How You and IPR Can Save the Colorado River
In its annual list of America’s Most Endangered Rivers of 2013, American Rivers has named the Colorado River as the number-one Most Endangered River in the country. Bob Irvin, President of American Rivers, identified that the Colorado River is “so over-tapped that it no longer reaches the sea.”
The Colorado River is, simply put, the lifeline of the Southwest. It supplies drinking water to 36 million people from Denver to LA, irrigates four million acres of land and supports a 26 billion dollar outdoor recreation economy.
Yet it currently stands as the Most Endangered River in America because of outdated water management that can’t respond to the pressures of over-allocation and persistent drought. This led American Rivers to sound the alarm for Congress to support state-of-the-art water supply programs that can positively and sustainably impact how the water in the Colorado River is managed.
This also highlights to the significance of what we can do in San Diego—both as a region through potable reuse and individually as water-conscientious citizens and community members.
Currently, the City of San Diego is deciding whether to move forward with full-scale water purification projects in San Diego. San Diego Coastkeeper and the Water Reliability Coalition—a groundbreaking collaboration between environmental and business-oriented groups—are encouraging the San Diego City Council to approve full-scale water purification projects to create more potable water in San Diego. Creating a reliable, secure local water supply is both good for the environment and good for business.
Potable reuse projects use special technology to purify water, leaving it extremely clean. Just how clean? The ultra-purified water is actually cleaner than the water we import from the Colorado River or the Sacramento-San Joaquin River Delta. The ultra-purified water can then be mixed with imported water either at a reservoir or at a drinking water treatment plant before it gets another round of treatment.
The City of San Diego has run a pilot project of this technology since early 2012. When they tested the ultra-purified water for over 300 compounds, the purified water met all drinking water standards. Not only that, but the purified water contained only two of the 91 Chemicals of Emerging Concern, while imported water that makes up the bulk of our drinking water contained 13 of these chemicals.
While the City of San Diego is working to implement potable reuse projects, there are a lot of things that we can do, both large and small, that can make an impact on water conservation efforts like that of saving the Colorado River. See what positive changes you can make to reduce your daily water use. And please contribute to Coastkeeper’s efforts with the City and other decision makers.
Together, we can make a lasting impact on San Diego’s water supply and save the Colorado.
We're running out of water.
San Diego imports more than 80% of our water supply, with approximately half our water coming from the Colorado River. As Mike Lee's recent article in the Union Tribune emphasized, our water supply has passed a tipping point. The Colorado River no longer reaches the Gulf of California, and the river is over-allocated--meaning that when water rights were handed out, they were based on the wettest years on record. The only certainty is that imported water prices will continue to rise.
And while we're running out of water, we're also flushing approximately 175 million gallons of partially-treated sewage out into the ocean every day. San Diego has repeatedly sought special permission from the Environmental Protection Agency to let the Point Loma Sewage Treatment Plant skirt Clean Water Act rules that the rest of the country has to follow about how clean our wastewater needs to be before we can dump it into local waters. Those rules were passed in 1972, a mere nine years after Point Loma opened. For 40 years, San Diego has failed to meet the national standard, instead relying on the "301(h) waiver" as justification to pollute our ocean.
But there's hope. Yesterday, the City Council unanimously accepted the City's Recycled Water Study, which lays out a path forward to increase local water supply as we decrease our pollution from the Point Loma Sewage Treatment Plant. As Council member David Alvarez said, indirect potable reuse is "one solution to two problems."
Indirect Potable Reuse, or IPR, involves hyper-treating wastewater and then injecting it into groundwater or adding it to a reservoir, which ultimately joins the rest of the water supply. The Recycled Water Study sets out several alternatives for offloading over 100 million gallons a day from Point Loma and treating it to create both non-potable and potable water.
San Diego Coastkeeper urged the City Council to accept the study and move forward with implementation. We were joined by friends and colleagues from Coastal Environmental Rights Foundation, Surfrider Foundation, the Independent Rates Oversight Committee, Otay Water District, and the Metro Wastewater Joint Powers Authority.
City Council members spoke with one voice in emphasizing that water supply is a critical issue for San Diego. Council member David Alvarez, chair of the Natural Resources and Culture Committee, championed the issue, urging that we need to move forward with IPR implementation now. Council member Sherri Lightner, who led the City's recent efforts to create a Comprehensive Water Policy, reacted to the recycled water proposal with a simple request: "More, please!" Council member Marti Emerald recognized the need for San Diego to stop relying on the 301(h) waiver.
Council member DeMaio explained his view that an effective water policy includes water supply options that are (1) affordable, (2) secure, (3) reliable, and (4) environmentally responsible. He also recognized that all decisions about implementing IPR in San Diego need to be made in the context of the 301(h) waiver and invited environmental stakeholders to the table to discuss implementing IPR in conjunction with addressing pollution from Point Loma.
Council member Todd Gloria highlighted that "we are already reusing our water," since we are downstream from so many other users, like the city of Las Vegas. Council President Pro Tem Kevin Faulconer thanked Coastkeeper for our work "consistently nudging" the City to move forward on IPR.
Not only did the City Council adopt the study, but it authorized the Mayor "to refer a prioritization of the key implementation steps... to the Natural Resources and Culture Committee for its consideration." This means that the City Council has given the green light to move forward with next steps on IPR, which include determining how costs for the project are split between water and wastewater agencies and customers, figuring out who owns the water, and beginning to design the facilities.
San Diego Coastkeeper is committed, as part of our mission, to ensuring "drinkable" waters here in San Diego. This means that we will continue to be actively engaged on this issue to make full-scale indirect potable reuse a reality here in San Diego.
There are a number of ways to expand water supply in San Diego. San Diego Coastkeeper supports following the route of reduce, reuse, recycle, before attempting to find new sources.
First and foremost, we need to focus more on water conservation, or reducing the amount of water we actually use. It’s the easiest, cheapest way to boost our water supply. It is also the focus of the Be Water Wise 20 Gallon Challenge, a campaign to reduce the amount of water used per household by 20 gallons per day. Conservation techniques can include anything from taking shorter showers to starting a compost bin so you use less water running the disposal and much more.
Rainwater harvesting and greywater systems reuse water without treating it first. This is also a fairly simple way to increase supply, because less water is wasted. Capturing rainwater allows its use for irrigation and helps avoid using potable water for the purpose. It’s easily done at home, and requires very little installation.
Greywater also can be used for irrigation, with the added bonus of reducing the amount of water sent to treatment plants and released into the ocean. Using greywater at home is more complicated than catching rainwater, as it requires a plumber to divert water exiting bathroom sinks, washing machines, and showers (all with very low dirt-to-water ratios) to landscaping outside the house (storage of greywater is not advised). The low level of detergents and dirt can actually be good for the plants, but keep it on your property and avoid runoff to the street.
Wastewater recycling, or Indirect Potable Reuse (IPR) if used for drinking water, falls into this category. Sometimes called “toilet to tap” by detractors, the process uses advanced treatment processes to treat wastewater to levels even cleaner (page 108 of this report) than San Diego’s typical drinking water, then put it back in the water supply. A Demonstration Project is underway to prove the process safe for San Diego. If it succeeds, wastewater recycling could be the next step in increasing our water supply.
Purple pipe is the other side of wastewater recycling, where wastewater is only partially treated and used for irrigation. Coastkeeper is in favor of this strategy only in targeted areas, as it requires a separate plumbing system and is therefore very expensive to install.
After experimentation with the above sources, it might be necessary to look for new water sources. Further importation of water is theoretically possible, but San Diego already imports more than 80 percent of its water from the Sacramento/San Joaquin Delta and the Colorado River, supplies not under our control. Increasing that percentage would be risky, so any further imports would have to be done in combination with other techniques.
Desalination is another option, but while local, this source of water has a number of problems. A major one is the intake pipe: open-ocean intakes function as vacuums into the sea or lagoons where they suck in and kill marine life, a major issue. Subsurface intakes are better, as they take in salt water from under the sand and so greatly limit fish kills. The process of desalting ocean water is very similar to Indirect Potable Reuse, but because of the higher salt content, it is very energy-intensive. Besides the desired freshwater, the process also yields a very saline chemical-laden brine – diluted, the brine can be released into the ocean, but it can poison marine life if too concentrated. Menachem Elimelech, director of the environmental engineering program at Yale, said in a News Hour interview, “Desalination of seawater, because it is energy intensive should always be as a last resort…. It can be and should be part of the portfolio for water supply but only after all other measures are done.” Coastkeeper believes that desalination could have a place in San Diego’s water portfolio, but only on a limited scale and only using subsurface intakes.
Wastewater recycling, reclaimed water, and Indirect Potable Reuse (or IPR) are all ways of treating wastewater and reusing it rather than treating it and dumping it into the ocean.
San Diego reuses wastewater for irrigation, in its purple pipe system. Purple pipe is so-named because it requires two sets of plumbing, one for drinking water (potable use) and a second (purple) set for reclaimed water for irrigation. It’s easy enough to install when constructing a new building, but otherwise it’s a major retrofit, and either way it’s not cheap. But during a bad drought in 1989, purple pipe was touted as the only way we would
make it through with enough potable water for showers and drinking. The City Council even passed an aggressive ordinance to force anyone who could reasonably use reclaimed water for irrigation or industrial uses to do so. But the drought ended, and since then the ordinance has been largely forgotten and essentially unenforced. In fact, according to a Sign On San Diego article, San Diego only uses 15 percent of its two reclaimed water plants’ capacity.
Now, the city is taking another look at wastewater recycling for drinking water. (Check out how purple pipe and IPR compare – spoiler, IPR wins.) Mayor Jerry Sanders supports a new demonstration project to test the safety of IPR for drinking water – a definite improvement on his previous stance of ceremonially vetoing the “toilet to tap” project. The latest test builds on the successful use of wastewater recycling in:
Singapore, where they use reservoir augmentation, the very same process proposed for San Diego, and bottle and sell the stuff under the brand name NEWater
And closer to home, Orange County, where they use wastewater recycling for groundwater replenishment
The demonstration project will last a year and is required by the California Department of Public Health to prove the project adequately protects the public health. Tours of the facility are open to the public so you can see the high level of treatment the water receives.
The Advanced Water Purification process, which consists of microfiltration, reverse osmosis, and treatment with hydrogen peroxide and ultraviolet light, actually removes more contaminants from the water supply than do the processes used to clean raw imported water. IPR water has been found to contain lower levels of all but six of the 232 tested pollutants, and those six were all still below levels that cause health concerns (check out page 108 of this report for details). The tested pollutants include pharmaceuticals and endocrine disrupters, which are a common concern about IPR water.
In the words of Ronald Coss, the technical manager of the Water Reuse Study that made the above finding, “the human health risk from consuming [IPR water] directly is negligible, especially when compared to current drinking water standards and with other water supplies available to San Diego. Augmenting San Diego’s raw water supply with [IPR water] would result in an improvement to water quality over current water supplies.”
This is the fourth of a 5-part blog series examining the nature of our local water supply and how to increase the reliability of our supplies now and into the future.
Today’s match-up features two contenders, both aimed at solving San Diego’s water crisis.
In the first corner, the “purple pipe system” is looking to continue its reign in San Diego. San Diego currently reuses a small fraction of its sewage for irrigation. This recycled water is distributed through a separate purple pipe system. Because the water is non-potable, it is not fit for human consumption.
In the second corner, the up-and-coming “Indirect Potable Reuse” (IPR) is looking to solve San Diego’s water problems. In scientific terms, IPR is a process to treat wastewater and sewage using advanced technology to produce potable water fit for human consumption. Essentially, we would be drinking purified sewage. Right now, you are probably cringing at the thought of drinking recycled wastewater; I know I did. But then I did some research, and I found out that the water produced from IPR is actually superior to our existing water supply. How is this possible?
First, advanced water technology removes any remaining solids through microfiltration. Next, reverse osmosis is used to eliminate viruses, bacteria, pharmaceuticals, and other microbes. The water is then disinfected by UV light and hydrogen peroxide. Finally, it is added to groundwater or surface water reservoirs where it is further purified by natural processes. Once drawn from the groundwater or reservoir, the recycled water goes through the standard water purification process all drinking water undergoes to meet EPA standards. Once this IPR-produced water is fit for consumption, it is distributed through the existing drinking water infrastructure. Now that doesn’t sound so bad, does it?
Round 1: Costs
The cost of producing one acre-foot of water with IPR ranges from $1,200-$1,800. The purple pipe system ranges from $1,600-$2,600 per acre-foot.
Purple pipe recycled water cannot be added to the existing drinking water infrastructure, so it requires a separate pipe system which costs about $2 million per mile to build. It also requires homes and businesses to be plumbed with two sets of pipes—one for recycled water and one for potable water. This is beginning to sound expensive!
Although the purification process of IPR sounds expensive, the City of San Diego estimates that implementing IPR would be cheaper than expanding the purple pipe system. This is because IPR negates the need for a separate water infrastructure and would maximize the use of the available recycled water supply.
IPR – 1; Purple Pipes – 0
Round 2: Energy
The energy intensity of the IPR process is higher than that of the recycled water in purple pipes. Compared to non-potable recycled water, IPR generates a higher carbon footprint. However, IPR uses significantly less energy than other potential water sources in San Diego, such as desalination or imported water.
IPR – 1; Purple Pipes – 1
Round 3: Environmental Impact
By using recycled wastewater, IPR reduces the amount of waste flowing to the Point Loma Treatment Plant. In doing so, IPR reduces the amount of potentially harmful pollutants being released into the ocean from the Point Loma Plant’s effluent.
Purple pipe recycled water does have some red flags. Particularly, the use of non-potable recycled water can lead to the accumulation of byproducts over time in the irrigated soil.
IPR – 2; Purple Pipes – 1
Round 4: Water Quality/Safety
Studies show that water produced through IPR treatment processes contains fewer contaminants than our existing treated imported water supply. Further, a study performed by the National Research Council concluded that there were no significant health risks as a result of IPR.
Because the water in the purple pipes is not treated to the point that it is drinkable, it contains pathogens and harmful chemicals. Simply stated, the consequences of ingesting non-potable recycled water can be severe.
IPR – 3; Purple Pipes – 1
After four hard fought rounds, IPR has dominated the ring, proving that it would be a strong, viable addition to San Diego’s arsenal for fighting the water crisis.
Still think “from toilet to tap” sounds less than appetizing, or has your mind changed? Tell us what you think!
Our Tijuana River water quality tests from last week got me thinking about the safety of food grown at Suzie's Farm, located in the Tijuana River Valley. I receive my Community Support Agriculture (CSA) box from Suzie's Farm every Wednesday, and I wondered if the water quality of the Tijuana River put my organically certified grown food at risk.
So I asked.
Lucila, who owns the wonderfully titled job of Head Weed Puller, responded with this note:
Being a USDA certified organic farm we are concerned with water quality too. We use a well that is tested yearly and certified. The well has been found to be at a level consistent with 10,000 years ago; so it's pretty deep. Our well water is then run through a reverse osmosis system, so the water with which we irrigate our fields is more pure than San Diego City water. We do not irrigate with water from the river.
Feel free to contact us with more questions or concerns regarding our water quality or any of our agricultural practices.
This means that Suzie's Farm grows the food I serve for dinner with water so pure, it's better than what comes out of my tap. Which begs the question, could this process be used to help with our currently endangered water supply?
At Coastkeeper, we advocate for a wasterwater purification process to help our region find reliable sources of water. The Point Loma Sewage Treatment Plant currently treats sewage and pumps it into to our ocean. Rather than dispose of that water, we want the city to run it through a similar reverse osmosis process used by Suzie's Farm so that we can add the highly purified water to our drinking reservoir, and thus increase our water supply. It's water so pure, it's drinkable.
You can learn more about this process, called Indirect Potable Reuse, on our website. And I'd love to hear your thoughts on this potential water supply.