Item A-MWMC Facilities Plan - Laserfiche WebLink

Home Browse Search

5. BASIS OF PLANNING Total Dissolved Solids (TDS) The TDS standard in the Willamette River is 100 mg/L. There are currently no compliance issues with respect to effluent quality and TDS. Any numerical limit is unlikely to affect future recommended treatment technologies at the WPCF. However, alternative disinfection practices such as the addition of sodium hypochlorite can significantly increase TDS discharges. Dioxins and Furans A toxic equivalency factor approach for the human health criteria for dioxins and furans was considered by the DEQ for inclusion in the proposed changes for Oregon water quality standards, but at the time of writing it appears that this will not be included in the standards revision package to be considered by the EQC, currently planned for May 2004. Any limits for dioxins and furans are unlikely to affect future recommended treatment technologies at the WPCF and will likely be implemented as source control reductions. 5.1.4 Biosolids Quality Both federal and state regulations apply to land application of biosolids from wastewater treatment plants (WWTPs). Federal regulations include 40 CFR 257 and approved 40 CFR, Part 503. State of Oregon regulations include OAR 340-50. Since the passing of the federal 503 regulations, the state has prepared and passed amendments to OAR 340-50 that adopt provisions outlined in the 503 regulation. For disposal of biosolids as interim cover or as fill at a solid waste landfill, federal regulations 40 CFR, Part 258, apply. If the biosolid$ is incorporated in the final cover for the landfill, the 503 regulations would still apply. State regulations take precedence over federal regulations, where applicable. In some instances, state regulations may impose more stringent requirements than federal regulations. However, federal regulations apply if no state regulations are declared. Regulations Current federal regulations for land treatment of biosolids are listed in the Federal Register under 40 CFR, Part 257, "Criteria for Classification of Solid Waste Disposal Facilities and Practices," dated September 13, 1979. In the past, Part 257.3-5 has regulated solid waste application to food crops; however, these regulations have been considered too general. Therefore, new regulations under 40 CFR, Part 503, were required by Section 405 (d) of the Clean Water Act of 1977 (as amended by the Water Quality Act of 1987). The new regulations under 40 CFR, Part 503, have gone through several scientific community and public reviews and were released as final in late 1992. In December 1984, DEQ defined rules for the land application and disposal of sewage treatment plant biosolids and biosolids-derived products, including septage (OAR 340-50). These regulations are currently in the process of being updated to conform to the adopted federal regulations. MWMC_5,0_REV8_VKS.DOC 5-13