16 Del. Admin. Code § 4462-18.0
Current through Register Vol. 28, No. 7, January 1, 2025
Section 4462-18.0 - Recycle Rule18.1 Applicability: All surface water or ground water under the direct influence of surface water systems that employ conventional filtration or direct filtration treatment and that recycle spent filter backwash water, thickener supernatant, or liquids from dewatering processes must meet the requirements in subsections 18.2 through 18.4.18.2 Reporting: A system must notify the Division in writing by December 8, 2003 if the system recycles spent filter backwash water, thickener supernatant, or liquids from dewatering processes. This notification must include, at a minimum, the information specified in subsections 18.2.1 and 18.2.2. 18.2.1 A plant schematic showing the origin of all flows that are recycled (including, but not limited to, spent filter backwash water, thickener supernatant, and liquids from dewatering processes), the hydraulic conveyance used to transport them, and the location where they are reintroduced back into the treatment plant.18.2.2 Typical recycle flow in gallons per minute (gpm), the highest observed plant flow experienced in the previous year (gpm), design flow for the treatment plant (gpm), and Division-approved operating capacity for the plant where the Division has made such a determination.18.3 Treatment Technique Requirement: Any system that recycles spent filter backwash water, thickener supernatant, or liquids from dewatering processes must return these flows through the processes of a system's existing conventional or direct filtration system as defined in Section 1.0 or at an alternate location approved by the Division by June 8, 2004. If capital improvements are required to modify the recycle location to meet this requirement, all capital improvements must be completed no later than June 8, 2006.18.4 Recordkeeping: The system must collect and retain on file recycle flow information specified in subsections 18.4.1 through 18.4.6 for review and evaluation by the Division beginning June 8, 2004.18.4.1 Copy of the recycle notification and information submitted to the Division under subsection 18.2.18.4.2 List of all recycles flows and the frequency with which they are returned.18.4.3 Average and maximum backwash flow rate through the filters and the average and maximum duration of the filter backwash process in minutes.18.4.4 Typical filter run length and a written summary of how filter run length is determined.18.4.5 The type of treatment provided for the recycle flow.18.4.6 Data on the physical dimensions of the equalization and/or treatment units, typical and maximum hydraulic loading rates, type of treatment chemicals used and average dose and frequency of use, and frequency at which solids are removed, if applicable.16 Del. Admin. Code § 4462-18.0
19 DE Reg. 517( 12/1/2015) (Final)