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.
Blackwater generally travels from where it is produced as sewage to either an onsite septic system or, in urban areas, through pipes to a wastewater treatment plant managed by the same agency that provides the potable water to user. At the treatment plant, sewage is run through a series of steps to clean the water prior to its release into a creek, lake, river or ocean.
Blackwater that has been cleaned via treatment and captured for reuse is called “recycled” or “reclaimed” water. The term “recycled water” is specific to treated blackwater and is not used when talking about graywater, rainwater or stormwater.
Blackwater contains billions of bacteria, viruses, and parasites, including pathogenic organisms, in every gallon. Management of blackwater is an important function for protection of public health and the environment, governed in the United States at federal, state and local levels. Strict wastewater treatment and disposal standards are in effect in all fifty states.
Reuse of treated blackwater (ie, “recycled” or “reclaimed” water) fits well within an integrated water management plan, along with more efficient use of water and modified personal water use habits. Increasingly in California and elsewhere, blackwater is considered as an invaluable water source for reuse in all applications where potable water is normally utilized. There is an increasing trend to recycle this cleaned and treated water, sending it through purple pipes for various nonpotable uses such as irrigation for landscapes, golf courses, and industrial processes. With technologically advanced treatment systems, blackwater can be treated to the appropriate level to become a product “fit for the intended use”, even for direct potable reuse. Reuse of treated blackwater can occur on any scale: at individual buildings, in a cluster of buildings, at a centralized facility for a whole city, or even at a regional treatment plant serving several cities. At each of these scales, water recycling offers unique opportunities and faces varying challenges.