# IWK Is Not a Water Company: Understanding the National Sewerage Operator's Real Role

> The name 'Indah Water' leads many people to assume the company supplies drinking water. In fact IWK is the sole operator of Peninsular Malaysia's sewerage (kumbahan) system — an entirely different end of the pipe from the state water companies — and the charges it imposes are periodic charges based on premise category, not a water bill.

- Category: property
- Language: en
- Status: published
- Updated: 2026-07-24
- Canonical: https://negaraku.md/en/property/indah-water-sewerage

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## Not water supply — the other end of the pipe

Many people see the name "Indah Water" on a bill and assume it is related to
the tap water that comes out of the faucet. It isn't. Air Selangor, SAJ, PBAPP
and the other state water companies manage drinking water supply — the "in"
end. **Indah Water Konsortium (IWK)**, on the other hand, manages the "out"
end: sewage and waste water after it leaves your house or building. Two
entirely different services, run by two different kinds of company, even
though they are sometimes listed on the same bill.

## A single company for almost the entire Peninsula

IWK began as a federal government concession on 2 April 1994, under the
Sewerage Services Act 1993 (Act 508). Before that, sewerage matters fell
under the respective Local Authorities (PBT) — meaning each municipal council
managed its own system, to inconsistent standards.

In June 2000, the government took over full equity of the company through
the Minister of Finance (Incorporated), making IWK wholly government-owned.
Since then, IWK has been the sole operator of sewage treatment plants and the
public sewerage pipe network across Peninsular Malaysia and the Federal
Territory of Labuan. Sabah and Sarawak fall outside its coverage — both
states manage their own sewerage services.

## Two types of system, two ways it touches you

| System type | How it works |
| --- | --- |
| Connected system | The premise's sewerage pipe connects directly to the public network and is treated at an IWK-owned Sewage Treatment Plant (STP) |
| Individual septic tank | Sewage is collected in a tank on the premise itself, and must be desludged on a schedule by IWK |

For premises with septic tanks, the desludging schedule is set under the
desludging service regulations — every 24 months for premises within a PBT
area, and every 36 months for premises outside a PBT area. This is not
optional; it is an enforced scheduled obligation.

## Who actually sets the charge

This is the part most often misunderstood: **IWK is not free to set its own
charge rates**. Sewerage service charge rates are set by the government,
based on principles of affordability and equity, so that the amount
collected from various categories of customer is sufficient to fund the
management and operation of a modern sewerage system nationwide.

The charge structure generally combines two components:

- A **fixed base charge**, which varies according to premise category and
  the type of sewerage service received; and
- An **excess charge**, which is calculated based on the premise's water
  consumption above a certain level per month.

Customer categories also differ in basis — domestic, commercial, industrial
and government premises each have their own charge formula (for industrial
premises, for example, the charge also takes into account the number of
employees). This article deliberately does not state any specific charge
amount, because rates and structure may be revised from time to time by the
government — check IWK's official Customer Charges page for the current rate
applicable to your premise.

## Common mistakes

- **Assuming the IWK bill is a water bill.** It is a sewerage service
  charge, calculated separately from the water supply bill even though the
  two are sometimes combined on one bill for payment convenience.
- **Ignoring the scheduled desludging notice.** Septic tank desludging is
  not an optional service — it is a scheduled obligation that can lead to
  enforcement action if it continues to be ignored.
- **Assuming IWK only exists in major urban areas.** Its coverage extends
  to almost all connected premises across Peninsular Malaysia, not only
  metropolitan areas.

## What's next

- Why the authority to manage sewerage sits with the federal government,
  not the states or Local Authorities: [Federal-State Division of Powers](/en/government/federal-state-division)
- The role of the Local Authorities that used to manage sewerage before
  the 1994 privatisation: [Local Councils](/en/states/local-councils)

## Sources

- Pengenalan (Overview) — https://www.iwk.com.my/my/overview (Indah Water Konsortium Sdn Bhd)
- Sistem Pembetungan — https://www.iwk.com.my/my/sewerage-systems (Indah Water Konsortium Sdn Bhd)
- Caj Pelanggan — https://www.iwk.com.my/my/customer-charges (Indah Water Konsortium Sdn Bhd)
- Caj Nyahenap Cemar Domestik — https://www.iwk.com.my/my/charges-domestic-desludging (Indah Water Konsortium Sdn Bhd)
- Sewerage Services Act 1993 (Act 508) — https://www.fao.org/faolex/results/details/en/c/LEX-FAOC033534/ (FAOLEX (FAO) — teks perundangan Malaysia)
- Akta Industri Perkhidmatan Air 2006 (Akta 655) — https://www.span.gov.my/document/upload/QAAvUfw5vCwjntqBhov88xHPlLq28c9H.pdf (Suruhanjaya Perkhidmatan Air Negara (SPAN))
- Fungsi Suruhanjaya — https://www.span.gov.my/category/view/11 (Suruhanjaya Perkhidmatan Air Negara (SPAN))

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Source of truth: https://github.com/negaraku-md/NegaraKu.md
License: CC BY-SA 4.0