In pursuit of water for San Diego
Posted by George J Janczyn on August 2, 2010
Check this tidbit from a new National Geographic series on global water issues:
Throughout the Southwest, and particularly in a region that I know, the Colorado River Basin, the so called “water buffalos” (those who line their pockets with virtual water) commonly talk about this river as though it has not run dry.
In Las Vegas I interviewed Mulroy and saw the largest reservoir in the nation, Lake Mead, sunken to an alarming low tide. So low, in fact, that the Southern Nevada Water Authority is drilling a pipeline under the lake so that it can continue to take its share until the river-fed reservoir runs dry.
Take a look to the east of Las Vegas with Google or Bing satellite images and you can find lakeside developments and boat launch ramps near Lakeshore Rd. that are stranded far from the water (and those images could be years old, it was better then). I sometimes wonder if Lake Mead will ever again look full; indeed, if everybody doesn’t cut back on their withdrawals, I wonder if it will ever stop dropping. Las Vegas doesn’t seem optimistic about that.
Northern California and the Delta are another unpleasant thought. Natural disasters and political and legal warfare between statewide environmental, agricultural, and urban/rural interests are a constant threat to a stable supply of water for San Diego.
Either way, San Diego clings to the extreme end of a couple of long, worn, tenuous, lifelines — with lots of hangers-on above us.
So, in the spirit of reducing reliance on outside water, the San Diego City Council just approved a small-scale demonstration IPR water treatment facility. For one year it will produce 1 million gallons per day while limnology models are studied and water quality is analyzed. After the demonstration is finished, San Diego will face a bigger decision — whether to expand that into a full-scale IPR reservoir augmentation system producing 16 million gallons per day.
That’s not very much water. During the debate over the demonstration facility, one of Councilmember Sherri Lightner’s stated reasons for opposing the plan was that it’s too small to make a difference. In that I think she’s right. It’s not much water, and I suspect the modest parameter of the current project reflects political timidity about IPR more than a realistic appraisal of our situation and feel sure that many regional water agency planners would agree. Certainly the just-released Equinox Center report would agree.
The output of the Carlsbad desalination plant will be 50 million gallons per day. That’s a fair amount of water. Why don’t we aim higher for IPR as well? While there’s still time for us to make adjustments to the design plan, I think it would behoove us to instead at least match that 50 mgd. If we’re going to do IPR, we should do it in serious volume.
I don’t think it can be repeated enough: San Diego’s in no position to relax about developing local water sources, and our options are limited. It certainly doesn’t look good for us if a drain under Lake Mead is now needed for Las Vegas as the water level drops below their “drinking straw.” In San Diego we’ve pursued desalination, we’ve pursued conservation, we’ve pursued more groundwater, but we’ve hesitated about IPR. What we should do is pursue even more IPR.
A bathtub ring reveals low level at San Vicente Reservoir while the dam is being raised to increase capacity. When that's finished, IPR could help keep it full.
GrokSurf's San Diego 
Belinda Smith said
Great post, George. I would say not only should we pursue more IPR, we should cut out the Indirect part, and just pursue potable reuse. Each neighborhood could have it’s on small scale PR facility that treats and supplies water.
Jim Breitinger said
Excellent post. Thanks.
George Aniston said
Good post. As a long-term water/wastewater chemist and biologist my problem with IPR/PR is what we don’t know about 1) the waste stream and 2) possible deficiencies in the treatment process. Before we conduct a long-term experiment in public health we need a solid factual grip on things like: endocrine disruptors, prions, bioaccumulative chemicals like those seen in Teflon and fire retardants. Don’t get me wrong, you passionate activists, we are in dire need of a sustainable water supply and IPR/PR should be examined as an important piece of the solution. Yes, I know IPR is used in a few places around the world, but has anyone looked at the cancer epidemiology for these places? And why has the discussion completely given up on the concept of purple pipe for irrigation, since this is still the major use of domestic potable water?
Burt Freeman said
George,
You are so right about the So Cal water dilema; we are extremely vulnerable to nature, in terms of natural and catastrophic events! And you are so right about decreasing our reliance on distant and fragile sources.
But there is limited capital and political will for solutions; we need smart, reliable and ECONOMICALLY VIABLE solutions. Indeed, we need a lot more than 10% solutions, such as Poseidon, good as that may be; the total bill will be large, but necessary for our security. So, George, where we seem to differ is on my emphasis on local solutions that are known to be economically viable and large enough (around 200,000-300,000Af/y).
Now, IPR may qualify as a partial solution. But from what we now know, it will be too little and will be quite expensive (no matter what Equinox says). What we do know is that DESAL is a true supply, is in unlimited quantity and has been delivering safe, local water around the world for the better part of a decade using established engineering solutions at a price that is competitive with that of our imported water. SDCWA is developing Pendleton to provide a major part of our needs; we need to support that effort and urge them to develop even more SWRO water.
Belinda Smith said
@George Aniston:
we need a solid factual grip on things like: endocrine disruptors, prions, bioaccumulative chemicals like those seen in Teflon and fire retardants.
With all due respect, are you aware that we are already drinking water with all these things in it from our normal water supply?
And why has the discussion completely given up on the concept of purple pipe for irrigation, since this is still the major use of domestic potable water?
Because it will cost billions of dollars to re-plumb the city with a whole new set of pipes, just so homeowners can water their lawn. That is not a good use of our money, nor our resources.
@Burt Freeman:
DESAL … price that is competitive with that of our imported water.
We shall see what that price is soon. It was only ‘affordable’ when it was getting the Met’s subsidy. Now that it’s not, we’ll see what that means to potential investors.
Burt Freeman said
Note:
The IPR proposal is based on tertiary-treated water from the North County Water Treatment Plant. Unfortunately this plant has a limited capacity that is partially dedicated to the current recycled (purple pipe) service. Expanding the proposed IPR runs into this capacity limitation. The expert study (that produced the current proposal in its report to the city in 2006) also contained several other options for water reuse. They are estimated to be even more expensive that the current one.