Water Treatment Companies in the United States are essential to public health, industry, agriculture, manufacturing, hospitals, food production, power generation, data centers, and municipal infrastructure. Their work helps remove contaminants, improve water quality, treat wastewater, protect equipment, meet environmental rules, and keep communities supplied with safe water.
The U.S. water market is becoming more urgent because utilities and industries face aging pipes, stricter water-quality rules, drought, PFAS contamination, industrial discharge limits, wastewater reuse, and rising treatment costs. American Water says it is the largest regulated water and wastewater utility in the United States, serving about 14 million people across 14 regulated states and 18 military installations.
The industry includes municipal utility operators, industrial water treatment firms, filtration manufacturers, chemical suppliers, wastewater technology companies, engineering consultants, PFAS treatment specialists, membrane companies, and local residential water treatment providers.
This guide profiles leading Water Treatment Companies in the United States and explains how buyers should evaluate providers for drinking water, wastewater, industrial process water, filtration, desalination, PFAS removal, and reuse.
Industry Overview: Water Treatment Companies in the United States
Water treatment covers drinking water treatment, wastewater treatment, industrial water systems, process water, boiler water, cooling water, ultrapure water, filtration, disinfection, desalination, sludge treatment, stormwater, water reuse, and contaminant removal.
Demand is being shaped by regulation. EPA’s PFAS drinking-water rule affects public water systems, and EPA estimated that about 6% to 10% of roughly 66,000 public drinking water systems may need action to reduce PFAS. EPA also announced proposed PFAS drinking-water rule changes in May 2026, including an option for some systems to seek more time for compliance.
Major opportunities include PFAS treatment, water reuse, industrial recycling, membrane systems, smart monitoring, wastewater modernization, desalination, and advanced filtration.
Ranking Methodology
This directory evaluates companies based on U.S. market relevance, treatment technology, municipal and industrial capability, public reputation, regulatory usefulness, service range, geographic reach, equipment quality, project experience, and buyer value.
Best Water Treatment Companies in the United States
Xylem
Overview
Xylem is one of the most important water technology companies serving the United States. Its capabilities include water transport, treatment, analytics, digital monitoring, wastewater, industrial water, and utility infrastructure. Evoqua is now part of Xylem, expanding Xylem’s treatment and service capabilities.
Services Offered
Water treatment, wastewater treatment, pumps, analytics, filtration, disinfection, digital water systems, industrial water, municipal systems, and service support.
Industries Served
Municipal utilities, industrial facilities, commercial buildings, food and beverage, healthcare, power, manufacturing, and infrastructure.
Notable Projects
Not publicly listed here.
Competitive Advantages
Xylem combines treatment equipment, digital water technology, pumps, analytics, and industrial service depth.
Headquarters
Washington, D.C.
Website
xylem.com
Why It Stands Out
Xylem stands out for municipal and industrial water systems, wastewater, analytics, and integrated water technology.
Veolia Water Technologies
Overview
Veolia is a global water, waste, and energy company with a strong U.S. water treatment presence. It is widely recognized for municipal water, industrial water, wastewater treatment, desalination, reuse, and environmental services.
Services Offered
Water treatment, wastewater treatment, desalination, industrial water systems, sludge treatment, water reuse, operations, maintenance, and environmental services.
Industries Served
Municipalities, utilities, industrial plants, food and beverage, chemicals, pharmaceuticals, power, oil and gas, and public agencies.
Notable Projects
Veolia is frequently listed among leading global water and wastewater treatment companies.
Competitive Advantages
Its advantage is global water treatment experience, broad technology coverage, and municipal-industrial scale.
Headquarters
Global headquarters: Paris, France. U.S. operations serve national markets.
Website
veoliawatertechnologies.com
Why It Stands Out
Veolia stands out for municipal treatment, industrial water, wastewater, reuse, and desalination.
Ecolab / Nalco Water
Overview
Ecolab, through Nalco Water, is a major U.S.-based water treatment and process optimization company. It is especially strong in industrial water, cooling water, boiler water, food safety, hygiene, process treatment, and water efficiency.
Services Offered
Industrial water treatment, chemical treatment, cooling systems, boiler treatment, process water, monitoring, water efficiency, hygiene, and sustainability services.
Industries Served
Food and beverage, hospitality, healthcare, manufacturing, power, chemicals, refining, commercial facilities, and institutional clients.
Notable Projects
Ecolab is commonly identified among leading North American water treatment chemical companies.
Competitive Advantages
Ecolab’s advantage is chemical treatment, service programs, monitoring, and water efficiency for industrial and commercial clients.
Headquarters
St. Paul, Minnesota.
Website
ecolab.com
Why It Stands Out
Ecolab stands out for industrial water treatment, chemical programs, cooling systems, and water efficiency.
American Water
Overview
American Water is the largest regulated water and wastewater utility company in the United States. It provides drinking water and wastewater services to millions of people and operates regulated systems across multiple states and military installations.
Services Offered
Drinking water service, wastewater service, treatment operations, distribution, utility management, infrastructure investment, military services, and customer service.
Industries Served
Residential customers, municipalities, military installations, commercial users, public agencies, and industrial customers.
Notable Projects
American Water marked 140 years of service in 2026 and continues expanding regulated water and wastewater operations.
Competitive Advantages
Its advantage is regulated utility scale, long operating history, and drinking water and wastewater infrastructure experience.
Headquarters
Camden, New Jersey.
Website
amwater.com
Why It Stands Out
American Water stands out for regulated drinking water and wastewater utility service.
Pentair
Overview
Pentair is a major water treatment and filtration company serving residential, commercial, industrial, pool, and municipal-adjacent markets. It is especially relevant for filtration, pumps, water softening, reverse osmosis, and water quality systems.
Services Offered
Water filtration, water softening, reverse osmosis, pumps, pool systems, commercial water treatment, residential water systems, and industrial water products.
Industries Served
Homes, commercial buildings, foodservice, hospitality, pools, light industrial users, and water equipment dealers.
Notable Projects
Not publicly listed here.
Competitive Advantages
Pentair’s advantage is broad product availability across residential, commercial, and light industrial water treatment.
Headquarters
Golden Valley, Minnesota.
Website
pentair.com
Why It Stands Out
Pentair stands out for filtration, softening, reverse osmosis, pumps, and residential-commercial water systems.
Culligan
Overview
Culligan is one of the most recognized residential and commercial water treatment brands in the United States. It serves homeowners and businesses through dealer networks offering filtration, softening, reverse osmosis, bottled water, and drinking water systems.
Services Offered
Water softeners, filtration systems, reverse osmosis, drinking water systems, bottled water, commercial water treatment, testing, installation, and maintenance.
Industries Served
Homeowners, offices, restaurants, hotels, schools, small businesses, healthcare facilities, and commercial properties.
Notable Projects
Not publicly listed here.
Competitive Advantages
Culligan’s advantage is consumer recognition, dealer access, and practical residential-commercial water solutions.
Headquarters
Rosemont, Illinois.
Website
culligan.com
Why It Stands Out
Culligan stands out for home water treatment, softeners, drinking water systems, and local service networks.
Calgon Carbon
Overview
Calgon Carbon is a major activated carbon and treatment media company. It is especially relevant for PFAS removal, taste and odor control, industrial treatment, municipal drinking water, air purification, and contaminant adsorption.
Services Offered
Activated carbon, adsorption systems, PFAS treatment media, reactivation, equipment, drinking water treatment, wastewater treatment, and industrial purification.
Industries Served
Municipal water utilities, industrial plants, environmental remediation, food and beverage, chemicals, power, and environmental contractors.
Notable Projects
Calgon Carbon is commonly included among leading water and wastewater treatment equipment companies.
Competitive Advantages
Its advantage is activated carbon expertise, which is important for PFAS and other contaminant removal.
Headquarters
Moon Township, Pennsylvania.
Website
calgoncarbon.com
Why It Stands Out
Calgon Carbon stands out for activated carbon, adsorption, PFAS treatment, and contaminant removal.
Aquatech International
Overview
Aquatech International is a U.S.-based water technology company focused on industrial water treatment, desalination, zero liquid discharge, wastewater reuse, and process water systems.
Services Offered
Industrial water treatment, desalination, zero liquid discharge, wastewater reuse, membrane systems, evaporators, crystallizers, and project delivery.
Industries Served
Power, oil and gas, chemicals, mining, semiconductors, pharmaceuticals, food and beverage, and heavy industry.
Notable Projects
Aquatech is listed among leading water and wastewater treatment equipment companies.
Competitive Advantages
Its advantage is complex industrial water treatment and high-recovery systems.
Headquarters
Canonsburg, Pennsylvania.
Website
aquatech.com
Why It Stands Out
Aquatech stands out for industrial water, desalination, wastewater reuse, and zero liquid discharge.
DuPont Water Solutions
Overview
DuPont Water Solutions supplies membrane, ion exchange, reverse osmosis, ultrafiltration, and specialty separation technologies used in municipal, industrial, pharmaceutical, food, semiconductor, and desalination applications.
Services Offered
Reverse osmosis membranes, ion exchange resins, ultrafiltration, nanofiltration, electrodeionization, specialty separations, and technical support.
Industries Served
Municipal water, desalination, industrial water, pharmaceuticals, semiconductors, power, food and beverage, and laboratories.
Notable Projects
Not publicly listed here.
Competitive Advantages
DuPont’s advantage is advanced membrane and separation technology.
Headquarters
Wilmington, Delaware.
Website
dupont.com/water
Why It Stands Out
DuPont Water Solutions stands out for membranes, reverse osmosis, ion exchange, and high-purity water applications.
Solenis
Overview
Solenis is a water treatment chemical and process solutions company serving industrial and institutional markets. It provides water treatment chemicals, monitoring, process aids, and sustainability-focused solutions.
Services Offered
Water treatment chemicals, process treatment, cooling water, boiler water, wastewater treatment, monitoring, paper process chemicals, and industrial service programs.
Industries Served
Pulp and paper, industrial facilities, food and beverage, institutional customers, manufacturing, power, and chemical processing.
Notable Projects
Solenis is commonly identified among leading water treatment chemical companies in North America.
Competitive Advantages
Its advantage is chemical treatment expertise and industrial process knowledge.
Headquarters
Wilmington, Delaware.
Website
solenis.com
Why It Stands Out
Solenis stands out for industrial water treatment chemicals, process treatment, and wastewater optimization.
Industry Trends Affecting Water Treatment Companies
PFAS Treatment Demand
PFAS rules are driving demand for activated carbon, ion exchange, membranes, testing, and system upgrades. Utilities and private well owners increasingly need practical treatment plans.
Water Reuse
Industrial plants, municipalities, and drought-prone regions are investing in reuse to reduce freshwater demand and improve resilience.
Smart Water Systems
Sensors, remote monitoring, leak detection, analytics, and digital twins are helping utilities and industries manage water quality and system performance.
Industrial Water Recycling
Manufacturers, data centers, food processors, semiconductor plants, and power facilities are looking for closed-loop and high-recovery water systems.
Desalination and High-Purity Water
Desalination remains important in coastal and water-stressed regions, while high-purity water demand is growing in pharmaceuticals, semiconductors, and laboratories.
Cybersecurity and Resilience
Water systems are critical infrastructure. Cybersecurity and operational resilience are now major concerns for utilities and treatment operators.
Buyer’s Guide: How to Choose Water Treatment Companies
Match the Company to the Problem
PFAS, hard water, wastewater, industrial process water, drinking water, desalination, and ultrapure water require different expertise.
Start With Testing
Do not buy treatment equipment before testing the water. The right system depends on contaminants, flow rate, chemistry, temperature, pressure, and regulatory limits.
Check Certifications and Standards
For drinking water, review NSF/ANSI certifications, local approvals, state requirements, and manufacturer documentation.
Understand Operating Costs
Water treatment costs include equipment, media replacement, chemicals, membranes, electricity, labor, sludge handling, monitoring, and maintenance.
Ask About Service Support
Treatment systems need ongoing service. Confirm maintenance plans, spare parts, monitoring, emergency support, and operator training.
Watch for Red Flags
Red flags include no water test, vague contaminant claims, no certifications, unrealistic guarantees, no maintenance plan, and unclear warranty terms.
Why Water Treatment Companies Matter in the United States
Water treatment companies protect public health, industrial productivity, environmental quality, and infrastructure performance. They help remove contaminants, treat wastewater, reduce discharge risks, protect equipment, and support safe drinking water.
Good water treatment can prevent illness, equipment damage, regulatory violations, environmental harm, corrosion, scaling, and production downtime. Poor treatment can create safety, legal, financial, and operational risks.
As water quality challenges grow, Water Treatment Companies in the United States will remain essential to communities, businesses, and public infrastructure.
Conclusion
The leading Water Treatment Companies in the United States include Xylem, Veolia Water Technologies, Ecolab/Nalco Water, American Water, Pentair, Culligan, Calgon Carbon, Aquatech International, DuPont Water Solutions, and Solenis. Xylem and Veolia are strong in municipal and industrial systems. Ecolab and Solenis lead in industrial treatment programs. American Water is the largest regulated water and wastewater utility. Pentair and Culligan are important for residential and commercial systems. Calgon Carbon is highly relevant for PFAS and adsorption. Aquatech and DuPont are strong in advanced industrial and membrane-based treatment.
For buyers, the best water treatment company is the one that understands the contaminant, application, regulations, operating cost, maintenance requirements, and long-term performance expectations.
Frequently Asked Questions
What are the best Water Treatment Companies in the United States?
Some of the best-known Water Treatment Companies in the United States include Xylem, Veolia Water Technologies, Ecolab/Nalco Water, American Water, Pentair, Culligan, Calgon Carbon, Aquatech International, DuPont Water Solutions, and Solenis. The best choice depends on whether the buyer needs municipal drinking water, wastewater, industrial water, residential filtration, PFAS treatment, desalination, or high-purity water.
Who is the largest water utility in the United States?
American Water is the largest regulated water and wastewater utility company in the United States. It says it provides drinking water and wastewater services to about 14 million people, with regulated operations in 14 states and on 18 military installations.
What does a water treatment company do?
A water treatment company designs, supplies, installs, operates, or services systems that improve water quality. Services may include filtration, softening, reverse osmosis, disinfection, wastewater treatment, chemical dosing, PFAS removal, desalination, sludge handling, monitoring, and industrial process water treatment.
How do I choose a water treatment company?
Start with a water test and define the problem clearly. Then choose a company with relevant experience, certifications, service support, references, and transparent operating costs. A home water softener provider may not be suitable for a municipal PFAS project, and an industrial chemical supplier may not be the right fit for residential drinking water filtration.
Which companies are best for PFAS water treatment?
Calgon Carbon, Xylem, Veolia, DuPont Water Solutions, and specialized engineering firms may be strong candidates for PFAS treatment depending on project size and water chemistry. PFAS treatment often uses granular activated carbon, ion exchange, reverse osmosis, or combinations of technologies.
What is the difference between water filtration and water treatment?
Water filtration usually removes particles, sediment, or specific contaminants through physical or media-based filters. Water treatment is broader and may include filtration, disinfection, chemical treatment, softening, reverse osmosis, ion exchange, membranes, oxidation, biological treatment, and wastewater processing.
Which companies are best for industrial water treatment?
Ecolab/Nalco Water, Solenis, Xylem, Veolia, Aquatech International, DuPont Water Solutions, and Kurita are strong names in industrial water treatment. Industrial buyers should evaluate process needs, chemical programs, monitoring, service response, discharge permits, and operating cost.
How much does water treatment cost?
Costs vary by contaminant, flow rate, technology, equipment size, chemicals, energy use, media replacement, labor, permits, and maintenance. A home filtration system costs far less than a municipal PFAS plant, industrial wastewater system, desalination facility, or zero liquid discharge project.
What are warning signs of a bad water treatment provider?
Warning signs include selling equipment without testing water, vague contaminant claims, no certifications, no service plan, unclear warranty, unrealistic “one system solves everything” promises, and no explanation of maintenance costs. For regulated water, weak documentation is a major red flag.
Why are water treatment companies important?
Water treatment companies help protect drinking water, public health, industrial operations, and the environment. Their systems remove contaminants, treat wastewater, reduce pollution, prevent scaling and corrosion, and support safe, reliable water use.
