;2016;2017;2018;Change in per cent; 2017 - 2018; Percentage of population connected to municipal wastewater facilities (per cent);84.4;84.9;85.3;0.5; Total length of sewage pipelines (metres);37373027;37399466;37918481;1.4; Percentage of total wastewater pipeline system renewed, 3-year-average (per cent;0.61;0.61;0.60;-1.6; Average age of wastewater pipeline system (year);30.0;30.0;30.0;0.0; Length of separate stormwater pipelines (metres);17940738;18318610;18824072;2.8; Number of sewage overflow in sewage pipelines and manhole covers (numbers/km pipeline);0.053;0.054;0.051;-5.6; Total wastewater load in treatment plants (kg tot-P);3037997;3096898;2987737;-3.5;