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 Capacity pollution equivalents by type Total capacity pollution equivalents (1 000 pollution equivalent) Urban waste water treatment plants Capacity pollution equivalents by type Mechanical treatment (1 000 pollution equivalent) Urban waste water treatment plants Capacity pollution equivalents by type Trickling filters (1 000 pollution equivalent) Urban waste water treatment plants Capacity pollution equivalents by type Aeration tanks (1 000 pollution equivalent) Urban waste water treatment plants Capacity pollution equivalents by type Oxidation tanks (1 000 pollution equivalent) Urban waste water treatment plants Capacity pollution equivalents by type Oxidation ditches (1 000 pollution equivalent) Urban waste water treatment plants Capacity pollution equivalents by type Carrousels (1 000 pollution equivalent) Urban waste water treatment plants Capacity pollution equivalents by type Discontinuous systems (1 000 pollution equivalent) Urban waste water treatment plants Capacity pollution equivalents by type Parallel installations (1 000 pollution equivalent) Urban waste water treatment plants Capacity pollution equivalents by type Multi-stage installations (1 000 pollution equivalent) Urban waste water treatment plants Capacity pollution equivalents by type Compact installations (1 000 pollution equivalent) Urban waste water treatment plants Capacity pollution equivalents by type Membrane bioreactor (1 000 pollution equivalent) Urban waste water treatment plants Capacity pollution equivalents by type Nereda granular sludge reactor (1 000 pollution equivalent) Urban waste water treatment plants Capacity pollution equivalents by type Hybrid Nereda - active sludge system (1 000 pollution equivalent) Influent waste water Quantities Pollution Equivalents (1 000 pollution equivalent) Discharge of waste water (effluent) Quantities Pollution Equivalents (1 000 pollution equivalent)
Nederland 2021 29,957 0 54 10,225 4,585 1,111 10,058 91 956 1,598 91 0 827 363 26,781 1,998
Noord-Nederland (LD) 2021 3,369 0 54 651 375 81 1,454 40 186 97 91 0 0 340 2,841 254
Oost-Nederland (LD) 2021 6,768 0 0 1,922 1,648 317 2,322 0 185 211 0 0 140 23 6,374 419
West-Nederland (LD) 2021 13,382 0 0 4,396 2,118 98 4,739 51 585 927 0 0 468 0 11,562 854
Zuid-Nederland (LD) 2021 6,438 0 0 3,255 443 615 1,543 0 0 363 0 0 218 0 6,004 471
Groningen (PV) 2021 1,017 0 0 180 110 13 260 40 17 56 0 0 0 340 894 94
Fryslân (PV) 2021 1,336 0 54 0 170 16 964 0 0 41 91 0 0 0 1,136 95
Drenthe (PV) 2021 1,016 0 0 471 95 51 230 0 169 0 0 0 0 0 811 65
Overijssel (PV) 2021 2,198 0 0 899 632 219 218 0 21 186 0 0 0 23 1,871 129
Flevoland (PV) 2021 754 0 0 0 65 0 689 0 0 0 0 0 0 0 660 29
Gelderland (PV) 2021 3,816 0 0 1,023 951 98 1,415 0 164 25 0 0 140 0 3,843 262
Utrecht (PV) 2021 2,110 0 0 185 108 0 1,365 0 0 19 0 0 432 0 1,840 101
Noord-Holland (PV) 2021 4,565 0 0 1,930 1,038 82 785 51 433 246 0 0 0 0 3,979 298
Zuid-Holland (PV) 2021 5,908 0 0 1,833 786 16 2,546 0 65 662 0 0 0 0 5,165 385
Zeeland (PV) 2021 799 0 0 448 186 0 43 0 86 0 0 0 36 0 578 70
Noord-Brabant (PV) 2021 4,386 0 0 2,772 16 615 620 0 0 363 0 0 0 0 4,234 308
Limburg (PV) 2021 2,051 0 0 484 427 0 922 0 0 0 0 0 218 0 1,770 163
The river Eems 2021 1,134 0 0 366 102 0 270 0 0 56 0 0 0 340 986 105
The river Rijn (North Rijn) 2021 1,521 0 54 0 178 45 1,054 40 17 41 91 0 0 0 1,285 110
The river Rijn (East Rijn) 2021 6,819 0 0 1,515 1,707 314 2,814 0 190 186 0 0 70 23 6,200 397
The river Rijn (Central Rijn) 2021
The river Rijn (West Rijn) 2021 13,096 0 0 4,641 1,968 130 4,190 51 662 952 0 0 502 0 11,614 839
The river Maas 2021 6,085 0 0 2,784 427 606 1,686 0 0 363 0 0 218 0 5,620 430
The river Schelde 2021 1,302 0 0 919 202 16 43 0 86 0 0 0 36 0 1,074 117
Source: CBS.
Explanation of symbols

Dataset is not available.


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 22 March 2023:
The figures of 2021 has been added.

When will new figures be published?
New figures on 2022 will be published by March 2024.

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.
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.
Total capacity pollution equivalents
Mechanical treatment
Installation where suspended matter is extracted from waste water by settlement.
Trickling filters
Waste water is sprinkled over a layer of porous stones covered with bacteria (biofilm). Thus, organic compounds in the waste water are degraded.
Aeration tanks
Pre-settled waste water runs through an intensively aerated basin containing active sludge (bacteria). Organic pollutants are degraded by oxygen and active sludge. The treatment process takes up only a short period of time and the sludge load is high which is typical of aeration basins.
Oxidation tanks
Operates by the same principle as the aeration tank but the sludge load is significantly lower. The resulting sludge is highly mineralised and will therefore decompose more slowly.
Oxidation ditches
In oxidation ditches, waste water is directed through a aeration circuit several times. The process takes up 2 or 3 days. Consequently, the sludge load is extremely low.
Carrousels
This technology is chiefly applied in large installations. Typical of carrousels are the depth (between 2 to 4 metres) and the aeration method.
Discontinuous systems
Oxidation basins and oxidation ditches. Waste water is let in batch-controlled.
Parallel installations
Various combinations of treatment systems (so-called 'streets') are applied in one installation.
Multi-stage installations
A serial process consisting of two systems, for instance, a trickling filter and an aeration basin. The waste water runs through both stages.
Compact installations
A system consisting of a basin subdivided into four segments. Waste water flows into the aeration segment. Subsequently, the sludge is separated in the central aeration zone. Then part of the sludge is conditioned in the reaeration zone and led back into the aeration zone. The other part (surplus sludge) is stabilised in the sludge mineralisation zone and subsequently removed.
Membrane bioreactor
A system where the sludge is separated from the waste water by using a membrane.
Nereda granular sludge reactor
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 micro-organisms from the treated wastewater.

As from 2019 this new treatment type is distinghuished separately in Statline. In the period 2011-2018 already 4 Nereda systems became operational. Until 2019, these installations were classified as oxidation tanks and/or discontinous systems.
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.
Influent waste water
Data on concentrations and quantities of pollutants in the waste water running into urban waste water treatment plants (influent).
Quantities
Pollution Equivalents
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.
Discharge of waste water (effluent)
Data on concentrations and quantities of pollutants in treated waste water (effluent) discharged from urban waste water treatment plants.
Quantities
Pollution Equivalents
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.