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Popular Fact

“But what people don’t know is the environmental damage almond plantations are doing in California, and the water cost. It takes a bonkers 1,611 US gallons (6,098 litres) to produce 1 litre of almond milk,” says the Sustainable Restaurant Association’s Pete Hemingway.
- The Guardian - Ditch the almond milk: why everything you know about sustainable eating is probably wrong - 2018

This cites Almond Milk vs. Cow Milk Life Cycle Assessment - Jacqueline Ho, Ingrid Maradiaga, et al. - 2016, which has figures that are highly suspect due to methodological concerns (see below).

Reality

Almond milk uses around 99 US Gallons of water per litre in comparison to cow’s 158 US Gallons per litre.
- TalkVeganToMe summary via Poore and Nemecek

Original Sources

Reducing food’s environmental impacts through producers and consumers - Poore and Nemecek - 2018

While the original article does not address almond milk specifically, Joesph Poore (one of the authors) provided comparative statistics for different milks water usages to the BBC for their article Climate change: Which vegan milk is best? - 2019. In the graph it suggests that it takes 70-80L of water per 200ml of Almond Milk. Taking the middle point (75L) that gives us 375L of water to produce 1L of Almond Milk (or 99 US Gallons per litre).

To understand this figure better I reached out to Joseph Poore via email and ze explained that zir figures were based on an confidential Life Cycle Analysis (LCA) from an almond milk production company and based on that LCA confirmed that:

[I used] the post-farm data for soymilk (almond milk processing isn’t a major user of water, so this is a good proxy)
- Joseph Poore - Email to Author - 2019

Joseph also pointed out that there was a huge difference in the footprint between US and European sourced almonds because the Floridian almonds sourced in the US are predominantly irrigated and the Spanish almonds sourced in Europe and rainfed. For the statistics in the BBC article ze took global data for almond water usage.

Almond Milk vs. Cow Milk Life Cycle Assessment - Jacqueline Ho, Ingrid Maradiaga, et al. - 2016

This figure is the average of two calculations, one partly based on an industry analysis and one wholly based on a statistical model. The former is as follows:

Almond production + almond processing =
0.20113 kgal + 1.068555 kgal = 1.269685 kgal water / 1L almond milk
Almond Milk vs. Cow Milk Life Cycle Assessment - 2016 - p13

The first figure of 201 gallons per litre of almonond milk (consumed in the growing of the almonds) is derived from Almond Eco­Efficiency Analysis (BASF Corporation, 2011). The second figure of 1,068 gallons per 1 litre of Almond milk (consumed in the processing of almonds into milk) is the vast majority of the total and is rather suspect.

Almond Processing Figure

Due to a lack of statistical data regarding almond processing, the almond processing figure (1,068 gallons of water to 1 litre of almond milk) is derived using the ratio of water usage in soybean production to soybean processing. p11.

The ratio of water usage in producing vs processing soybeans came out as 0.83x p11 (i.e. producing the soybeans took 0.83x as much water as processing them).

It seems very strange to use a ratio of water to grow vs water to process for this, as just because almonds take more water to grow, it does not follow that they take more to process. It seems far more likely (without evidence to the contrary) that the amount of water to process soybeans is broadly similar. The amount of water used to process soybeans they cite is 136 gallons p12. It seems staggering to believe that almonds use more than 8x as much water for processing as soybeans without any additional details on the process.

This ratio of 0.83x is then applied to 0.885 kgal for farming.

0.82822086 = Tree nut farming / x
0.82822086 = 0.885 kgal / x
x = 1.068555 kgal water used in processing almonds into almond milk
- p13

This gives us the 1,068 gallons of water used in the processing of almonds into milk to yield to 1 litre of milk. But where does the 0.885 kgal come from?

The 0.885 kgal figure was calculated using the EIOCLA US 2002 Benchmark Producer Price Model - Tree Nut Farming with an input of the average retail price of almond milk per litre (1.7858$/litre) p12. The EIOCLA is a rather clever statistical model that uses data from a variety of public sources to calculate the environmental impact of various industries per million dollars of the producer price.

To be clear, they are using data on the amount of water it takes to grow (produce) nuts to infer the amount of water it takes to process the (already grown) nuts into milk

The dollar value input for the EIOCLA model is naturally crucial, and the tutorial for the calculator warns:

The dollar value entered represents producer price - the cost to make the output; it is not the consumer price - the cost to purchase the output. For an average automobile, the producer price is around $20,000. A consumer would purchase this average vehicle for $25,000 to $30,000.
- EICLA Tutorial

Unfortunately it seems that in this study, the retail price has been used, inflating the results significantly. The study justifies this by saying:

We are assuming that the cost of packaging is negligible thereby allowing us to use the retail price as the economic activity for EIOLCA.
- p12

But this ignores retail markup, distribution costs, not to mention the fact that the dataset we’re working against is for the Tree Nut Farming industry p12, not the almond milk industry which skews the result due to the farming industry having a much lower ‘producer price’ (price the farmer/factory sells it at) by virtue of being further back in the value chain.

We therefore regard the numbers cited here for almond processing as highly suspect due to:

  1. The conflation of retail and producer pricing
  2. The conflation of nut milk producer pricing and nut farming producer pricing
  3. The inference of processing water usage from farming water usage (two completely unrelated numbers)
  4. The assumption that the ratio (0.83x) of production (farming) water usage to processing (almonds into milk) water usage from data regarding soybeans somehow applies to almonds.

Using the datasets and methodologies that the study provides it is impossible to come to a reliable conclusion regarding the total water usage per litre of almond milk.

Speculating further

Out of curiousity however, we can use the data the authors provided to make two still unsupportable, but arguably more accurate calculations for water usage per litre of almond milk.

Use soybeans’ processing water usage per litre as a comparison

Almond Farming + Soybean Processing = Approximate Total gallons per litre of milk
0.20113 kgal p13 + 0.136 kgals p12 = Approximate Total
Approximate Total = 0.33713 kgals

So our total would be 337 gallons of water per litre of almond milk rather than their cited 1,611. This makes the assumption that almond processing takes exactly as much water as soybean processing, but that seems a more defensible assumption than the wild speculation of the figures based on the model. (See the 4 bullet points above for why.)

Use the Almond Eco­Efficiency Analysis figure with the 0.83 ratio

Almond Farming Water Usage / Almond Processing Water Usage = 0.83 p11)
0.2 kgals / x = 0.83
x = 0.24 kgals
Almond Processing Water Usage = 240 gallons

Which would make our total (Almond Farming + Almond Processing): 0.44 kgallons, or 440 gallons of water to make 1 litre of almond milk rather than the cited 1,611 gallons.

Important: The calculation above is still completely spurious and is merely an extrapolation based on the article’s own unfounded assumption of a universally applicable ratio between farming water usage and processing water usage.

Sources

Article Contributors

Sam Martin
Author