Homeowners in Los Angeles County may soon have the right to complain about a new municipal waste fee: the Clean Water, Clean Beaches Water Quality tariff. The fee is designed to spread out the cost of trash and pollution that head down the LA waterways and end up on the beaches or in the ocean. It’s debatable whether this is the best approach, but some in the article argue for federal or state funding to resolve the issue. Really? Isn’t it arrogant to assume that the cost burden of a problem specific to the Los Angeles basin should be distributed across the entire state or worse, the entire US? I actually like the idea of a fee that encourages people to consider the impact of their behavior on the local waterways and beaches, though I’m not sure this is it — it’s easy to grumble, write a bigger check, and move on.
Something that I’ve been thinking a lot about recently is water. Typical. Specifically, where major American cities get their water. European cities were historically built on rivers or lakes, where an obvious clean water source could be found. They developed common sense procedures like withdrawing drinking water upstream of discharging wastewater. In the US, major cities also developed on rivers, but city planners looked further afield to remote unpopulated water basins to deliver higher quality and sometimes greater quantities of water. In fact, even today, the highest rated tap water, according to its consumers, comes from New York City, which tapped watersheds up to 163 miles away in the Catskills, and San Francisco, which tapped the Hetch Hetchy reservoir in what would later become Yosemite, 167 miles away. The east side of the San Francisco Bay, which includes Berkeley, where I currently live, and Oakland, where I currently work, gets its water from one watershed north of the Hetch-Hetchy basin.
In light of this reality, maybe the diversion of the Owens and Colorado Rivers into the Los Angeles Aqueduct and Colorado River Aqueduct, respectively, isn’t so bad – it’s just a longer distance (419 miles and 242 miles) than the aqueducts used by the “environmentally conscious” San Francisco Bay Area. And Atlanta, my hometown, can’t really be blamed for taking as much water as possible from the Chattahoochee River just to the north. The city is located in a relatively resource-poor area when it comes to surface water, and the Supreme Court recently affirmed its right to the waters of Lake Lanier (though the exact quantity is still TBA).
Las Vegas is located essentially on Lake Mead, and gets its drinking water from the lake as well as discharges its treated wastewater to the lake. Is this more sustainable than Phoenix, whose recent growth relies on the availability of the Colorado River, 336 miles away? I’m having a hard time judging cities in their pursuit of water resources from remote, pristine areas, because very few American cities are located adjacent to sufficient water supplies. Environmentalists in San Francisco bemoan the fate of the salmon in the Sacramento-San Joaquin delta, whose habitat is shrinking due to water grabs from southern California and the Central Valley, but their water comes from an area that was literally made into a National Park! Water supply inevitably involves some big tradeoffs, so “Let he who is without blame cast the first stone”…
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.
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.
When you look at the water balance for a municipality, at how much water is treated to high-quality drinking water standards vs. how much actually ends up in our wastewater treatment system, there is a striking imbalance. Of the treated drinking water in the Los Angeles basin, for example, my numbers suggest that maybe 50-60% makes it to a wastewater treatment facility. Assuming minimal use of off-grid septic systems, where is the other 40-50% going?
The short answer is outdoor water use. Grass and non-native plants require a lot of water to stay healthy, and in our “I have a right to cheap water” mindsets, the water for our plants and cars is not a big deal. Cinnamon McIntosh, a water conservation specialist for Casitas Municipal Water District in Southern California, recently stated that typical overwatered lawns in Southern California receive twice the amount of water as there is rainfall in Ireland. Granted, there’s a lot more evaporation in SoCal than in Ireland, but surely we can do better than this.
Add water scarcity to the equation, and you can understand why water agencies have an interest in water conservation among the people they serve. From paying customers to switch to native plants and grasses to implementing outdoor watering restrictions to price increases, various methods are being tried. Los Angeles has been fairly successful in these techniques, and its per capita water use of 123 gallons per day is the lowest in any US city with a population over 1 million. That said, the LA Department of Water and Power has noticed an uptick in water use this dry winter, especially among single-family homes…which likely points to outdoor water use.
I hesitate to say we should go so far as to jail those who water lawns or wash cars outdoors, but sometimes threat of penalty (the proverbial “stick”) reaches people’s minds more readily than this situation’s proverbial “carrot”: more efficient water use.