A. Applicability. All Subpart H systems that employ conventional filtration or direct filtration treatment and that recycle spent filter backwash water, thickener supernatant, or liquids from dewatering processes shall meet the requirements in §§BD of this regulation.
(1) Suppliers of water shall notify the Approving Authority in writing by December 8, 2003, if the system recycles spent filter backwash water, thickener supernatant, or liquids from dewatering processes.
(2) Notification under this section shall include, at a minimum:
(a) A plant schematic showing the origin of all flows which 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;
(b) 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 State-approved operating capacity for the plant where the Approving Authority has made such determinations.
C. Treatment Technique Requirement.
(1) By June 8, 2004, any system that recycles spent filter backwash water, thickener supernatant, or liquids from dewatering processes shall return these flows through the processes of a system's existing conventional or direct filtration system or at an alternate location approved by the Approving Authority.
(2) If capital improvements are required to modify the recycle location to meet this requirement, all capital improvements shall be completed not later than June 8, 2006.
D. Record Keeping.
(1) Beginning June 8, 2004, a supplier of water shall collect and retain on file recycle flow information specified in §D(2) of this regulation for review and evaluation by the Approving Authority.
(2) The following recycle flow information shall be retained:
(a) A copy of the recycle notification and information submitted to the Approving Authority under §B of this regulation;
(b) A list of all recycle flows and the frequency with which they are returned;
(c) The average and maximum backwash flow rate through the filters;
(d) The average and maximum duration of the filter backwash process in minutes;
(e) The typical filter run length;
(f) A written summary of how filter run length is determined;
(g) The type of treatment provided for the recycle flow; and
(h) If applicable, data on the physical dimensions of the equalization units, treatment units, or both, 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.