more than physics

People talk about water scarcity like it’s a physics problem: why don’t we tow icebergs from Alaska to alleviate the southwest’s water issues?  what about pumping water from the Great Lakes across the Rockies?  Sometimes that sort of grand thinking works, like the diversion of California’s water resources from the upper Sierra Nevada mountains southward to the Central Valley and Southern California.  But that’s only part of the equation.  One reason that California’s State Water Project and Central Valley Project are successful is that the source is virtually pristine snowmelt.  Move clean water from an area of relative abundance to an area of relative scarcity, add in a comment about humans adapting the environment to their needs, and voila, problem solved!

In my last post, I remarked on China’s limited water resources and their lack of wastewater treatment.  Well, not surprisingly, the Chinese government is trying their darndest to move water around to alleviate chronic water scarcity in the north (think Beijing) with relative abundant water from parts south (think the Yangtze River).  They’re apparently getting close on parts of this great diversion – the Danjiangkou Reservoir should be sending water northward next year.  The physics problem has been solved for a mere $81 billion!  Good job.

One small problem: the water to be transported is currently not fit for drinking.

A water pollution plan issued by the State Council, or China’s cabinet requires that the water quality for all five rivers that flow into the Danjiangkou meet a “grade III” standard by 2015.  But four of those rivers are now rated “grade V,” deemed for “agricultural use only” and the fifth river is considered “grade IV,” for “industrial use only,” reports China’s state-run news agency Xinhua.  “The target is very unlikely to be met as many pollution control projects lag behind schedule due to a fund shortage,” said Cheng Jiagang, vice mayor of Shiyan in Hubei province.

Oh.  What kind of fund shortage, when you just spent $81 billion on construction??

I’ve remarked previously on the lack of fame associated with building brand new shiny underground water infrastructure, and this appears to be a similar problem.  According to the above article, the local government needs about $500 million (just a fraction of that $81 billion price tag!) to build a wastewater treatment plant with nearly 700 miles of sewer pipelines.  So far, they’ve shuttered “329 factories in the last few years, but that has cut revenues by $130 million annually”.

Well, I hope they can find the money.  Until then…good luck to those intending to rely upon the diverted water.  Physics ain’t everything, folks.

Advertisements

a long way to go

Hello again, readers!  I’m finally rejoining the world of blogging, now that it’s been nearly 6 months since my last post.  In the meantime, I got married and changed my name — I’m now Claire Farnsworth Wildman, but otherwise blog content should remain unchanged.  I’m going to try to get into posting again once a week, and throw some links on my twitter feed when I can’t get to posting on interesting news.  Hopefully this will work!

~ Claire

So today’s post is a comment on China’s limited water supplies.  Bloomberg is noting that China’s coal mines are beginning to feel the crunch of limited water.  China has a fundamental problem that a bunch of development (agriculture and cities, and apparently many coal mines) is in the north, whereas the majority of their rainfall and streamflow is in the south.  This is not too different from the issues of the American southwest, where cities in dry areas keep expanding on the premise that they can access water from distant snowfall in the Rockies or Sierras via rivers and aqueducts.

The difference is that the US generally has pretty decent water resources (9,044 cubic meters = 2.4 million gallons per capita), but China’s are relatively sparse (2,093 cubic meters = 0.55 million gallons per capita), so moving water around won’t ultimately resolve all of their issues.

What struck me in the above article, though, was this: “…Veolia Water, which treated 1.2 billion tons of waste water in China last year…”  That sounds like use of numbers to imply large volumes of treated wastewater…but remember, China has 1.354 billion people as of January 2013.  So, one of the world’s largest water and wastewater treatment plant operators treated nearly 1 ton of wastewater per capita in China last year.  Let’s put that in perspective: an American city with low water use has about 150 gallons per day per capita, which we can assume goes to the wastewater treatment system.  This number is probably way too high for per capita water use for places without reliable drinking water supplies, but let’s use it for a back-of-the-envelope calculation:

150 gallons/day/person x 365 days/year x 8.34 lbs/gallon / (2000 lbs/ton) = 228 tons of wastewater per person in the US

Ok, again, very rough numbers.  Per capita water use is tricky to measure, but this website cites a 2006 UN Development Program report to suggest China averages something like 23 gallons/day/person (quoted as 86 liters/day/person).  Plug that in to the above equation, and you come up with 34 tons of wastewater per person in China, not including industrial wastewater.  Again, one of the world’s largest wastewater treatment companies was proud to hit the target of ~1 ton per person last year.  Whatever the per capita water use in China, it sounds like wastewater treatment has a long way to go…

the Great Lakes don’t drain where you think

The water levels in the Great Lakes look to remain low for the foreseeable future, according to projections by the U.S. Army Corps of Engineers.  This time, though, there’s a new suspected culprit for the prolonged declines, according to a local politician: the Chicago Sanitary and Ship Canal (CSSC).

You may not know it, but the CSSC connects Lake Michigan and the Chicago River to the Illinois River, which flows into the Mississippi River.  So besides the main outlet of the Great Lakes through the St. Lawrence River, there’s also some flow that is diverted towards the Gulf of Mexico. Originally, the city of Chicago was similar to Berlin, Germany and Las Vegas, Nevada, in that its wastewater discharged into the same body of water from which it withdraws its water supply.  But this was back in the late 1800s, when there wasn’t wastewater treatment but there was cholera.  People were rightly worried about public health.

So, the engineers came up with the easiest option: build a separate canal to connect Lake Michigan to the Mississippi River (flowing water away from the city), ostensibly for shipping, and then dump the city’s wastewater in it.  Problem solved! (Except for Milwaukee’s wastewater, but that’s a separate topic.)

With Chicago taking water from Lake Michigan and diverting its wastewater to the CSSC, a large quantity of water is diverted from the Great Lakes system, on average some 1.2 billion gallons per day, or 450 billion gallons per year.  That’s a lot of water.  But how much water is normally flowing through the Great Lakes?  Ultimately, the water in the Great Lakes goes over Niagara Falls, which has an average flow rate of approximately 4 million cubic feet per second, or roughly 944 trillion gallons per year.  So, back of the envelope says that Chicago is diverting 0.05% of the flows from Niagara to the Mississippi.  I suspect that this is not as significant as the climactic effects of record droughts and low snowpack, but that’s a bigger calculation than I’m willing to take on for today.  We’ll see if the Michigan politician mentioned in the article above ends up stirring the pot further on this question.

new toilets: round 2 goes to the Swiss

As I’ve mentioned before, the Gates Foundation is funding research to reinvent the toilet for the developing world, with minimal water use and maximum energy output (no-waste toilets).  A group from Caltech won the competition, and a group from Eawag (the Swiss Federal Institute for Aquatic Science and Technology) won the award for “best user interface”.  (Having done part of my PhD at each institute, I’m certainly proud of my former colleagues.)  In other words, round 1 went to the “Star Trek” toilet, as I’ve heard it described, with a consolation prize to the “more likely to be used in the developing world” toilet.

It looks like round 2, the implementation phase, will begin in Durban, South Africa, which is plagued by limited water supplies and rising consumer demand for fancier flush toilets.  Middle class isn’t quite the same when you still have to use a pit toilet.  With your neighbors (mandatory cringe from all of us in the developed world).  The city of Durban has entered a partnership with Eawag and the Gates Foundation to build no-waste toilets for the 230,000 families among the 3.8 million inhabitants of Durban that still lack access to safe and hygienic toilets.  Round 2 appears to go to the Swiss!

Given that the upcoming World Toilet summit (yes, that’s a real thing) will take place in Durban this December, this looks like a huge win for the Swiss, especially in the realm of getting more contracts.  The Americans will have their work cut out for them, if they want to make a comeback in round 3, location TBD.

a lot of hype about s**t

The Gates Foundation funded a big research push among specially invited top universities and institutes around the world to “reinvent the toilet”.  The idea is that the toilet is as old as indoor plumbing, and we could surely use high-level technology to bring safe, sanitary toilets to the developing world, where water and wastewater treatment are hard to come by.  It’s a nice idea, and the Foundation does a good job of throwing money at problems to solve them rather than study them (see AIDS and malaria, for example).

It just so happens that a recent competition among the new toilet grant winners was won by a group from my alma mater, Caltech.  Their toilet uses

a photovoltaic panel to generate energy, stored in batteries, to power an electrostatic unit that purifies liquids drawn from a small septic tank. The unit produces hydrogen as it cleans the water, potentially a supplementary source of toilet power on cloudy days or at night. The unit also purifies the solid waste which can then be used as biofuel or fertilizer.

That’s great, and I’m glad for the breakthrough.

One teeny tiny criticism of the whole thing: will anyone in the developing world ever use something this fancy and complicated?  This is not meant as a patronizing comment, but rather a comment that reflects some of the serious issues on the ground when it comes to Western improvements of lives in the developing world.  My research institute in Switzerland, Eawag, has done a fair bit of research into human waste management in the developing world, including the dreaded (to engineers) social sciences of surveying people in impoverished communities, and came to a very different conclusion than the Gates Foundation: urine separation is key.  We therefore had urine-separating toilets installed throughout the institute.  I happen to know that Eawag declined the opportunity to bid on the Gates Foundation grant because the top researchers would have been forced to do something that their experience suggests would never work on the ground.  (One example of the relevance of social science in Bangladesh: some local people prefer the metallic taste of groundwater that happens to be high in arsenic.  Non-metallic taste is associated with the local surface water, which is visibly contaminated with bacteria.  So some refuse to drink from safer groundwater wells that lack the geochemistry to have the metallic taste. That’s not engineering, that’s psychology.)

The Gates Foundation is doing a good thing, don’t get me wrong.  Who knows, maybe this technology will start turning up in the US as well.  But I worry that by involving researchers based on their school’s credentials, rather than their experience in this field, which is brand new to them, will lead to a lot of whiz-bang engineering feats that won’t translate well on the ground.  Well, it could be that Gates has the money to spare…

fracking: the problem is not what you think

Researchers just published a paper that claims that hydraulic fracturing (“fracking”) poses a substantial risk to water pollution, but not how you might think.  Fracking, at this point, is viewed as an evil process that’s destroying America’s heartland and poisoning major water supplies.  Unfortunately, the public remains misinformed about actual threats to water supplies, and some widely popular “facts” claimed by fracking opponents turn out to be myths.  Apparently neither side of the fracking debate is doing a good job of using science rather than emotion.

Which brings me back to the paper that just came out.  The paper did not claim that fracking fluids would contaminate groundwater supplies, but rather stated that the risk from fracking wastewater is substantial to surface water bodies.  Most of the water that is injected for fracking comes back out of the wells with the natural gas, and has high concentrations of naturally occurring salts, trace metals, and radioactivity due to its contact with the shale rock at depth.  The large volumes of wastewater have the potential to overwhelm existing wastewater treatment plants (and downstream water treatment plants).  The authors suggest that regulators should consider mandating procedures and methods to reduce wastewater volumes, so as to mitigate the risk of accidental wastewater release.

Oddly enough, the extensive drought across the US is already encouraging drillers to recycle their fracking wastewater to be reused for injection elsewhere.  I’ve previously alluded to some of the research that’s being done to develop water reuse technologies for fracking, and now anti-fracking groups are pressing legislators to mandate water reuse and limit the amount of fresh water that can be used for fracking.  To me, this is eminently sensible – it would be very hard for an environmental group to stop fracking altogether at this point, but it should be possible to hold drilling companies accountable to today’s environmental standards.

invisible infrastructure

As I noted a couple of days ago, it appears that China’s bold, new infrastructure in the area around Beijing was not accompanied by basic stormwater management infrastructure.  Well, an article today interviewed some Chinese residents about that very thing.

Beijing remains peppered with sinkholes, including one collapsed pavement in its central business district over 100 square feet wide. Meanwhile, the developer of a water-damaged affordable-housing complex in the suburbs has been accused of cutting corners to boost profits.

Hm.  That sounds not good.  In fact, the article goes on to state that the local government cannot issue bonds for more expensive infrastructure, like storm drains and sewer lines, that don’t generate revenue.  Plus, government officials are intent upon building bold, beautiful infrastructure that all can see and appreciate — the “invisible” infrastructure that should ideally accompany and protect the “visible” stuff is not held in high regard.

I would say that this is a problem with modern society in general.  Do you have any sense of what infrastructure is necessary to provide you with clean drinking water, to dispose of your trash, to treat your wastewater, and to recycle your papers and plastics?  Or for that matter, what about the infrastructure necessary to provide your car with gasoline or to synthesize that soap or cleaning solution you like?  There’s a lot we don’t notice behind the scenes.  A lot of it gets taken care of by the private sector here, and the utilities do what they can in the public sector.  But China’s government hasn’t yet figured out this local scale public sector stuff, it seems.  After all, how many officials want sewer pipelines named after themselves?

we could do better

I recently wrote about some studies that suggest that our wastewater treatment plants are not effective at removal of DNA fragments and viruses, and I even suggested that UV disinfection for wastewater treatment deserves consideration.  A paper that just came out in Applied and Environmental Microbiology analyzed samples from 129 receiving waters around wastewater treatment plants.  Over half of the environmental samples had E. coli strains identical to those in the wastewater treatment plants, and of those strains, 95% carried virulence genes associated with intestinal or urological pathogens.  The authors conclude that some of the strains originate in animals near the receiving waters, but a large fraction of the virulent strains likely come from wastewater treatment plant effluent.

In other words, this study provides further evidence that our wastewater treatment plants may not be sufficiently protecting human health and the environment.  Wastewater treatment has come a long way in ~60 years, and it is very good at reducing the load of human-derived wastes on the environment.  But as our analytical technology has evolved, it’s becoming clear that we could do better.  We could have cleaner, healthier, safer bodies of water.  We just have to decide if we want to pay for it…

just put it on the credit card

Going bankrupt usually limits one’s ability to pay for new things, at least until all the other creditors are satisfied.  And as you may have heard, the city of Stockton, California, recently became the largest municipal bankruptcy in the US.  With the nation’s highest crime rate and lowest police staffing rate, among other dire statistics, things do not look good.

Never required to consider cost in requiring environmental compliance, the EPA is kind of piling on.  Stockton has an aging wastewater treatment plant that just doesn’t meet regulations, as it was built some 70 years ago, and during heavy storms, it often results in combined sewer overflows (CSOs).  (CSOs result when the wastewater treatment plant’s intake capacity is overwhelmed, and the plant then temporarily allows stormwater and sewage to bypass treatment, discharging directly into the environment.)  The EPA has been going after more and more municipalities for CSOs, notably Atlanta (my hometown bias, sorry), in the past few years.  Apparently the Stockton wastewater treatment plant needs a $156 million upgrade, and EPA will surely issue fines for CSOs until this happens.

That said, Stockton apparently shouldn’t have too much trouble issuing new bonds to pay for this upgrade.  The reason is that the wastewater treatment customer fees represent a consistent inflow of money to repay the bond, and the city could then issue revenue bonds rather than general fund bonds, the latter of which no one would offer, given the city’s recent attempt to default.  Odd that the economics work out that way, but I guess this is some good news for the Stockton economy – a tiny stimulus package that will deliver long-term infrastructure benefits.

disaster can drive success

A hot topic in the public sphere these days is fracking.  I’m not interested in discussing the safety of fracking itself, but rather in the wastewater that it generates.  You may have heard things like injecting wastewater underground can cause earthquakes, or that fracking wastes are contaminating surface waters across Pennsylvania.  There’s science behind that.  But there’s also an economic opportunity.  The EPA will supposedly issue regulations for disposal of wastewater from fracking in the future, and the baseline condition is trucking the wastewater out of state, at least for parts of Pennsylvania.  Lots of things are cheaper than that.

So start-ups are targeting this market and developing new technology.  If they can treat the wastewater to a level where it can be reused for injection, then everyone wins: the net water withdrawals decrease, the treatment load on local municipal water and wastewater treatment plants decreases, and American ingenuity creates jobs.  (Side note: no jobs would be created if we had no EPA.  Keep that in mind, those who complain that regulations inhibit job creation.)  Some ideas are a little out there, like the idea to use soybean oil to capture pure water from the wastewater stream, but I’m glad that they’re thinking about it.  With costs like $15 to ship a barrel of wastewater from Pennsylvania to Ohio for disposal, or $5 million to drill a new disposal well, there’s a lot of room to be creative.