Thailand's Water and Waste Sector: 4,818 Firms, 2026
In short
Thailand's water supply, sewerage and waste management sector, registered as Section E, holds 4,818 companies as of 7 July 2026. Together they report 146.79 billion baht in revenue and 10.72 billion baht in net profit. That is a 7.31 percent net margin, well above the 4.10 percent national average. Inside the section, water utilities alone earn a 28.48 percent margin, beating the sector wide margin of financial and insurance companies. Yet Section E is the one lettered industry on this site still without its own profile page.
How big is the water and waste sector, and how does it perform?
Thailand's water supply, sewerage and waste management sector carries the registry letter Section E, and it counts 4,818 companies as of 7 July 2026 (DBD, 2026). Combined, those companies reported 146.79 billion baht in revenue and 10.72 billion baht in net profit. That works out to a 7.31 percent net margin, compared with 4.10 percent across the whole registered economy. Return on equity in the section reaches 8.66 percent against a national average of 6.12 percent. Return on assets reaches 4.15 percent against 2.55 percent nationally. The section is also small by any measure. Its 4,818 companies are just 0.24 percent of the 1,986,489 companies with a classified industry, and its revenue is just 0.18 percent of the national total. Ranked by company count, only three of the 21 lettered sections are smaller, and two of those are public administration and extraterritorial bodies, not real market sectors. Sixteen of the other twenty sections already have a dedicated profile page on this site. Section E does not, despite outrunning the whole economy on every profitability measure that matters.
Water and waste returns versus the whole economy
- Section E net margin7
- National net margin4
- Section E return on equity9
- National return on equity6
- Section E return on assets4
- National return on assets3
Figures in percent.
Every profitability line for Section E clears its national counterpart, and by a wide margin on return on assets.
What is actually inside Section E?
Section E is not one business but four distinct activities filed under the same registry letter. Water collection, treatment and supply holds just 427 companies, 8.86 percent of the section, yet it produced 29.50 billion baht in revenue and a 28.48 percent net margin, the richest slice of the sector and higher than the 25.40 percent margin financial and insurance companies earn across the whole economy. Sewerage holds 664 companies, 13.78 percent of the section, and a 13.52 percent margin. Waste collection, treatment, disposal and materials recovery is the crowd: 3,462 companies, 71.86 percent of the section and 72.74 percent of its revenue, running a net margin of just 0.98 percent. Remediation and other waste management services is the smallest slice, 265 companies and a 6.94 percent margin. One utility company, TTW, alone anchors the water division's strong return, a reminder that a handful of large operators can carry a whole division's numbers.
Section E broken down by its four ISIC divisions
| Division | Companies | Revenue, billion baht | Net margin |
|---|---|---|---|
| Water collection, treatment and supply | 427 | 30 | 28.48% |
| Sewerage | 664 | 8 | 13.52% |
| Waste collection, treatment, disposal and materials recovery | 3,462 | 107 | 0.98% |
| Remediation and other waste management services | 265 | 2 | 6.94% |
| Section E total | 4,818 | 147 | 7.31% |
Water and waste companies grouped by parent ISIC division, computed from 5 digit TSIC codes, as of 7 Jul 2026.
Why this matters
Water and waste management is core infrastructure, not a niche category. Only 34 percent of Thailand's domestic wastewater is safely treated according to the UN's SDG 6 monitoring initiative, so the capacity behind these numbers has real public health stakes, not just accounting interest. A sector this small in headcount, 4,818 companies against nearly two million classified nationwide, is doing outsized financial work: a 7.31 percent net margin, a 3.21 point premium over the national average, and a water utilities division that quietly out earns finance and insurance. A labor heavy corner, waste collection and disposal, keeps that margin near zero while carrying most of the section's companies and most of its revenue. Every other billion baht industry on this site, from mining to telecom to real estate, already has a home page built around its numbers. Section E earned one.
Definitions
- Section E
- The lettered ISIC Rev 4 classification for water supply, sewerage, waste management and remediation activities, one of 21 top level industry sections used to group Thai companies by main business activity.
- ISIC division
- A two digit subdivision of a lettered industry section. Section E splits into four divisions: 36 water collection treatment and supply, 37 sewerage, 38 waste collection treatment disposal and materials recovery, and 39 remediation activities.
- Net margin
- Aggregate net profit divided by aggregate revenue for all companies in a group, expressed as a percentage. It shows how much of each baht of revenue converts into profit.
- Return on equity
- Aggregate net profit divided by aggregate shareholder equity, a measure of how efficiently a group of companies turns owners' capital into profit.
- Return on assets
- Aggregate net profit divided by aggregate total assets, a measure of how efficiently a group of companies turns its asset base into profit.
- Active company
- A company classified as operating rather than dormant in the registry's most recent size band assessment, used to compute the survival rate.
Assumptions
- Revenue and profit totals include only companies that filed a financial statement, not every registered company in the section.
- Division level figures are grouped by the first two digits of the 5 digit TSIC code, following the standard ISIC Rev 4 division structure, since sub industry names are not published in the underlying data.
- A single very large company, such as a listed water utility, can shift a division's average margin, so division figures describe the group, not a typical firm within it.
Methodology
Figures are drawn from the DBD registry's aggregate tables as of 7 July 2026. Section totals come from the section level aggregate for Section E, water supply, sewerage, waste management and remediation activities under the TSIC and ISIC Rev 4 classification. Division figures group the section's 5 digit TSIC codes by their two digit parent division, using the standard ISIC Rev 4 division structure, 36 water collection treatment and supply, 37 sewerage, 38 waste collection treatment disposal and materials recovery, 39 remediation activities. Revenue and profit are aggregates of filed financial statements only. Net margin is aggregate net profit divided by aggregate revenue, not an average of individual company margins. National figures are the whole economy totals across all 21 lettered sections.
How we verified this
- Section E net margin recomputed as 10,724,237,841.25 divided by 146,787,986,851.42, giving 7.3059 percent, matching the reported 7.31 percent.
- Section E's share of national companies recomputed as 4,818 divided by 1,986,489 classified companies, giving 0.2425 percent, and its revenue share as 146,787,986,851.42 divided by 80,148,033,688,000.39, giving 0.1831 percent.
- The four division counts, 427, 664, 3,462 and 265, sum to 4,818, matching Section E's total company count exactly.
- The four division revenues, 29,501,500,100.86, 8,252,807,466.60, 106,780,294,408.32 and 2,253,384,875.64 baht, sum to 146,787,986,851.42 baht, matching Section E's total revenue exactly before rounding.
- The four division net profits, 8,403,026,768.69, 1,115,983,128.31, 1,048,818,344.58 and 156,409,599.67 baht, sum to 10,724,237,841.25 baht, matching Section E's total net profit exactly before rounding.
- Water division margin recomputed as 8,403,026,768.69 divided by 29,501,500,100.86, giving 28.48 percent, confirmed higher than financial and insurance's section wide margin of 25.40 percent.
- Section E's rank by company count was checked against all 21 lettered sections: only public administration with 38 companies, households with 32 companies and extraterritorial organizations with 4 companies have fewer.
- Confirmed by directory listing that 16 of the other 20 lettered sections have a dedicated profile page on this site, and Section E has none.
References
- Department of Business Development. (2026). Registered juristic persons and financial statement aggregates. Ministry of Commerce, Thailand. https://www.dbd.go.th/
- UN-Water Integrated Monitoring Initiative for SDG 6. (2024). Thailand: Country data on water and sanitation. SDG 6 Data Portal. https://www.sdg6data.org/en/country-or-area/Thailand
Frequently asked questions
How many water and waste companies are registered in Thailand?
4,818 companies are classified under Section E, water supply, sewerage, waste management and remediation activities, as of 7 July 2026.
Is the water and waste sector profitable?
Yes. Its aggregate net margin is 7.31 percent, well above the 4.10 percent national average across all registered companies.
Which part of the sector earns the most?
Water collection, treatment and supply, with a 28.48 percent net margin, higher than the 25.40 percent sector wide margin earned by financial and insurance companies.
Why does waste collection earn so little if the sector overall is profitable?
Waste collection, treatment, disposal and materials recovery holds 71.86 percent of the section's companies and 72.74 percent of its revenue, but its net margin is only 0.98 percent, dragging down what would otherwise be an even stronger sector average.
Cite this page
Chatpong L. (2026). Thailand's Water and Waste Sector: 4,818 Firms, 2026. Max Data Insights. https://maxdatathailand.com/insights/water-supply-and-waste-management-companies-in-thailand-2026
Data & corrections
Download the data (CSV)Spot something off, or want to ask about the data? Email insights@maxsolutions.co.th. We publish corrections.
Written by
Chatpong L.Founder, Max Data, Max Solutions Co., Ltd.
Chatpong L. leads Max Data, a company-intelligence platform built on Thailand's official business registry. He writes about the structure of the Thai economy using primary registry data. His work covers company formation, industry concentration, and regional business activity.
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This page reports company-level and aggregate statistics only. It names no individuals and makes no claims about any person. Figures are provided for information and may be revised as source data updates.