When someone asks us, "What's the best way to lower my water footprint?" the conversation always drifts to meat eating. That's because meat, especially beef, has a high water footprint - 1,800 gallons of water per pound of beef produced.
"But what about pasture-raised beef," you say? "It's sustainable, so isn't the water footprint much lower?" The answer, according to the limited amount of available research is, "Beef (still) has a high water footprint." But that doesn't necessarily mean it's unsustainable. Here's why.
Water footprints are broken out into three parts:
- The green water footprint (consumption of rain water);
- The blue water footprint (consumption of surface and groundwater); and
- The grey water footprint (pollution of surface and groundwater).
Learn more about green, blue and grey water footprints.
Regardless of how the animals are raised, most of the water footprint of beef comes from how they're fed, and more specifically the water it took to grow their feed. While they may start out eating grass, in the US, 99 percent of all livestock spends some final portion of their life "finishing" in a feedlot or concentrated animal feeding operation (CAFO) where they eat mostly corn- and soy-based feed, along with forage like alfalfa. The other 1 percent continue grazing on pastureland and are given very little supplemental feed. Both systems have a very high green water footprint because both rely heavily on rainfall; pastureland grasses and most corn and soy crops are typically not irrigated.
Industrial producers also get a portion of their feed from irrigated grains, which increases their blue water footprint. Pastureland systems occasionally require irrigation or provide irrigated supplemental feed. This, in turn, raises their blue water footprint. The details of these systems are discussed below.
Industrial beef has a high grey water footprint because of nutrient runoff (which sounds nice but isn't) from fertilizers and pesticides applied to the corn and soy crops and contaminated runoff from mismanagement of cattle manure. Pasture-raised beef have low grey water footprints because there is little pollution from runoff of fertilizers and pesticides.
Cattle Production and Blue, Green and Grey Water Footprints
A direct comparison of the water footprints of both production systems is difficult, because, in the studies done so far by water footprint researchers, data calculations are done using national averages and estimations. Also, different studies use different assumptions and definitions about what makes up each type of system. In addition, there is a lot of variability in how the cattle are raised from country to country, and detailed, US-specific studies don't exist. As such, we avoid specific numbers in our discussion of the components of the water footprints of each system. Nevertheless, here's what we do know.
Cattle Feed: Corn vs. Forage
The water footprint of beef is primarily impacted by how much and what the cattle eat, and where the feed comes from. This is because:
- Beef cattle eat massive quantities of feed but are inefficient in converting that feed to meat (compared to, say, chickens or pigs). More feed = more water.
- Across the US, about 10-15 percent of corn, about 8 percent of soy crops and 35 percent of alfalfa crops are irrigated. Almost 90 percent of that corn is grown in areas where groundwater pumping rates are unsustainable and competition for water is high.
- Currently, over a third of the US corn crop - 36 percent - is used for livestock feed (including pigs and poultry) and as more livestock is grown in industrial systems, the need for irrigated grains will increase.
- Feed from regions with more rainfall is typically less reliant on irrigation, but when there's no rain, this is can be a big problem. Droughts can happen anywhere; in May 2014, over half of the US was in some level of drought.
- Irrigation provides insulation from drought. It also increases crop productivity, and as a result, the percentage of irrigated acres in the US is increasing, even in humid areas.
Industrial Systems (CAFOs)
The overwhelming majority of beef produced in the US comes from CAFOs, also sometimes called factory farms. Industrially- raised cattle typically spend the first six to nine months of their lives with their mothers in a fairly open, sometimes pasture-raised, environment on what's called a calf-cow operation. Once they're weaned, they eat grass and forage. Then they're transitioned onto grain feed before being shipped to CAFOs.
CAFOs can contain hundreds to thousands of cattle, which are confined in close quarters. This system evolved to give beef producers a method of maximizing profits by fattening animals as quickly as possible. Feedlots offer factory-style efficiency and the cattle gain weight quickly by eating specially developed feed made up of protein- and energy-packed grain concentrate (e.g., corn, soy and grain distillates leftover from biofuel operations). The feed also often includes low-dose antibiotics, growth hormones and other supplements to promote faster growth. Feed conversion efficiency is increased, which shortens the time it takes to get cattle to market weight (from years down to about 12 months).
High numbers of cattle lead to vast quantities of highly concentrated waste. For instance, a typical beef cow poops out about 120 pounds per day (as much as 20-40 people). A single CAFO, therefore, can produce as much waste as a city. The manure is collected in large pools called "manure lagoons," (which again, sound nicer than they are) or is applied to fields as fertilizer. Both forms of manure management are known to pollute groundwater through aquifer infiltration and surface water through runoff from over-application of fertilizer and construction failures.
Water Footprint Components of Industrial Cattle:
Blue Water Footprint: MODERATE-HIGH The main component of the blue water footprint comes from irrigation of specially formulated feed using surface and groundwater. Agricultural locations that rely heavily on irrigation for crop production tend to have relatively dry climatic conditions, are more prone to drought and have greater constraints on and demands for surface water and groundwater resources. This is especially troubling when competing demands over water resources spark battles for water use between sectors, in court and in the larger community.
There are other, minor water uses that add to the blue water footprint, but they're small. Since most CAFOs get the majority of feed ingredients from offsite sources, water use comes from offsite production of fossil fuel-heavy (and water-intensive) fertilizers and pesticides and fuel for farming equipment, etc. There are also small amounts of direct water uses such as onsite water for feed preparation and mixing, animal drinking and facility maintenance.
Green Water Footprint: LOW-MODERATE In the early cow-calf stage of production, rainfed grasses and forage are eaten on pasture. Once cattle are on feedlots, a significant portion of their feed comes from rainfed corn and/or soy crops, depending on where the grain came from.
Grey Water Footprint: HIGH Major indirect water pollution occurs because of farm field runoff of fertilizers and pesticides that were applied to corn and soy crops. Synthetic fertilizers are one of the primary causes of dead zones in US freshwater and marine systems.
In addition, cattle produce enormous amounts of manure. More cattle mean more manure and at large CAFOs, concentrated waste and pollution is a big problem. Unfortunately, this is the most underestimated component in current agricultural water footprint research (a fact that is readily acknowledged by researchers).
CAFO waste is hazardous and can contain antibiotics, bacteria, pathogens and heavy metals. The waste is nutrient-rich, which, in overabundance, contributes to algae blooms in water bodies that create oxygen-depleted "dead zones" that are inhospitable to most aquatic life.
Pasture-Raised (Pastured) Systems
In a pasture-raised livestock system, almost all of the animal feed comes from pastures and rangelands where the cattle live. Because a pastured beef cow or steer eats less energy-dense food, the amount of time it takes to fatten it to the point where it's ready to be slaughtered (anywhere from 18 to 30 months) is longer than for those that are industrially raised.
Because they're relatively free to roam, the number of cattle per acre is low, which means that manure excreted by cattle - which is prodigious compared to most other animals - is spread out and assimilated into the soil. Manure is nutrient-rich and, in the right amounts, is conducive to plant growth and soil health.
Water Footprint Components of Pasture-Raised Cattle:
Blue Water Footprint: LOW In general, cattle don't rely on irrigated crops from offsite farms, although most pasture operations supplement with hay during winter and/or drought conditions, and that feed may sometimes have been irrigated.
Green Water Footprint: HIGH Cattle rely primarily on rainfed grasses and forage that is grown or cultivated on pastures and rangeland. This more natural diet lengthens the time it takes to get cattle to market weight. The green water footprint is high but there is significantly less impact on local water resources.
Grey water footprint: LOW Since the number of cattle per acre is low, less manure is produced so there's far less pollution from manure runoff. There is also little to no indirect water contamination resulting from pesticides, fertilizers, growth hormones and other feed supplements found in the industrial system, because these substances are not typically present in the pasture-raised cattle system.
Reducing Your Water Footprint
It's important to emphasize that CAFOs create other major problems, most notably air pollution, public health threats, animal abuse and adverse socioeconomic impacts. In terms of the overall degree of sustainability of beef, the water footprint is only one factor, but given the severity of the drought in California right now and the heavy agricultural demands that threaten to dry up Midwestern aquifers like the Ogallala and High Plains, the water requirements of specific agricultural items is timely and important.
Unquestionably, your diet has a huge environmental impact. The demand for meat remains very high in the US and as it increases worldwide, the problems associated with CAFOs - increased demand for feed, increased irrigation of crops and increased pollution from fertilizers and manure - will only get worse, leading to over-taxed water resources and more highly polluted water bodies around the country.
The easy answer to the question, "How do I lower my water footprint?" is "Eat less meat, and when you do eat it, make sure it comes from a pasture-raised source." You'll still have a higher water footprint than if you ate a vegetarian or vegan diet, but as the analysis above illustrates, the impact to the environment will be significantly less than eating meat produced in a resource-intensive and environmentally-harmful industrial system. Don't be swayed by the argument that "more efficient" CAFOs are the answer because the real costs to the environment and to society are often hidden behind those efficiencies.
It would be beneficial to have real data from rigorous and comprehensive field studies to help supporters of sustainable food production answer those questions for which there is mainly anecdotal information to answer.
Image "Cattle Grazing in the High Country" by J.N. Stuart on Flickr used under a Creative Commons Attribution-NoDerivs 2.0 Generic license.