 600 pounds per day. A second digester and sludge lagoon were added several years later. This plant was located on a site now occupied by the Grand Sierra Resort property. In 1959, consultant engineer John A. Carollo recommended constructing a new plant immediately due to high flows and low performance. Flows were averaging between 15-23 MGD with peak flows exceeding 30 MGD and were causing damage to plant equipment. Carollo engineers noted that the city’s per capita water consumption was approximately 459 gallons per day per resident compared to 143 gallons of 27 other cities (and what is currently used the Truckee Meadows Regional Planning Association of 175 gallons per day per resident). This excess water burdened the plant which averaged between 15-23 MGD during the summer months of the late 1950’s with peak flows exceeding 30 MGD. Much of this excessive flow was due to the combined storm/sewer system which was also reflective in the biochemical oxygen demand loading to plant being diluted and relatively weak at 114 mg/L. The city went through much effort in the 1960's to separate these two systems to reduce unnecessary flows to the treatment facility.
The original City of Sparks plant was designed by Kennedy Engineers and constructed in 1930. This plant was designed as a combined storm/sewer system to treat 1.5 MGD and was located on the east side of Nugget Avenue at the site currently occupied by the City of Sparks Marina Lake Park Denitrification Facility. By the mid 1940’s, the City of Sparks plant was receiving between 2.5-3 MGD and the plant capacity was eventually expanded to 4 MGD in 1955. This plant was comprised of a set of bar racks, comminutor, primary clarifiers, rock media trickling filter, secondary clarifier, and chlorinator for the liquid treatment and primary and secondary digesters followed by drying beds for the solids handling. By the early 1960’s the average flow was 3.36 million gallons. Similar to Reno, Sparks flows were also excessively high due to the addition of storm water with the per capita flow of 330 gallons per day.
During the growth in the decades following the construction of each plant, with capacity concerns mounting and expansions of both treatment plants becoming necessary, a set of recurring discussion on creating a regional and more cost effective effort to sewer management began. This was first proposed in 1946 by sanitation engineer Harry Jenks. In 1952 Brown and Caldwell engineers again made the recommendation which was pushed forward by Reno City Manager Thomas Hilberg without success. Brown and Caldwell again recommended the unified approach in 1957 followed by John A. Carollo in 1959.
In April of 1961 the Director of the Nevada State Health Department’s Bureau of Environmental Health, Wallace White, directed the cities of Sparks and Reno to remove 90% of solids by 1980 and 96% of solids by 2000, a goal that Sparks officials determined required a new plant due to the relative inability to expand treatment processes at the plant location which was only removing 60%. The City of Reno also felt that this treatment standard was challenging for their existing plant due to it being overworked from inadequate storm drainage causing hydraulic capacity challenges and an unsatisfactory collection system. As a result the summer of 1962 brought about renewed discussions between both cities on the collaborative approach that eventually came to fruition with the start of construction of the new Reno-Sparks Joint Water Pollution Control Plant, now referred to as TMWRF, in 1964.
TMWRF was built to handle the majority of wastewater generated within the Cities of Reno and Sparks. Flow from the cities travels through a system of collection sewers and interceptors to two main trunk lines that feed the plant where it is treated and discharged to the Truckee River via Steamboat Creek. The plant is located at the mouth of the Truckee Meadows drainage area on the south bank of the Truckee River, east of Steamboat Creek.
The Truckee Meadows Water Reclamation Facility is jointly owned by the Cities of Reno and Sparks with the relationship outlined in an interlocal agreement. The plant was constructed with an original design capacity of 20 MGD and each city owned 10 MGD of capacity. Original plant facilities included:
- Preliminary Treatment: Two bar racks, Comminutor, Aerated grit chamber
- Primary Treatment: Three primary sedimentation tanks
- Secondary Treatment: Three aeration tanks,Three secondary sedimentation tanks
- Polishing/Disinfection: Post aeration tank, Chlorine disinfection
- Solids Handling: Three anaerobic digesters with floating lids, Sludge drying beds
- Support Facilities: Administration building, Electrical sub-Station, Electrical building, Blower building, Laboratory, Garage
Over time, the treatment facility has undergone major expansion projects to increase the plant capacity as well as to increase the effluent water quality. A timeline of the major plant modifications is shown below:
| Year | Project | Project Driver | Additions |
| 1964 | Initial Construction | - | - |
| 1978 | Plant Expansion | Capacity to 30 MGD Phosphorus Removal |
Two Bar Screens One New Grit Tank Grit Cyclones Two New Primary Clarifiers One New Aeration Tank Two New Secondary Clarifiers New Post-Aeration Tank Dechlorination Tank Five PhoStrip Process Tanks Two WAS Thickeners Digester 4 |
| 1983 | Sludge Dewatering | Solids Handling |
Dewatering Building Three Centrifuges Septage Receiving Facility |
| 1985 | Plant Expansion | Capacity to 40 MGD Nitrogen Compliance |
Fourth Raw Sewage Pump One New Primary Clarifier One New Secondary Clarifier One New PhosStrip Tank Equalization Basin Four Nitrifying Trickling Filters Twelve Dual Media Filters Backwash Recovery Tank New Chlorine Contact Tank Digester 5 |
| 1987 | Denitrification | Nitrogen Compliance |
Four Denitrifying Fluidized Bed Reactors Methanol Facility Fire Protection System |
| 2004 | Plant Expansion | Capacity to 46.5 MGD |
One New Primary Clarifier One New Aeration Tank Two New Secondary Clarifiers Two New Nitrifying Trickling Filters Acid Phase Digester Primary Screening Facility |
| 2015 | Energy Conservation | Resource Recovery |
Gas Conditioning System New Cogeneration Unit New Septage Receiving Headworks Improvement Nutrient Recovery Facility |
