Eating Just 10% Less Meat Could Help Protect Drinking Water

The environmental case for plant-based burgers is often focused on climate — as greenhouse gas emissions for pea protein or soy are a fraction of what it takes to produce beef. But new research finds swapping conventional meat for alternatives — defined by the researchers as plant-based, insect-based or cultured meat — could do more. The switch would reduce rising levels of water pollution from meat and dairy farming, resulting in cleaner water in agricultural communities.

In a study published in Nature Food on June 13, scientists found that replacing just 10 percent of the meat Americans eat with alternative options would reduce the risk of dangerously high levels of nitrate in groundwater by up to 20 percent. More specifically, the researchers estimated this shift could cut fertilizer use by 3.4 percent, slash manure output by 10.7 percent and reduce water use by 4.5 percent.

And if people swapped half the meat in their diets with alternative proteins, the impact would be even bigger — improved water quality would be likely in 60 percent of regions across the United States — especially in areas where fertilizer runoff and livestock manure are widespread.

“This suggests that even modest dietary changes can have the greatest impact in regions with heavy agricultural activity,” Zhilin Guo, one of the authors of the study, told Sentient in a subsequent email.

The new study looks at how conventional meat production has contributed to nitrate contamination in groundwater across the United States from 1985 to 2020, and how switching to alternative proteins could improve water quality.

Americans consume an average of 224.9 pounds of red meat and poultry per person each year, according to data from the U.S. Department of Agriculture from 2022. To meet this and export demands, the meat industry is projected to produce 26.36 billion pounds of beef, 6.95 billion pounds of pork and 47.58 billion pounds of chicken meat in 2025.

But producing that much meat comes at a steep environmental cost. Meat production is among the most resource-intensive sectors, requiring vast amounts of feed, land and water. These costs aren’t uniform across livestock production. Farming cattle and other ruminant animals creates massive amounts of climate emissions, while manure from dairy and pork farms releases methane and pollutes waterways (poultry waste also contributes to pollution).

Wells have reached record-low levels of water over the past decade, while the use of nitrate fertilizers on fields has continued to rise, says Matt Hotze, who leads the science and technology operations of alternative meat advocacy group the Good Food Institute. Nitrate leaches into underground aquifers of agriculture-heavy regions largely through runoff from fertilizers and livestock manure on farms.

“That is draining into aquifers that are getting smaller. So it’s not a huge surprise that if we could actually reduce the amount of fertilizer we’re using for the purpose of raising animals, then we could reduce the amount of nitrate that’s going into these depleting groundwater sources,” Hotze, who was not involved with the study, tells Sentient.

Nitrate Pollution in Water

A 2020 analysis by the Environmental Working Group found that drinking water systems serving around 21 million people across California, Illinois, Iowa, Kansas, Maryland, Nebraska, Oklahoma, Pennsylvania, Texas and Wisconsin — America’s agricultural heartland — were contaminated with nitrates.

Under the Safe Drinking Water Act, the U.S. Environmental Protection Agency has set the legal limit of 10 milligrams per liter for nitrate in drinking water. However, levels higher than 3 mg/L in groundwater drinking systems typically signal contamination.

Ingesting too much nitrate can lead to methemoglobinemia — also known as baby blue syndrome — a condition that reduces the blood’s ability to carry oxygen, particularly in infants. Studies have also linked nitrate in drinking water with an increased risk of colorectal cancer, thyroid disease and certain birth defects.

The real solution to the problem of nitrate runoff, Hotze argues, is rethinking the food system entirely, not just tweaking feedlot design. “We have a solution in front of us that actually can help that problem,” he says, referring to alternative proteins. “That actually cuts out the middleman, if you will, from food production.

The Most Sustainable Meat Is Plant-Based

Beef is the most resource-intensive protein. Producing just one kilogram of beef requires 519 grams of fertilizer, 49.5 cubic meters of water and 218.3 square meters of land. Each kilogram of beef produced also generates 214.5 kilograms of CO2 equivalent greenhouse gas emissions— about the same as driving a typical gas-powered car for about 546 miles.

Producing one kilogram of pork, meanwhile, uses 520.9 grams of fertilizer, 17.2 cubic meters of water, and 71.3 square meters of land. Poultry production is slightly less demanding, requiring 389.6 grams of fertilizer, 11.7 cubic meters of water and 48.5 square meters of land. Pork and poultry productions emit 43.2 kg CO₂e and 29.3 kg CO₂e, respectively — a fraction of what beef production emits.

In contrast, plant-based meat — especially the soy-based varieties that dominate the market — is far more sustainable. By cutting livestock out of the equation, soy-based meat requires just 26.4 grams of fertilizer, 12.7 square meters of land, and produces only 1.9 kg CO₂e per kilogram of product.

In other words, says Hotze, plant-based meat takes far less of a toll. “It reduces water use by 95 percent. There’s 93 percent less pollution and it reduces the amount of land that you need by 79 percent. Really quite dramatic reductions,” Hotze says.

To produce a kilogram of insect-based meat, 30.9 grams of fertilizer, 11.5 cubic meters of water and 16.5 square meters of land are needed. It emits just 12.7 kg CO₂e. Though farming insects does raise welfare concerns, as there is growing scientific evidence of insect intelligence and sentience.

Cultivated meat — sometimes called lab-grown meat despite objections to the term — uses just 3.1 cubic meters of water to produce a kilogram of protein, making it the most water-efficient option. However, it emits 98.3 kg CO₂e — second only to beef among all the protein sources analyzed. Some other research models have found lower emissions for cultivated meat, but these assume a future transition to clean energy sources.

Despite the many environmental benefits, all forms of alternative protein included in the study face major hurdles to adoption — chief among them low consumer acceptance and underinvestment.

Steep Investment Needed for Alternative Proteins to Compete

In 2024, more than half of Americans tried plant-based meat, but only 24 percent said they eat it at least once a month, according to research by the Good Food Institute. Conventional meat still dominates American plates. Analysts project the U.S. meat market will grow to $215.76 billion by 2028 — up from $172.94 billion in 2021.

The U.S. ranks second alongside Spain for the highest per capita meat consumption, with both countries averaging 144 kilograms—or 317.5 pounds—per year, according to data from the Food and Agriculture Organization of the United Nations. In the U.S., poultry made up the largest share at 53 kilograms (116 pounds) per person annually, followed by beef at 38 kilograms (84 pounds) and pork at 30 kilograms (66 pounds). Portugal ranked first with 151 kilograms (333 pounds) per capita, largely due to its high fish consumption.

Making alternative proteins more affordable and accessible is essential to boosting their uptake, Guo says. But that won’t happen without significant investments. A 2024 report from The Breakthrough Institute stressed that public investment in food innovation like alternative proteins should match the scale of clean energy funding, especially given that meat, particularly beef, is a major source of climate emissions.

The Farm Bill should make it easier to diversify the country’s protein sources and give farmers more options, argues Hotze, like growing peas or mung beans for plant-based meat. While Hotze is not optimistic that major changes will happen in the next version of the bill, he remains hopeful. Farmers would love to grow more than just soy and corn, he says. “They’d love to have different opportunities to expand what they’re doing and have new sources of revenue that would be great for them.”