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Frequently Asked Questions

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The following is a list of common questions on recycled water. Please contact us if your question is not answered here.

What is recycled water?

State and Local Recycled Water Standards, Regulations, & Guidelines

Applications of Recycled Water

Water Quality

Management and Operation

Equipment, Storage, and Distribution

What is recycled water?

Recycled water is water that is purified through several treatment processes to a level that is safe for a variety of beneficial uses. To produce recycled water, domestic wastewater from tubs, toilets, and sinks inside homes, offices, industrial facilities, and businesses is collected and conveyed to one of the Sanitation Districts’ 10 water reclamation plants (WRPs) for treatment through a three-stage (tertiary) process. Use of recycled water helps to conserve drinking water and promote sustainability by reducing the need to import water over long distances or pump our limited groundwater supplies.The treatment and use of recycled water is subject to regulation by various public agencies at the local and state levels to ensure that it is safe.

State and Local Recycled Water Standards, Regulations, & Guidelines

Who regulates recycled water in California?

A number of regulatory agencies have adopted requirements that must be followed when producing, distributing, and using recycled water. The California Department of Public Health (CDPH) has adopted strict public health and safety requirements and guidelines, which help protect the public from any potential risk associated with use of recycled water. These requirements are described in Titles 17 and 22 of the California Code of Regulations. Permits to oversee the production, conveyance, and use of recycled water are granted by the State Water Resources Control Board (SWRCB) and the corresponding Regional Water Quality Control Board(s) (RWQCB). Local Departments of Public Health may also have guidelines and inspection requirements for the use of recycled water, such as requirements for the use of backflow devices to prevent mixing of recycled water with potable water. The Sanitation Districts have adopted Ordinances and Requirements for Recycled Water Users pertaining to the use of recycled water that incorporate requirements and regulations imposed upon the Sanitation Districts by other regulatory agencies.

Applications of Recycled Water

What are the approved uses of recycled water?

Properly treated recycled water has been proven to be a safe for many uses, and the Sanitation Districts treat most of the water to the highest level, known as “tertiary recycled water.” Due to its high level of treatment, tertiary recycled water can be used for a broad range of reuse applications as listed below (essentially everything short of direct drinking water and the manufacturing of food and drink). However, it is important to remember that each recycled water permit issued to the Sanitation Districts spells out the specific uses that are approved for the recycled water produced at each treatment plant, so it is important to check with the Sanitation Districts’ Water Recycling Coordinator at 877-REUSE-83 (877-738-7383) or reuse@lacsd.org to find out which uses are allowed in your area.


  • Food crops
  • Parks and playgrounds
  • Schoolyards
  • Residential landscaping
  • Golf courses
  • Cemeteries
  • Freeway landscaping
  • Ornamental nurseries
  • Pasture for milk animals
  • Orchards
  • Vineyards
  • Fodder, fiber, and seed crops

Supply for Impoundments:

• Recreational impoundments (even those that allow swimming)
• Landscape impoundments

Supply for Cooling and Air Conditioning:

• Industrial/commercial cooling towers
• Industrial/commercial evaporative condensers

Other Uses:

• Groundwater recharge (case-by-case basis)
• Flushing toilets and urinals
• Priming drain traps
• Industrial processing
• Industrial boiler feed
• Fire fighting
• Decorative fountains
• Commercial laundries
• Consolidation of backfill material around pipelines
• Artificial snow making
• Commercial car washes
• Soil compaction
• Mixing concrete
• Dust control on roads and streets
• Cleaning roads, sidewalks, and outdoor work areas
• Flushing sanitary sewers

Where else is recycled water used?

Recycled water is used throughout the world for many different applications, including all those listed above. The United States, Israel, Jordan, Singapore, Spain, and Australia are considered leaders in the use of recycled water. For nearly 100 years, recycled water has been used in many ways and in many U.S. states and territories. Besides traditional uses such as industrial processes, agricultural irrigation, and the irrigation of lawns, landscapes, cemeteries and golf courses, California, Arizona, Texas, Virginia, and Florida add recycled water to and blend it with other water sources in reservoirs and underground storage basins that are used as drinking water supplies. Other states, including North Carolina, Hawaii, Georgia, Colorado, New Mexico, Washington, New Jersey, and Tennessee, recycle water to some degree.

In addition to the Sanitation Districts’ current water recycling program, recycled water is used in other California communities like Calabasas, Glendale, Burbank, Windsor, Rohnert Park, Petaluma, San Jose, Redwood City, Sunnyvale, Orange County, Santa Clara County, San Bernardino County, Riverside County, and San Diego County.

For more information on water recycling projects, see the WaterReuse Association Information and Resources link.

What is ‘industrial reuse’ and how can recycled water be used by commercial businesses and industries?

Industrial water reuse broadly refers to the use of recycled water for uses other than irrigation or groundwater recharge. Use of recycled water by industry has increased substantially in the last two decades due to increases in the cost of drinking water, combined with on-again/off-again water shortages that can limit business activities. Cooling water systems, particularly at power plants and oil refineries, are the largest industrial applications for recycled water, due to the large water demand in their cooling towers and boilers. Other industrial applications include chemical plants, metal finishers, textile and carpet dying, paper manufacturing, cement manufacturers, and other cooling and process applications. Recycled water can also be used for dust control and soil compaction at construction sites. Finally, commercial laundries and carwash facilities, as well as toilet flushing, can be served with recycled water.

How is recycled water used for car washes?

Commercial car washes are allowed to use tertiary recycled water. Recycled water may be used as an alternative to drinking water and the car wash may even recycle water several times during the washing process. These facilities may choose to soften the recycled water before use (as they often do with the drinking water supply).

Are cities using recycled water for street sweeping and fire hydrants? What requirements are there for those applications?

Recycled water may be used for these applications; however, proper procedures for its use must be followed. Separate hoses designated only for recycled water must be used and signage declaring the use of recycled water must be in place on the vehicles.

What is the difference between gray water and recycled water? Are they regulated differently?

Gray water is untreated residential wastewater that does not come from a toilet or garbage disposal (i.e., bathroom sink, bathtub, shower, laundry, etc.). Gray water is regulated by the state of California, and a building permit must be obtained before installing a gray water system to collect and send this water to the resident’s landscaping, but water quality is not routinely monitored. Recycled water, on the other hand, is water that is purified through several treatment processes to a level that is safe for a variety of beneficial uses. A number of regulatory agencies have adopted requirements that must be followed when producing, distributing, and using recycled water. Water quality is strictly monitored and routinely reported to the respective Regional Water Quality Board. A summary of the regulations and requirements for recycled water are provided in the Sanitation Districts’ Recycled Water Users Handbook (JOS/SCV and AV).

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Water Quality

Is recycled water safe?

Yes, water recycling is a safe way to preserve our natural water resources. Water recycling and reuse have been actively practiced by the Sanitation Districts since 1962. Throughout the United States, there has not been a single documented incident of illness or disease caused by the proper use of adequately treated recycled water. The Sanitation Districts’ water reclamation plants (WRPs) are designed and operated to produce a safe product that protects public health and the environment. The WRPs are permitted to function, under specific guidelines, by the State of California Department of Public Health, the California Water Resources Control Board, and the U.S. Environmental Protection Agency, and they produce a highly treated, filtered, and disinfected product that meets the State Health Department criteria. The WRPs are operated by Wastewater Plant Operators licensed by the State of California. Many safeguards are incorporated into every WRP, and the recycled water they produce is rigorously tested to meet or exceed national, state, and local regulatory standards (even many of those for drinking water). While recycled water is not intended for direct human consumption, it poses no threat to public health from accidental contact or even ingestion. All State and Federal permits and regulations, along with Operator Certifications, are available upon request. Click here for more information about the Sanitation Districts’ treatment facilities: LACSD Wastewater & WRP Facilities.

If recycled water is safe then why are there so many restrictions?

To ensure continued public acceptance for recycled water use, comprehensive restrictions are imposed to allow for the public to have full confidence that any potential health or environmental impacts associated with the use of recycled water are minimized. As noted above ("Is recycled water safe?"), recycled water is extensively treated and monitored in accordance with various laws and regulations. This high level of treatment allows for recycled water to be used in a variety of applications, including full body contact recreation. The restrictions ensure a consistent, high level of safety for each designated use at every use site. This proactive approach fosters the trust and acceptance necessary so that recycling water continues to be considered a safe and economical way to provide a significant water resource.

What are the uses of recycled water in the Sanitation Districts’ service area?

Currently, the Sanitation Districts provide recycled water to over 600 locations for a variety of uses. These uses include landscape irrigation at parks, golf courses, cemeteries, and street and highway medians. Recycled water is used to irrigate athletic fields at various school sites, ranging from day care facilities to universities. Other sites include the landscaping around commercial buildings and residential developments. Agricultural irrigation takes place at small local nurseries as well as farm operations, such as Cal Poly Pomona. Industrial uses include power plant cooling towers, concrete mixing, metal finishing, carpet dyeing, street sweeping, and construction. And finally, a large portion of the Sanitation Districts’ recycled water supply is used to prevent saltwater intrusion, through direct subsurface injection, or is applied in spreading basins to replenish the underground water table.

Does salt get removed by the process to produce recycled water?

Salinity is a quantitative measure of soluble salts, otherwise known as the total dissolved solids (TDS), in water. Conventional recycled water treatment processes do not remove salt. However, the salt levels in recycled water produced by the Sanitation Districts’ WRPs are at levels that allow it to be used for almost all types of reuse applications, even irrigation of sensitive plants, and are usually below that of water imported from the Colorado River. If necessary, additional advanced treatment, such as reverse osmosis, may be required to reduce salt in recycled water for specific reuse applications, like boiler feed water.

Is recycled water corrosive?

It can be, but this is generally only a concern for industrial processes such as cooling towers that are in constant contact with the water. Corrosion is an electro-chemical reaction on metallic surfaces caused by the presence of highly reactive ions in recycled water, such as chloride, sulfide, or sulfate, and can be increased by high pH levels, alkalinity, and reduced oxygen concentrations. The recycled water produced by the Sanitation Districts WRPs generates minimal corrosion, and most cooling towers operators need to add corrosion inhibitors to their water supply, regardless of its source.

Does recycled water stain concrete, granite, tile, or headstones?

Recycled water produced by the Sanitation Districts is well within the EPA drinking water standards for color, and will not stain most surfaces. Staining is associated with the calcium, iron, and copper content of water, which is generally low in the recycled water produced by the Sanitation Districts. Mineral deposits may occur, but at levels no more than what would generally occur with potable water.

Should we be concerned about microconstituents (pharmaceutical compounds, endocrine disrupting compounds, and/or personal care products) in recycled water?

This topic is being actively investigated. Preliminary studies indicate that these compounds can be present in recycled water, although at extremely low levels (in the part per trillion range, or the equivalent of a drop of water in an Olympic-size swimming pool). Experts tend to agree that a person would have to directly consume excessively large amounts of recycled water to approach exposure levels of these chemicals that would have any effect, harmful or otherwise. Some recent reports suggested that there is little difference between concentrations of microconstituents in recycled water compared to other water supplies, particularly surface water used as a drinking water supply. For nonpotable, low human contact uses of recycled water, such as watering of lawns, there is no indication of adverse health affects or damage to the environment from these low levels of microconstituents.

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Management and Operation

What is a recycled water user Site Supervisor and are they required?

A recycled water user Site Supervisor represents the owner, tenant, or property manager. The Site Supervisor is designated to be the main person to interact with the water purveyor and respond to inquiries and emergencies. The Site Supervisor must have the authority to carry out all of the user site requirements, including participation in inspections and cross connection testing. Current Site Supervisor information must be provided to the Sanitation Districts for each recycled water use site, including an address and phone number where he/she can be reached at all times.

What training is required to use recycled water?

All sites where recycled water is used are required to designate a recycled water user Site Supervisor. All Site Supervisors are required to have appropriate training to assure proper operation of recycled water facilities, worker protection, and compliance with all applicable laws and regulations, the Sanitation Districts’ permits, and other requirements. To help recycled water users fulfill their training obligations, the Sanitation Districts developed the Recycled Water Site Supervisor Training Program. Free classes are currently being offered periodically throughout the year at various locations. These classes provide information on the basics of recycled water, including how it is produced, site management, regulatory criteria, cross-connection prevention, health issues, and record keeping. Click here for the registration information.

Who needs to take the site supervisor course?

Any location using recycled water must have a designated Site Supervisor that is appropriately trained.The Site Supervisor is then responsible for the proper use of recycled water by everyone at that location. In the Antelope Valley, including Lancaster and Palmdale, all staff involved in the operation and maintenance of the recycled water system in use receive appropriate training.

Whose responsibility is it to make sure Site Supervisors have the proper information?

The Sanitation Districts, as reuse permit holder and producer of the recycled water, along with the wholesale and/or retail water purveyor(s) who deliver the recycled water, are responsible for this duty. This information can be obtained through the Sanitation Districts’ Site Supervisor Training and its Reuse Site Inspection programs. This information is also available on the Sanitation Districts’ website at www.lacsd.org.

Are the Site Supervisors and Site Inspectors the same person?

No, Site Inspectors verify that the system meets specifications and that the Site Supervisor is using recycled water appropriately.

Should Site Inspectors take the Site Supervisors training class?

Yes, they should. By understanding the duties of the Site Supervisors, in terms of managing the recycled water system at their site, Inspectors will be better able to perform their duties.

When is a site inspection required?

Regular visual inspections (approximately on an annual basis) are required in order to identify problems, such as potential cross connections, missing signs and labels, ponding and/or overspray, etc. The California Department of Public Health requires that backflow prevention devices used to protect potable water be tested annually. This will be done by the local water purveyor. Coordinating site inspections with backflow preventer testing is recommended.

When should a shutdown test be performed to ensure that back flow problems and cross connections do not exist?

An AWWA-certified specialist (or equivalent) must perform a cross-connection shutdown test before a new reuse site begins receiving recycled water and after any major modification to the drinking or recycled water system at reuse sites with both water supplies.

Do the Districts have training/educational materials available to help interested parties develop programs?

Yes, the materials that we provide in the Site Supervisor training classes are available on the Sanitation Districts’ recycled water website: Resources.

Do you need to use gloves with recycled water?

No, gloves or other protective clothing or equipment do not need to be worn when in contact with recycled water because recycled water is safe and allowed for full body contact. Typical good hygiene practices (e.g., wash hands before eating) are recommended when in contact with recycled water. However, recycled water is not allowed for use as a direct drinking water source.

What is the best time to water medians, lawns, and golf courses?

Landscape irrigation of public access areas, like parks, should be done at night from 10:00 PM until 6:00 AM, to reduce evaporation and limit public exposure (e.g. someone drinking/bathing using a sprinkler). Irrigation of sites with no public contact, such as freeway slopes and commercial nurseries, can be done during daylight hours.

If it’s safe to swim in, why do we limit public contact?

Limiting incidental public contact (e.g. sprinkler overspray) has to do with consent. People who swim in a pond or lake that is clearly marked as being filled with recycled water are making an informed “choice” to be in contact with recycled water. Having the sprinklers come on in a park during the day when people are present results in involuntary contact with the recycled water.

Can you irrigate public access areas with recycled water before 10:00 PM?

Yes, you can. Many irrigation sites have areas that require additional water for their plants’ health and appearance, such as golf courses. Daytime irrigation is permitted just as long as the irrigation is manually controlled and supervised to prevent public contact.

We installed a recycled water system to fill a pond in one of our City parks. Since then, we have experienced problems with algae growth that has affected the pond’s clarity and color. How should we manage our recycled water impoundments to prevent algal growth?

Algal growth is a result of residual nutrients (nitrogen, potassium, and phosphorous) in the recycled water, which can be minimized by implementing a program to prevent optimal growing conditions. The most efficient way to reduce or eliminate algal growth is to use the pond as a source of irrigation water for the park, thereby cycling fresh recycled water into and out of the pond and applying the nutrients to the park’s landscaping. Also, ponds receiving recycled water should be at least 10 feet deep, as the reduced sunlight penetration also helps decrease algal growth. Preventing grass clippings and other organic material from entering the pond has been noted to help reduce algal growth, as has aeration of the ponds by means of waterfalls or fountains.

What is incidental runoff? Is there a threshold?

Incidental runoff refers to recycled water that flows outside of its intended use area, such as from sprinkler overspray. Recycled water use sites should be designed to minimize incidental runoff, as small amounts can be allowed, but systems regularly discharging significant amounts of recycled water may require a discharge permit.

Should I be concerned about controlling sprinklers and exposures during high winds?

Wind should be considered when designing and implementing a recycled water irrigation system. A buffer zone may be required between irrigated areas and drinking fountains, eating areas, residential neighbors, and domestic wells. See the user manual for specific requirements.

Why do you need separate signage indicating recycled water use for each irrigation control/valve box identified even if you have posted signs indicating that the entire site is using recycled water? Can you place the signage indicating recycled water use inside the irrigation control cabinet?

By code, every aboveground appurtenance (valves, control boxes, pumps, etc.) on the recycled water irrigation system must be identified. This can be done in various ways, including externally, by using a purple PVC valve box for example, or internally, by using tags or stickers. This identification is necessary so that on-site workers immediately know that they are working with recycled water. This should greatly minimize the chances that any recycled water lines might be mistakenly cross-connected to a potable water line.
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Equipment, Storage, and Distribution

Do you have to replace all existing irrigation pipes with purple pipes in order to hook up recycled water?

No, you do not. While purple is the designated color for recycled water facilities, existing pipes need not be replaced when a site switches over to recycled water. However, above ground facilities, like irrigation valves and control boxes, must be labeled or tagged. In addition, it is recommended that new recycled water installations use purple PVC pipe or be marked with purple tape. Valve boxes are also available in purple PVC, as are quick couplers and sprinkler heads with purple PVC caps.

What equipment and hoses are needed for recycled water use when transporting the water?

Hoses must be designated for recycled water use only. Hose bibbs, even those with removable handles, may only be used in locations with restricted access to the public. In most locations, quick coupler connections that are not compatible with typical drinking water connections must be used. Tanks used to store or transport recycled water must be disinfected after use if they are also used for storage or transport of drinking water. All areas from which recycled water can be drawn must be clearly labeled as associated with recycled water.

Who owns, operates, and maintains the backflow prevention devices?

Backflow preventers are devices installed on the potable water line entering a site, just downstream of the meter. These devices prevent any recycled water from backflowing into the drinking water distribution system. These are owned and maintained by the domestic water provider.

Who is responsible for creating an emergency plan in the event of a cross-connection?

Each user must develop an emergency cross-connection response plan. A template for an emergency cross-connection response plan can be found in the Recyced Water Users Handbook. At a minimum, such a plan should include which staff members are responsible for shutting off both domestic and recycled water supplies, notification lists (e.g., Health Department, water purveyor, Sanitation Districts), etc.

Is there a minimum separation required between recycled water and sewage pipes?

Recycled water distribution pipes must be separate from both potable water and sewage pipes. In most instances, the pipes must have a minimum separation of horizontally by 4 feet and vertically by 1 foot, with recycled water going underneath potable water lines and over sewers.

Are there issues with regrowth of microorganisms in storage tanks, ponds, and distribution systems and how do you control it? Is there chlorine residual in the distribution system?

Yes, regrowth of microorganisms can occur in storage tanks, ponds, and distribution systems. This occurs in all water systems, but can happen faster with recycled water as a result of the residual nutrients it contains. Because regrowth can occur in distribution lines used for the transport of recycled water to a distribution system, chlorine residual on the order of 1 to 3 mg/L, depending on local conditions, should be maintained in the pipeline. This is a common practice used to control biofilms and re-growth in any water distribution system. The Sanitation Districts supply recycled water with a chlorine residual to our water purveyor partners; however, if additional residual is needed farther down the distribution system, it is the purveyor’s responsibility to provide this. Additional detailed information is available in a technical manual: “Guidance Document on the Microbiological Quality and Biostability of Reclaimed Water Following Storage and Distribution (WRF 05-002)” available on the WateReuse Research Foundation website (http://www.watereuse.org/).

Is there a master plan to install/retrofit recycled water into older areas?

The Sanitation Districts rely on regional and local water agencies to supply recycled water from the WRPs to the end users, as it is their mission to deliver any source of water. We cannot expand distribution systems to deliver recycled water to individual user sites. Please contact your local water provider (purveyor) to obtain their current or proposed plan for providing recycled water in your area.

How is a reuse project started?

First, a regional or local water purveyor signs a contract to buy recycled water from the Sanitation Districts. The water purveyor then builds a pump station to move the recycled water from the Sanitation Districts’ WRP into a transmission system of pipelines it builds throughout its service area, which is completely separate from the drinking water and waste water piping systems. The water purveyor then works with potential users to establish connection points at the sites that would like to use recycled water. Each reuse site is retrofitted to separate the drinking water system from the recycled water irrigation system. Once signs are posted, irrigation system appurtenances are properly marked, a cross-connection shut down test is performed, and after the County Health Department approves the retrofit, then recycled water deliveries can begin.

When consultants are hired to start new projects, where do they begin? Is there a project initiation checklist?

See the Sanitation Districts’ Recycled Water Users Handbook for guidelines and a checklist.

When can a new project start using recycled water?

Typically, recycled water can start to be used at a newly connected site once all of the retrofit conditions imposed by the water supplier have been met, the plan check by the County Health Department has been approved, and a cross-connection shut down test has been successfully completed.

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