There were about 1,000 residents in 1925 in Indio with the largest employers being citrus, date ranching and the railroad. The residents knew that continued use of septic tanks for sewage disposal posed a threat to town water supplies. To help prevent well contamination and decrease the threat to public health citizens filed a petition and obtained a favorable public vote to form the Indio Sanitary District (District) on March 20, 1925. The name changed to Valley Sanitary District (VSD) in 1965. The District was formed under the authority of the Sanitary District Act of 1923 with local governance by a five person elected board of directors. Subsequent to District formation, residents dug trenches and installed pipe from residential and business blocks.
The first sewer system was bounded by Deglet Noor, Indio Blvd.(then Hwy 99) and Avenue 46 (Hwy 111), plus Southern Pacific's railroad yard. The original area encompassed about thirty six blocks (one half square mile), the current district boundary is approximately 19.5 square miles. The wastewater treatment plant was located on the current site about one half mile east of the original district next to the storm channel.
The 1950’s brought advanced technology, for the time, to VSD with the addition of a bar screen, primary clarifiers, secondary clarifiers, trickling filter, digester and Chlorine contact chamber. Treatment remained virtually unchanged from formation of VSD into the 1950's. An Imhoff Tank was used to separate solids and liquids and the liquids discharged to the Whitewater Channel. In the early 1950's additional improvements to the treatment system became necessary as the Indio population had grown to 8,000+ and Indio continued to be the center of commerce in the Valley.
The pond system was increased 14 acres and the existing ponds modified for mechanical aeration to increase treatment capacity in the 1960's. A wet air oxidation treatment, Zimmerman Process, was added in the late 1960's.
In the early 1970's, the District aggressively pursued and obtained federal grants that made it possible to add approximately five times the wastewater treatment capacity. In 1978 VSD was serving approximately 9,500 accounts with an average daily flow of about 3.5 million gallons per day (MGD). The Districts sphere of influence was bounded by Avenue 38 to the north, Avenue 51 to the south, Harrison Street to the east and Washington Street to the west.
Improvements in the 1980's included the 48 inch Van Buren Trunkline and treatment pond modifications and upgrades.
In the 1990's it was determined that the future VSD build out service area would serve a population of about 128,000 and that the current 7.5 MGD treatment plant capacity would need to increased to 18 MGD. At the time the population was approximately 44,000 and there was about 125 miles of public sewer. The average daily flow at the treatment plant was about 4.6 MGD. The 1990's brought about construction of a new treatment plant headwork's and two new trunk sewers.
In 1993 VSD recognized the potential for development north of Interstate 10 in what is now known as "Shadow Hills" VSD partnered with the City of Indio to form the Assessment District and installed sewer infrastructure in preparation for future development.
VSD celebrated its 70th anniversary in 1995. The five member board of directors has had thirty seven members over the past seventy years. Population growth in VSD's service area had grown 36 percent over the past decade and the collection system pipeline increased 104 percent, from 63 to 133 miles.
The development boom in 2004 caused completion of the remaining 1993 Shadow Hills interceptor sewer improvements at a cost of $9.6 Million.The 2004 Shadow Hills Interceptor sewer improvements included the directional bore installation of a 54 inch carrier pipeline under the Whitewater storm Channel and Interstate 10.
From new headwork's construction in 1998 through the treatment plant improvements constructed in 2006 $42.9 Million was spent on capital improvements.
In 2005 Phase 1 construction of $24.5 Million in treatment plant improvements were constructed to treat increased flows due to development. The treatment plant improvements included modifications for increased air flow for the activated sludge plant and construction of new circular clarifiers.
Phase 2A treatment plant improvements, began in 2012 at an estimated cost of $19.2M, with completion in 2013. This improvement added primary clarification, anaerobic digestion and other process improvements. A new Supervisory Control and Data Acquisition (SCADA) system for the plant process was installed. Additionally a new Administration Center, Operations Center and Laboratory were constructed.
In 2016, the District commissioned a 1 MegaWatt Photovoltaic Solar System, providing approximately 40 percent of energy needs for the facility. An adjunct project was the completion of a Perimeter Security System, consisting of advanced fencing, lighting, CCTV and intrusion alert system.
The Requa Sewer project was completed in 2017, and added approximately 22,000 feet of 10 to 36 inch pipe beginning at the treatment plant on Van Buren Street extending west to the intersection of Shields Road and Highway 111.
Phase 2B plant improvements are expected to begin in 2018, and will have a major emphasis on energy consumption, to bring the facility to near Net Zero in energy consumption.
The District is a member of a Joint Powers Authority (East Valley Reclamation Authority) with the Indio Water Authority to undertake the beneficial re-use of water by developing a reclaimed and re-cycled water system.