Alabama Administrative Code › Title 335 - ALABAMA DEPARTMENT OF ENVIRONMENTAL MANAGEMENT › WATER DIVISION - WATER SUPPLY PROGRAM › Chapter 335-7-2 - PRIMARY DRINKING WATER STANDARDS › Section 335-7-2-.11 - Stage 1 Disinfection Byproducts

Current through Register Vol. 42, No. 9, June 28, 2024
Community 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:
CONTAMINAN
T
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.