La. Admin. Code tit. 51 § XII-1117

Current through Register Vol. 50, No. 11, November 20, 2024

Section XII-1117 - Non-Filtering Systems

A. General. On a case-by-case basis, DHH may waive filtration requirements for suppliers using GWUDISW. To be considered, non-filtering systems shall conform to the criteria of this Section. All suppliers using surface water shall employ filtration.

B. Source Water Quality to Avoid Filtration

1. To avoid filtration, a system shall demonstrate that either the fecal coliform concentration is less than 20/100 ml and/or the total coliform concentration is less than 100/100 ml in the water prior to the point of disinfectant application in 90 percent of the samples taken during the six previous months. Samples shall be taken prior to blending, if employed.

a. If both fecal and total coliform analysis is performed, only the fecal coliform limit shall be met, under this condition, both fecal and total coliform results shall be reported.

b. Sample analyses methods may be the multiple-tube fermentation technique or the membrane filter technique as described in the Standard Methods for the Examination of Water and Wastewater, 19th Edition.

c. Minimum Sampling Frequencies

Table 3
Population	Samples/Week
[LESS THAN EQUAL TO] 500	1
501-3300	2
3301-10,000	3
10,001-25,000	4
> 25,000	5

d. Also, one coliform sample shall be taken and analyzed each day the turbidity exceeds 1 NTU prior to disinfection.

2. To avoid filtration, the turbidity of the water prior to disinfection cannot exceed 5 NTU based on grab samples collected every four hours (or more frequently) that the system is in operation. Continuous turbidity measurement is allowed provided the accuracy of the turbidity measurements are validated at least weekly in accord with §1107. D of this Chapter. If there is a failure in the continuous turbidity monitoring equipment, the system shall collect and analyze a grab sample every four hours in lieu of continuous monitoring. Systems shall maintain the results of these turbidity measurements for at least three years.

C. Disinfection Criteria to Avoid Filtration

1. To avoid filtration, a system shall demonstrate that it maintains disinfection conditions which inactivate 99.9 percent (3 Log) of Giardia cysts and 99.99 percent (4 Log) of viruses everyday of operation except any one day each month. To demonstrate adequate inactivations, the system shall monitor and record the disinfectant used, disinfectant residual at peak hourly flow, disinfectant contact time at peak hourly flow, pH, and water temperature, and use these data to determine if it is meeting the minimum total inactivation requirements of this rule.

a. A system shall demonstrate compliance with the inactivation requirements based on conditions occurring during peak hourly flow. Residual disinfectant measurements shall be taken hourly. Continuous disinfectant residual monitors are acceptable in place of hourly samples provided the accuracy of the disinfectant measurements are validated at least weekly in accord with §1109. B or C, as applicable, of this Chapter. If there is a failure in the continuous disinfectant residual monitoring equipment, the system shall collect and analyze a grab sample every hour in lieu of continuous monitoring.

b. pH and temperature shall be determined daily for each disinfection sequence prior to or at the first customer.

2. To avoid filtration, the system shall maintain minimum disinfectant residual concentrations in accordance with the requirements of §355 and §357 of this Part. Performance standards shall be as presented in §1119. B and C of this Chapter.

3. To avoid filtration, the disinfection system shall be capable of assuring that the water delivered to the distribution system is continuously disinfected. This requires:

a. redundant disinfection equipment with auxiliary power and automatic start up and alarm; or

b. an automatic shut off of delivery of water to the distribution system when the disinfectant residual level drops below 0.5 mg/l free chlorine residual or 0.5 mg/l chloramine residual (measured as total chlorine).

D. Site Specific Conditions to Avoid Filtration. In addition to the requirement for source water quality and disinfection, systems shall meet the following criteria to avoid filtration: maintain a watershed control program, conduct a yearly on-site inspection, determine that no waterborne disease outbreaks have occurred, comply with the total coliform MCL at least 11 months of the 12 previous months that the system served water to the public and comply on an ongoing basis, comply with Disinfection By-Product (DBP) regulations for total trihalomethanes (TTHM), haloacetic acids (five) [HAA5], bromate, and chlorite, and comply with Maximum Residual Disinfection Level (MRDL) regulations for chlorine, chloramines, and chlorine dioxide.

1. Watershed Control Program. A watershed control program for systems using GWUDISW shall include as a minimum the requirements of the Wellhead Protection Program (WHPP), delineated as follows:

a. specify the duties of state agencies, local governmental entities and public water supply systems with respect to the development and implementation of the WHPP;

b. determine the wellhead protection area (WHPA) for each wellhead as defined in 42 U.S.C.A. 300h-7(e) based on all reasonably available hydrogeologic information, groundwater flow, recharge and discharge and other information the state deems necessary to adequately determine the WHPA;

c. identify within each WHPA all potential anthropogenic sources of contaminants which may have any adverse effect on the health of persons, specifically with the goal of minimizing the potential for contamination of the source water by Giardia lamblia cysts, viruses, and Cryptosporidium oocysts;

d. describe a program that contains, as appropriate, technical assistance, financial assistance, implementation of control measures, education, training and demonstration projects to protect the water supply within WHPAs from such contaminants;

e. present contingency plans for locating and providing alternate drinking water supplies for each public water system in the event of well or wellfield contamination by such contaminants;

f. consider all potential sources of such contaminants within the expected wellhead area of a new water well which serves a public water system; and

g. provide for public participation.

2. On-Site Inspection. An annual on-site inspection is required to evaluate the watershed control program and disinfection facilities. The system shall be reviewed by a qualified engineer for the systems adequacy for producing safe drinking water. The annual on-site inspection shall include as a minimum:

a. review the effectiveness of the watershed control program;

b. review the physical condition and protection of the source intake;

c. review the maintenance program to insure that all disinfection equipment is appropriate and has received regular maintenance and repair to assure a high operating reliability;

d. review improvements and/or additions made to disinfection processes during the previous year to correct deficiencies detected in earlier surveys;

e. review the condition of disinfection equipment;

f. review operating procedures;

g. review data records to assure that all required tests are being conducted and recorded and disinfection is effectively practiced; and

h. identify any needed improvements in the equipment, system maintenance and operation, or data collection.

3. Sanitary Survey. In addition to the above requirements, a sanitary survey shall be performed every three years for community water systems and every five years for non-community water systems which use GWUDISW without filtration. The sanitary survey shall include:

a. review the condition of finished water storage facilities;

b. determine that the distribution system has sufficient pressure throughout the year;

c. verify that distribution system equipment has received regular maintenance;

d. review cross connection prevention program, including annual testing of backflow prevention devices;

e. review routine flushing program for effectiveness;

f. evaluate the corrosion control program and its impact on distribution water quality;

g. review the adequacy of the program for periodic storage reservoir flushing;

h. review practices in repairing water main breaks to assure they include disinfection;

i. review additions, improvements incorporated during the year to correct deficiencies detected in the initial inspection;

j. review the operations to assure that any difficulties experienced during the year have been adequately addressed;

k. review staffing to assure adequate numbers of certified operators are available in accord with LAC 48:V.Chapter 73;

l. verify that a regular maintenance schedule is followed;

m. audit systems records to verify that they are adequately maintained; and

n. review bacteriological data from the distribution system for coliform occurrence, repeat samples and action response.

4. No Disease Outbreaks. To avoid filtration, a system using GWUDISW shall not have been identified as a source of waterborne disease. If such an outbreak has occurred and (in the opinion of DHH) was attributed to a treatment deficiency, the system shall install filtration unless the system has upgraded its treatment to remedy the deficiency to the satisfaction of DHH.

5. Coliform MCL Regulations. To avoid filtration, a system shall have complied with the MCL for Total Coliforms, established in the Total Coliform Rule, for at least 11 out of 12 of the previous months unless DHH determines the failure to meet this requirement was not caused by a deficiency in treatment.

6. DBP Regulations. For a system using GWUDISW to continue using disinfection as the only treatment, the system shall comply with the DBP regulations, including TTHM, HAA5, bromate, and chlorite, as applicable.

7. MRDL Regulations. For a GWUDISW system to continue using disinfection as the only treatment, the system shall comply with the MRDLs for chlorine, chloramines, and chlorine dioxide, as applicable.

La. Admin. Code tit. 51, § XII-1117

Promulgated by the Department of Health and Hospitals, Office of Public Health, LR 28:1341 (June 2002), amended LR 28:2520 (December 2002), LR 35:1242 (July 2009), Amended LR 42411 (3/1/2016).

AUTHORITY NOTE: Promulgated in accordance with R.S. 40:4(A)(8)(13) and 40:5(2)(3)(5)(6)(17)(20).