Recycled water is municipal wastewater that has been treated to meet State of California regulations. These treatment standards are set for different types of water reuse. The recycled water delivered within the Carlsbad Municipal Water District service area has received an advanced level of treatment known as tertiary treatment.
This treatment process mirrors nature's own treatment, only at an increased speed. Primary treatment settles the solids out of the wastewater. In the secondary treatment stage, biological systems consume organic waste. In the third or tertiary stage, wastewater is filtered through fine sand or charcoal. The recycled water is then disinfected before leaving the treatment plant. The finished product is a high quality water that is safe for landscape irrigation and other non-drinking uses.
Each year, the Carlsbad Municipal Water District distributes nearly 1.23 billion gallons of recycled water to local irrigation customers. This is more than 16 percent of the total supply of water and recycled water distributed by the water district.
- Signs must be posted in areas where recycled water is used to indicate it is not safe to drink.
- Recycled pipes, valves and sprinkler heads are easily recognizable by their purple color.
How is using recycled water different from drinking water?
Although recycled water is a highly treated product, it is not treated to the same standards as drinking water delivered to homes and businesses. For this reason, conditions for the use of recycled water have been established.
Recycled water is not suitable for drinking. Recycled water customers must post informational signs, mark sprinkler heads, pipes and other appurtances, and ensure there are no cross-connections between drinking (potable) and recycled water systems.
Irrigating with recycled water is generally allowed before 6 a.m. and after 10 p.m. This minimizes misting and evaporation for more effective irrigation. It also minimizes the chance of public contact.
Recycled water contains nitrogen and phosphorus which can provide a fertilizer benefit. However, the salt level is slightly elevated, so depending on soil and plant characteristics, periodic overwatering, also known as leaching, may be necessary.
The City of Carlsbad has approximately seven miles of recycled distribution pipeline. This distribution system currently supplies more than 500 recycled use sites. The sites served by recycled water include La Costa Resort and Spa, Park Hyatt Aviara Resort, Legoland California, Grand Pacific Palisades Hotel, Karl Strauss Brewery and the world renowned Flower Fields. Recycled water is also supplied to many of the City of Carlsbad parks, median strips, shopping areas, freeway landscaping and "common areas" of many homeowner associations.
Recycled water distributed by the water district is supplied by three different sources, including the Meadowlark Treatment Plant, owned and operated by the Vallecitos Water District, the Gafner Treatment Plant, owned and operated by the Leucadia Wastewater District and the Carlsbad Water Recycling Facility, owned by the Carlsbad Municipal Water District and operated by the Encina Wastewater Authority.