With California’s continuing drought, there is heightened interest in the use of recycled water. For decades, California has developed “purple pipe” and some dual pipe systems to use treated wastewater for golf courses, parks, soccer fields, and in some cases, residential landscaping.

In the 1960’s and 1970’s, water agencies in Southern California began using treated wastewater to recharge underground water basins. More recently in 2008, the Orange County Water District received a lot of press for their use of recycled water to recharge the underground aquifer, with that aquifer being a source of drinking water. This Groundwater Replenishment System is called an “Indirect Potable Reuse” use of such treated wastewater.

The abbreviation DPR is for “Direct Potable Reuse”, which means that wastewater is treated to such a high level that it can essentially be directly put to use as potable (drinkable) water. High tech systems using membrane filters, reverse osmosis and UV light treat water at such a high level that it is typically “cleaner” than available surface and groundwater water supplies. Two cities in Texas, who have been extremely hard hit by the drought there, are the first communities in the United States to use DPR. There are also a number of communities around the globe who have used DPR, including one in Namibia where DPR has been used for years.

If California’s drought continues, it is only a matter of time before DPR will come to fruition as the next “reliable” source of potable water. Stay tuned.