Urban waste water treatment per province and river basin district

Urban waste water treatment per province and river basin district

Regions Periods Urban waste water treatment plants Numbers by type Hybrid Nereda - active sludge system (number) Urban waste water treatment plants Capacity pollution equivalents by type Hybrid Nereda - active sludge system (1 000 pollution equivalent) Urban waste water treatment plants Capacity inhabitant equivalents by type Hybrid Nereda - active sludge system (1 000 inhabitant equivalents)
Nederland 2020 2 363 255
Noord-Nederland (LD) 2020 1 340 237
Oost-Nederland (LD) 2020 1 23 18
West-Nederland (LD) 2020 0 0 0
Zuid-Nederland (LD) 2020 0 0 0
Groningen (PV) 2020 1 340 237
Fryslân (PV) 2020 0 0 0
Drenthe (PV) 2020 0 0 0
Overijssel (PV) 2020 1 23 18
Flevoland (PV) 2020 0 0 0
Gelderland (PV) 2020 0 0 0
Utrecht (PV) 2020 0 0 0
Noord-Holland (PV) 2020 0 0 0
Zuid-Holland (PV) 2020 0 0 0
Zeeland (PV) 2020 0 0 0
Noord-Brabant (PV) 2020 0 0 0
Limburg (PV) 2020 0 0 0
The river Eems 2020 1 340 237
The river Rijn (North Rijn) 2020 0 0 0
The river Rijn (East Rijn) 2020 1 23 18
The river Rijn (Central Rijn) 2020
The river Rijn (West Rijn) 2020 0 0 0
The river Maas 2020 0 0 0
The river Schelde 2020 0 0 0
Source: CBS.
Explanation of symbols

Table description


This table presents the most significant results of the annual survey Public treatment of urban waste water. The results are presented per province and river basin district (Rijn, Maas, Eems and Schelde) and include:
- number and capacity of the urban waste water treatment plants by type of treatment;
- the volume and concentration of organic matter, nutrients and heavy metals in the waste water running into waste water treatment plants (influent) and the volume of treated waste water (effluent). As of 2017, data on heavy metals are only inventoried for even years.
- the volume and destination of the sludge released, with nutrients and heavy metals. As of 2017, sludge data are only inventoried for even years.
Additional data on urban waste water treatment plants, process technology, energy consumption, generation of energy and sludge dewatering can be accessed on the Dutch version of StatLine.

Data available from: 1981

Status of the figures:
The figures in this table are definitive.

Changes as of 12 May 2022:
The figures of 2020 has been added.
Due to new information on 2019, total influent load of CZV and total Pollution Equivalents of the influent has increased with 4 percent in 2019 compared to the previous version. This results for the two parameters also in small changes in underlying classifications.

When will new figures be published?
New figures on 2021 will be published by March 2023.

Description topics

Urban waste water treatment plants
The number and capacity of urban waste water treatment plants in the Netherlands where nearly all domestic waste water and waste water from the private sector is treated. The plants are all operated by regional water quality control authorities.
Numbers by type
Number of sewage water treatment plants broken down by method of treatment.
Hybrid Nereda - active sludge system
System consisting of a parallel operated Nereda granular sludge reactor and activated sludge system.

In the Nereda granular sludge reactor the wastewater is purified by micro-organism clogged in natural granular structures of high density. These granules have a high biological activity and make it easy to separate the sludge from the treated wastewater.

In activated sludge systems the wastewater is treated in bassins with flocculated sludge . This sludge clumps exists of microorganisms that feed on the the organic pollution in wastewater.

As from 2019 this new treatment type is distinghuished separately in Statline. In the period 2013-2018 already 2 hybrid Nereda - activated sludge sytems became operational. Until 2019, these installations were classified as parallel installations.
Capacity pollution equivalents by type
Capacity urban waste water treatment plant:
A value that indicates how much organic pollution theoretically can be treated by a waste water treatment plant.

The pollution equivalent is the official unit that quantifies the pollution in waste water; one pollution equivalent = 150 g TOD (Total Oxygen Demand).
One pollution equivalent is the daily quantity of oxygen-demanding material in the waste water of one person. The degree of pollution in the waste water produced by the private sector is also expressed in pollution equivalents.
This unit is used as of 2010, so for previous years no values are available.
Hybrid Nereda - active sludge system
System consisting of a parallel operated Nereda granular sludge reactor and activated sludge system.

In the Nereda granular sludge reactor the wastewater is purified by micro-organism clogged in natural granular structures of high density. These granules have a high biological activity and make it easy to separate the sludge from the treated wastewater.

In activated sludge systems the wastewater is treated in bassins with flocculated sludge . This sludge clumps exists of microorganisms that feed on the the organic pollution in wastewater.

As from 2019 this new treatment type is distinghuished separately in Statline. In the period 2013-2018 already 2 hybrid Nereda - activated sludge sytems became operational. Until 2019, these installations were classified as parallel installations.
Capacity inhabitant equivalents by type
Capacity urban waste water treatment plant:
A value that indicates how much organic pollution theoretically can be treated by a waste water treatment plant.

The capacity expressed in Inhabitant Equivalents is determined on basis of: one inhabitant equivalent = 54 g BOD (Biological Oxygen Demand).
One inhabitant equivalent is the daily quantity of oxygen-demanding, organic substances in the waste water of one person.
Nowadays, the use of the unit inhabitant equivalent is decreasing. The most common unit is the pollution equivalent.
Hybrid Nereda - active sludge system
System consisting of a parallel operated Nereda granular sludge reactor and activated sludge system.

In the Nereda granular sludge reactor the wastewater is purified by micro-organism clogged in natural granular structures of high density. These granules have a high biological activity and make it easy to separate the sludge from the treated wastewater.

In activated sludge systems the wastewater is treated in bassins with flocculated sludge . This sludge clumps exists of microorganisms that feed on the the organic pollution in wastewater.

As from 2019 this new treatment type is distinghuished separately in Statline. In the period 2013-2018 already 2 hybrid Nereda - activated sludge sytems became operational. Until 2019, these installations were classified as parallel installations.