Water reclaimed from blackwater is generally more expensive to produce and deliver than potable water bought from water agencies. However, that cost is considerably lower than the cost of the next available “alternative” water supply, such as water imported from another basin, seawater desalination or brackish water desalination).
Filtration and disinfection of secondary effluent are key to production of tertiary-treated recycled water. Tertiary-treated recycled water is the most common quality of water reclaimed from blackwater, and used in urban, industrial, and agricultural applications. Disinfected tertiary reclaimed water is near the quality of potable water—the difference being extremely low concentration of organic compounds and elevated salt levels.
Recycled water is defined in the California Water Code as “water which, as a result of treatment of waste [water], is suitable for a direct beneficial use or a controlled use that would not otherwise occur.” Depending on the level of treatment, blackwater, treated to appropriate reclaimed water standards is fit for all non-potable uses.
Reclamation of blackwater and its reuse represents a reconfiguration and acceleration of the natural hydrological cycle. It is well established that nature recycles water ad infinitum. All water on planet Earth is recycled water. It’s the same water that the dinosaurs drank!
Urban areas in California have wastewater collection (sewerage) systems that convey blackwater to centralized treatment systems in buried pipes. In these cases, collection is not the issue, as it is already being collected.
Blackwater contains all types of wastewater from residential, commercial, and industrial sites, including: human waste, graywater; combined sewer/ stormwater systems also convey rain/ stormwater. Blackwater is also referred to as sewage, wastewater and sewer water.
