N.H. Code Admin. R. Env-Ws 380.29

Current through Register No. 25, June 20, 2024

Section Env-Ws 380.29 - Recycle Provisions and Recordkeeping Requirements

(a) Each water system owner that employs conventional filtration or direct filtration treatment and that recycles spent filter backwash water, thickener supernatant, or liquids from dewatering processes shall meet the requirements in (b) through (f) of this section.

(b) Pursuant to 40 CFR 141. 141.76(b), a system owner shall notify the department in writing by December 8, 2003, if the system recycles spent filter backwash water, thickener supernatant, or liquids from dewatering processes.

(c) The notification shall include, at a minimum, the following information:

(1) A plant schematic plan showing the origin of all flows which are recycled including, but not limited to:

a. Spent filter backwash water;

b. Thickener supernatant; and

c. Liquids from dewatering processes;

(2) The hydraulic conveyance used to transport them;

(3) The location where the flows are reintroduced back into the treatment plant;

(4) Typical recycle flow in gallons per minute gpm;

(5) The highest observed plant flow experienced in the previous year in gpm;

(6) Design flow for the treatment plant in gpm; and

(7) The department approved operating capacity for the plant if the department has made such determinations.

(d) Pursuant to 40 CFR141.76(c), the owner of 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 department by June 8, 2004.

(e) If capital improvements are required to modify the recycle location to meet the requirements in (d) above, all capital improvements for the system shall be completed no later than June 8, 2006.

(f) Pursuant to 40 CFR 141.76(d), the system owner shall collect and retain on file the following information for review and evaluation by the department beginning June 8, 2004:

(1) A copy of the recycle notification and information submitted to the department under (b) and (c) above;

(2) A list of all recycle flows and the frequency with which they are returned;

(3) The average and maximum backwash flow rate through the filters and the average and maximum duration of the filter backwash process in minutes;

(4) The typical filter run length and a written summary of how filter run length is determined;

(5) The type of treatment provided for the recycle flow;

(6) Data on the physical dimensions of the equalization and or both treatment units including;

a. Typical and maximum hydraulic loading rates;

b. Type of treatment chemicals used and average dose and frequency of use; and

c. The frequency at which solids are removed, if applicable.

N.H. Code Admin. R. Env-Ws 380.29

#7754, eff 8-21-02; ss by #8352, eff 5-14-05