The Industrial Wastewater Treatment Facility (IWTF) has been treating Industrial Wastewater from agriculture- based industries for many years. In an agreement with the City, E.H. Spiegl, a local businessperson, originally began building elements of the facility in 1943, to serve his dehydrated vegetable manufacturing plant that supplied the civilian population and the armed forces during World War II.  In accordance with the agreement, ownership and operation of the facility transferred to the City after the war.

Prior to 1966, the facility consisted of a series of percolation ponds covering approximately 20 acres with a percolation capacity of 0.75 MGD. In 1966, the City expanded the facility to 35 acres with 3 acres of anaerobic settling ponds, thus increasing the disposal capacity to 1.5 MGD. During this time, the facility had a difficult time controlling odor generated by the treatment processes.

Under the California Clean Water Grant Program and the Federal Water Pollution Control Act, the City received State and Federal assistance to upgrade the facility, which was completed in 1973.  The newly upgraded facility included an aeration lagoon that would enhance treatment and reduce odor problems.

In 1983, Federal Regulations contained in 40 CFR 403 required that a Pretreatment Program be developed and implemented.  The City retained James Montgomery Consulting Engineers, Inc. (JMM) to create the Pretreatment Program. The EPA approved the City’s new Pretreatment Program in May 1983.

The following year, in 1984, the Central Coast Regional Water Quality Control Board (CCRWQCB) revised requirements to prohibit discharge of treated water to the Salinas River.  To comply with this requirement, construction of a pumping station began in October 1984.  Completed in March 1985, this pumping station allowed the discharge of water from Pond #3 to 67 acres of disposal beds.  However, the City continued to request the Regional Board’s permission to discharge to the River during wet weather when the treatment facility’s percolation capacities were reduced.

Responding to the City’s request, the CCRWQCB granted the City a new NPDES permit in 1987, which allowed the City to discharge into the Salinas River when there was 100:1 river water to wastewater dilution.

A threat to the continued operation of the facility arose in 1990-91 when several of the facility’s largest users left the area. The loss in revenues obligated the City to consider raising rates to meet operational costs.

In 1992, the CCRWQCB issued a revised discharge permit. This permit included a higher TDS limit of 1,500 mg/L in recognition of increasing levels of salt in the wells used to supply the industries.

Additionally, this discharge permit acknowledged the reduced flows and past pretreatment compliance of the industries and granted some relief on Pretreatment Program reporting requirements.

To help recover revenues lost in 1991, the City completed a collection system expansion project in June 1994 adding almost a mile of Industrial Waste sewer line.  This project allowed the connection of three significant volume dischargers that were outside of the City’s former service area, thereby improving the financial viability of the IWTF.

In 1995, a 500-year storm event resulted in the flooding of the Salinas River. In addition to damaging the pond levees and roadways, the Salinas River deposited silt into the ponds and disposal beds. For several years after, the City negotiated with the Federal Emergency Management Agency (FEMA) on determining reimbursable costs to repair the facility. Throughout these years, adequate treatment and disposal continued to be accomplished. In 2000, the City began repairs to the damages caused by past storms. Final work on the storm damage repairs was completed in early 2002 that included repair of access roads at the plant and completion of the damaged perimeter fencing.

In 2002, after reviewing the requirements for renewing the City’s NPDES permit, and with the RWQCB’s recommendation, the City applied for a new Waste Discharge Requirement (WDR) in lieu of a NPDES permit. An NPDES permit is designed to protect the water quality of the receiving water body (the Salinas River). New NPDES requirements would have resulted in a significant increase in required monitoring, along with associated costs.