Sewage Sludge Directive Council Directive 86/278/EEC of 12 June 1986 on the protection of the environment, and in particular of the soil, when sewage sludge is used in agriculture (OJ L 181, 4.7.1986, pp. 6-12) https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=CELEX:31986L0278

UWWT Directive (EU) 2024/301 concerning urban wastewater treatment (recast) https://eur-lex.europa.eu/legal-content/EN/TXT/PDF/?uri=OJ:L_202403019

'sludge' means :
(i) residual sludge from sewage plants treating domestic or urban waste waters and from other sewage plants treating waste waters of a composition similar to domestic and urban waste waters;
(ii) residual sludge from septic tanks and other similar installations for the treatment of sewage;
(iii) residual sludge from sewage plants other than those referred to in (i) and (ii)

‘sludge’ means organic and inorganic residue resulting from the treatment of urban wastewater from an urban wastewater treatment plant, excluding grit, grease, other debris and any other screenings and residues from the pre-treatment step;

UWWT Directive (EU) 2024/301 concerning urban wastewater treatment (recast)