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 Total number (number) Urban waste water treatment plants Numbers by type Mechanical treatment (number) Urban waste water treatment plants Numbers by type Trickling filters (number) Urban waste water treatment plants Numbers by type Aeration tanks (number) Urban waste water treatment plants Numbers by type Oxidation tanks (number) Urban waste water treatment plants Numbers by type Oxidation ditches (number) Urban waste water treatment plants Numbers by type Carrousels (number) Urban waste water treatment plants Numbers by type Discontinuous systems (number) Urban waste water treatment plants Numbers by type Parallel installations (number) Urban waste water treatment plants Numbers by type Multi-stage installations (number) Urban waste water treatment plants Numbers by type Compact installations (number) Urban waste water treatment plants Numbers by type Membrane bioreactor (number) Urban waste water treatment plants Numbers by type Nereda granular sludge reactor (number) Urban waste water treatment plants Numbers by type Hybrid Nereda - active sludge system (number) 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) Urban waste water treatment plants Capacity inhabitant equivalents by type Total capacity inhabitant equivalents (1 000 inhabitant equivalents) Urban waste water treatment plants Capacity inhabitant equivalents by type Mechanical treatment (1 000 inhabitant equivalents) Urban waste water treatment plants Capacity inhabitant equivalents by type Trickling filters (1 000 inhabitant equivalents) Urban waste water treatment plants Capacity inhabitant equivalents by type Aeration tanks (1 000 inhabitant equivalents) Urban waste water treatment plants Capacity inhabitant equivalents by type Oxidation tanks (1 000 inhabitant equivalents) Urban waste water treatment plants Capacity inhabitant equivalents by type Oxidation ditches (1 000 inhabitant equivalents) Urban waste water treatment plants Capacity inhabitant equivalents by type Carrousels (1 000 inhabitant equivalents) Urban waste water treatment plants Capacity inhabitant equivalents by type Discontinuous systems (1 000 inhabitant equivalents) Urban waste water treatment plants Capacity inhabitant equivalents by type Parallel installations (1 000 inhabitant equivalents) Urban waste water treatment plants Capacity inhabitant equivalents by type Multi-stage installations (1 000 inhabitant equivalents) Urban waste water treatment plants Capacity inhabitant equivalents by type Compact installations (1 000 inhabitant equivalents) Urban waste water treatment plants Capacity inhabitant equivalents by type Membrane bioreactor (1 000 inhabitant equivalents) Urban waste water treatment plants Capacity inhabitant equivalents by type Nereda granular sludge reactor (1 000 inhabitant equivalents) Urban waste water treatment plants Capacity inhabitant equivalents by type Hybrid Nereda - active sludge system (1 000 inhabitant equivalents) Influent waste water Quantities Volume waste water (1 000 m3) Influent waste water Quantities Pollution Equivalents (1 000 pollution equivalent) Influent waste water Quantities Chemical oxygen demand (COD) (1 000 kg) Influent waste water Quantities Biochemical oxygen demand (BOD) (1 000 kg) Influent waste water Quantities Nitrogen compounds as N (total) (1 000 kg) Influent waste water Quantities Phosphorus compounds as P (total) (1 000 kg) Influent waste water Quantities Copper (kg) Influent waste water Quantities Chromium (kg) Influent waste water Quantities Zinc (kg) Influent waste water Quantities Lead (kg) Influent waste water Quantities Cadmium (kg) Influent waste water Quantities Nickel (kg) Influent waste water Quantities Mercury (kg) Influent waste water Quantities Arsenic (kg) Discharge of waste water (effluent) Quantities Volume waste water (1 000 m3) Discharge of waste water (effluent) Quantities Pollution Equivalents (1 000 pollution equivalent) Discharge of waste water (effluent) Quantities Chemical oxygen demand (COD) (1 000 kg) Discharge of waste water (effluent) Quantities Biochemical oxygen demand (BOD) (1 000 kg) Discharge of waste water (effluent) Quantities Nitrogen compounds as N (total) (1 000 kg) Discharge of waste water (effluent) Quantities Phosphorus compounds as P (total) (1 000 kg) Discharge of waste water (effluent) Quantities Copper (kg) Discharge of waste water (effluent) Quantities Chromium (kg) Discharge of waste water (effluent) Quantities Zinc (kg) Discharge of waste water (effluent) Quantities Lead (kg) Discharge of waste water (effluent) Quantities Cadmium (kg) Discharge of waste water (effluent) Quantities Nickel (kg) Discharge of waste water (effluent) Quantities Mercury (kg) Discharge of waste water (effluent) Quantities Arsenic (kg) Sewage sludge Wet sewage sludge by destination Total wet sludge (1 000 kg) Sewage sludge Wet sewage sludge by destination Agriculture (1 000 kg) Sewage sludge Wet sewage sludge by destination Wet oxidation (1 000 kg) Sewage sludge Wet sewage sludge by destination Composting (1 000 kg) Sewage sludge Wet sewage sludge by destination Landfill (1 000 kg) Sewage sludge Wet sewage sludge by destination Incineration (1 000 kg) Sewage sludge Wet sewage sludge by destination Cement industry (1 000 kg) Sewage sludge Wet sewage sludge by destination Co-incineration at power plants (1 000 kg) Sewage sludge Wet sewage sludge by destination Other destinations (1 000 kg) Sewage sludge Dry solids by destination Total dry solids (1 000 kg) Sewage sludge Dry solids by destination Agriculture (1 000 kg) Sewage sludge Dry solids by destination Wet oxidation (1 000 kg) Sewage sludge Dry solids by destination Composting (1 000 kg) Sewage sludge Dry solids by destination Landfill (1 000 kg) Sewage sludge Dry solids by destination Incineration (1 000 kg) Sewage sludge Dry solids by destination Cement industry (1 000 kg) Sewage sludge Dry solids by destination Co-incineration at power plants (1 000 kg) Sewage sludge Dry solids by destination Other destinations (1 000 kg) Sewage sludge Nutrients and heavy metals Ashes (1 000 kg) Sewage sludge Nutrients and heavy metals Nitrogen compounds as N (1 000 kg) Sewage sludge Nutrients and heavy metals Phosphorus compounds as P (1 000 kg) Sewage sludge Nutrients and heavy metals Copper (kg) Sewage sludge Nutrients and heavy metals Chromium (kg) Sewage sludge Nutrients and heavy metals Zinc (kg) Sewage sludge Nutrients and heavy metals Lead (kg) Sewage sludge Nutrients and heavy metals Cadmium (kg) Sewage sludge Nutrients and heavy metals Nickel (kg) Sewage sludge Nutrients and heavy metals Mercury (kg) Sewage sludge Nutrients and heavy metals Arsenic (kg)
Nederland 2022 313 0 1 62 49 44 120 2 11 11 1 0 10 2 29,995 0 54 10,411 4,362 1,182 10,005 91 1,092 1,502 91 0 843 363 23,661 0 60 8,445 3,260 945 7,757 72 794 1,320 60 0 692 255 1,807,838 26,146 1,010,854 409,133 92,433 12,944 115,023 14,284 386,774 23,686 282 16,758 131 6,037 1,807,838 1,827 67,228 7,107 12,960 1,609 8,881 2,198 69,221 1,333 60 7,360 18 2,531 1,299,154 0 0 0 6,521 919,802 16,591 321,536 34,704 300,041 0 0 0 1,494 220,991 15,503 53,936 8,116 89,938 17,755 11,004 109,077 11,795 298,603 23,100 280 7,670 134 3,006
Noord-Nederland (LD) 2022 61 0 1 9 10 5 28 1 3 2 1 0 0 1 3,369 0 54 651 375 81 1,318 40 322 97 91 0 0 340 2,531 0 60 501 288 59 970 32 250 74 60 0 0 237 206,923 2,683 104,878 44,650 9,195 1,378 11,362 1,767 41,703 2,686 32 2,064 20 576 206,923 225 8,803 901 1,269 169 980 256 7,678 159 10 868 3 247 148,202 0 0 0 4,977 95,265 0 47,961 0 35,381 0 0 0 1,137 22,639 0 11,605 0 11,350 1,848 1,222 10,616 1,435 29,981 2,495 26 971 20 291
Oost-Nederland (LD) 2022 81 0 0 13 13 19 25 0 3 3 0 0 4 1 6,812 0 0 1,922 1,684 389 2,333 0 185 115 0 0 162 23 5,170 0 0 1,508 1,218 306 1,761 0 134 95 0 0 130 18 350,550 6,125 238,280 94,039 21,311 3,001 24,036 2,485 72,237 3,809 48 2,899 27 1,006 350,550 385 13,894 1,275 2,673 384 1,800 385 13,437 215 7 1,224 3 400 346,792 0 0 0 315 80,817 0 248,427 17,233 60,993 0 0 0 100 20,013 0 36,404 4,475 19,282 4,113 2,149 20,789 2,710 64,136 4,149 59 1,612 25 565
West-Nederland (LD) 2022 121 0 0 25 21 6 56 1 5 5 0 0 2 0 13,382 0 0 4,582 1,860 98 4,811 51 585 927 0 0 468 0 10,374 0 0 3,572 1,421 77 3,690 40 410 779 0 0 386 0 821,170 11,461 437,711 181,388 41,594 5,572 53,428 5,317 168,671 12,118 143 5,916 60 3,166 821,170 794 28,568 3,108 6,019 710 4,030 746 25,853 644 32 2,638 9 1,346 535,501 0 0 0 1,229 494,583 0 22,218 17,471 129,250 0 0 0 257 120,161 0 5,190 3,641 34,216 7,706 4,735 48,515 3,829 122,985 10,578 105 2,706 56 1,639
Zuid-Nederland (LD) 2022 50 0 0 15 5 14 11 0 0 1 0 0 4 0 6,432 0 0 3,255 443 615 1,543 0 0 363 0 0 212 0 5,586 0 0 2,865 334 503 1,336 0 0 372 0 0 176 0 429,196 5,878 229,985 89,056 20,334 2,993 26,197 4,715 104,164 5,073 59 5,878 23 1,289 429,196 423 15,964 1,823 2,999 346 2,071 811 22,252 315 11 2,630 3 538 268,659 0 0 0 0 249,137 16,591 2,931 0 74,417 0 0 0 0 58,178 15,503 737 0 25,090 4,088 2,899 29,156 3,821 81,501 5,877 90 2,382 33 511
Groningen (PV) 2022 22 0 0 4 4 2 8 1 1 1 0 0 0 1 1,017 0 0 180 110 13 260 40 17 56 0 0 0 340 741 0 0 130 80 11 195 32 15 41 0 0 0 237 67,837 807 32,512 12,675 2,557 412 3,351 633 12,227 766 9 543 7 164 67,837 83 3,313 437 528 54 296 71 2,507 44 2 200 1 69 47,572 0 0 0 0 0 0 47,572 0 11,497 0 0 0 0 0 0 11,497 0 4,283 396 445 3,967 446 10,951 835 12 336 7 107
Fryslân (PV) 2022 27 0 1 0 4 1 18 0 1 1 1 0 0 0 1,336 0 54 0 170 16 828 0 136 41 91 0 0 0 1,006 0 60 0 120 10 604 0 119 33 60 0 0 0 84,960 1,074 40,830 18,883 3,929 565 4,573 758 15,595 1,170 16 989 6 291 84,960 83 3,398 254 380 69 422 150 2,813 80 6 439 1 129 68,894 0 0 0 4,839 64,055 0 0 0 15,566 0 0 0 1,096 14,470 0 0 0 4,826 956 510 4,370 754 12,615 1,169 9 426 11 159
Drenthe (PV) 2022 12 0 0 5 2 2 2 0 1 0 0 0 0 0 1,016 0 0 471 95 51 230 0 169 0 0 0 0 0 784 0 0 371 87 38 172 0 116 0 0 0 0 0 54,126 802 31,535 13,093 2,710 401 3,438 376 13,881 750 7 532 7 121 54,126 59 2,092 210 360 47 261 35 2,357 35 2 229 1 49 31,736 0 0 0 138 31,210 0 389 0 8,318 0 0 0 41 8,169 0 108 0 2,241 497 266 2,279 235 6,415 492 5 209 3 25
Overijssel (PV) 2022 32 0 0 9 6 10 2 0 1 2 0 0 1 1 2,196 0 0 899 632 290 218 0 21 90 0 0 22 23 1,740 0 0 703 508 223 182 0 14 75 0 0 17 18 109,322 1,761 67,663 26,818 6,295 894 9,159 741 28,440 1,702 18 1,121 8 259 109,322 111 4,312 322 785 100 649 60 4,388 56 2 479 1 97 94,144 0 0 0 315 54,274 0 39,555 0 16,570 0 0 0 100 14,410 0 2,059 0 6,047 1,359 697 7,790 1,077 21,143 1,425 16 605 8 121
Flevoland (PV) 2022 5 0 0 0 1 0 4 0 0 0 0 0 0 0 765 0 0 0 65 0 700 0 0 0 0 0 0 0 612 0 0 0 52 0 560 0 0 0 0 0 0 0 28,153 630 23,742 10,656 2,355 307 2,001 172 5,472 153 4 146 2 272 28,153 26 929 76 185 16 126 46 1,038 10 0 59 0 61 39,174 0 0 0 0 25,178 0 10,451 3,545 8,566 0 0 0 0 5,320 0 2,425 822 1,865 607 272 1,911 178 4,553 165 4 127 3 206
Gelderland (PV) 2022 44 0 0 4 6 9 19 0 2 1 0 0 3 0 3,851 0 0 1,023 986 98 1,415 0 164 25 0 0 140 0 2,818 0 0 805 658 83 1,020 0 120 20 0 0 113 0 213,075 3,734 146,875 56,565 12,661 1,799 12,877 1,573 38,324 1,954 26 1,632 17 475 213,075 249 8,652 877 1,702 269 1,025 279 8,010 150 5 686 2 241 213,474 0 0 0 0 1,365 0 198,421 13,689 35,857 0 0 0 0 283 0 31,920 3,654 11,371 2,147 1,179 11,088 1,455 38,440 2,560 39 880 14 238
Utrecht (PV) 2022 23 0 0 3 4 0 14 0 0 1 0 0 1 0 2,110 0 0 185 108 0 1,365 0 0 19 0 0 432 0 1,680 0 0 145 79 0 1,082 0 0 14 0 0 360 0 116,165 1,836 71,234 29,148 6,407 829 8,398 1,068 31,010 1,731 22 894 11 309 116,165 105 3,920 404 759 79 879 129 5,211 91 3 337 2 107 92,257 0 0 0 0 75,417 0 16,454 386 19,947 0 0 0 0 15,867 0 3,985 94 5,136 1,316 737 5,913 505 18,254 1,361 14 325 7 119
Noord-Holland (PV) 2022 30 0 0 8 5 3 8 1 3 2 0 0 0 0 4,565 0 0 1,930 1,038 82 785 51 433 246 0 0 0 0 3,727 0 0 1,737 781 63 587 40 305 213 0 0 0 0 268,451 3,915 147,878 70,846 14,551 1,968 21,034 1,663 57,825 4,628 62 1,503 18 835 268,451 285 9,734 1,098 2,016 204 1,364 211 7,919 237 16 644 2 333 162,631 0 0 0 1,229 138,579 0 5,764 17,058 47,815 0 0 0 257 42,811 0 1,205 3,542 12,450 2,465 1,750 19,384 1,358 46,997 3,660 37 936 21 483
Zuid-Holland (PV) 2022 53 0 0 3 12 3 32 0 1 2 0 0 0 0 5,908 0 0 1,833 714 16 2,618 0 65 662 0 0 0 0 4,405 0 0 1,242 561 13 1,989 0 46 552 0 0 0 0 388,599 5,144 197,702 73,518 18,436 2,533 20,458 2,244 68,080 4,915 48 3,151 26 1,670 388,599 353 13,127 1,403 2,882 386 1,536 355 10,840 288 10 1,545 5 745 256,767 0 0 0 0 256,741 0 0 27 55,679 0 0 0 0 55,674 0 0 5 14,659 3,617 2,058 20,270 1,757 50,664 4,984 47 1,308 26 877
Zeeland (PV) 2022 15 0 0 11 0 0 2 0 1 0 0 0 1 0 799 0 0 634 0 0 43 0 86 0 0 0 36 0 563 0 0 447 0 0 31 0 59 0 0 0 26 0 47,954 565 20,898 7,876 2,200 242 3,538 341 11,755 844 11 368 5 352 47,954 51 1,786 203 363 41 252 51 1,883 29 3 113 1 160 23,846 0 0 0 0 23,846 0 0 0 5,809 0 0 0 0 5,809 0 0 0 1,971 308 190 2,948 208 7,069 573 6 137 3 160
Noord-Brabant (PV) 2022 33 0 0 11 2 14 5 0 0 1 0 0 0 0 4,386 0 0 2,772 16 615 620 0 0 363 0 0 0 0 3,933 0 0 2,501 11 503 547 0 0 372 0 0 0 0 293,066 4,155 163,147 65,292 14,254 2,294 19,453 2,975 59,772 3,003 44 2,996 15 734 293,066 273 10,661 1,103 1,951 268 1,664 482 13,434 170 9 1,449 2 290 221,601 0 0 0 0 218,671 0 2,931 0 51,111 0 0 0 0 50,374 0 737 0 16,847 2,843 2,111 22,969 2,604 54,659 4,116 60 1,485 21 393
Limburg (PV) 2022 17 0 0 4 3 0 6 0 0 0 0 0 4 0 2,046 0 0 484 427 0 922 0 0 0 0 0 212 0 1,653 0 0 365 323 0 790 0 0 0 0 0 176 0 136,129 1,723 66,838 23,764 6,080 699 6,743 1,740 44,392 2,070 15 2,883 9 555 136,129 150 5,303 719 1,048 79 407 329 8,819 145 2 1,181 2 248 47,058 0 0 0 0 30,466 16,591 0 0 23,306 0 0 0 0 7,803 15,503 0 0 8,242 1,245 788 6,188 1,218 26,841 1,761 30 897 11 118
The river Eems 2022 16 0 0 7 3 0 4 0 0 1 0 0 0 1 1,134 0 0 366 102 0 270 0 0 56 0 0 0 340 819 0 0 267 73 0 201 0 0 41 0 0 0 237 72,258 895 35,939 14,210 2,863 446 3,955 724 14,165 822 10 585 11 157 72,258 94 3,663 494 581 60 368 71 3,083 49 2 202 1 66 47,572 0 0 0 0 0 0 47,572 0 11,497 0 0 0 0 0 0 11,497 0 4,283 396 445 3,967 446 10,951 835 12 336 7 107
The river Rijn (North Rijn) 2022 38 0 1 0 5 4 23 1 2 1 1 0 0 0 1,521 0 54 0 178 45 918 40 153 41 91 0 0 0 1,157 0 60 0 127 33 678 32 134 33 60 0 0 0 97,767 1,218 46,572 21,157 4,398 642 5,150 814 18,032 1,297 18 1,052 7 324 97,767 97 3,926 312 468 82 466 158 3,213 86 7 464 1 143 68,894 0 0 0 4,839 64,055 0 0 0 15,566 0 0 0 1,096 14,470 0 0 0 4,826 956 510 4,370 754 12,615 1,169 9 426 11 159
The river Rijn (East Rijn) 2022 73 0 0 13 14 15 23 0 2 2 0 0 3 1 6,863 0 0 1,515 1,742 385 2,825 0 190 90 0 0 92 23 5,178 0 0 1,174 1,284 299 2,137 0 130 75 0 0 61 18 346,273 5,927 229,013 91,330 20,960 2,885 23,342 2,393 79,034 4,119 49 2,849 29 996 346,273 362 13,299 1,012 2,444 307 1,852 374 14,362 223 6 1,257 3 367 347,596 0 0 0 453 110,662 0 218,862 17,619 62,139 0 0 0 141 27,899 0 29,529 4,569 19,054 4,237 2,236 20,522 2,754 64,864 4,214 58 1,667 25 534
The river Rijn (Central Rijn) 2022
The river Rijn (West Rijn) 2022 114 0 0 16 22 9 52 1 6 6 0 0 2 0 13,096 0 0 4,641 1,896 130 4,262 51 662 952 0 0 502 0 10,240 0 0 3,692 1,442 104 3,263 40 472 799 0 0 429 0 804,996 11,543 443,721 183,669 41,274 5,676 52,260 5,253 158,091 11,424 135 5,983 55 2,868 804,996 793 28,320 3,230 6,065 767 3,828 728 24,176 625 32 2,676 9 1,235 537,465 0 0 0 1,229 466,980 0 52,171 17,085 129,504 0 0 0 257 113,527 0 12,173 3,547 34,453 7,694 4,688 47,707 3,786 120,748 10,354 103 2,704 56 1,516
The river Maas 2022 52 0 0 14 3 14 16 0 0 1 0 0 4 0 6,079 0 0 2,784 427 606 1,686 0 0 363 0 0 212 0 5,242 0 0 2,428 323 496 1,448 0 0 372 0 0 176 0 401,301 5,512 215,642 83,674 19,088 2,771 25,447 4,160 100,628 4,923 60 5,340 24 1,207 401,301 383 14,318 1,721 2,686 272 2,014 648 21,673 307 11 2,419 3 502 245,175 0 0 0 0 225,653 16,591 2,931 0 69,438 0 0 0 0 53,198 15,503 737 0 22,729 3,876 2,712 26,641 3,465 75,911 5,436 82 2,195 31 452
The river Schelde 2022 20 0 0 12 2 2 2 0 1 0 0 0 1 0 1,302 0 0 1,105 16 16 43 0 86 0 0 0 36 0 1,024 0 0 884 11 13 31 0 59 0 0 0 26 0 85,243 1,051 39,966 15,093 3,850 524 4,869 940 16,824 1,101 11 950 5 485 85,243 98 3,703 338 716 121 353 220 2,715 42 3 341 1 218 52,453 0 0 0 0 52,453 0 0 0 11,897 0 0 0 0 11,897 0 0 0 4,593 597 413 5,870 590 13,513 1,093 15 342 6 239
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 April 2024:
The figures of 2022 has been added.

When will new figures be published?
New figures on 2023 will be published by March 2025.

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.
Total number
The total number of urban waste water treatment plants in the Netherlands.
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.
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.
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.
Total capacity inhabitant equivalents
The total capacity of all urban waste water treatment plants.
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
Volume waste water
The annual volume of influent waste water.
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.
Chemical oxygen demand (COD)
Chemical oxygen demand (COD). Measure of the amount of oxygen consumed when a substance is degraded chemically.
Biochemical oxygen demand (BOD)
Biological oxygen demand (BOD). Measure of the amount of oxygen consumed when a substance is biodegraded.
Nitrogen compounds as N (total)
The total amount of nitrogen in organic compounds (e.g. proteins) and inorganic compounds (e.g. nitrate and ammonium)
Phosphorus compounds as P (total)
The total amount of phosphates and other phosphorus compounds in waste water, measured as phosphorus (P).
Copper
Chromium
Zinc
Lead
Cadmium
Nickel
Mercury
Arsenic
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
Volume waste water
The annual volume of effluent waste water.
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.
Chemical oxygen demand (COD)
Chemical oxygen demand (COD). Measure of the amount of oxygen consumed when a substance is degraded chemically.
Biochemical oxygen demand (BOD)
Biological oxygen demand (BOD). Measure of the amount of oxygen consumed when a substance is biodegraded.
Nitrogen compounds as N (total)
The total amount of nitrogen in organic compounds (e.g. proteins) and inorganic compounds (e.g. nitrate and ammonium).
Phosphorus compounds as P (total)
The total amount of phosphates and other phosphorus compounds in waste water, measured as phosphorus (P).
Copper
Chromium
Zinc
Lead
Cadmium
Nickel
Mercury
Arsenic
Sewage sludge
Residue of treated waste water consisting of suspended solids and excess active sludge (biomass). Sewage sludge is measured including water (see Total wet sludge) or as dry solids.
Wet sewage sludge by destination
The volume of wet sewage sludge, i.e. including water by destination (processing method).
Total wet sludge
Total wet sludge discharged.
Agriculture
Application of manure or soil improver in agriculture. Due to rigid legislation impossible since 1995.
Wet oxidation
Wet oxidation of sludge in so-called VerTech installations: the sludge is oxidised under high pressure in a deep shaft.
Composting
Landfill
Dumping of sludge on regional landfill sites or special sludge depots.
Incineration
Incineration of sludge in special sludge incineration plants or in household waste incinerators.
Cement industry
Co-incineration in cement ovens.
Co-incineration at power plants
Sewage sludge used as a secondary fuel at a power plant.
Other destinations
Mainly reuse.
Dry solids by destination
Discharged sewage sludge in kilogrammes of dry solids by destination (processing method). Dry solid is the residue of sewage sludge after evaporation at 105 degrees centigrade.
Total dry solids
Agriculture
Application of manure or soil improver in agriculture. Due to rigid legislation impossible since 1995.
Wet oxidation
Wet oxidation of sludge in so-called VerTech installations: the sludge is oxidised under high pressure in a deep shaft.
Composting
Landfill
Dumping of sludge on regional landfill sites or special sludge depots.
Incineration
Incineration of sludge in special sludge incineration plants or in household waste incinerators.
Cement industry
Co-incineration in cement ovens.
Co-incineration at power plants
Sewage sludge used as a secondary fuel at a power plant.
Other destinations
Mainly reuse.
Nutrients and heavy metals
The total weight of nutrients and heavy metals removed with the sludge. Most heavy metals adsorb strongly to the sludge particles.
Ashes
The residue of non-inflammable, inorganic matter after incineration.
Nitrogen compounds as N
The total amount of nitrogen in organic compounds (e.g. proteins) and inorganic compounds (e.g. nitrate and ammonium).
Phosphorus compounds as P
The total amount of phosphorus in sewage sludge is analysed as P205 (diphosphorus pentoxide) converted to P total.
Copper
Chromium
Zinc
Lead
Cadmium
Nickel
Mercury
Arsenic