Environmental Barrier

If highly treated water from water purification processes is discharged to a reservoir or groundwater, the time spent in storage before use is said to form an environmental barrier. Some believe this step is needed to put the water “back to nature” where it can mix with other sources and lose its identity because the public lacks knowledge of the water cycle and the word “nature” is helpful to enhance acceptance. Others suggest that blending the water into an existing water supply source is required in case there is an operational upset resulting from plant breakdowns or operator error. Some consider that the insistence on an environmental barrier indicates that something is wrong with the water and it needs further treatment in the environment or the utility lacks faith in its technology and operators. However, no consensus exists whether the environmental barrier attenuates or amplifies public concern. The notion of an environmental barrier may have come from a prior time when technology was not as robust as it is today and dilution and delay were needed to improve the quality of the effluent. There have been no studies to determine if, in fact, dilution and delay are needed for safety or whether proper treatment, by itself, without an environmental barrier can reliably produce water of appropriate quality. Modern-day technologies with a number of process safeguards produce a reliably high quality of water . Some reason that the environmental barrier could well be replaced with a simple storage tank that serves to dampen out flows to the downstream system as well as serve as a final quality measuring station.