Ala. Admin. Code r. 335-7-6-.24

Current through Register Vol. 42, No. 11, August 30, 2024

Section 335-7-6-.24 - Treatment Performance Toolbox Components

(1) Combined filter performance. Systems using conventional filtration treatment or direct filtration treatment receive an additional 0.5-log Cryptosporidium treatment credit during any month the system meets the criteria in this paragraph. Combined filter effluent (CFE) turbidity must be less than or equal to 0.15 NTU in at least 95 percent of the measurements. Turbidity must be measured using an EPA approved method and must be measured every 15 minutes that the water treatment plant is in operation.

(2) Individual filter performance. Systems using conventional filtration treatment or direct filtration treatment receive 0.5-log Cryptosporidium treatment credit, which can be in addition to the 0.5-log credit under paragraph (1) of this section, during any month the system meets the criteria in this paragraph. Compliance with these criteria must be based on individual filter turbidity monitoring as described in rule 335-7-2-.06.

(a) The filtered water turbidity for each individual filter must be less than or equal to 0.15 NTU in at least 95 percent of the measurements recorded each month.

(b) No individual filter may have a measured turbidity greater than 0.3 NTU in two consecutive measurements taken 15 minutes apart.

(c) Any system that has received treatment credit for individual filter performance and fails to meet the requirements of subparagraph (2)(a) or (b) of this rule during any month does not receive a treatment technique violation under rule 335-7-2-.06 if the Department determines the following:

1. The failure was due to unusual and short-term circumstances that could not reasonably be prevented through optimizing treatment plant design, operation, and maintenance.

2. The system has experienced no more than two such failures in any twelve month period.

3. Any system that that has two such failures in any 12 month period must complete a self assessment according to EPA's handbook: Optimizing Water Treatment Plant Performance Using the Composite Correction Program or as specified by the Department. The report must be submitted to the Department within 90 days of the second occurrence.

(3) Demonstration of performance. The Department may approve Cryptosporidium treatment credit for drinking water treatment processes based on a demonstration of performance study that meets the criteria in this paragraph. This treatment credit may be greater than or less than the prescribed treatment credits in this chapter and may be awarded to treatment processes that do not meet the criteria for the prescribed credits.

(a) Systems cannot receive the prescribed treatment credit for any toolbox box option in this chapter if that toolbox option is included in a demonstration of performance study for which treatment credit is awarded under this paragraph.

(b) The demonstration of performance study must follow a Department-approved protocol and must demonstrate the level of Cryptosporidium reduction the treatment process will achieve under the full range of expected operating conditions for the system.

(c) Approval by the Department must be in writing and may include monitoring and treatment performance criteria that the system must demonstrate and report on an ongoing basis to remain eligible for the treatment credit. The Department may designate such criteria where necessary to verify that the conditions under which the demonstration of performance credit was approved are maintained during routine operation.

Ala. Admin. Code r. 335-7-6-.24

New Rule: Filed December 18, 2007; effective January 22, 2008.

Author: Dennis D. Harrison

Statutory Authority:Code of Ala. 1975, §§ 22-23-33, 22-23-49, 22-22A-5, 22-22A-6.