CALL CENTER QUESTIONS & ANSWERS RCRA 1. Requirements for Characteristic Sludge Removed from a Wastewater Treatment Unit A facility manages characteristic wastewater in an on-site wastewater treatment unit (WWTU) regulated by the Clean Water Act (CWA). The WWTU is exempt from the RCRA requirements for permitted and interim status treatment, storage, and disposal facilities in 40 CFR Parts 264 and 265 and the permitting requirements in §270.1(c)(2)(v). During treatment, the facility generates wastewater effluent and characteristic nonwastewater sludge. The wastewater effluent is discharged to a publicly owned treatment works (POTW) through a public sewer, while the sludge is removed, collected, and stored before land disposal. How is the characteristic nonwastewater sludge regulated? Will land disposal restrictions (LDR) requirements apply to the sludge? Treatment sludge generated from the management of characteristic wastewaters in a WWTU must be managed as hazardous once removed from the tank if it exhibits a characteristic of hazardous waste (66 FR 27266, 27272; May 16, 2001). Therefore, the sludge will be subject to full Subtitle C regulation, including all applicable hazardous waste management standards such as on-site storage standards and off-site transportation requirements. In addition, hazardous sludges removed from CWA treatment trains and subsequently land disposed are subject to the LDR requirements (55 FR 22520, 22657; June 1, 1990). If the nonwastewater sludge does not exhibit a characteristic of hazardous waste when it is removed from the tank, then it is no longer subject to the requirements of Subtitle C, but LDR requirements may still apply (§261.3(d)(1)). Sludge generated during the treatment of a wastewater that results in a change from wastewater to nonwastewater is considered a change in treatability group. A change in treatability group for a characteristic treatment residual is a new point of generation for LDR purposes (64 FR 25408,25411; May 11, 1999). If the sludge has undergone a change in treatability group and is no longer characteristic, then it is not a RCRA hazardous waste, and the generator would not need to comply with the LDR requirements in Part 268. ------- |