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?

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Kansas and Texas: the next Yemen

I wrote earlier about the groundwater overdraft in Yemen, which was largely due to irrigated farming (specifically for qat, a mild stimulant).  I sort of brushed off the idea that the Ogallala aquifer was drying up.  But, researchers recently used satellite data to show that yes, it is drying up, and at an alarming rate.  In the southern portions, the aquifer may be unable to support irrigation as soon as 30 years from now.  The northern portions seem to be holding steady in water level, due to rainfall and infiltration from lakes, so only Kansas and Texas would be affected.  The same study showed that groundwater tables fluctuate widely in California’s Central Valley, although a clear decline is not evident.  These are major farm belts in the US, and the loss of irrigation water would be, quite simply, devastating for those areas.  We would do well to take heed and adopt proper policy measures to sustain these critical but not unlimited water resources.

if you build it, the water will come

I’ve mentioned before that Cadiz, Inc. is trying to get approval to extract groundwater from the Mojave desert near Cadiz to sell it to water agencies in southern California.  The big part of their plan that left me confused was their plan to overextract the groundwater for 50 years, then allow the water table to recover for 50 years.  Why not pump at the recharge rate, rather than at a rate at least 1.5 times the recharge rate?  One obvious reason is to make money: 50,000 acre feet/year (AF/y) makes you a player in SoCal water resources; 5,000 AF/y does not.

I read through the Cadiz project’s draft EIR (the whole document is nearly 3000 pages! that’s crazy!), and their rationale is that they need to get the existing groundwater out of the way, so that they will have space for all the surface water that they’re going to store in the aquifer.  If you store water in the aquifer in its current state, it will just induce faster flow towards the dry lake basins, and much of the stored water will be lost to evaporation.  But if you make the space for it, you can store as much water as you need, for an indefinite period.  This phase of their project is “Phase II”.  Phase I was when they got about 10 smaller water agencies in southern California to sign on to buy the Cadiz water, if it’s ever produced.  So, who will store their water in the Cadiz aquifer?  So far, no one.

There are a couple of reasons why no one has signed up.  First of all, no one has extra water.  It has been pretty darn dry of late, and climatologists suggest this is the trend for the future.  Second, if Metropolitan Water District of SoCal (MWD) gets extra water from the Colorado River, they store it in Lake Mead, which has plenty of space right now (51% full at the moment).  The Colorado Aqueduct already operates at full capacity, so they can’t immediately deliver extra water even if they get it.  Third, the State Water Project’s supply from the Bay-Delta region is up in the air, due to endangered species issues for the delta smelt, and even if a peripheral canal of some sort is built, don’t expect the other stakeholders in the California Aqueduct to go along with sending all the “excess” water towards water-hungry L.A.  A fourth and final point is that in the first generation of this Cadiz project, geologists recognized naturally occurring arsenic and chromium in the Cadiz valley groundwater.  Arsenic and chromium geochemistry is such that adding oxygenated surface water to the groundwater could, in fact, enhance mobilization of arsenic and chromium into the stored groundwater, making it toxic during storage, so that it would need expensive treatment before it could be delivered to customers.  I certainly wouldn’t want to bank my future water supply in that aquifer without a lot more study!

I’m a big proponent of water recycling and innovative water storage solutions, such as managed underground storage, but this project is not about sustainable water management — it’s about money.  And Cadiz, Inc. plans to make a lot of it by withdrawing a bunch of groundwater from a remote desert valley, regardless of whether phantom water deposits ever show up.

future water supplies

Long term water supplies in California are quite limited if we continue to use water at present rates and the population grows.  The engineers and regulators know this, and theoretically so do the farmers and politicians.  We’ve already overallocated the Colorado River, such that it vanishes into the sediments at its mouth, no longer flowing directly into the Gulf of California.  And wet years for the Sacramento-San Joaquin River watershed doesn’t mean as much for the river flowrate as it does for the downstream farmers in the Central Valley who want to irrigate as much of their land as possible, or for the southern California utilities who want to store the extra water for drought conditions.

On top of expected in trends in population growth, climate change could potentially decrease the precipitation and/or streamflow in most of the southwest.  Furthermore, environmental concerns are pushing water regulators to scale back the allotted flows in the California and Colorado River aqueducts.  If you were the water manager for the city of Los Angeles, what would you do?  The net balance of your inflows is likely to decrease, while the delivery people demand is increasing…

There are a couple of options for new water supplies.  One is to build massive desalination plants, at a high energy cost and a high environmental cost for the disposal of brine waste.  In California you also run into the problem that necessary locations on the shoreline have really high property values and a bunch of neighbors screaming NIMBY.  Another is to look for temporary solutions like underused groundwater basins or watersheds.  Las Vegas is in the process of shipping groundwater from a remote valley of ranchers along the Nevada-Utah border to its water supply.  There’s also a project to mine a groundwater basin in the Mojave Desert in California, between Joshua Tree and Death Valley, for water supply to the L.A. basin.

But to me, the most reliable long-term option is indirect water reuse, which is already in place in Orange County, a relatively conservative portion of southern California.  I am slightly skeptical of direct reuse of wastewater effluent, even when treated beyond normal potable water standards, just because of the lack of a buffer or factor of safety if anything goes awry at the wastewater/water treatment plant.  But indirect potable reuse makes a lot of sense: treated wastewater is injected into a storage basin, most often an aquifer, and then after some flow distance, it is re-extracted as raw water for drinking water supply (i.e., it gets treated again after extraction).  During its travel in the subsurface, the water is filtered naturally by the soil and mixes a little bit with the native groundwater.  Quite a few cities employ this system with lakes, notably Las Vegas, Milwaukee, and Berlin (Germany), but there’s a lot more mixing and dilution in lakes than in groundwater.

To be honest, the indirect reuse in Europe, which has been working in some cases for over 120 years (see Berlin), is very convincing to me.  Water recycling could regenerate roughly 50% of the water supply of the entire L.A. basin (a lot of water is lost to outdoor uses like pools and lawns), and would make water supply as reliable as the wastewater supply.  An odd concept, perhaps, but in the case of Los Angeles this would be less wasteful than all the treated wastewater currently discharged to the ocean.  Given the right geology, water recycling would also require far less infrastructure than desalination plants or large water pipelines.

Would the public go along with this, if properly informed?  Sydney, Australia provides an example of the PR gone wrong – after a contentious public debate, they built a massive desalination plant.  But again, Orange County is already employing this successfully, so we should be able to point to them as a model.  As Orange County goes, so goes the country?  It’s not something I would normally expect to hold.

don’t mind me with my head in the sand

Recently the California State Water Board hired UC Davis to perform a $2 million independent study of groundwater nitrate contamination in the Central Valley, specifically the Tulare Lake Basin and Salinas Valley.  Surprisingly for a government project, the study was completed on time, but not surprisingly the results have already generated some controversy.  UC Davis estimates that 96% of the nitrate in groundwater comes from agricultural  sources, with sources like wastewater treatment plants, septic systems, and manure lagoons minor on the basin scale but potentially significant on a local scale.  Since no one measures basin-wide nitrogen inputs to croplands, the UC Davis researchers had to derive the agricultural data from historical land use per crop, plus a crop-specific nitrogen mass balance.  The approach looks pretty sound to me.

 Two months after the release of data, Tulare County Supervisors are about to strike back.  They voted last week to send a letter of concern to the State Water Resources Control Board, which is coming up with what to do about the nitrate contamination.  The UC Davis report suggests that nitrogen fertilizers should be taxed to cover groundwater remediation for drinking water sources.  This scares the Tulare County agricultural interests, and the Tulare County Supervisors will claim in their letter of concern that the UC Davis report did not consider sources of nitrogen, but rather assumed that the source was agricultural.  Further study is necessary!

I find this very confusing.  In looking at the UC Davis approach, they did consider the source of nitrogen contamination, and in fact Figure 1 of the Executive Summary shows their breakdown of the nitrogen sources.  So what gives?  I think this is a last-ditch effort of agricultural interests to resist the reality of numbers staring them in the face.  After all, these are some of the most productive agricultural lands in the world (including 10% of US milk production), so anything that might decrease productivity is a threat.  But the number of drinking water wells with elevated nitrate in these basins is only increasing with time, and for agriculture to refuse to acknowledge complicity in the problem is to live with their heads in the sand.

Loopholes and Desert Springs

Making the rounds in the California news these days is a ploy by the owners of water rights in the Mojave Desert near Cadiz, to mine groundwater and sell it to utilities in southern California.  Currently, rainfall in the basin enters the groundwater table, traveling slowly underground to two dry salt lakebeds, where the water resurfaces and evaporates away.  The business group Cadiz, Inc. thinks that this is a waste of perfectly good water resources, and wants to extract the water just upstream of the lakes, deliver it just 50 miles to the Colorado River Aqueduct (map here), then make lots of money from the water sale.

There are a couple of problems with this approach.  First, the groundwater in question supplies natural springs in the Mojave Natural Preserve, and the actual impact of pumping on the springs is likely to be different than the “no impact” that the businessmen assume.  Secondly, the exraction plan is completely unsustainable.  The Cadiz group has estimated the annual recharge of the basin for the past 50 years, and assumes that this will continue for the coming 100 years.  They then intend to extract 100 years’ worth of recharge in just 50 years.  The second 50 years will allow the basin to rebound from the intensive extraction.  Third, even with such an odd plan, independent scientists suggest that the actual natural recharge rate is 10-50% of the rate that Cadiz assumes, meaning that it will take many centuries for the basin to recover.

I saw the Cadiz scientists present their data monitoring plan in Sacramento a couple of weeks ago at a Groundwater Resources Association of California legislative symposium.  It was a terrible presentation, in my opinion — lots of figures with tiny writing and too many slides, so that we never got the full message of each slide.  It felt like they were trying to sell us on something bogus.  There were many questions from the professionals in the room, ranging from the impact of extraction on local rainfall to the potential of the dry lakebeds to turn into environmental hazards in the way that Owens Lake has. (Owens Lake’s inflow was diverted to the Los Angeles Aqueduct nearly 100 years ago, but the dry lake sediments that have been exposed are a huge dust and air pollution problem, and LA has been forced to cut back on its diversions to keep the sediments wet.)  Theoretically this would be addressed in the Environmental Impact Report, but Cadiz is trying to get away with the minimum impact assessment because they’re on former railroad territory, which gets an exemption from much of the state and federal environmental legislation.

The issue that they didn’t cover that day, and haven’t covered in any subsequent press, is why on earth they would devise such an intense extraction plan.  If they were to withdraw groundwater at roughly the recharge rate, they could deliver water indefinitely, which would be years upon years of profit.  Instead, they are focused on a 50-year time window for their sales.  Maybe it would require that much in water sales to make the rest of the capital costs for the 50-mile pipeline come out in the black.  But to me, it all reeks of short-term profit-seeking.  What will the southern Californian water utilities do when the 50-year extraction is over?  They’ll have just delayed the inevitable, and let more people get used to unsustainable water resources.  It just sounds like a bad idea.

yes but what will they drink?

Anyone out there ever had unexpected house guests?  You’ve got your plan for the evening, maybe just enough food for yourself or your family, and surprise, there’s an old friend at the door.  You try to play it cool and look like it’s no inconvenience, praying that you have enough in the fridge and maybe an extra bottle of wine or couple of beers to be hospitable.  It’s a tight position.

In the Middle East, Jordan is a relatively responsible water manager.  Limited in water supplies, the country’s population growth has stalled and development has been relatively well planned to balance ecological needs with human needs.  But Jordan has a lot of unstable neighbors, and therefore tons of unexpected, unplanned-for guests in the form of refugees.  Palestinians escaping Israel account for one third of the country’s 6.5 million people, plus they took on influxes of Iraqis in 1990 and 2003 (roughly 450,000 remain), and today, they are the refuge for many Syrians.  In an effort to meet the unexpected extra demand, the country started tapping its main aquifer in the 1980s for the Palestinians, and briefly stopped the extraction for ecological purposes (save the wetlands!) but could not supply the refugees without it.

Now the Azraq aquifer declines approximately 1 m annually, as about 56 million cubic meters are annually withdrawn; the aquifer can only naturally support 20 million cubic meters of annual withdrawal.  Taps in Amman run dry in the summer, and the declining levels are increasing the groundwater’s mixing with a deeper saline reservoir, so that the remaining groundwater is saltier and saltier.  Jordan is trying its best to do the right thing — take care of the refugees, preserve the wetlands, supply everyone with water, and get the withdrawals back in balance with natural recharge.  Jordan already recycles its wastewater for indirect potable reuse, it has plans for desalination, and it’s trying to get local people and neighbors on board with water plans.  So type A.  But it won’t last forever if these refugee surges keep coming…I’m guessing they wish their neighbors would all just get along.

recycling isn’t everything

I thought I should post this, after my enthusiasm for recycling in my last post: sometimes turning a waste stream into a marketable resource is a bad idea.  In fact, sometimes it’s a disaster.  Turns out, chemical companies thought about this a lot over the years, especially in the pre-regulation days.  In the 1940s and 1950s, Dow Chemical and Shell produced plastics from allyl chloride, and one of the by-products was a chemical called 1,2,3-trichloropropane (TCP).  Side research suggested that this compound could be added to a popular fumigant (Shell’s was called D-D, Dow’s was called Telone) without ill effects.  A Shell memo from 1981 suggests that the company made $6.3 million in fumigant sales, and saved $3.2 million in disposal costs for TCP.  In effect, the companies were able to use this waste as “filler” in a marketable good — perfect!

Originally the companies claimed that TCP was effective at killing nematodes, but subsequent research was unable to prove these claims.  In the meantime, the fumigants were used extensively in California’s Central Valley, where the compounds most resistant to degradation entered the groundwater, and the EPA, Clean Water Act, Safe Drinking Water Act, and Superfund law all came into effect.  Furthermore, we know today that TCP is a carcinogen, and more than 200 water wells across the Central Valley have elevated levels of TCP.  Although Shell stopped selling D-D in the 1980s and Dow changed its Telone formula in the 1990s, TCP will persist in affected groundwater for years.  This means that there are quite a few lawsuits out there to force these two companies to pay for additional treatment for existing water supplies and for external water supplies where treatment is unavailable.   The companies already settled with one small municipality for $13 million, which suggests that there are a few more settlements headed their way…

So to be clear, recycling works when you’re not dealing with hazardous material that may become a human health risk in the future.  It does not work when you try to hide toxic materials in useful products.