City of San Luis Obispo - Utilities Department Water Reuse

Water, like used motor oil, newspapers and aluminum cans, can be recycled, hence our recycled water slogan, “ Once is never enough.” If possible, all our precious resources need to be carefully used, reused and recycled.

Removing contaminants from the water produces recycled water. The State of California Department of Public Heath regulates the uses of recycled water based on the level of treatment.

The Story of Recycled Water
Recycling water for reuse is our opportunity to meet some of our City's water supply needs. While using recycled water is new to San Luis Obispo, it is not a new idea. The Golden Gate Park in San Francisco has been irrigated with recycled water since the 1930's. The golf courses at Pebble Beach are irrigated with recycled water. The City of Santa Barbara has been selling recycled water for irrigation for a number of years. In our own county, several golf courses are irrigated with recycled water.

How will the City's wastewater be recycled for reuse?
Through a very complex treatment system, our water reclamation facility is treating and disinfecting wastewater to produce a high-quality water supply that can safely be reused for irrigation. Producing recycled water became feasible to the City when the reclamation facility was upgraded in the early 1990's. The water that is produced is safe to release into the creek and can be reused to irrigate our parks and landscaping.

It's Nature's Way.
Water is constantly cycling through phases and processes. In nature, water evaporates, condenses, falls to the earth as rain, is absorbed into soil, plants and animals and then is processed into water and solid byproducts. Wastewater treatment at a plant is simply an accelerated process that mirrors nature’s way of recycling water and replenishing water supply.

Recycled water has become key to meeting the water needs of communities such as ours where water supplies are limited and dependent on rainfall. Rather than using precious drinking water supplies to irrigate landscape, recycled water can be used. It is a more dependable water supply for irrigation because it is not rain-dependent, and, therefore recycled water will be available even during droughts.

Recycled water is safe and approved for irrigation of school grounds, parks and golf courses. It can also be used for groundwater recharge and certain commercial and industrial uses. Purple pipes and signs mark the locations where recycled water is being used.

The State of California has adopted the goal of providing at least 1.5 million acre-feet per year of recycled water by the year 2020.

What level of treatment is provided?
The City of San Luis Obispo produces disinfected, tertiary-treated recycled water. Because the water is treated to this highest quality-level, it can be used for any purpose other than drinking, preparing food, or filling swimming pools. All water from the Water Reclamation Facility is treated to the tertiary level. Some of the tertiary treated water is distributed for irrigation and some is discharged to San Luis Obispo Creek for maintenance and enhancement of habitat.

What is the process for reclaiming water?
The Water Reclamation Facility uses processes similar to those found in a natural stream to purify water. However, energy is used to accomplish the task at an accelerated rate in a confined space. Sedimentation removes most of the suspended materials, microbes remove dissolved material and then the microbes are removed by sedimentation, filtration removes very fine suspended materials and remaining microbes, and finally chlorine is added for disinfection.

Where is the City’s Water Reclamation Facility?
The Water Reclamation Facility is located between Highway 101 and San Luis Obispo Creek at 35 Prado Road.

How can we get a tour?
Tours can be arranged by calling Jim Autry, the plant supervisor, at (805) 781-7240.

Where will recycled water be used in the City of San Luis Obispo?
Beginning in 2006, recycled water was distributed through a newly constructed recycled water distribution system in the south end of the City to water customers that use large amounts of water for irrigation. These included City parks, schoolyards, athletic fields, landscaping along Highway 101 and street landscaping along pipeline routes.

What route will the City’s recycled water distribution system follow?
The recycled water pipeline will begin at the Water Reclamation Facility and go west along Los Osos Valley Road to the City limits and up Madonna Road to Laguna Lake Park. Another line will head east along Prado Road and then cross to Broad Street and continue east on Tank Farm Road. See the project map.

What parks and schools will be irrigated with recycled water?
Laguna Hills Park
Laguna Middle School
Laguna Lake Golf Course
Laguna Lake Park
DeVaul Park
Damon Garcia Sports Fields
French Park
Islay Hills Park

How will I know when recycled water is being used?
Purple signs will identify all areas that are irrigated with recycled water.

Where is recycled water currently used in this County?
San Luis Obispo Country Club Golf Course
Chalk Mountain Golf Course
Black Lakes Golf Resort
Dairy Creek Golf Course

When was recycled water first used in California?
The first regulations for recycled water were adopted in California in 1918 - nearly 90 years ago! The first actual wastewater reclamation facility in the U.S. was constructed at the Grand Canyon in 1926. The recycled water was used for flushing toilets, irrigating landscape and cooling and boiler feed water at the Grand Canyon powerplant. In 1929, the City of Pomona began providing recycled water to irrigate lawns and gardens. In 1932, the City of San Francisco began using recycled water for irrigating lawns, shrubs and recreational lakes in Golden Gate Park.

What are the approved uses of recycled water?
The California Department of Public Health has approved the use of disinfected tertiary recycled water for the following (and more) uses:

Irrigation of parks, playgrounds and landscaping
Watering food crops
Industrial cooling
Groundwater recharge
Flushing toilets and urinals
Decorative fountains
Commercial laundries
Firefighting

Recycled water is NOT approved for human ingestion or food preparation.

Is recycled water good for plants?
The recycled water produced by the City of San Luis Obispo contains nitrogen and phosphorus, which will reduce the amount of fertilizer that needs to be applied. The amount of salts in the recycled water is higher than the amount in potable water supplied in the City of San Luis Obispo but it is not high enough to adversely affect any of the normal landscape plantings used in the area.

Is recycled water safe?
The City of San Luis Obispo produces “disinfected tertiary recycled water”. After extensive studies showed this quality of recycled water to be essentially pathogen-free, the Department of Public Health promulgated California Code of Regulations Title 22, Recycled Water Criteria defining treatment levels and appropriate uses for recycled water. It is safe to use for the approved purposes.

Does recycled water smell or look different than tap water?
No. Recycled water is the end product of a three-stage treatment process. Following tertiary treatment, the water is clear, colorless, odorless and virtually indistinguishable from tap water to the human senses. The recycled water does not contain any constituents that exceed federal and state drinking water standards for heavy metals, minerals, trace organic compounds, pesticides, microorganisms or radionucleides.

What would happen if I were to accidentally drink it? Or my dog drinks it?
No health related problems have ever been traced to any of the water recycling projects throughout the country. However, recycled water is NOT approved for human ingestion, food preparation, or filling swimming pools.

Is it necessary to wear protective clothing when working with recycled water?
Protective clothing is not necessary when working with recycled water and incidental overspray is not harmful. Although recycled water is safe to touch, it is good sanitary practice to wash your hands before eating.

How reliable is recycled water as a source of supply during periods of drought?
During recent droughts, there has not been a significant reduction in the amount of water treated at the Water Reclamation Facility. This water is not distributed for potable use. Therefore customers using recycled water can expect to see a steady supply being delivered even during drought conditions when severe restrictions are imposed on irrigating with potable water.

How much does recycled water add to the City’s current water supply?
The Water Reclamation Facility produces approximately 1,200 acre-feet of recycled water per year that could be distributed for reuse. In the future, recycled water will provide for the irrigation of parks and playgrounds and other landscaping associated with planned development in the City.

What will it cost?
Customers using recycled water will pay 90% of the approved water rate.

What is the difference between graywater and recycled water?
Recycled water is the highly treated disinfected water produced by the City’s Water Reclamation Facility and is suitable for most uses other than human ingestion, food preparation, and filling swimming pools.

Graywater as defined in Appendix G of Title 24, Part 5, California Administrative Code is untreated waste water which has not come into contact with toilet waste. Graywater includes waste water from bathtubs, showers, bathroom wash basins, clothes washing machines, and laundry tubs. It does not include waste water from kitchen sinks, photo lab sinks, dishwashers, or laundry water from soiled diapers.

Graywater can be used on the property where it is produced provided the local Building Department approves of the plans and issues a permit for the installation of a graywater system. The graywater must be discharged through an underground distribution system and cannot be allowed to rise to the surface.