back to blogging

After a long hiatus of being distracted by many other things, I am itching to get back to blogging. Look for more posts coming soon.

As you’ve noticed (since my readers are of course the savviest folks around when it comes to water policy and water use 🙂 ), the drought in California in the past three years has really shifted perspectives on the importance of water reuse, desalination, and managed aquifer recharge. On a professional front, as a remediation engineer, I’m seeing more and more places in Southern California with public pressure not only to clean up contaminated groundwater but to reuse it for potable water supply. It is certainly an exciting time to be an engineer interested in building new projects to provide stability to the water supply in light of changing conditions!

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getting carbon sequestration to work

One magic bullet that engineers like to talk about for global warming is carbon capture and sequestration (CCS) — pumping carbon dioxide into the right water-saturated geological formations just might form carbonate minerals, converting carbon dioxide gas (greenhouse gas!) to a greenhouse-neutral rock.  There are some hurdles, though, that haven’t quite been resolved.  Most of the current CCS projects inject the captured gas into oil formations to enhance oil recovery — this is means that some of the gas often comes back out with the oil.  It’s a different task to inject carbon dioxide to form minerals.

First, you have to have the right geochemistry in the water and in the rock.  Carbonates are actually really slow to precipitate, and in some cases in the lab, oversaturated solutions took months to precipitate out solids (chemistry note: thermodynamics is separate from kinetics).  Second, you have to get the pressurization right in the geological formation.  On the one hand, this means putting in the proper well casing and piping (the “walls” of the well hole) — see the BP oil spill for an example of improper well construction.  On the other hand, this means ensuring that the geological formation doesn’t open up cracks under pressure and leak that carbon dioxide back to the surface.  (This is the suspicion of what might go wrong in some fracking, for example: that certain formations might open preferential pathways for migration of gases and solutions upward into overlying aquifers of drinking water.  This is also an unknown, but not one that I’ll address here.)  Finally, there’s the risk that injecting pressurized fluids will lead to increased seismic activity.  This is currently being documented as it occurs, but we’re far from predicting when and where it might occur (other than “in locations where we injected stuff…after we injected the stuff” which isn’t that helpful for planning or engineering purposes).

Well, as usual, scientists are working on stuff that will eventually be useful.  A recent paper evaluated a new way to detect carbon dioxide leaking into shallow soils from deep formations.  Traditional technology has required an extensive collection of background data to understand how carbon dioxide might naturally move through a geological formation.  But the new method uses measurements of nitrogen, oxygen, carbon dioxide, and methane in soil gas to distinguish between naturally occurring processes and an extra influx of carbon dioxide from, say, a CCS injection site.

This is pretty sweet, because knowledge is going to save money on these projects, as well as give clearer answers that the traditional method could.  Plus, this will resolve a big question, at least in my mind, as to the viability of this technology.  We can deal with it if the kinetics of carbonate mineralization are slow underground, but if the carbon dioxide gas leaks back out, it isn’t really sequestered after all…

taking advantage of messes

A paper came out this week in Environmental Science and Technology, probably my favorite technical journal, suggesting a “risk-managed route” for the Keystone XL pipeline.  The original route made enough stakeholders in Nebraska nervous about their groundwater supplies that the governor requested President Obama to deny the Presidential Permit, and so it was done.  Keystone has a new proposed route, which will avoid much of the Nebraska Sandhills, but still go through some ecologically sensitive areas.  The authors of this paper propose a route that avoids surface water crossings in the canyons of the northern part of the Ogallala aquifer, and instead intentionally crosses spray-irrigated, row-cropped land underlain by nitrate-contaminated groundwater.  The route eventually connects with the existing Keystone 1 pipeline north of the Platte River, rather than the proposed connection in Steele City, NE.

Now, I’m sure that Keystone has its own agenda for why it chose the route it did, and there are parts of this “risk-managed route” that are left unmentioned in the paper (it’s only 5 pages, so it can’t cover everything).  That said, the authors’ proposed route has an interesting idea as far as the irrigated cropland goes.  They assume that pipeline spills are inevitable (over the past 10 years, they cite statistics of 0.8 spills per 1000 miles of pipeline, averaging 364 barrels of oil), and that dilbit will partition into the part that volatilizes (evaporates away) and the part that floats on the water surface (light components called “light non-aqueous phase liquids” or LNAPLs).  The existing irrigation infrastructure is already set up to deal with LNAPL spills in the groundwater: the irrigation wells can extract the water+hydrocarbons, and the irrigation sprayers can enhance volatilization of the components pumped out of the ground.  Interesting thoughts, and true.

The big red flag in my mind is the actual composition of the dilbit (diluted bitumen) to be carried in the pipeline.  Normal crude oil is largely lighter than water, and does in fact float.  But bitumen is more like tar, and it’s diluted with lighter hydrocarbons so it can even flow in pipelines.  I don’t know if bitumen composition is a trade secret or something (I couldn’t find much information), but it’s possible that it would sink under the water table (making it a dense non-aqueous phase liquid, or DNAPL) rather than float.  In fact, the Enbridge spill in Michigan suggests that dilbit will, in fact, sink, though in that case, the dilbit got mixed in with sand and sediment that caused it to sink into the riverbed along 40 miles of the Kalamazoo River.  There’s not much mixing like that in groundwater — things are pretty static.

But think about this: LNAPLs are easier to remediate than DNAPLs, based on the physics of water and non-aqueous phase liquids.  I found a statistic that the average spill cost is ~$2,000/barrel for normal crude oil, but the spill in Michigan is already past $29,000/barrel.  Multiply that by 364 barrels/average spill, and you’re talking a $10.6 million starting point, on average.  That’s an expensive project.

I guess my take-home message is, I like the thinking outside of the box in the paper, but if dilbit is, in fact, DNAPL rather than LNAPL, we need to do a lot more due diligence and risk mitigation before we approve anything.

any press is good press?

The ill-fated Cadiz groundwater extraction project keeps accumulating approvals, but not without dredging up more opposition.  The San Bernardino County supervisors approved the Environmental Impact Report, with one stipulation: groundwater drawdown must not exceed 80 feet below the normal water table.  If the USGS estimate of recharge (approximately 5,000 acre-feet per year) is accurate, the 80-ft metric will be reached in roughly 10 years.  If the Cadiz estimate of recharge (approximately 32,000 acre-feet per year) is accurate, they’ll have a few more years of leeway (I’m going to be lazy and not look through their 1700-page EIR for the exact drawdown they project, sorry).  I’m glad that they at least added something nominal to the EIR, but the four supervisors who voted to approve the plan may have a tough time being reelected: the lone dissenter, Neil Derry, noted, “My constituents have been very vocal about not taking water out of the desert.”  There are also documented donations from Cadiz, Inc. to the coffers of the Board of Supervisors — to the tune of $107,000.  I won’t speculate on the influence of money in politics.

Besides the local opposition, Cadiz has a couple of very powerful opponents: Senator Dianne Feinstein and the Metropolitan Water District of Southern California.  Senator Feinstein’s office is pushing for a federal review of the EIR, which is likely both to generate red tape for an unfavored project and to subject the EIR to much more stringent environmental standards.  MWD is apparently still smarting from the last time this project came up, failed to materialize, and then spawned a lawsuit from Cadiz.  Besides the bad blood (lawsuits rarely happen between friends…), MWD operates a mostly full Colorado River aqueduct with very high quality drinking water — no need to add the Cadiz water, which may just have high levels of arsenic and chromium in it (data about which was conveniently omitted from the aforementioned EIR), to the relatively smooth operations.  The MWD annual report for 2011 mentions three programs to ensure that the Colorado Aqueduct operates as close to full as possible, and more to ensure the California Aqueduct does as well.  There may still be room for that Cadiz water, but MWD sounds like it’s only willing to make room for a friend…and Cadiz, Inc. may not fall under that umbrella…

The press coverage has also led to a flurry of lawsuits against the Cadiz project.  The tally of lawsuits is now up to five: one from the company mining the nearby evaporating lake beds for salt, three from environmental groups that want to protect the delicate desert spring ecosystems nearby, and one from a labor union that claims the environmental impact report does not assess the danger of unexploded ordnance from WWII-era military exercises in the area.  Cadiz definitely has a long way to go, but a path littered with lawsuits, federal red tape, and an unfriendly potential business partner suggest it will be a very expensive one.

I have a suggestion: why not try bottling water?  Bottled water companies harvest desert spring water all the time — Crystal Geyser wants to expand its operations in Olancha, California, known for its hot, dusty vistas of the eastern side of the Sierras and the dry lakebed of Owens Lake.  Sure, it’s expensive to bottle water, but you also get to charge more for it, and there aren’t as many pesky political issues in the way…at least as long as they stay out of the press.  Maybe Cadiz thinks any press is good press, but I would advise them to rethink that philosophy.

why they’re angry

I wanted to briefly revisit the water supply of Yemen, a known hotbed for al Qaeda and frequent target of American drone attacks.  During the uprising against former “president” Saleh, tribal militiamen fought the Republican Guard in the streets of Sanaa, and to the south, tribesmen blew up a key pipeline connecting the capital city with its source of domestic fuel supplies, the port of Ras Issa.  With the fuel supplies cut off, citizens of Sanaa found out what life is like without water — their groundwater table is so deep that the resource can only be pumped out with diesel pumps, so the lack of energy and an electricity blackout meant that water was a hot commodity on the black market.

Sadly, this is the wave of the future for Yemen, unless a new supply (desalination or mass water recycling) is found.  The article I cited above has a section about the cultural losses from water mismanagement:

Every quarter of the Old City has its own walled garden, owned by the state and rented to local residents at a nominal fee. Local families tend to the gardens on behalf of their neighbors, distributing the fruit and vegetables they produce on the basis of need. In the past, each garden had its own well, attached to the local mosque, which also serviced the local community, while most crops were largely rain-fed. Until a new sewage system was built in the 1980s, wastewater from the mosques and houses was also used to irrigate the crops.

…Now, the garden is irrigated using water from new diesel pumps which draw water from wells drilled hundreds of yards underground. Most of the water is now fed to a set of taps built along the side of the local mosque, from which locals who can’t afford trucked supplies collect water most mornings.

Today, the walled-in gardens are full of cracked earth and the wells are long dried up.  Anything that grows is irrigated with diesel pumps.  One reason the diesel pumps appealed is that the government heavily subsidizes fuel, but the water supply doesn’t respond to subsidies — it responds to good management and rainfall.  I wouldn’t be surprised if Yemen is a hotbed of disgruntled people for years to come.

just keep pumping

A lot of the world’s major agricultural regions are irrigated by groundwater rather than surface water.  Even locations with enough rainfall to avoid irrigation under normal conditions are adding capacity to irrigate with groundwater under drought conditions (my home state of Georgia is a prime example).  Well, worrywart scientists have done some large-scale analysis to put numbers on which of 800 aquifers worldwide are being overexplioited for irrigation.  Lots of anecdotal evidence does not make a scientific fact, after all.

It must be an important study, because it was published recently in Nature:

…in most of the world’s major agricultural regions, including the Central Valley in California, the Nile delta region of Egypt, and the Upper Ganges in India and Pakistan, demand exceeds these reservoirs’ capacity for renewal.

…In calculating how much stress each source of groundwater is under, Gleeson and colleagues also looked in detail at the water flows needed to sustain the health of ecosystems such as grasses, trees and streams.

That’s a troubling development, which doesn’t surprise me of course, because of the implications for agriculture when these groundwater sources run out.  And before agricultural collapse, we’ll probably see major impacts to the environment as far as ecosystems drying out and creeks/streams drying up.  We won’t even have anything nice to look at while we die of starvation.

Ok, it’s not quite that dire, of course.  The first step is to identify the problem after all.  But at some point, nations will need to examine the unregulated groundwater extraction for irrigation and ask if the water use is worth the risk.  The ongoing US drought, for example, has many wondering why you would ever grow rice, cotton, or pecans in a place like California or Texas.  In news that should shame us, Saudi Arabia made a push in 2009 to shift its domestic agriculture away from water-intensive wheat and soy beans in order to conserve its limited water supplies.  Of course, non-representative government doesn’t really have to worry about public outcry to get things done (see: China).  But let’s hope that our governments take heed before the tragedy of the groundwater commons plays out on a large scale.

the answer is beneath your feet

California is facing some worrisome pressures from increasing water demand for a growing population and decreasing supply reliability due to climate change and environmental pressures on the Bay-Delta region.  What should California do, when faced with extreme drought?  A new study released by the California Energy Commission recommends creating and maintaining a water storage bank underground.  That is, California should store excess water underground, and then pump it out as needed when extreme drought arrives.  I’ve been a fan of this idea (“Managed Aquifer Recharge” or “Managed Underground Storage” are two broad names for the idea) since I first heard about it some 6 years ago in grad school, and it’s great to see that policy advisers and think-tanks are starting to come around.  If we can educate the rest of California, including politicians, then we might actually have a shot at making things happen.

you and what water?

Apparently Utah sits on a large reserve of tar sands, especially in the northeastern part of the state near Dinosaur National Monument.  A Canadian company has leased about 32,000 acres to open a pit mine.  The process would be similar to that in Alberta, Canada, but would be less water-intense and would not rely on strip-mining.  Rather, it would rely on deep, salty groundwater (~2500 feet below the ground surface) and a relatively non-toxic compound called limonene to extract the oil.  Water recycling in the pits would ensure that no wastewater ponds sit onsite and potentially harm local ecology.  It does sound like an improvement on Alberta’s methods, but I have to admit that my ears perk up at the thought of mining tar sands in Utah.  You should see the satellite image of the area north of Ft. McMurray in Alberta – that’s a massive mining operation.  I’ve traveled a lot in southern Utah and appreciate its remote and inhospitable scenery.  I start to feel like an environmentalist: “Protect the wilderness from all encroachment!!”

Sometimes, though, nature solves its own problems.  There is very little rain or surface water in northeastern Utah, and apparently the aquifer 2500 feet below ground isn’t quite as productive as the mining company expected:

But records on file with the Utah Division of Water Rights hint U.S. Oil Sands may be struggling to find the deep water. The company drilled three dry wells before finding water somewhere between 2,000 and 2,500 feet in a fourth well, according to Dennis Sorensen, with the Utah Division of Water Rights. In June the company requested a drilling permit for a fifth well.

Ok, well, that will settle things, then, won’t it?  Hard to get the oil off the sands if you don’t have any water.  And drilling wells 2500 feet deep is expensive, not to mention pumping salty water out of those wells from those depths.  I’d say that if this company figures out how to make profit with that water source and without contaminating the local area or strip mining, they’ll have fully earned their money.

Cadiz project refuses to die

The Cadiz project to extract groundwater from the Mojave desert was just approved the other night to move forward, environmental impact statement complete.  They’ve used some loopholes to get non-traditional agencies to approve their environmental impact assessment, building along a railroad right-of-way for example, and partnering with a water agency in Orange County, roughly 200 miles away, as the project lead.

I read through a lot of their Environmental Impact Report (EIR), the comments by various agencies, and Cadiz responses.  Whenever possible, the project team’s response has been to throw paper at the problem, without really saying anything new.  The Final EIR is some 1700 pages!  One example of the project’s low quality assessment is their analysis of desert springs likely to be affected by the groundwater pumping.  The project asserted that no springs would be affected by the pumping for some semi-legit scientific reasoning.  Then they went out to survey the local springs.  Once.  At the end of the long dry season, before the rainy season began, in November.  What a surprise, they didn’t find any significant springs!  Thorough analysis requires at least multiple trips at different times of year, with the least weight given to surveys done in the very driest part of the year!  They also have provided no — zero — water quality data to show that the groundwater they extract will be drinkable at all.  As a water chemist, this seems like a major oversight to me, especially because it was the water chemistry that played a major role in killing the project 10 years ago…

No matter, the Santa Margarita Water District has approved the project and hungrily awaits its 5,000 acre-feet per year to be delivered from 200 miles away.  What’s that?  How will the water get to the Santa Margarita Water District?  Oh, of course, by using the Metropolitan Water District’s (MWD’s) Colorado River Aqueduct.  Though this sounds efficient and reasonable, did anyone check with MWD, the largest consolidated player in Southern California’s water market?  MWD rejected nearly this same plan just 10 years ago due to environmental concerns and potentially contaminated groundwater.  I was planning to write an Op-Ed for the LA Times or somewhere similar to highlight the comments that MWD made on the EIR, but I’m happy to say that an LA Times reporter beat me to the punch.  The main issue, besides the potential for naturally occurring arsenic and chromium to enter the SoCal water supply, is this:

Metropolitan has also informed Cadiz that the aqueduct space the company is counting on may not always be available, especially during dry years when demand for the Cadiz water would likely be the greatest.

…But Kightlinger said Metropolitan has spent the past decade developing supplementary programs, such as acquiring irrigation water and holding supplies in Lake Mead, that could fill the aqueduct in dry years.

“We would pull [the Mead water] and say there is no wheeling capacity available. We’ve filled up our aqueduct,” Kightlinger said. “That’s just something they need to understand.”

Oops.  Cadiz has been asserting that the aqueduct doesn’t run full — I read the MWD annual reports from the past couple of years, and turns out, MWD has been using nearly the full capacity of that aqueduct.  I guess I would trust the aqueduct’s operator over a third party that doesn’t really believe in science!

One final note is about finances, which I read about on a message board and therefore cannot verify.  Apparently the Cadiz group (CDZI) has a bond due next year, and not enough assets to pay it off, though they do have an inflated stock price.  It is in their interest to look like the project will go forward, so they can dump their stock at a high price to meet their bond call.  I have to wonder if this whole thing has been a show all along…

Bottom line, good luck with extracting all that groundwater in Mojave.  Cuz you’ll be trucking it to Orange County at this rate.

fracking reality

As you surely know, fracking gets a lot of publicity these days.  One thing that gets less publicity is the science about fracking.  In the case of the threat that fracking poses to drinking water supplies, things have gotten a little out of hand.  The image of lighting one’s tap water on fire is pretty powerful stuff.  But from what I’ve read, it sounds like the initial issues with fracking fluid and natural gas entering local aquifers derived mainly from poor well construction, specifically the well casings, by inexperienced workers eager to cut corners to make more money.  Furthermore, the wells affected were generally private wells, owned by the very landowners making money off the natural gas being extracted.  Private wells are not subject to the same rigorous testing as public wells and public water supplies, although the EPA recommends that well owners have their wells tested regularly.  So these issues have not generally affected public water supplies.

That’s not what the public believes.  A recent survey published in Environmental Science and Technology found that more Dallas residents worried that fracking was the greatest threat to their water supply [27%] than knew that they lived in a watershed [10%].  (Hint on the watershed question: you live in one.)  This is not just another sad comment on the lack of public science education, rather this is a key piece of information when we discuss water use in general.  Urban water use drives demand in most American cities, not industrial use.  Cutting back on urban water consumption in places like Dallas, with a per capita water use of ~220 gallons per day, has far greater potential impact on the regional water balance than fracking could ever hope to have.  The major coastal cities in California use closer to ~120 gallons per person per day, so it can be done.

I was riding BART the other night, trying to mind my own business despite a loud group of French teenagers.  My ears perked up, though, when one teenager asked her chaperone, a young American woman about my age, if it was safe to drink the tap water everywhere in the US.  At first I was annoyed that Europeans consider us so third-world as to even need to ask such a thing.  (In China, for example, no city yet delivers safe tap water to all its residents.)  But then the American’s response floored me: “Uh, sure, maybe except in areas with a lot of fracking.”  It took all of my willpower not to launch into a tirade of facts about water.  It’s frankly impressive how quickly environmentalists have won the P.R. battle about fracking.  If only we could harness that momentum to educate the public about far more pressing issues when it comes to water supply…