Wastewater Treatment


Beginning in the 1920’s up to the late 1950’s, the Redlands “Sewer Farm” (a common term during that time) was located north and west of the City, on the north side of the Santa Ana River, near Alabama Street. Treatment technology at that time was limited and the treatment provided was minimal. Raw sewage was placed in a large tank, and allowed to settle. The solids were then transferred to large drying lagoons, and the liquid portion, without further treatment, was discharged to the Santa Ana River.

In the late 1950’s federal legislators enacted nationwide regulations which required upgrades of all wastewater treatment facilities and the elimination of all pipelines crossing water courses wherever possible.

As a result of these new regulations, the City of Redlands facility was relocated in the early 1960’s to the south side of the river at the north end of Nevada Street and modified to provide secondary wastewater treatment. With this method of treatment the wastewater solids are settled in large tanks and then removed, dried and then disposed of off site. The liquid portion is combined with “safe to humans” bacteria and processed further as the bacteria consume over 95% of the waterborne pollutants. The processed water is then percolated back into the groundwater basin.

The Redlands Wastewater Treatment Facility is located on approximately 50 acres. The facility currently employs a staff of 23 plus 6 Operator-in-training volunteers and operates on a continuous basis. The facility has the ability to process 9.5 million gallons of wastewater per day, and is currently processing about 6 million gallons per day. The facility is very efficient in it’s ratio of gallons of wastewater treated to number of employees, and the degree of treatment achieved. The facility has never been cited for any violation and maintains a good reputation in the industry.


The City of Redlands operates a certified environmental laboratory for monitoring its drinking water supply and wastewater effluent. The laboratory is certified by the State of California, Department of Health Services. The laboratory has two objectives. First, the laboratory provides information to the operational staff of the City’s water and wastewater treatment facilities, and sanitary landfill. Second, the laboratory provides monitoring information to the State of California’s environmental regulatory agencies. The laboratory staff is trained in highly technical testing procedures, and uses sophisticated instrumentation, such as ion chromatography and total organic carbon, to perform required laboratory analysis.

The City’s laboratory is located in the Training Center Building at the City’s Wastewater Treatment Plant. The laboratory is in operation every day of the year, to provide the laboratory analysis and reports required for daily water and wastewater operations to meet all regulatory standards. The laboratory is currently staffed with five positions, including a regulatory compliance officer and four laboratory technicians.

The City’s laboratory operates cost-effectively and responsively to meet the joint needs of the City’s three Municipal Utilities, water, wastewater, and solid waste (landfill), to ensure compliance with regulatory requirements for safe drinking water, for a high degree of wastewater treatment and disposal, and protection of groundwater quality.