Purple Pipe White Knight – it’s actually Lavender

Drinking-Water-Sign-NHB-14608_600What’s the difference between Recycled Water and Reclaimed Water?

These terms are generally used interchangeably and which word is used depends on the region. Recycled or reclaimed water is water that is used more than one time before it passes back into the natural water cycle. Thus, water recycling is the reuse of treated wastewater for beneficial purposes such as agricultural and landscape irrigation, industrial processes, toilet flushing, or replenishing a groundwater basin.

The leaders in use of reclaimed water in the U.S. are Florida and California, with Irvine Ranch Water District as one of the leading developers. They were the first district to approve the use of reclaimed water for in-building piping and use in flushing toilets.

In a January 2012 U.S. National Research Council report, a committee of independent experts found that expanding  the reuse of municipal wastewater for irrigation, industrial uses, and drinking water augmentation could purple-pipesignificantly increase the United States’ total available water resource. The committee noted that a portfolio of  treatment options is available to mitigate water quality issues in reclaimed water. The report also includes a risk analysis that suggests the risk of exposure to certain microbial and chemical contaminants from drinking reclaimed water is not any higher than the risk from drinking water from current water treatment systems—and in some cases, may be orders of magnitude lower. The report concludes that adjustments to the federal regulatory framework could enhance public health protection and increase public confidence in water reuse.

In many cities using reclaimed water, it is now in such demand that consumers are only allowed to use it on assigned days. Some cities that previously offered unlimited reclaimed water at a flat rate are now beginning to charge citizens by the amount they use.

Nonpotable reclaimed water is often distributed with a dual piping network that keeps reclaimed water pipes completely separate from potable water pipes. In the United States and some other countries, nonpotable reclaimed 20120123_Dairy_2593_jpg_CROP_original-originalwater is distributed in lavender (light purple) pipes to distinguish it from potable water. The use of the color purple for pipes carrying recycled water was pioneered by the Irvine Ranch Water District. The EPA publication Guidelines for Water Reuse  and the Uniform Plumbing Code designates the color for reclaimed water piping as Pantone #512C or #522C.

In California’s San Joaquin Valley more than 800,000 acre feet of municipal wastewater is reclaimed annually for agriculture. That equates to nearly 840 million gallons per day irrigating non-food and fodder crops. In Wasco, California, all of the treated wastewater effluent is used for crop irrigation.

There will be more communities investing in systems that recycle water for use on lawns and crops, but much of the growth, especially in Southern California, will be in turning human wastewater into drinking water, according to Dave Smith, the managing director of  WateReuse California.

In October 2014, Gov. Jerry Brown signed a bill that requires state health and water officials to report by September 2016 on the feasibility of developing uniformwater-law-logo standards for recycling wastewater for “direct potable reuse.” That means purified wastewater would flow straight to household faucets.

“California needs more high-quality water, and recycling is key to getting there,” Brown said in his signing message for SB 322, authored by Sen. Ben Hueso, D-San Diego.