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.

please put this lady in charge of everything

Las Vegas is known as a water-intensive place in the middle of the desert — the fountains in the Bellagio, the canals at the Venetian, the pirate ship at Treasure Island.  But you might be surprised to know that its per-capita water use is tiny.  The city uses 3% of the state’s water and produces some 70% of its revenue.  How does that happen?  Well, there was a multi-year drought about 20 years ago that brought this to the forefront of developers’ minds (they were required to attach proof of water supply to their development plans and SEC filings).  Also, the regional water agencies merged to form the Southern Nevada Water Authority, and they put this woman in charge: Pat Mulroy.

Pat Mulroy, in my opinion, is one of the savviest water politicians in this country.  Because of its location, Las Vegas has had to adopt cutting edge water recycling technology (water comes out of a pipe in Lake Mead, gets used in Vegas, and discharged to Las Vegas Wash, which runs back into Lake Mead) as well as cutting edge policies to convince locals to dig up grass lawns in favor of desert landscaping.  SNWA has a very high-level analytical lab to make sure that trace organic compounds aren’t reaching the drinking water supply.  And Mrs. Mulroy has worked with regional water agencies as well as the other 6 states in the Colorado River Compact to come to an agreement about what to do when a major drought hits the southwest.

I had the pleasure of meeting Pat Mulroy, back at Eawag in Switzerland, where she kept an international audience rapt with her stories of getting things done and water policy-making in the “wild west”.  But you can see her give a talk at the recent WaterSmart Innovations Conference or just read the transcript of an interview she gave.  Either will give you a sense for her shrewd, yet no-nonsense manner.  I’m hoping that some bigger-name politician will recognize her for her work and make her Secretary of the Interior, so the country could have a truly sensible and effective federal water policy.  Heck, I’d elect her President based on what she’s been able to accomplish…

tragedy of the groundwater commons

In rural areas served by private wells, people’s water supplies are susceptible to regional declines in the water table.  Essentially, if the groundwater is not managed sustainably, some people’s wells can just dry up.  This happened recently in a rural community north of the California town of Clovis.  Those whose wells dried up had requested the local council to consider connecting the area to a public water supply, and the rural area proposed a tax to take on the $23.4 million cost of the water treatment facility and pipelines.  The tax broke down into roughly $58,000 per household.  It was voted down.

Apparently the county was unable to secure financial assistance from state or federal funding, so the residents had to split the cost among themselves.  As area resident Shawna Speake said, “We cannot come up with equivalent of a Chevy Tahoe brand new. I want to vote yes with my neighbors, but I feel like more of us think this is a burden.”  Some area residents will likely be forced to walk away from homes with virtually no value, due to the lack of water supply.  The tragedy of the commons, embodied – and who knows how long the other residents will have a reliable groundwater supply?