Water availability: Water Wars

An Ethiopian pastoralist crouches down at the edge of a dry crater that was a large watering hole for his livestock. Drought and other issues are shrinking water availability, increasing tensions in communities across the globe (photo credit: Andrew Heavens)


While energy production and the lack of it is taking centerstage right now, I believe the water availability problem is just barely hanging out below the surface. When it bursts, it will be BIG.

As discussed in the Water Problem post, water availability is a MAJOR problem. With a growing population, increasing pollution, and climate change causing extreme weather conditions like droughts, communities around the world are clashing (sometimes violently) to stake out dwindling water reserves.

The New Scientist today posted an interesting article about Barcelona's attempts to buy boatloads of water from France. Here's a bit:

As Barcelona runs out of water, Spain has been forced to consider importing water from France by boat. It is the latest example of the growing struggle for water around the world – the "water wars". [...]

If you are interested in the topic of water wars, here are a few resources to get you started:

- Blue Gold, the book. Also here's a preview of the powerful documentary based on the book:


- Popular journalist Daljit Daliwal's piece on the subject, in ethiopia.


- HBO's film "H2O up for sale" gives more information on this:


- here's the link to Botswana's existing water wars. I can't embed, but you can watch 20 mins of the documentary by following this link.

- If you think that water wars aren't a part of the United States, think again. There is plenty of literature out there about California's and Michigan's water wars. Here Jim Lehrer does a piece on his Newshour program on PBS.

part 1: (4 mins)


part 2: (4 mins)


- Vandana Shiva's (2002) book Water Wars.

- The Global Policy Forum's collected links on previous water wars.

- Water Wars and International Conflict, a website put together by the Univ of Wisconsin in Eau-Claire

- World Water Wars.com

Water 102: Water Distribution

Men, women, and children rush to get water from a well in Ethiopia (photo credit: Andrew Heavens)

Now that we've covered the processes involved in water treatment, the next stage is water distribution.

As stated in the Water 101: What is the Water Problem post, a huge part of the larger "water problem" is the transportation, storage, and distribution of clean water. In developed countries like the U.S, Canada, and most European countries, and urban parts of some developing countries, water is generally treated and distributed the same way. Its generally treated at a treatment plant, then distributed in pipes. The water usually comes disinfected and ready for drinking. People don't need to store the water, because the distribution system keeps the water clean and disinfected until you need it.* Once water comes in contact with contaminated areas or is exposed to the air, it gets contaminated.


Water flows out of a pipe in the UK countryside (photo credit: Martin Anataman)

*This may NOT be true of developing countries. Quite often there are water shortfalls, or the water distribution is so low that even in urban centers, families have their own boreholes that they pump water out of for use. They then regularly boil the water for drinking or order drinking water from wholesale providers.

In most developing countries, particularly in peri-urban, slum, semi-rural, and rural communities, water needs to collected from a central point (either from a tap, tubewell, borehole, river, lake, pond or other open water source), then carried to their homes. This is generally the work of women and children, who walk six miles (9.6 kms) to and from the water collection area. Water is heavy, weighing approximately 1 kg per litre or 8.34 lbs per gallon of water. Often the water collection and storage units are contaminated; if not, the pots or other collection units are open to the air and easily get contaminated. And finally when drinking the water, they dip their hands into the pots to get the water. Essentially, its very easy for water to get contaminated at any point.

In developing countries, people are responsible for the water collection, storage, and decontamination, which is why this is a major problem for them. The risk for illness and health issues resulting from lack of clean water or neck/head/back problems are very high. Therefore, besides availability of water, transportation and decontamination are major issues that need to be addressed when designing technology for developing countries.



L-R: A water truck carrying water into the periurban areas in Kenya (photo credit: Stig Nygaard); A line of colorful pots mark the queue for women and children in line to collect water in India (photo credit: McKay Savage).


Young women carry water back to their homes in Somalia (Copyright: Heather Arney / WaterPartners International)

Water 102: Water and Wastewater Treatment Plants

photo credit: Andrew Wallace

Its time to move on. Granted we're making a big jump from the basics to the more advanced. But I'll try my best to explain this as simply as possible.

Water (and wastewater/sewage) treatment can be done on an individual basis or en masse. Treatment plants are just mass water decontamination sites. They both use a combination of the processes discussed in "Water 101: Decontamination" to clean water.

Most developed countries (and the urban areas of developing countries) use centralized water distribution and sewer collection systems. Centralizing water and wastewater have their ups and downs, and I don't necessarily think that centralizing everything is the best way for every country, but its the way things are done at the moment.



Schematic Diagram of a Wastewater Treatment Plant (source: Ohio State University)

What's the difference between a water and wastewater treatment plant??

Generally, its the type of water that comes in--a Water Treatment Plant (WTP) generally takes water from ground, surface, or rainwater sources, makes it drinkable and distributes it to water storage tanks or directly to people; a Wastewater Treatment Plant (WWTP) generally collects sewage and other waste water (and in some cases stormwater) from various sites, cleans it and releases it back into the environment at a safe level for humans, fish, and plants to be around. Golf courses or parks that say "watered with reclaimed wastewater" often refer to this water.

WTPs generally are smaller operations than WWTPs, because of the water quality coming in. Generally WTPs just need a bit of cleaning and disinfection (because the water is generally clean already). WWTPs take pretty nasty sewage water (from industries and homes and businesses and schools) and get rid of most of the nastiness. This is why WWTPs are much larger and more elaborate. The solids generally end up going to landfills, the liquid (water) is cleaned and purified until it is safe for humans, animals and plants.

Is reclaimed wastewater potable??

Depends...on how clean they (the WWTPs) make the water before releasing it. It is definitely possible to take wastewater and put it through a series of cleaning steps to make it potable. But it can be expensive, which is why most wastewater treatment plants in the world don't generally do these extra steps. But as clean water resources get scarcer and the human population grows, it will become increasingly likely (and less expensive) to create fully recycled water plants.

Personally, I think the biggest barrier is not the technology or the expense, but rather the human factor. People are just not comfortable drinking water that entered a factory as sewage a few days before.


Reclaimed water: potable or not?? (photo credit: Peyri Leigh)


Resources:
Howstuffworks.com : Wastewater plants
The USGS site for wastewater Treatment
How Water Treatment Plants work
FAQs about WWTPs
http://www.ec.gc.ca/soer-ree/English/soer/MWWE1.cfm
The Water Environment Federation's engaging presentation on WTP and WWTP
Using microorganisms in cleaning up water

Water 101: Decontamination, the basics

Clean drinking water - the goal of decontamination [1]

In my last post of the 101 series, we discussed how water contamination happens. In this post we'll talk about how to decontaminate water.

Decontamination really involves two main steps:

1. Figuring out what the contaminants are, and their levels of concentration:

As we talked about before, most contaminants cannot be seen by the human eye. You need to do a series of lab tests on the water to determine the types of contaminants and their concentrations. The concentration of the various contaminants is particularly important because you need to know how dangerous the water really is, and how powerful a cleaning process you need. The United States Environmental Protection Agency (US EPA), the European Union (EU), and the World Health Organization (WHO) (each country has their own such organization as well) all outline safe levels of contaminants for the human body. The thing is, many contaminants are naturally occurring in water, and they are not harmful upto a certain levels. It is beyond that level that the contaminant is dangerous for human consumption, and that's the point that a cleaning process needs to be used.


Water samples need to be lab tested to determine contaminants [2]


2. Using a series of cleaning steps or processes to remove the contaminants:

Once you have determined the nature of the contaminants and their concentrations, you need to find the right processes for each contaminant.

Decontamination generally involves the following overarching processes or a combination of processes (this is an oversimplified version, we can get into the details later):


A series of cleaning processes can get the water on the left to be clean like on the right [3]

a. Sedimentation: This is the best process for separating liquid and solids. Essentially you take the dirty water and let it sit for a while. Gravity kicks in, and all the heavier stuff will settle at the bottom (flotation, where lighter stuff floats on the top of the water and is skimmed off, is a subset of sedimentation).


Water sedimentation: notice how the heavier contaminants have settled to the bottom [4]

b. Decantation: Decantation is the process following sedimentation, where you pour the cleaner liquid (or let the liquid overflow) out, leaving behind the heavier stuff (sediments).


A Cambodian woman decants sedimented water [5]

c. Filtration: Filtration is the process where the most bad stuff gets taken out. Usually you pass the liquid through some sort of porous membrane (like cloth or other things). The bad stuff gets held back or stuck on one side of the membrane, while the cleaner water flows through to the other side. The efficacy of filtration depends on the quality of the filter, like how small the pores in the membrane are and how well it keeps the bad stuff on the other side.


Schematic diagram of a simple water filter. Water first flows through the sand, then the gravel, and finally a cloth filter. The sand and gravel take out the coarser contaminants; the cloth takes out the fine contaminants. [6]


d. Distillation: Distillation is the most effective water treatment process, but it is also the most expensive because of how much energy it uses. Essentially, you boil the water, collect the steam and cool it down. Its effective in removing metals (like arsenic, calcium and magnesium...which is why its good for your iron as it leaves no residue) and killing germs. However the removal of organic chemicals (derived from petroleum or such) have a variable removal rate. Chemicals that have boiling points lower than that of water, for example, will also vaporize with the water and contaminate it even in steamed form. For chemicals like these, advanced water cleaning processes are used.


Schematic diagram of distillation (in a lab). This can be done without the use of lab instruments as well, en masse. [7]


e. Disinfection: Disinfection is the process of killing germs. Sometimes the water is free of metals and the other grunge, and just has a bunch of germs which need to be killed. Or often, even the cleanest water that is exposed to air quickly gets contaminated by germs in the air or area surrounding the water. Disinfection is generally the last step of water treatment.


A woman disinfects her bucket of drinking water with chlorine. [8]


Photo Sources:
[1]: Tim Norris
[2]: Juvertson
[3]: http://muriellascorneronmoringa.googlepages.com/
[4]: http://www.easttennesseewildflowers.com/Teacher_Resource.php
[5]: Tom Sprague photo
[6]: http://www.blithfieldeducationcentre.co.uk/kp/waterpages/make_a_water_filter.htm
[7]: www.chemistrydaily.com
[8]: http://www.usaid.gov/press/speeches/2005/ty050915.html

Water 101: the water problem (the video version)

World Water Day, (celebrated this year on March 22, 2008) brought out a lot of publicity on the water crisis.

CBS's Katie Couric did a nice quick take on water stats:



UNICEF's video: how much water do you really need?




Good Magazine's work:



And last but definitely NOT least, Stephen Colbert's take on it:

Water 101: Contamination

Little indigenous kids play in a pond just by an oil field in Venezuela. It is highly likely that the water is contaminated with oil and oil drilling chemicals.
source: Raphael Millan


In the previous Water 101 post, we covered what the water problem is - that there ultimately isn't that much potable (drinkable) water available for us. Really, the problems were accessibility (how to get water) and availability (amount of water available).

So how do we solve these??

Well, infrastructure is a major part of it. Infrastructure is the whole piping/plumbing system that gets water out from where the water is to where people are (usually animals and other plant life naturally go to where the water is...its the people that cause problems). So maybe we should improve water infrastructure and that would solve the problem.

Well, only partially...

Because there is the larger issue of contamination. It doesn't matter if we have the piping, if the water being piped is dirty. So let's start with understanding contamination.

How does water get contaminated??

Webster's dictionary defines contamination as "The process of...being made impure or unclean." So water that is made impure or unclean is contaminated water. Water gets contaminated in two ways:

1. Natural Contamination: This means contamination from non-human involvement. The thing is, all life needs water to survive. This includes pests like mosquitoes, and germs like bacteria, viruses and protozoa that are bad for us, who also go and live in the water. They make it impure or unclean for us causing a range of waterborne diseases like diarrhea and dysentery or water-related diseases like malaria, etc . Another way that water gets contaminated naturally is with high mud content (aka turbidity), salts, and minerals that the water picks up when it lands on or travels through the earth. For example, the soils in parts of South Asia and Africa naturally have very high amounts of arsenic and fluoride, which the water picks up when it is traveling through. These high levels of arsenic and fluoride can make people very sick. Or coastlines generally have a high rate of salinity (salt) in the groundwater, which makes it non-potable (drinkable).


Left to Right: man with advanced skeletal fluorosis[1]; girl with dental fluorosis. Both are caused by excess fluoride in drinking water[2]. Woman with acute arsenic poisoning [3]. Water with high mud content (turbidity) [4]


2. Artificial (man-made) Contamination: This type of contamination is primarily human-induced. Dumping chemicals or waste from industries and homes, as well as overdraining the water table can severely contaminate the precious water resources we have. There are far too many examples of this, including the stories highlighted in the award-winning movie, Erin Brockovich. One of the examples that really (in my opinion) brought industrial water poisoning to light was what has been known as the Minamata Tragedy, where mercury poisoning caused a series of mysterious illnesses. Other examples include the Mono Lake's increased salinity, caused by excessive draining of the lake and its feed rivers.


From L-R: Factory dumping in Minamata [5]. A sign we are all too familiar with, one that indicates polluted water [6]


A common mistake people make, particularly in communities with lesser education, is that they think contamination can be seen or tasted. But this is not the case. Most contamination is not visible to the human eye. For example, water with high fluoride, arsenic, bacteria or viruses, for example, can look just like regular purified drinking water. This is because the particles are so small that they can only be seen under a microscope or with testing in a lab. It is also important to note that its the concentration of these (generally measured in ppm or parts per million, as in parts of dirt per million parts of water) that can be lethal. It is generally safe to assume that water you get from an open-water source (like a lake, stream, river or pond) is contaminated. You definitely need to decontaminate these (we'll talk about decontamination in the next post). Groundwater is generally clean. I say generally because if it has been exposed to air or touched contaminated surfaces, or has mineral contamination, then its still not fit to drink.

Next time (and finally), we'll get into decontamination. And then I can show you all the fun technologies I've been storing up...

sources:
[1]: www.assam.org
[2]: www.unicef.org
[3]: http://www.martiinc.com/arsenic.htm
[4]: http://www.lenntech.com/turbidity.htm
[5]: credit: W.Eugene Smith
[6]: credit: William Hartz

Water 101: what is the water problem?

source: http://www.flickr.com/photos/anatomist/221165572/sizes/m/

Right, its about time I get into the meat of technology. My specialties are water, sanitation, and energy. This doesn't mean that I know everything about it, but if you put anything to do with these things in front of me, I'd likely figure it out and understand it fairly quickly. So if you have questions about these, ASK!!

I'm going to start with water technologies. But before we get into the technology, its important that you understand the water problem.

A common question that I'm asked by people is...there's so much water everywhere...how can people just not have access??
So here's your answer:

1. Well, you are right...there's a lot of water on this earth...about 326,000,000,000,000,000,000 gallons (326 million trillion gallons) of the stuff (roughly 1,260,000,000,000,000,000,000 liters). Considering that there are 6.6 billion people, that's like 49 billion gallons of water per person.

2. But most of it is NOT drinkable (also known as non-potable):


percentage of usable water (source: USGS)



water distribution by percentage (source: USGS)

Estimates by geologists and other scientists state that 97-99% (see above pictures) of all that water is stored in the oceans. Oceans have very salty water, which cannot be used for drinking, washing clothes, cooking or for dishes. You can't use it for cleaning either, because the high salt content can corrode or adversely react with many materials (which is why most things dumped into the ocean decay rather quickly than on land). Of that 1-3%, over half is hanging out in the North and South poles in the form of ice-caps and glaciers. The leftover is in the form of lakes, swamps, and groundwater. I'd probably say that's the percentage that's eligible for drinking (with a caveat, see point 3). So now, the water count is more like 158 million gallons of water per person (for your entire life). Assuming you live for 67 years (which is the current life expectancy of an average person in the world), that means you have 6500 gallons a day. Now you might think that's a lot, but its not really...because...

3. Most of the part that's drinkable has issues of pollution, accessibility or availability:



projected annual water available per capita by geography in 2025
source: Water Resources Institute, Page 200

Availability?? YES! Firstly most of this water is not yours. We haven't accounted for the animals or plants or the rest of the ecosystem that share this earth with you (and frankly, outnumber you by a large margin). So that itself, takes the per person amount significantly. Plus the water is often not anywhere near you. Water usually concentrates itself in specific areas, not equally across the land surface. And generally large amounts of water are in places that people proportionately don't live in or near - like forests, rivers, and large lakes. Which means that the water needs to be piped over to you. But if you are in a poor country and don't have the means to pay for a pipe, chances are you won't get any water. And you have to walk miles to fill up a pot of dirty water. Add on top of that the pollution of the few water sources we do have - natural and man-made - and that decreases the accessibility even more. This is how over 1 billion people in the world have NO access to freshwater. So really, there's a shortage of fresh drinking water on the planet!!


(source: http://holamun2.com/wp-content/uploads/2007/08/dirty-water.jpg
http://www.miraclesinaction.org/pb/wp_83f479b6/images/img39644ea612fadd13.jpeg
source: http://www.flickr.com/photos/beija-flor/)

So this is what we are trying to address in the water technology parts - technology that improves accessibility and/or reduces pollution, particularly for the poorer people that have no access.

Please note:
1 gallon = 4.78 liters
1 billion = 10^9 (the US definition)
1 million = 10^6

More information:
United States Geological Survey site for water: http://ga.water.usgs.gov/edu/
The Pacific Institute's Water Think Tank: http://www.worldwater.org/
WHO Water Page: http://www.who.int/topics/water/en/
World Bank Wat/San page: http://go.worldbank.org/PRR44UVHT0
How Stuff Works on water: http://science.howstuffworks.com/h2o.htm
The World Resources Institute: http://www.wri.org/