Industrial water is water used in manufacturing and production processes, from cooling machinery and washing products to becoming an ingredient in the final product itself. The U.S. Geological Survey defines it as water used for fabricating, processing, washing, diluting, cooling, or transporting a product, as well as for sanitation within a manufacturing facility. In the United States, industrial facilities withdrew about 14.8 billion gallons per day in 2015, making it a major category of water use alongside agriculture and power generation.
How Industries Use Water
Water plays different roles depending on the industry, but most industrial water use falls into a handful of categories. Cooling is one of the biggest. Power plants, steel mills, and chemical facilities generate enormous amounts of heat, and water absorbs and carries that heat away. Fossil fuel and nuclear power plants use hundreds of liters of water for every kilowatt-hour of electricity they produce, largely for this purpose.
Processing and fabricating are the next major uses. Paper mills need high volumes of water to turn wood pulp into sheets. Semiconductor manufacturers use ultrapure water to wash silicon wafers during chip production, since even microscopic contaminants can ruin a circuit. Food and beverage plants use water as both a processing aid and a direct ingredient. Textile operations consume large quantities during dyeing and finishing, making apparel one of the more water-intensive industries globally.
Beyond these, water serves as a solvent for diluting chemicals, a transport medium for moving materials through pipes, and a cleaning agent for washing equipment between production runs.
Where Industrial Water Comes From
Surface water, meaning rivers, lakes, and reservoirs, accounts for 82 percent of all industrial water withdrawals in the United States. Groundwater makes up most of the remainder. Some facilities also purchase treated water from municipal supplies, particularly in urban areas or when their processes demand higher baseline quality. In water-scarce regions, recycled municipal wastewater is increasingly used as a supplemental source.
The specific source matters because it determines how much treatment the water needs before use. River water carries sediment, organic matter, and variable mineral content. Groundwater tends to be cleaner but can contain dissolved minerals like iron or calcium that interfere with certain processes. Municipal water arrives pre-treated but still may not meet the strict purity standards some industries require.
Quality Standards Vary by Industry
Not all industrial water is the same quality. A concrete plant can tolerate water with dissolved minerals and some particulates. A pharmaceutical manufacturer cannot. The FDA requires that water used in drug production meet USP Purified Water standards, both chemically and microbiologically. An even stricter grade, Water for Injection, can only be produced through distillation or reverse osmosis and is used in sterile drug products.
Semiconductor fabrication sits at the extreme end of the purity spectrum. The water used to rinse chips during manufacturing must be virtually free of ions, particles, bacteria, and dissolved gases. Producing this ultrapure water requires multiple treatment stages and constant monitoring. At the other end, water used solely for cooling a steam turbine needs far less treatment, though it still must be managed to prevent corrosion and mineral buildup in pipes.
How Industrial Wastewater Gets Treated
Water that has been used in an industrial process picks up contaminants specific to that process: heavy metals from metal finishing, organic compounds from chemical manufacturing, oils from petroleum refining. Before this water can be discharged or reused, it needs treatment. The EPA maintains a database of treatment technologies, and several are widely used across industries.
Biological treatment uses microorganisms to break down organic pollutants. Aerobic systems pump in air to support oxygen-dependent bacteria, while anaerobic systems operate without oxygen and are better suited for high-strength organic waste. Membrane filtration physically separates contaminants by forcing water through barriers with tiny pores. Microfiltration catches particles down to about 100 nanometers, ultrafiltration reaches 10 nanometers, and reverse osmosis removes dissolved salts and ions by pushing water through an even tighter membrane under high pressure. Membrane bioreactors combine biological treatment with ultrafiltration in a single system, reducing both organic matter and suspended solids.
Regulations Governing Discharge
In the United States, the Clean Water Act requires industrial facilities to meet Effluent Guidelines before discharging wastewater into rivers, lakes, or municipal sewer systems. The EPA sets these standards for more than 50 industry categories, from aluminum forming and petroleum refining to pulp and paper production. The standards are technology-based, meaning they reflect what proven treatment systems can achieve rather than being calculated from environmental risk models for a specific waterway.
Each industry category has its own set of limits. A metal finishing plant faces different discharge requirements than a dairy processing facility. Some of these guidelines date back to the 1970s, while others have been updated recently. Steam electric power generation and meat and poultry products both received updated standards as recently as 2025. Facilities that discharge directly into surface water need a permit, and those sending wastewater to a municipal treatment plant must meet pretreatment standards so they don’t overwhelm or damage the public system.
Long-Term Trends in Industrial Water Use
Industrial water use in the U.S. has dropped significantly over the past half-century. Withdrawals peaked at 47 billion gallons per day in 1970, then fell to 14.8 billion gallons per day by 2015, a decline of nearly 70 percent. The drop from 2010 to 2015 alone was 9 percent. This reflects a combination of efficiency improvements, process changes, stricter regulations, and the shift of some manufacturing overseas.
One approach gaining traction is zero liquid discharge, or ZLD. These systems treat and recycle all wastewater within a facility so that nothing is released into the environment. A typical ZLD setup combines pretreatment, reverse osmosis, and thermal evaporation with crystallization to recover both clean water and solid salts. The recovered salts can sometimes be sold or reused, offsetting part of the operating cost. ZLD systems are expensive to build and run, but three forces are pushing adoption: tightening environmental regulations, rising water costs, and genuine scarcity in regions where freshwater is increasingly contested between cities, farms, and factories.