Industrial water treatment companies sell programs, not only chemicals: 5 service models, from a full-service program with loaned feed equipment to a sealed annual chemical bid, decide who doses, tests and reports for a cooling tower, boiler, closed loop, membrane plant or wastewater system. US federal guidance tells facilities to compare cooling-tower providers on the cost to treat 1,000 gal (3.785 m³) of make-up water, not on the price of a drum, so what else separates one provider from the next?
A provider answers for the chemistry, the feed and control equipment, the testing and the compliance records, and the service model sets which of these duties stay with the site. The provider doses chemicals from the same 16 families of water treatment chemicals that a plant could also buy directly.
This page compares the 5 service models, the inputs a quote needs, the 2 numbers that compare cooling-tower quotes, contract KPIs such as mild steel coupons below 3 mpy (0.076 mm/y) and total bacteria below 10,000 cfu/mL, 4 compliance checks and 15 questions to ask. It names no company; match requests go to independent providers and suppliers.
Every value on this page is checked against primary sources (US DOE FEMP, public procurement documents, ASHRAE, US EPA, NSF listings, UK HSE); see our methodology and fact-checking process.
What Does a Water Treatment Program Provider Do?#
A water treatment program provider is a company that supplies treatment chemicals together with the feed and control equipment, testing, service visits and reports that keep a water system inside agreed limits. Its 4 duties are chemistry selection, dosing and control, monitoring and testing, and records for compliance, such as corrosion coupon reports, Legionella sample results and biocide logs.
The provider designs the chemical program for each system of the site, and the industrial water treatment programs by application are compared on the application index.
Which systems do water treatment companies cover?#
Water treatment companies cover 6 system types: cooling towers, boilers and steam, closed loops, membrane plants, wastewater and drinking water, and the program differs by system in chemistry, test frequency and compliance record. The 6 system types below differ in what the provider controls.
| System | What the program controls |
|---|---|
| cooling tower water treatment | scale, corrosion, microbes and Legionella, cycles and blowdown |
| boiler water treatment | feedwater, internal treatment, condensate |
| closed loop water treatment | corrosion and microbes in chilled, heating and glycol loops |
| reverse osmosis and membrane chemicals | antiscalant, cleaning, biofouling |
| wastewater treatment chemicals | coagulation, sludge, pH, permit parameters |
| industrial wastewater treatment chemicals | industry-specific contaminants |
| drinking water treatment chemicals | coagulation, disinfection, corrosion control |
One contract can cover several systems: a published 2016 HVAC scope (CNE) puts cooling towers, closed loops and glycol systems under one scope.
Cooling tower water treatment companies and boiler water treatment companies are usually the same firms; the difference is the contract scope, not the company type.
Program provider or chemical supplier: which one do you need?#
A program provider answers for the result, such as corrosion rates, microbial counts and cycles, while a chemical supplier answers for the product, such as its grade, strength, certification and delivery. A site with operators, test kits and feed pumps needs product; a site without water staff needs a program.
Sites that run their own testing and only need product buy from manufacturers, blenders and distributors; those routes are compared under water treatment chemical suppliers. A product request names the chemical, grade and strength with basis, standard, NSF/ANSI/CAN 60 need, quantity, package and documents.
5 Service Models Offered by Water Treatment Companies#
Industrial water treatment services come in 5 service models: a full-service program, chemical supply with technical service, chemical-only supply under a bid, a monitoring-led service and a performance-based program. The 5 service models below differ in who operates the system, what the provider supplies and how the price is set.
| # | Service model | Who operates the system | What the provider supplies | Price basis seen | Typical buyer |
|---|---|---|---|---|---|
| 1 | Full-service program | provider runs the program with site staff | chemicals, loaned or leased feed and control equipment, visits, testing, reports, training | fixed monthly fee or per-unit prices | commercial buildings and plants without water staff |
| 2 | Chemical supply with technical service | site | product plus technical assistance stated in the offer | per-unit prices | plants with operators |
| 3 | Chemical-only supply under a bid | site (utility) | product to specification, delivered and off-loaded | USD per wet ton delivered, firm for the term | municipal utilities |
| 4 | Monitoring-led service | site, with provider oversight | online controller, remote lab, alarms, stored data | per-unit prices plus a line-item controller quote | multi-site and remote systems |
| 5 | Performance-based program | provider and site against agreed targets | chemistry and service tied to results | cost per 1,000 gal (3.785 m³) of make-up, water saved or corrosion targets | sites with metered make-up and blowdown |
Plant operation and maintenance outsourcing is a sixth contract type, but it buys equipment operation and staff, not a chemical program. Which model fits a site that has no water staff of its own?
1. Full-service program: chemicals, feed equipment, visits and reports#
A full-service program bundles the chemicals with feed and control equipment, often loaned or leased, plus scheduled visits, testing, reporting and operator training. In a published 2016 HVAC scope (CNE), the vendor provides chemical tanks and containment at no charge, delivers hands-free through a licensed specialist and takes the equipment back at contract end. The loaned chemical feed systems stay the provider's property, so their return date belongs in the contract.
2. Chemical supply with technical service#
Chemical supply with technical service leaves the operation of the system with the site, while the provider delivers product and adds technical help, such as test reviews and dose advice. Municipal bids ask vendors to state whether technical assistance is included, so the service level is written into the bid rather than assumed (City of Mansfield, Texas, Bid 2023-25-01). The model fits plants with their own operators.
3. Chemical-only supply under a municipal bid#
Chemical-only supply is a sealed annual bid on unit price and specification compliance, the usual model for municipal utilities, with each chemical bid separately and awarded on a lowest-and-best basis. The City of Mansfield, Texas (Bid 2023-25-01) sets a 12-month term with up to four 1-year renewals and firm delivered prices per wet ton of solution (short ton, 2,000 lb (907 kg)), off-loading included. At most one price increase a year is allowed, with manufacturer evidence and 30 days written notice.
The bid package carries a certificate of analysis, a notarized AWWA conformance statement and the NSF/ANSI 60 certificate with the maximum use level (MUL) in mg/L; Texas (TCEQ) requires NSF 60 and NSF 61 conformance for every treatment chemical and medium. How utilities write and award the specification is covered under water treatment chemical bids.
4. Monitoring-led service: controllers, remote lab and alarms#
A monitoring-led service centers the program on an online controller, a remote laboratory and alarms, so the provider sees conductivity, pH, ORP and inhibitor levels between visits. In the 2016 CNE scope, the controller measures the active inhibitor, controls its feed and reports to a 24x7x365 remote lab that stores 1 year of data.
US federal guidance recommends automated chemical feed on cooling towers above 100 tons (352 kW) of capacity (DOE FEMP, BMP #10). The hardware side is explained under water treatment controllers.
5. Performance-based program#
A performance-based program ties payment to results, such as the cost per 1,000 gal (3.785 m³) of make-up, the volume of water saved or corrosion targets, instead of to pounds of product delivered. The 2 numbers that US federal guidance uses to compare quotes also measure a performance contract. The contract has to name the baseline, the meter and the KPI method, or the savings cannot be verified.
How to Compare Water Treatment Program Quotes#
Water treatment program quotes compare fairly only when every provider prices the same scope, from the same system data, against the same KPIs and on the same price basis. What data does a provider need before it can price a program?
What does a water treatment company need to quote a program?#
A water treatment company needs the size, water analysis, metallurgy and control setup of each system to quote a program: tons or recirculation rate for a cooling tower, pressure, steam rate and condensate return for a boiler, and flow and permit limits for wastewater. A provider needs the minimum inputs below to price a program for each system.
| System | Minimum inputs |
|---|---|
| Cooling tower | tons (kW) or recirculation rate (m³/h, gpm); system volume (m³, gal); make-up source and analysis; current cycles; blowdown control; metallurgy; make-up and blowdown meters; Legionella plan status (ASHRAE 188); water and sewer cost per 1,000 gal (3.785 m³) |
| Boiler | type and pressure (bar, psig); steam rate (t/h, lb/h); condensate return %; pretreatment; deaerator; feedwater and boiler water analysis |
| Closed loop | loop type; volume; metallurgy; make-up rate; glycol %; current nitrite or molybdate residual |
| RO / membranes | permeate flow; recovery; feed analysis; SDI; membrane model; cleaning frequency |
| Wastewater | flow; permit limits (NPDES or pretreatment); contaminants; sludge handling; jar-test availability |
| All systems | site type; location; current provider; contract end date; timeline; desired service model |
Every request also carries the site type, location, current provider, contract end date, timeline and desired service model; quotes built on different data are not comparable.
Compare quotes on cost per 1,000 gal of make-up and cycles of concentration#
Cooling-tower quotes compare on 2 numbers, the cost to treat 1,000 gal (3.785 m³) of make-up water and the highest cycles of concentration the provider will commit to, because those 2 numbers set the water, sewer and chemical bill together (US DOE FEMP, Best Management Practice #10).
FEMP also warns that some vendors may be reluctant to raise water efficiency, because the facility then buys fewer chemicals. Many systems still run at 2 to 4 cycles (DOE FEMP), while typical towers run at 2.5 to 7 (NREL / Better Buildings, 2018).
Worked example: a 500-ton (about 1,760 kW) open tower at full load evaporates about 900 gal/h (3.41 m³/h) at 1.8 gal (6.8 L) per ton-hour; blowdown = E / (C - 1) and make-up = E x C / (C - 1), with drift and leaks ignored. Moving from 3 to 6 cycles cuts make-up from 1,350 to 1,080 gal/h (5.11 to 4.09 m³/h), the 20 % cut FEMP gives for that step.
| Cycles of concentration | Evaporation | Blowdown | Make-up | Make-up vs 3 cycles |
|---|---|---|---|---|
| 3 | 900 gal/h (3.41 m³/h) | 450 gal/h (1.70 m³/h) | 1,350 gal/h (5.11 m³/h) | baseline (blowdown is 33 % of make-up) |
| 6 | 900 gal/h (3.41 m³/h) | 180 gal/h (0.68 m³/h) | 1,080 gal/h (4.09 m³/h) | minus 20 % |
Cycles of concentration also set the scale and corrosion risk the chemistry has to carry, and the formula, limits and calculation are explained under cycles of concentration.
Contract KPIs and Testing: What a Water Treatment Contract Should Guarantee#
A water treatment contract should guarantee 3 groups of KPIs, corrosion rates, microbial counts and service terms, each with a numeric limit, a test method and a test frequency written into the scope. The KPI values below come from published federal ranges, a public HVAC scope and UK guidance; they are contract examples, and each contract sets its own.
| KPI | Value | Basis and method | Source | System |
|---|---|---|---|---|
| Copper corrosion | below 0.2 mpy (0.005 mm/y) | 90-day coupon | GSA ranges (NREL / Better Buildings, 2018) | cooling tower |
| Mild steel corrosion | below 3 mpy (0.076 mm/y) | 90-day coupon | GSA ranges | cooling tower |
| Galvanized steel corrosion | below 4 mpy (0.10 mm/y) | 90-day coupon | GSA ranges | cooling tower |
| Stainless steel corrosion | below 0.1 mpy (0.0025 mm/y) | 90-day coupon | GSA ranges | cooling tower |
| Carbon steel corrosion (UK) | generally below 5 mpy (0.13 mm/y), preferably below 2 mpy (0.05 mm/y) | coupon | HSE HSG274 Part 1 (2024), Table 1.1 | cooling tower |
| Mild steel and copper, closed loops | mild steel below 1.0 mpy (0.025 mm/y); copper below 0.2 mpy (0.005 mm/y) | 180-day coupons plus online probes; quarterly loop coupons | CNE scope (2016) | closed loop |
| Inhibitor residual, closed loops | minimum nitrite residual stated per loop | per loop test; glycol tested monthly; detail under closed loop water testing | CNE scope (2016) | closed loop |
| Total bacteria | below 10,000 cfu/mL | dual biocide, automated feed; SRB and denitrifiers monitored | CNE scope (2016) | towers and loops |
| Aerobic count (UK) | at or below 1 x 10^4 cfu/mL under control; above 1 x 10^5 cfu/mL action | dip slide or lab count, 30 °C (86 °F), at least 48 h | HSE HSG274 Part 1 (2024) | cooling tower |
| Legionella (UK) | not detected or at most 100 cfu/L target; above 1,000 cfu/L immediate action | culture | HSE HSG274 Part 1 (2024) | cooling tower |
| Chemistry control | pH 7.3 to 9.0; conductivity below 2,400 µS/cm; iron below 4 mg/L (ppm); sulfate below 250 mg/L (ppm); ORP above 300 mV | site test or controller | GSA ranges (NREL / Better Buildings, 2018) | cooling tower |
| Visit frequency | every other week (3 plants) or monthly (2 sites) | service log | CNE scope (2016) | all |
| Remote monitoring | 24x7x365 remote lab, alarm response under 1 h, 1 year of data | controller and probes | CNE scope (2016) | all |
System-by-system control ranges sit in cooling tower water testing and control ranges.
Corrosion KPIs: coupons, probes and closed loop limits#
Corrosion KPIs are written as coupon rates in mpy (mm/y), and the US GSA acceptable ranges for 90-day cooling-tower coupons set 4 limits by metal (NREL / Better Buildings, 2018). The 4 GSA coupon limits are listed below.
- Copper: below 0.2 mpy (0.005 mm/y).
- Mild steel: below 3 mpy (0.076 mm/y).
- Galvanized steel: below 4 mpy (0.10 mm/y).
- Stainless steel: below 0.1 mpy (0.0025 mm/y).
Closed loops run tighter: mild steel below 1.0 mpy (0.025 mm/y), copper below 0.2 mpy and a minimum nitrite residual per loop (CNE, 2016). HSE HSG274 Part 1 (2024) puts UK carbon steel generally below 5 mpy (0.13 mm/y), preferably below 2 mpy (0.05 mm/y).
The CNE scope also asks for 180-day coupons plus online probes on towers and loops and quarterly closed-loop coupons; coupon racks and probes are described under corrosion coupons and corrosion monitoring.
Microbial and Legionella KPIs#
Microbial KPIs set a count limit and a biocide regime: one public HVAC scope requires total bacteria below 10,000 cfu/mL, dual oxidizing and non-oxidizing biocides fed automatically, and monitoring of sulfate-reducing and denitrifying bacteria (CNE, 2016). UK HSE HSG274 Part 1 (2024) treats an aerobic count at or below 1 x 10^4 cfu/mL as under control and above 1 x 10^5 cfu/mL as an action level, with Legionella not detected or at most 100 cfu/L as the target and above 1,000 cfu/L as the trigger for immediate action.
Legionella sampling dates and actions belong in the contract too, and the program side is covered under Legionella control in cooling towers.
Service, monitoring and reporting KPIs#
Service KPIs fix how often the provider comes, what it measures and how the data reaches the site; one published scope sets visits every other week at 3 plants and monthly at 2 sites (CNE, 2016). The 5 service KPIs that published scopes write down are listed below.
- Visit frequency: every other week or monthly, per site.
- Controller and probe set: active inhibitor, conductivity, pH, ORP, turbidity, temperature and corrosion probes.
- Remote lab hours: 24x7x365, with alarm response under 1 h and 1 year of stored data, as the scope requires.
- Price breakdown: 4 price categories plus a line-item controller quote.
- KPI table: each KPI with its test method and frequency.
Boiler contracts list their own parameters and test frequency, covered under boiler water testing.
Which Certifications and Compliance Duties Should a Water Treatment Company Cover?#
A water treatment company should bring 4 compliance items to the contract: a Certified Water Technologist on the account, an ASHRAE 188 water management program for building water systems, FIFRA-registered biocides and NSF/ANSI/CAN 60 certified products wherever water becomes drinking water. Each item is checkable before signing.
Certified Water Technologist (CWT) on the account#
The Certified Water Technologist (CWT) credential of the Association of Water Technologies requires at least 5 years of field experience, an exam taken through Pearson VUE, an application within 1 year of passing and recertification every 5 years. Ask for the CWT holder by name on the account, not only on the company letterhead.
ASHRAE 188 water management programs#
ANSI/ASHRAE Standard 188-2021 sets the minimum legionellosis risk-management requirements for building water systems, and ASHRAE Guideline 12-2023 adds the operating guidance that a provider's program follows. The standard covers a building survey, the water management program and its documentation, preventive measures, and commissioning.
New York City requires Legionella sampling of cooling towers at least monthly, no more than 31 days apart, by an ELAP-accredited lab (24 RCNY 8-05(f)(3), effective 2026-05-08); New York State outside the city requires culture at intervals of 90 days or less and within 14 days of seasonal start-up (10 NYCRR 4-1.4(b)(2)). The program itself is explained under ASHRAE 188 and Legionella water management programs.
FIFRA-registered cooling tower biocides#
Cooling-tower biocides sold in the United States are non-public-health antimicrobial pesticides that must carry an EPA registration under FIFRA, and more than 4,000 antimicrobial products are registered with EPA (US EPA).
A proposal names the registration of each biocide the provider plans to feed, and the label sets the dose; the rules behind the label are covered under FIFRA registration of water treatment biocides. A registration confirms the product, not the program.
Oxidizing and non-oxidizing options, contact times and feed are compared under cooling tower biocides.
NSF/ANSI/CAN 60 certified products for drinking water#
NSF/ANSI/CAN 60 listings are issued per company, per facility and per trade designation, each with its own maximum use level stated as product, so a quote for a potable system needs the listing of the exact product and plant that will ship it (NSF listings, 2026-10-20). Certification is required in 49 US states (NSF survey of ASDWA members).
The MUL is the total dose as product across all application points, and how MULs are set and read is explained under NSF/ANSI/CAN 60.
15 Questions to Ask a Water Treatment Company Before Signing#
The 15 questions below turn a sales proposal into a comparable contract; questions 1 to 13 follow the public proposal checklist for water treatment contracts and questions 14 and 15 apply the US federal selection metrics.
- Which systems and which points of each system does the scope cover?
- Which products are proposed, each with its SDS?
- Is every dose stated as product or as active ingredient?
- Which KPIs are guaranteed, with test method and frequency?
- How often are visits made, and what is the alarm response in the contract?
- Who owns the tanks, pumps and controllers, and when are they returned?
- What is the price basis, and how does it escalate?
- What are the term and the termination terms?
- Who carries insurance and spill responsibility?
- Which NSF/ANSI/CAN 60 listing and MUL applies to each potable-use product?
- Which EPA FIFRA registration does each cooling-tower biocide carry?
- Who writes and maintains the ASHRAE 188 water management program?
- Which Certified Water Technologist works on the account?
- What is the cost to treat 1,000 gal (3.785 m³) of make-up water?
- What are the highest cycles of concentration the provider will commit to?
A provider that answers all 15 in writing has given a quote that can be compared line by line.
Who Is the Best Water Treatment Company for an Industrial Site?#
The best water treatment company for an industrial site is the provider whose written quote meets the site's KPIs, cycles and compliance duties at the lowest cost per 1,000 gal (3.785 m³) of make-up, and no ranking of company names replaces that test. This site names, ranks and endorses no provider; match requests go to independent providers and suppliers.
Are the largest water treatment companies the best choice?#
Size alone does not decide the choice: the global water treatment chemicals market is about USD 35.8 billion and the industrial share about USD 18.2 billion in Grand View Research's 2025 estimates, split among global groups, regional providers and distributors.
Market sizes and the leading water treatment companies by revenue are covered in the market overview.
How much do water treatment services cost?#
Water treatment services are priced on 3 bases: USD per wet ton delivered in municipal chemical bids, a fixed monthly fee or per-unit prices in service programs, and the cost per 1,000 gal (3.785 m³) of make-up that US federal guidance uses to compare cooling-tower vendors.
How service contracts are priced, and what drives the price, is covered under water treatment program cost.
How often does a water treatment company visit the site?#
Visit frequency is a contract term, not a fixed rule: one published HVAC scope sets visits every other week at 3 plants and monthly at 2 sites (CNE, 2016), while New York City's monthly Legionella sampling sets a floor for cooling towers there.
Who owns the feed equipment when the contract ends?#
In a full-service program the provider can keep ownership: one published scope has the vendor supply tanks and containment at no charge and remove them at contract end, so the handover date belongs in the contract.