Saturday, September 21, 2013

W is for water

Last, but by no means least in our consideration of resource recovery, is Water. It seems obvious to say that the most valuable resource we can recover from waste-water is most often the water itself. In arid regions like Israel, Cyprus, Nevada and Southern California, the pressure on water resources is so great that there is little choice but to reuse the "used water" (to borrow a phrase from Singapore). In other regions, water stress is not yet a concern but it's coming as populations increase and weather patterns shift.

The topic of water reuse is huge and well-established and I don't think I could do it justice in a blog such as this. Instead, I just want to highlight a few interesting articles. The August edition of the IWA Journal, Water 21 has a nice article on global water reuse that I highly recommend. Unfortunately you have to be an IWA member to access the article, or you can buy the book on which the article was based!

The Energy-Water Nexus is a topic that's courts a lot of attention, and rightly so. Energy is a key element that drives economic development and the modern amenities the western world has come to rely on. Energy production requires a lot of water and water production and wastewater treatment require energy which links the two quite strongly. I should note that the balance in this linkage is pretty skewed toward Energy production needing a huge volume of water whereas water production and wastewater treatment requires a small piece of the energy pie! There are many, many article discussing this topic. Here's one for starters.

Extending this topic a little further, we need to think about the other activity that uses a huge quantity of water, and that's agriculture. I'm not a water resources guy (poop engineer remember!) so it was really enlightening to see the water source and use diagrams for the US. The amount we use and produce for domestic use is tiny in comparison to irrigation and energy production. Ecowest has an informative presentation that describes some figures produced by the Lawrence Livermore National, in their case focusing on the western states of the US.

So, where does this leave us in thinking about water reclamation and resource recovery? Certainly it's a topic that is region specific. If you have an abundance of water and sources of a high quality, then it makes most sense to treat our wastewater and return it to the natural environment to help preserve our rivers and waterways as we've traditionally done it treatment plants for years. But in regions where there's a shortage of water we need to see our wastewater streams as valuable sources for reclamation and reuse. I like to think of it in a wider context of reduce-reuse-recycle. First of all, let's use whatever measures we can to conserve and not waste the water - in our homes, industries, agriculture and energy prodcution. Then let's look for ways of reusing water within these different arenas. Then finally we look at treating and recycling the used water at our wastewater treatment plants.

As I said, this is a huge topic and way beyond the scope of a little blog like this. But hopefully I've helped you to stop and think about the part that wastewater treatment facilities can play in our regional water cycles and to see the value of our most precious resource of all: water.


Sunday, September 1, 2013

Energy Info

I thought about giving this blog a corny name like "Sourcing Energy Info" but on seconds thoughts that might be too confusing! Before I turn my attention to the "W" in resorurce recovery, I wanted to wrap up the discussion of Energy by passing on a few of my favorite websites on the topic. Not the most riveting of blogs for sure, but I want my blogs to contain useful information through the links and not just be this crazy limey blathering on about his latest beef or pet project! So here are a few sites I've found in the mass of information on the glorious mess that is the world-wide-web (do we still call it that, or am I showing my age already?).

U.S. Energy Information Administration (

This one has to be the top of the pile for any data junkies like me. They have historical data for every energy source by state, end use and major energy provider. If you want to know the $/kWh for electricity or $/btu for natural gas, and heaven knows what other pricing or production stats, this is the place to start. Although focused on US pricing, they have some good International stuff and their Energy Outlook takes a shot at trying to guesstimate future energy costs. A warning to data junkies though, you may find yourselves lost in piles of data for days on end so have a friend feed your cat whilst you're using it!

U.S. EPA ( or

The EPA website has to be one of the most data-rich but frustrating sites I've used over the years. They have a huge amount of information - data, electronic documents, maps - but it can be tough to dig into it to find any of the useful stuff. Thankfully their search is pretty good and so you can usually find what you're looking for after a while. On the topic of energy in wastewater treatment facilities, I recommend starting with: as the front door to a lot of general information to help folks to be more energy efficient. Another good spot to look is the Energy Star site which includes a section for wastewater treatment (which, ironically, I can no longer find!!!). Portfolio manager is the closest thing to a national standard for assessing energy efficiency at a treatment facility. I'm not a big fan of their regression analysis for the scoring (maybe a topic for a future blog!) but as a tool for assessing energy performance and planning improvements it's pretty decent.

The Ecoinvent Database (

In a previous blog I spoke about Life Cycle Assessment (LCA) as a powerful tool for assessing the environmental impact of processes and products. A huge piece in the LCA puzzle is energy use and so the LCA databases are a great source for understanding how such diverse things as chemical use or driving to/from the treatment plant are tied to global energy use. As noted in that article, I access the databases through the Simapro simulator.

Water Environment Research Foundation (

My last blog focussed heavily on the work being done by WERF, so I won't go on about it agian, except to point you toward their Energy Knowledge Area: (hmmm, you'd think we could have a shorter URL...)

Wikipedia (

"Really Andy, you're suggesting Wikipedia as a useful reference? It's not peer reviewed and there's also sorts of mis-information on there." Well, I have to confess to being a big fan of Wikipedia. If you need a basic overview of any topic such as what the heck is a Carnot cycle or a Rankine Engine, I can't think of a better place to start than Wikipedia. Usually you get a nice and succinct definition in a paragraph or two and a link to sites with more depth and then some reasonable references at the end if you want to chase more information. I've heard the criticism that it's not peer reviewed and may be full of errors, but I've seen errors in books and supposedly peer-reviewed papers. Many text books and most papers have a myopic view of topics that is put to shame by the consensus approach of Wikipedia. If I ever get to the point of being a prof in a University I'll tell my students to use Wikipedia and other web-based resources instead of text books as much as possible. (Come on, tell me I'm crazy!)

So, there are a handful of sites to get you started in your investigations into Energy and wastewater treatment. I'd be interested in hearing from others on useful sites you've found so please comment below!