Beef has a large water footprint and the system in which cattle are produced can make a substantial difference in the size of the footprint. While pasture-raised beef can be more sustainable, many assume that its water footprint is always smaller than that of industrially produced beef. This is not necessarily the case, although it can be more water friendly.
Beef’s Big Water Footprint
People often ask, “What’s the best way to reduce my water footprint?” and the conversation always drifts to meat eating. That’s because meat, especially beef, has a large water footprint — 1,800 gallons of water per pound of beef produced.
The follow-up is often, “But what about pasture-raised beef? It’s sustainable, so isn’t the water footprint much smaller?” The answer, according to the available research is, “Beef has a big water footprint no matter how it is produced.” Yet a big water footprint does not 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).
Regardless of the system in which 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 United States, approximately 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 approximately 1 percent continue to graze on pastureland and are given little supplemental feed. Both systems have a very large 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 enlarge their blue water footprint. Pastureland systems occasionally require irrigation or provide irrigated supplemental feed. This, in turn, expands their blue water footprint. The details of these systems are discussed below.
Industrial beef has a sizable grey water footprint because of nutrient runoff (e.g., nitrogen, phosphorus) from fertilizers and pesticides applied to the corn and soy crops and contaminated runoff from mismanagement of cattle manure. Pasture-raised beef have smaller grey water footprints because there is little pollution from runoff of fertilizers and pesticides. (For detailed information about beef production and the benefits of pasture-raised beef, go to the FoodPrint of Beef report.)
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:
- Due to their great size, 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 United States, about 10-15 percent of corn, about 8 percent of soy crops and about 33 percent of alfalfa crops are irrigated.
- An analysis estimated that about 87 percent of irrigated US corn is grown in regions deemed to have high or extremely high water stress, which indicates that a significant portion of developed water supplies are already allocated. Located in the American Breadbasket, these vulnerable regions expected to feel the negative effects of climate change and currently experience unsustainable groundwater pumping rates and competition over limited water.
- Currently, over one third of US corn crop – 36 percent – is used for livestock feed (including hogs 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 is little to no rain, this is can become problematic. Droughts can happen anywhere; for instance, in May 2014, over half of the United States was in some level of drought.
- Irrigation buffers crops from drought. It also increases crop productivity/yields, and as a result, the percentage of irrigated acres in the United States is increasing, even in humid areas.
Cattle Production and Blue, Green and Grey Water Footprints
A direct comparison of the water footprints of industrial and pasture-raised production systems is difficult, because, in the studies done so far by water footprint researchers, data calculations are done using national averages and estimates. 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 water footprint studies are rare. As such, specific numerical values are avoided in the discussion of the three components of the water footprints for each production system. Because of the dearth of precise data, more general indicators of SMALL, MEDIUM and LARGE are given to gauge the impact that the steps involved in the production system have for each of the blue, green and grey water footprints.
Industrial Systems (CAFOs)
The overwhelming majority of beef produced in the United States comes from CAFOs, sometimes called factory farms. (For greater detail on the lifecycle of beef production, see the EPA Ag101 archive or the FoodPrint of Beef report.) 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 in 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 from a few hundred to up to tens of thousands of head of cattle, which are confined in close quarters. This system evolved to give beef producers a method of maximizing profits by controlling the environment and fattening animals as quickly as possible. Feedlots offer factory-style efficiency and the cattle gain weight quickly by eating specially developed feed comprised of protein- and energy-packed grain concentrate (e.g., corn, soy and grain distillates leftover from biofuel operations). The feed 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 a few years down to about 12 months).
High numbers of cattle lead to vast quantities of highly concentrated waste. For instance, a typical beef or dairy cow can excrete about 120 pounds of manure per day (as much as 20-40 people). A single CAFO, therefore, can produce as much waste as a medium-sized city. The manure is collected in large pools called “manure lagoons,” 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 lagoon construction failures.
Water Footprint Components of Industrial Cattle:
Blue Water Footprint: MEDIUM-LARGE The main component of the blue water footprint comes from the irrigation of specially formulated feed that uses surface and/or 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. Competing demands over water resources can spark battles over water rights, allocations and 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 are relatively small compared to total. Since most CAFOs get the majority of feed ingredients from offsite sources, water use comes as virtual water 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 required for feed preparation and mixing, animal drinking and facility maintenance.
Green Water Footprint: SMALL-MEDIUM In the early cow-calf stage of production, rainfed grasses and forage are eaten as cattle graze on pasture. Once moved to 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: LARGE 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 needed to bring it to market weight and ready it for slaughter (18 to 30 months) is longer than for those animals raised in industrial systems.
Since they are relatively free to roam, the number of cattle per land area is low (e.g., per acre, per hectare), 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: SMALL In general, cattle don’t rely on irrigated crops from offsite farms, although many pasture operations supplement with hay during winter months and/or drought conditions, and that feed may sometimes have been irrigated.
Green Water Footprint: LARGE Cattle rely primarily on rainfed grasses and forage that is grown or cultivated on pasture and rangeland. This more natural diet lengthens the time it takes to get cattle to market weight. The green water footprint is larger but there are significantly less impacts on local water resources.
Grey Water Footprint: SMALL Since the number of cattle per land area is low, less manure is produced and thus, far less pollution from manure runoff is incurred. 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 Water Footprints Through Dietary Changes
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 regular occurrence of water shortages and droughts on one side, and intense precipitation and flooding on the other, the water requirements for specific agricultural products is important and necessary in the United States and around the world.
Unquestionably, a person’s diet has a huge environmental impact. The demand for meat in the United States remains very high and as it increases worldwide, the problems associated with CAFOs – increased demand for feed, irrigation water for crops and pollution from fertilizers and manure – are expected to worsen. This leads to over-taxed water resources and greater pollution in water bodies and waterways throughout the country. For instance, heavy agricultural water demands threaten vital water resources like the over-allocated Colorado River and strained Ogallala Aquifer.
One strong response to the question, “How do I lower my water footprint?” is to advise people to eat less meat, and when they do eat it, to choose meat from well-managed pastured sources. People who eat pasture-raised beef and meat might have larger water footprints than those who eat vegetarian or vegan diets. But as the above analysis illustrates, the environmental impact could be reduced if pastured meat is eaten as opposed to meat produced from resource-intensive, environmentally harmful industrial systems. Although arguments for the efficiency of industrially produced beef are often advanced, those arguments often avoid the true costs of meat production systems inflicted on the environment and society, which are often hidden behind those efficiencies.
To gain greater insight about water impacts and water footprints for various beef and meat production systems, from pasture-raised to industrial, more site-specific data from rigorous and comprehensive field studies would be useful.
Image: “Cattle Grazing in the High Country” by J.N. Stuart on Flickr used under a Creative Commons Attribution-NoDerivs 2.0 Generic license.