Recycled Water

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Recycled water, also called reclaimed or reused water, is highly treated wastewater approved for reuse by the California Department of Public Health for a variety of applications. The City utilizes recycled water for irrigation and construction water on local development projects.

Over half of the City’s parks are currently irrigated with recycled water, and more are scheduled for connection as they are developed. Parks utilizing recycled water include Damon Garcia Park, Laguna Lake Park, Islay Park, DeVaul Park, EA-French Park, and the Laguna Lake Golf Course.

You may have seen the purple signs, piping and other infrastructure around town indicating Recycled Water is in use!

Why is Recycled Water Important?

Recycled water alleviates demand on the City’s potable water supplies. Its demand offsets 5% of the City’s annual water demand - that is 18 days of water each year that are left in our reservoirs as a result of our use of recycled water!

As operations for recycled water use continue to expand, the City will utilize less from our potable resources and ensure a drought resilient supply for the future.

If you are interested in obtaining a permit for recycled water service for either landscape irrigation or construction water, keep reading below!

Construction Water Permit

Recycled water for construction use is available for hauling at several locations throughout the City with an approved permit. Permits are effective for selected durations, and permits must be renewed each year. Permit fees are not prorated. All water hauling vehicles listed on the permit application are subject to inspection in order to satisfy permit requirements.

Fees

Effective October 1, 2024:

Permit Type	Duration	Base Fee (includes 1 vehicle)	Each Additional Vehicle
Annual	July-June	$1,954	$1,446
Semi-Annual Semi-Annual	July-December January-June	$1,124	$723
Quarterly	Q1 - July-September Q2 - October-December Q3 - January-March Q4 - April - June	$691	$361

Application Process

Review the Recycled Water Construction Water Permit Program brochure.
Submit permit application to UT_Services@slocity.org
- You must include project duration and select the appropriate permit duration.
- You must include ALL water hauling vehicles (water buffalo, tank truck, etc)
- Application will be reviewed and determined if inspection is needed
- Payment cannot be submitted unless application has been received and reviewed.
- Payment cannot be made until application is submitted and received.
- Staff will direct applicant to make payment to City's Finance Department.
Staff will schedule an inspection if needed to be conducted downtown at 879 Morro St
- ALL water hauling vehicles must display "NON-POTABLE" signage, contain air gap separation or backflow device and be equipped with a hydrant wrench
Permits and vehicle tags are issued in person once fee is paid and requirements are satisfied. All water haulers must keep a current copy of the permit in the vehicle at all times.

Enforcement

City staff actively monitor recycled water hydrant use and verify permit compliance. Any water hauler deemed non-compliant with permit requirements will risk the Construction Water Permit being revoked for the remainder of the current permit year.

Enforcement violations include:

Hauling vehicle displays improper signage
Hauling vehicle does not display current vehicle registration tag
Hauling vehicle is not carrying copy of current permit
Hauling vehicle is not listed on current permit
Hauling vehicle and associated company do not have current permit

Fines may be incurred as a result of these enforcement actions.

Landscape Irrigation

Landscape Irrigation Application Process

All new development, if applicable, is required to utilize recycled water for irrigation of common areas, parks, and parkways. The City is currently not accepting applications at this time for retrofitting existing potable irrigation.

If you are beginning a project, please follow this process as part if your building utility plan review:

Obtain recycled water use permit application (No Fee)
Submit Irrigation plans to the Community Development Department
- Must undergo approval by the City, Division of Drinking Water, and Regional Water Quality Control Board
- Must be designed to utilize recycled water grade materials, have required recycled water signage, and minimize risk of cross connection to potable water systems.
Required Site inspection, cross connection and coverage tests certification
- Prior to a recycled water meter being set, a cross connection test must be scheduled with the Utilities Department. Contact kfortner@slocity.org for more information.
Required site supervisor training. Per CFR Title 22, each site utilizing recycled water must have a single person designated as the Site Supervisor. This person is responsible for submitting site inspection reports to the City four times per year.
Submittal of an irrigation schedule.
Permits are issued once all requirements are satisfied.

Safety Information

Recycled water must meet the rigorous standards set forth by the State Water Resources Control Board and California Department of Public Health within Title 22 of the California Code of Regulations.

When used as approved by the State, recycled water is completely safe for use within the community. Recycled water is the end-product of a multi-stage, advanced treatment process that has multiple water quality sampling done to ensure that it is safe for use.

The Water Resource Recovery Facility (WRRF) infrastructure and treatment upgrades will further enhance the quality of the City’s recycled water and continue to provide the City with safe and readily available recycled water supplies.

If you are interested in learning more about how safe recycled water is for use as a resident utilizing a local park or golf course, or a landscaper working on an irrigation system that utilizes recycled water, please click one of the links below for user-specific information:

Information Sheet Source: Click Here

Recycled Water Sources

Where Does Recycled Water Come From?

Wastewater is collected by the City’s Water Resource Recovery Facility (WRRF) where it undergoes tertiary level treatment, one of the most advanced wastewater treatment levels presently available. Wastewater enters the facility from the wastewater/sewer collection system and passes through a two-step screening process where large objects are removed, and fine material is settled to the bottom. Suspended solids are then settled out in large clarification tanks where they are separated, treated, and beneficially used as biogas and compost production. After an enhanced biological treatment process that removes nutrients such as nitrogen, the water filters through membrane bioreactors to remove any remaining solids. Lastly, the water passes through a UV light disinfection system that breaks down, and renders inert, any remaining microorganisms.

This highly treated water is stored in a 700,000-gallon tank and distributed through 14 miles of recycled water pipeline to the community. The piping infrastructure used to deliver recycled water is completely independent of the City’s potable water distribution system and has the capacity to deliver up to 2.5 million gallons of recycled water throughout the City on an average day.

Production and distribution of tertiary treated recycled water is regulated under the City’s existing Waste Discharge Requirements/Master Reclamation Permit (Order No. R3-2003-081). The Permit outlines prohibitions, requirements for construction and irrigation use, and a monitoring program for use of recycled water. The entirety of the recycled water treated at the WRRF is compliant with Title 22 requirements, but only a portion is currently distributed to the community.

In addition to complying with the permit requirements described above, the City is required to comply with minimum daily average discharge requirements of 1.6 MGD from the WRRF to San Luis Obispo Creek for protection of downstream biological resources as required by National Oceanic Atmospheric Association, National Marine Fisheries Service (NOAA NMFS).

To learn more about the City’s upgrade of the WRRF, visit slowrrfproject.org.

Future Uses

Recycled Water Irrigation Expansion

Recycled water is currently available to southern portions of the City where it can be minimally pumped into the distribution system. The extent of the Recycled Water service area was developed to consider the high costs of installing pipelines, storage tanks, and other recycled water infrastructure while ensuring the City remains sustainably-minded in reducing energy demand and maximizing recycled water use demand.

New developments within the Recycled Water service area such as Righetti Ranch, Avila Ranch, and San Luis Ranch are required to utilize recycled water for landscape irrigation of common areas, parks, and parkways. To view more details about the City’s plan for expanding where recycled water is used, please click here.

Indirect Potable Reuse

Indirect potable reuse (IPR) is recycled water that has been introduced to an environmental buffer, either a surface water reservoir or a groundwater system. After rigorous testing, the water is subsequently safe for use as a drinking water supply. IPR is a technically complex process that utilizes a mixture of advanced treatment of recycled water and natural treatment through application to the natural environment (reservoirs or groundwater basins).

As the City moves towards utilizing groundwater as a potable source, capacity created within the groundwater basin may allow for recycled water to be used to recharge the basin during periods when natural recharge from rainfall and percolation from local creeks is not sufficient. The ability to recharge the groundwater basin with recycled water both increases the volume of groundwater available to the community, and makes beneficial use of recycled water which is a locally available, drought resilient water supply.

For more information about the City’s emerging groundwater supply, click here.

Direct Potable Reuse

Direct potable reuse (DPR) occurs when advanced treated recycled water is introduced directly into the drinking water distribution system. Recycled water must undergo significant levels of additional treatment and testing to ensure the water is safe for use by the community. The State of California recently adopted DPR regulations in 2023.

DPR has the potential to increase the City’s existing supply by reducing demand on our traditional source waters - Nacimiento, Salinas, and Whale Rock reservoirs, and making full use of the City’s recycled water supplies.

Please contact City of SLO Utilities Department at (805) 781-7215 for questions and most current information regarding the use of recycled water.

_{Please contact Recycled Water Specialist, Kellie Fortner at kfortner@slocity.org with any questions regarding this information.}

City of San Luis Obispo, CA

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