Ala. Admin. Code r. 335-7-11-.12

Current through Register Vol. 42, No. 12, September 30, 2024

Section 335-7-11-.12 - Corrosion Control Treatment Requirement

Any water system which has been deemed to have optimized corrosion control and has corrosion control treatment in place shall continue to operate and maintain treatment to ensure that optimal corrosion control is maintained.

(a) All water systems with an action level which exceeds a lead or copper compliance limit and any new drinking water source proposed for use after the effective date of these regulations shall install and properly operate optimum corrosion control processes continuously to reduce the potential for lead or copper exposure by the consumers. Within six months of exceeding the compliance limit a system shall provide a detailed report indicating the process and equipment to be used to provide corrosion control treatment. Installation and start up of the equipment must be completed within 24 months of approval of the Department. A corrosion control treatment study may be required by the Department to determine the optimum process to be installed. Those systems practicing corrosion control in their treatment process prior to the effective date of these regulations and acceptable to the Department may have the treatment study requirements waived. Systems required to perform a corrosion control treatment study shall complete the study and submit its results along with a proposal for the process to be used to the Department within 12 months of exceeding a compliance limit. This report must include a proposed construction schedule for installation of the equipment. This project must be completed no more than 24 months after the study submittal. All systems installing corrosion control treatment processes shall monitor initial site during the next two consecutive six-month compliance periods.

(b) The water in a water system is considered to meet optimum corrosion control when the distribution system:

1. Water quality parameters reflected on the Baylis Curve indicates no incrusting or corrosion will occur, or

2. The Langelier Index of the water is between -1.0 to +2,

3. The Ryznar Index is between 7 and 11,

4. A phosphate or silicate corrosion inhibitor is continuously applied at the manufacturer/supplier recommended level resulting in minimum complaints, or

5. The Calcium Carbonate Precipitation Potential (CCPP) is maintained between 4-10 mg/1, and

6. The water continuously meets the lead and copper compliance limits.

(c) Any water system may be considered to optimize corrosion control treatment if it demonstrates that it has conducted activities equivalent to the corrosion control steps outlined in this rule. Water systems deemed to have optimized corrosion control under this subparagraph shall operate in compliance with the State-designated optimal water quality control parameters and continue to conduct lead and copper tap and water quality parameter monitoring as required by these regulations. The system shall provide to the Department:

1. The results of all monitoring for each of the water quality parameters listed in 335-7-11-.13(c);

2. A report explaining the test methods used by the water system to evaluate the corrosion control treatments listed in 335-7-11-13(a), the results of all tests conducted and the basis for the system's selection of optimal corrosion control treatment;

3. A report explaining how corrosion control has been installed and how it is being maintained to ensure minimal lead and copper concentrations at consumer's taps; and

4. The information from tap water monitoring conducted in accordance with 335-7-11-.07 above the compliance limit.

(d) Any water system is deemed to have optimized corrosion control if it submits results of tap water monitoring conducted in accordance with 335-7-11-.08 and source water monitoring in accordance with 335-7-11-.15 that demonstrates for two consecutive six-month monitoring periods that the difference between the 90th percentile tap water level computed under 335-7-11-.03 and the highest source water lead concentration is less than 0.005 mg/1.

1. Those systems whose highest source water lead level is below the Method Detection Limit may also be deemed to have optimized corrosion control under this subparagraph if the 90th percentile tap water lead level is less than or equal to 0.005 mg/1 for two consecutive 6-month monitoring periods.

2. Any water system deemed to have optimized corrosion control in accordance with this subparagraph shall continue to monitor for lead and copper at the tap no less frequently than once every three calendar years using the reduced number of monitoring sites and conducting the monitoring at times and locations specified in these regulations.

3. Any water system deemed to have optimized corrosion control shall notify the Department in writing pursuant of any change in treatment or the addition of a new source. Any new source or long-term change in water treatment shall have written approval from the Department before being placed into service or implemented. The system may be required to conduct additional monitoring or to take other action to ensure that the system maintains minimal levels of corrosion in the distribution system.

4. Any system triggered into corrosion control because it is no longer deemed to have optimized corrosion control under this subparagraph shall implement corrosion control treatment in accordance with the deadlines in the regulations. Large systems shall adhere to the schedule specified in the paragraph for medium size systems; with the time periods for completing each step being triggered by the date the system is no longer deemed to have optimized corrosion control under this paragraph.

Ala. Admin. Code r. 335-7-11-.12

Adopted: September 23, 1992; effective November 9, 1992. Amended: Filed November 28, 1995; effective January 2, 1996. Amended: Filed February 6, 2002; effective March 13, 2002. Amended: Filed April 26, 2009; effective May 26, 2009. Amended: Filed December 14, 2010; effective January 18, 2011. Amended: Filed August 21, 2012; effective September 25, 2012.

Authors: Joe Alan Power, Dennis D. Harrison

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