Ala. Admin. Code r. 335-7-2-.11
Current through Register Vol. 42, No. 11, August 30, 2024
Section 335-7-2-.11 - Stage 1 Disinfection ByproductsCommunity and NTNC water systems that use a surface water source, groundwater source or purchase water from another public water system must monitor for disinfection byproducts (DBPs).
(a) The following are the MCLs for DBPs: | CONTAMINANT | MCL (mg/L) |
| Bromate | 0.010 |
| Chlorite | 1.0 |
| HAA5 | 0.060 |
| TTHM | 0.080 |
(b) Community and NTNC water systems using chlorine dioxide must collect daily samples for chlorite analysis at the entrance to the distribution system. If a daily sample exceeds the chlorite MCL of 1.0 mg/L, the system shall collect three additional samples from the distribution system the following day in addition to the daily sample required a the entrance to the distribution system. The distribution samples shall be collected from a location near the first customer, a location representative of the average residence time and a location representative of the maximum residence time.(c) In addition to daily chlorite monitoring, community and NTNC water systems using chlorine dioxide must collect at least three samples monthly for chlorite analysis. The samples must be collected in the distribution system on the same day from a location near the first customer, a location representative of the average residence time and a location representative of the maximum residence time. Monthly chlorite monitoring may be reduced to quarterly after one year of monitoring if no chlorite sample has exceeded the chlorite MCL. If any sample analyzed for chlorites exceeds the chlorite MCL, the system must revert to monthly monitoring.(d) Non-compliance with the chlorite MCL will occur when the average of any three distribution sample set exceeds the MCL.(e) Community and NTNC water systems using ozone must collect one sample per month for bromate analysis from each treatment plant using ozone. The samples shall be collected at the entrance to the distribution system while the ozonation system is operating under normal conditions. Systems required to analyze for bromate may reduce monitoring from monthly to quarterly if the system demonstrates that the system's running annual average bromate concentration is less than 0.0025 mg/L based upon representative monthly bromate measurements for one year. The system must return to routine bromate monitoring requirements if the running annual average bromate concentration is equal to or greater than 0.0025 mg/L based upon representative quarterly measurements.(f) Non-compliance with the bromate MCL will occur when the running annual average of monthly samples, computed quarterly, exceeds the MCL. If a system fails to complete 12 consecutive months' monitoring, compliance with the MCL for the last four-quarter compliance period must be based on an average of the available data.(g) Community and NTNC water systems utilizing surface sources or groundwater under the direct influence of surface water shall sample each treatment plant for Total Organic Carbon (TOC) analysis. One sample shall be collected from the raw water and one sample shall be collected from the point of combined filter effluent. These samples are referred to as paired samples and shall be collected at the same time. At the same time as the raw water sample is collected, the alkalinity in the raw water prior to any treatment must be determined. Systems must collect one paired sample and one source water alkalinity sample per month per plant at a time representative of normal operating conditions and raw water quality. Water treatment plants with an average treated water TOC of less than 2.0 mg/L for two consecutive years determined quarterly, or less than 1.0 mg/L for one year, may reduce monitoring for both TOC and alkalinity to one paired sample and one source water alkalinity sample per plant every 90 days if the system is on reduced TTHM and HAA5 monitoring. The water treatment plant must revert to routine monitoring in the month following the quarter when the annual average treated water TOC is greater than or equal to 2.0 mg/L or the system does not qualify for reduced TTHM and HAA5 monitoring. Systems with multiple water treatment plants must sample each water treatment plant at the same frequency.(h) Community and NTNC water systems must monitor for TTHMs and HAA5s according to the following subparagraphs until January 1, 2012: 1. Community water systems utilizing surface sources or groundwater under the direct influence of surface water shall collect each quarter and have analyzed for TTHMs and HAA5s at least four samples that are representative of each treatment plant used by the system. Twenty five percent of these samples shall be collected at a location reflecting the maximum residence time of the water even if the sample is collected outside the system's distribution area. The remaining 75 percent shall be collected at locations representative of the average residence time in the distribution system taking into account the number of persons served, different sources of water, and different treatment methods employed. The results of these samples will be averaged to provide the quarterly compliance value. In addition to the samples required above, each system will take one sample per quarter from each water treatment plant effluent.2. After four consecutive quarters of monitoring, a community water system using a surface source or groundwater under the direct influence of surface water may reduce the monitoring frequency to one sample per quarter for each treatment plant, if the annual average for TTHMs is less than or equal to 0.040 mg/L and the annual average for HAA5s is less than or equal to 0.030 mg/L and the source water TOC running annual average is = 4.0 mg/L at each treatment plant. The sample must be collected from a point in the distribution system reflecting the maximum residence time of the water.3. In order to qualify for reduced TTHM and HAA5 monitoring, systems that are required to monitor TOC shall take monthly samples every 30 days.4. Community and NTNC water systems utilizing only groundwater sources not under the direct influence of surface water and serving at least 10,000 persons shall collect each quarter and have analyzed for TTHMs and HAA5s one sample from a point in the total service area reflecting the maximum residence time of the water. After four consecutive quarters of monitoring, the frequency may be reduced to one sample per year between the months of June and September for each groundwater treatment plant if the annual average for TTHMs is less than or equal to 0.040 mg/L and the annual average for HAA5s is less than or equal to 0.030 mg/L. The sample must be collected from a point in the total service area reflecting the maximum residence time of the water.5. Community and NTNC water systems utilizing only groundwater sources not under the direct influence of surface water and serving less than 10,000 persons shall collect each year between the months of June and September and have analyzed for TTHMs and HAA5s one sample from a point in the total service area reflecting the maximum residence time of the water. The frequency may be reduced to one sample every three years between the months of June and September for each treatment plant if the annual average for TTHMs is less than or equal to 0.040 mg/L and the annual average for HAA5s is less than or equal to 0.030 mg/L for two consecutive years or if the annual average for TTHMs is less than or equal to 0.020 mg/L and the annual average for HAA5s is less than or equal to 0.015 mg/L for one year. The sample must be collected from a point in the total service area reflecting the maximum residence time of the water in the system.6. Community systems purchasing water from another system for more than 60 days a year must monitor for DBPs according to the following: (i) Community systems purchasing water from a system that is surface water or ground water under the influence of surface water must monitor for TTHMs and HAA5s at four locations per purchase connection per quarter. Twenty-five percent of these samples shall be collected at a location reflecting the maximum residence time of the water and the remaining seventy-five percent shall be collected at locations representative of the average residence time in the distribution system taking into account the number of persons served. The results of all samples will be averaged to provide the quarterly compliance value.(ii) After four consecutive quarters of monitoring, a community water system purchasing surface water or groundwater under the direct influence of surface water may reduce the monitoring frequency to one sample per quarter for each purchase connection if the annual average for TTHMs is less than or equal to 0.040 mg/L and the annual average for HAA5s is less than or equal to 0.030 mg/L. The sample must be collected from a point in the distribution system reflecting the maximum residence time of the water.(iii) Community and NTNC water systems purchasing water only from a system(s) that is ground water not under the influence of surface water and is serving at least 10,000 persons shall collect each quarter and have analyzed for TTHMs and HAA5s one sample from a point in the distribution system reflecting the maximum residence time of the water from each purchase connection. After four consecutive quarters of monitoring, the frequency may be reduced to one sample per year between the months of June and September for each purchase connection if the annual average for TTHMs is less than or equal to 0.040 mg/L and the annual average for HAA5s is less than or equal to 0.030 mg/L. The sample must be collected from a point in the distribution system reflecting the maximum residence time of the water.(iv) Community and NTNC water systems purchasing water only from a system(s) that is ground water not under the influence of surface water and serving less than 10,000 persons shall collect each year between the months of June and September and have analyzed for TTHMs and HAA5s one sample from a point in the distribution system reflecting the maximum residence time of the water from each purchase connection. The frequency may be reduced to one sample every three years between the months of June and September for each purchase connection if the annual average for TTHMs is less than or equal to 0.040 mg/L and the annual average for HAA5s is less than or equal to 0.030 mg/L for two consecutive years or if the annual average for TTHMs is less than or equal to 0.020 mg/L and the annual average for HAA5s is less than or equal to 0.015 mg/L for one year. The sample must be collected from a point in the distribution system reflecting the maximum residence time of the water in the system.(v) Multiple purchase connections to the same system may be reduced to one set of four samples for surface water or one sample for ground water provided that the system proves to the Department that the purchase connections have the same water quality.7. NTNC systems using a surface source or groundwater under the direct influence of surface water or purchasing surface water or ground water under the direct influence of surface water shall collect each quarter and have analyzed for TTHMs and HAA5s a minimum of one sample representing the maximum residence time in the distribution system for each plant and purchase connection.8. Systems on a reduced monitoring schedule may remain on the reduced schedule as long as the annual average of all samples collected in the previous four quarters (for systems that monitor quarterly) or the result of a sample (for systems which that annually or less frequently) is no more than 0.060 mg/L and 0.04 5 mg/L for TTHMs and HAA5, respectively. In addition, the source water TOC running annual average for a surface water or ground water under the influence of surface water must be = 4.0 mg/L. Systems that do not meet these levels must resume monitoring at the initial monitoring frequency in the quarter immediately following the quarter in which the system exceeds 0.060 mg/L and 0.04 5 mg/L for TTHMs and HAA5, respectively. For systems using only ground water not under the influence of surface water and serving fewer than 10,000 persons, if either the TTHM annual average is [Greater Than] 0.080 mg/L or the HAA5 annual average is [Greater Than] 0.060 mg/L the system must begin quarterly monitoring in the quarter immediately following the monitoring period in which the system exceeded 0.080 mg/L for TTHM or 0.060 mg/L for HAA5.9. Multiple wells drawing water from a single aquifer may be considered one treatment plant for determining the minimum number of samples required for TTHM and HAA5 analysis.10. All samples must be collected during periods of normal operating conditions.11. Should a community or NTNC water system make significant modification to the existing treatment process for the purpose of achieving compliance with TTHM standards, the system must submit an engineering report demonstrating that the treatment changes will allow the system to continue to meet bacteriological standards and that the quality of the water will not be adversely impacted by the treatment change.12. Upon exceeding the MCL, the system will be required to submit a schedule to either establish a treatment process using the EPA approved best available technology, specified in 40 CFR 141.64(a)(2) or (b)(1)(ii) as applicable, to achieve compliance with the MCL or cease using the source of supply in conjunction with a Department issued compliance schedule.13. If providing water to a consecutive system(s), the maximum and average residence time TTHM and HAA5 sample locations must reflect the entire distribution system including the consecutive system(s) that utilize water produced by the plant being sampled until December 31, 2006.14. Non-compliance with the TTHM and HAA5 MCL will occur when the running annual average of four consecutive quarterly analyses exceeds the MCL for systems that are sampling quarterly. For systems that have not completed the first four quarters of monitoring, should any individual quarter average cause the running annual average of that system to exceed the MCL, the system is in non-compliance at the end of that quarter. For systems monitoring less frequently than quarterly, compliance must be based on an average of samples collected that year. Systems on a reduced monitoring schedule whose annual average exceeds the MCL will not be considered in violation of the MCL until they have completed one year of routine monitoring. If a system on quarterly monitoring fails to complete four quarters' monitoring, compliance with the MCL for the last four-quarter compliance period must be based on an average of the available data.(i) Upon exceeding the MCL, the system will be required to submit a schedule to either establish a treatment process using the EPA approved best available technology, specified in 40 CFR 141.64(a)(2) or (b)(1)(ii) as applicable, to achieve compliance with the MCL or cease using the source of supply in conjunction with a Department issued compliance schedule.(j) Compliance dates. Surface water or ground water under the influence of surface water systems serving 10,000 or more persons must comply with this rule beginning January 1, 2002. Surface water or ground water under the influence of surface water systems serving fewer than 10,000 persons and systems using only ground water not under the direct influence of surface water must comply with this rule beginning January 1, 2004.(k) Analytical Methods: Analysis of all samples for compliance with MCLs contained in this rule shall comply with the approved EPA methodology found in 40 CFR 141.131 and by a laboratory certified by EPA or the Department.Ala. Admin. Code r. 335-7-2-.11
New Rule: Filed December 18, 2007; effective January 22, 2008. Amended: Filed April 21, 2009; effective May 26, 2009. Amended: Filed December 14, 2010; effective January 18, 2 011.Author: Dennis D. Harrison
Statutory Authority:Code of Ala. 1975, §§ 22-23-33, 22-23-49, 22-22A-5, 22-22A-6.