Year Discharged or transported to a public waste water treatment plant on a public sewerage network
only with mechanical also with biological also with advanced total
treatment technology
1990 475,968 280,426 22,979 779,373
1991 450,224 267,869 21,340 739,433
1992 449,544 244,066 19,667 713,278
1993 389,484 236,192 19,162 644,838
1994 344,383 235,859 13,536 593,778
1995 325,451 244,992 13,001 583,444
1996 265,888 239,665 15,431 520,984
1997 231,634 245,386 11,762 488,782
1998 222,593 232,777 32,400 487,769
1999 224,673 261,597 36,998 523,269
2000 168,910 252,978 57,304 479,192
2001 197,629 222,229 60,355 480,214
2002 185,064 214,865 91,738 491,667
2003 142,451 182,455 163,383 488,288
2004 165,074 193,404 177,357 535,835
2005 174,815 188,779 196,784 560,378
2006 152,939 249,641 133,379 535,959
2007 128,143 217,654 165,186 510,983
2008 135,845 204,820 179,123 519,787
2009 123,512 201,941 182,073 507,525
2010 17,607 280,760 255,008 553,375
2011 8,930 219,184 237,848 465,963
2012 859 111,270 317,283 429,411
2013 560 110,299 370,693 481,551
2014 638 97,136 375,978 473,753
2015 745 63,437 418,269 482,452
2016 473 65,783 478,297 544,552
2017 492 48,298 488,910 537,700
2018 513 49,252 510,111 559,876
2019 508 46,179 492,179 538,866
2020 551 44,248 488,232 533,031
2021 588 44,613 479,672 524,873
2022 307 42,979 465,381 508,668
.