Orange County Groundwater Replenishment System
The Orange County Water Replenishment System, or the (OCWR), is a large scale water recycling system in the heart of Orange County, California. This program replenishes groundwater and sends it out for many uses, making it one of the most expansive water purification systems for drinking. But how does it work?
It starts with pre-filtration. After taking in highly treated wastewater (from various wastewater treatment facilities across the county), it removes large debris that may hinder the drinkability of the water and may clog other stages of the process.
Next is carbon filtration. This removes many impurities (such as chlorine) that may hinder the taste, smell, or the safety of the water.
After this is reverse osmosis. A more in-depth explanation can be found here, but the purpose is generally similar to that of the carbon filtration systems. It takes out dissolved impurities such as metals, salts, and microplastics that are unwanted in the potable water supply.
Next is Ultraviolet Disinfection. In this process, ultraviolet rays are scattered across the water, which hit the cell walls of bacteria and viruses. This prevents their ability to infect by disrupting the reproductive capabilities in their DNA. Hydrogen peroxide may also be added during this process. With this addition of such a chemical, the UV rays react with the hydrogen peroxide to form a chemical that kills the bacteria and viruses on the spot.
When this filtration process is fully completed, it is distributed throughout the county. It is injected into percolation and groundwater basins, where they are further filtered as they pass to cities’ groundwater basins. Then, this groundwater is pumped to the over 400 wells across the county.
Groundwater is a vital part of a county’s survival. And with the OCWR, civil engineers have found a way to make sure this resource does not become endangered. Groundwater replenishment systems are simply one of many measures that engineers should take in drought-prone areas such as Southern California.
