Part 5, Subpart 5-1 Public Water Systems - Tables

Notice

The information contained on this website is not the official version of the Compilation of the Rules and Regulations of the State of New York (NYCRR). No representation is made as to its accuracy. To ensure accuracy and for evidentiary purposes, reference should be made to the Official Compilation of the Rules and Regulations of the State of New York, available from West Publishing at 1-800-344-5009.

Table 1. Inorganic Chemicals and Physical Characteristics
Maximum Contaminant Level Determination
Contaminants MCL (mg/l) 4 Determination of MCL violations
Asbestos

7.0 million fibers/liter (MFL)
(longer than 10 microns)


If the results of a monitoring sample analysis exceed the MCL, the supplier of water shall collect one more sample from the same sampling point within 2 weeks or as soon as practical.

An MCL violation for all contaminants listed in this table, except for Arsenic, occurs when the average1 of the initial sample and any confirmation sample exceeds the MCL.

MCL violations for Arsenic will be determined as follows:

Compliance with the Arsenic MCL shall be determined based on the analytical result(s) obtained at each sampling point.

For systems which are conducting monitoring at a frequency greater than annual, an Arsenic MCL violation occurs when the running annual average7,8,9 at any sampling point is greater than the MCL. If any one sample would cause the annual average to exceed the MCL at any sampling point, the system is out of compliance with the MCL immediately.

Systems monitoring annually or less frequently whose sample result exceeds the Arsenic MCL7 must begin quarterly sampling10. The system will not be considered in violation of the MCL until it has completed one year of quarterly sampling and the running annual average7,8,9 at that sampling point is greater than the Arsenic MCL. If any one sample would cause the annual average to exceed the MCL at any sampling point, the system is out of compliance with the MCL immediately.

Antimony 0.006
Arsenic 0.010
Barium 2.00
Beryllium 0.004
Cadmium 0.005
Chromium 0.10
Cyanide(as free cyanide) 0.2
Mercury 0.002
Selenium 0.05
Silver 0.1
Thallium 0.002
Fluoride 2.2
Chloride 250.0
Iron 0.32
Manganese 0.32
Sodium No designated limits3
Sulfate 250.0
Zinc 5.0
Color 15 Units
Odor 3 Units
Bromate5 0.010 Compliance is based on a running annual average of monthly samples, computed quarterly. If the average of samples covering any consecutive four-quarter period exceeds the MCL, the system is in violation of the MCL and must notify the public.
Chlorite6 1.0 Compliance is based on an average of each three-sample set taken in the distribution system in accordance with Table 8B. If the average exceeds the MCL, the system is in violation of the MCL and must notify the public.
  1. Rounded to the same number of significant figures as the MCL for the contaminant in question.
  2. If iron and manganese are present, the total concentration of both should not exceed 0.5 mg/L. Higher levels may be allowed by the State when justified by the supplier of water.
  3. Water containing more than 20 mg/L of sodium should not be used for drinking by people on severely restricted sodium diets. Water containing more than 270 mg/L of sodium should not be used for drinking by people on moderately restricted sodium diets.
  4. mg/L = milligrams per liter
  5. Community and nontransient noncommunity systems using ozone for disinfection or oxidation must comply with the bromate standard. Systems using surface water or ground water under the direct influence of surface water and serving 10,000 or more people must comply by January 1, 2002. Systems using surface water or ground water under the direct influence of surface water and serving fewer than 10,000 people, or systems using ground water must comply by January 1, 2004.
  6. Community and nontransient noncommunity systems using chlorine dioxide as a disinfectant or oxidant must comply with the chlorite standard. Systems using surface water or ground water under the direct influence of surface water and serving 10,000 or more people must comply by January 1, 2002. Systems using surface water or ground water under the direct influence of surface water and serving fewer than 10,000 people, or systems using ground water must comply by January 1, 2004.
  7. Arsenic sampling results shall be reported to the nearest 0.001 mg/L.
  8. Any sample below the method detection limit shall be calculated at zero for the purpose of determining the annual average. If a system fails to collect the required number of samples, compliance (average concentration) will be based on the total number of samples collected.
  9. If confirmation samples are collected, the average of the initial sample and any confirmation samples will be used for the determination of compliance and future monitoring requirements.
  10. Systems are only required to conduct the increased monitoring frequency at the sampling point where the MCL was exceeded and for only the specific contaminant(s) that triggered the system into the increased monitoring frequency.
Table 2 - Nitrate, Nitrite, Total Nitrate/Nitrite
Maximum Contaminant Level Determination
Contaminants MCL (mg/L) Determination of MCL violation
Nitrate 10 (as Nitrogen)1

If the results of a monitoring sample analysis exceed the MCL, the supplier of water shall collect another sample from the same sampling point, within 24 hours of the receipt of results or as soon as practical.2 An MCL violation occurs when the average of the two results exceeds the MCL.

Nitrite 1 (as Nitrogen)
Total Nitrate and Nitrite 10 (as Nitrogen)
  1. An MCL of 20 mg/L may be permitted at a noncommunity water system if the supplier of water demonstrates that:
    1. the water will not be available to children under six months of age;
    2. a notice that nitrate levels exceed 10 mg/L and the potential health effects of exposure will be continuously posted according to the requirements of a Tier 1 notification;
    3. the State will be notified annually of nitrate levels that exceed 10 mg/L; and
    4. no adverse health effects shall result.
  2. Systems unable to collect an additional sample within 24 hours must issue a Tier 1 notification and must collect the additional sample within two weeks of receiving the initial sample results.
Table 3. Organic Chemicals
Maximum Contaminant Level Determination
Contaminants MCL (mg/L) Type of water system Determination of MCL Violation
General organic chemicals Principal organic contaminant (POC) 0.005 Community, NTNC and Noncommunity If the results of a monitoring sample analysis exceed the MCL, the supplier of water shall collect one to three more samples from the same sampling point, as soon as practical, but within 30 days. An MCL violation occurs when at least one of the confirming samples is positive and the average of the initial sample and all confirming samples exceeds the MCL.
Unspecified organic contaminant (UOC) 0.05
Total POCs and UOCs 0.1
Disinfection byproducts1,2 Total trihalomethanes 0.08 Community and NTNC The results of all analyses per quarter must be arithmetically averaged and must be reported to the State within 30 days of the public water system's receipt of the analyses. A violation occurs if the average of the four most recent sets of quarterly samples (12-month running average) exceeds the MCL. If a system fails to complete four consecutive quarters of monitoring, compliance with the MCL will be based on an average of the available data. For systems monitoring less than quarterly, compliance must be based on an average of samples taken that year. If, during the first year of monitoring, any individual quarter's average will cause the annual average of that system to exceed the MCL the system is out of compliance at the end of that quarter.
Haloacetic acids 0.06
  Transient noncommunity Not applicable.
Specific Organic Chemicals Alachlor 0.002 Community, NTNC and Noncommunity If the results of a monitoring sample analysis exceed the MCL, the supplier of water shall collect one to three more samples from the same sampling point, as soon as practical, but within 30 days. An MCL violation occurs when at least one of the confirming samples is positive and the average of the initial sample and all confirming samples exceeds the MCL.
Aldicarb 0.003
Aldicarb sulfone 0.002
Aldicarb sulfoxide 0.004
Atrazine 0.003
Benzo(a)pyrene 0.0002
Carbofuran 0.04
Chlordane 0.002
Di(2-ethylhexyl)phthalate 0.006
Dibromochloropropane(DBCP) 0.0002
2,4-D 0.05
Dinoseb 0.007
Diquat 0.02
Endrin 0.002
Ethylene dibromide(EDB) 0.00005
Heptachlor 0.0004
Heptachlor epoxide 0.0002
Hexachlorobenzene 0.001
Lindane 0.0002
Methoxychlor 0.04
Methyl-tertiary-butyl-ether(MTBE) 0.010
Pentachlorophenol 0.001
Polychlorinated biphenyls(PCBs) 0.0005
Propylene glycol 1.0
Simazine 0.004
Toxaphene 0.003
2,4,5-TP (Silvex) 0.01
2,3,7,8-TCDD (dioxin) 0.00000003
Vinyl chloride 0.002
  1. Systems using surface water or ground water under the direct influence of surface water and serving 10,000 or more people must comply with the disinfection byproducts standards by January 1, 2002. Systems using surface water or ground water under the direct influence of surface water and serving fewer than 10,000 people, or systems using ground water must comply by January 1, 2004. Until then, community water systems serving fewer than 10,000 persons must comply with an MCL of 0.1 mg/L for total trihalomethanes.
  2. A system that is installing granular activated carbon (GAC) or membrane technology to comply with the trihalomethane and haloacetic acid MCLs may apply to the State for an extension of up to 24 months past the compliance dates for those MCLs. Systems must comply with any interim measures and schedules of compliance set by the State.
Table 3A. Maximum Residual Disinfectant Leval (MRDL) Determination
Disinfectant MRDL1 (mg/L) Type of Water System Determination of MRDL Violation
Chlorine 4.0 (as Cl2) Community and NTNC using chlorine or chloramines as disinfectant or oxidant Compliance is based on a running annual arithmetic average, computed quarterly, of monthly averages of all samples collected by the system. If the running annual average exceeds the MRDL, the system is in violation and must notify the public.
Chloramines2 4.0 (as Cl2)
Chlorine Dioxide 0.8 (as ClO2) Community, NTNC, and Transient Noncommunity using chlorine dioxide as disinfectant or oxidant Public Health Hazard
(Acute Violation)
Compliance is based on daily samples collected by the system. If any daily sample taken at the entrance to the distribution system exceeds the MRDL, and on the following day one (or more) of the three samples taken in the distribution system exceeds the MRDL, the system is in violation.
Nonacute Violation
Compliance is based on daily samples collected by the system. If any two consecutive daily samples taken at the entrance to the distribution system exceed the MRDL, and all distribution system samples taken are below the MRDL, the system is in violation.
  1. Systems using surface water or ground water under the direct influence of surface water and serving 10,000 or more people must comply by January 1, 2002. Systems using surface water or ground water under the direct influence of surface water and serving fewer than 10,000 people, or systems using ground water must comply by January 1, 2004.
  2. In cases where systems switch between the use of chlorine and chloramines for residual disinfection during the year, compliance must be determined by including together all monitoring results of both chlorine and chloramines.
Table 4. Entry Point Turbidity
Maximum Contaminant Level Determination 1
Contaminant MCL Determination of MCL Violation
Entry point turbidity (surface water and groundwater directly influenced by surface water) 1 NTU2,4 (Monthly Average)

5 NTU3,4

A violation occurs when the average of all daily entry point analyses for the month exceeds the MCL rounded off to the nearest whole number.

A violation occurs when the average of two consecutive daily entry point analyses exceeds the MCL rounded off to the nearest whole number.

  1. The requirements of this table apply to unfiltered systems that the State had determined, in writing pursuant to section 5-1.30 of this Subpart, must install filtration, until filtration is installed.
  2. If the daily entry point analysis exceeds one NTU, a repeat sample must be taken as soon as practicable and preferably within one hour. If the repeat sample exceeds one NTU, the supplier of water must make State notification. The repeat sample must be used for the monthly average and the two consecutive day average.
  3. If the two consecutive day average exceeds the MCL, the supplier of water shall analyze for microbiological contamination at a point downstream of the first consumer, but as close to the first consumer as is feasible. The additional microbiological sample should be taken within one hour as soon as feasible after determining the two consecutive day average. The supplier of water shall report the result of this microbiological analysis to the State within 48 hours of obtaining the result. The result of this analysis shall not be used for monitoring purposes.
  4. NTU = Nephelometric Turbidity Units
Table 4A. Surface Water Turbidity Performance Standards 1
Contaminant Filtration Type Performance Standard1 Determination of Treatment Technique Violation
Filtered water turbidity Conventional filtration and Direct Filtration 0.3 NTU2,4,5 A treatment technique violation occurs if more than five percent of the composite filter effluent measurements taken each month exceed the performance standard values. The turbidity level of representative samples of the filtered water must at no time exceed 1 NTU.4,5
Slow sand filtration 1.0 NTU2 A treatment technique violation occurs if more than five percent of the composite filter effluent measurements taken each month exceed the performance standard values. The turbidity level of representative samples of the filtered water must at no time exceed 5 NTU.
Diatomaceous earth filtration 1.0 NTU2
Alternative filtration 1.0 NTU2, 3
  1. The standards apply to systems with surface water sources or groundwater sources directly influenced by surface water.
  2. NTU= Nephelometric Turbidity Unit
  3. The performance standard applies to alternative filtration technologies capable of complying with requirement of section 5-1.30(b) of this Subpart as demonstrated to the department by pilot studies, unless the department sets a turbidity performance standard for a specific system.
  4. System serving 10,000 or more people must comply by January 1, 2002. If the combined filter effluent turbidity exceeds 1 NTU, the system must consult with the State in accordance with paragraph 5-1.78 (d)(3) of this Subpart.
  5. Systems serving fewer than 10,000 people must comply by January 14, 2005. If the combined filter effluent turbidity exceeds 1 NTU, the system must consult with the State in accordance with paragraph 5-1.78(d)(3) of this Subpart. Until January 14, 2005, the performance standard is 0.5 NTU and the turbidity level of representative samples of the filtered water must at no time exceed 5.0 NTU.
Table 5. Distribution System Turbidity
Maximum Contaminant Level Distribution
Contaminant MCL Determination of MCL Violation
Distribution Point Turbidity 5 NTU A violation occurs when the monthly average of the results of all distribution samples collected in any calendar month exceeds the MCL rounded off to the nearest whole number.
Table 6. Microbiological Contaminants Maximum Contaminant Level (MCL)/Treatment Technique (TT) Violation Determination
Contaminant Sample Location MCL or TT Performance Standard1,2 Determination of MCL/TT Violation
Total coliform Distribution Sample Sites MCL No positive sample4 An MCL violation occurs at systems collecting 40 or more samples per month when more than 5.0 percent of the total coliform samples are positive.
MCL An MCL violation occurs at systems collecting less than 40 samples per month when two or more samples are total coliform positive.
Escherichia coli (E. coli) MCL No positive sample4 An MCL violation occurs when a total coliform positive sample is positive for E. coliand a repeat total coliform sample is positive or when a total coliform positive sample is negative for E. coli but a repeat total coliform sample is positive and the sample is also positive for E. coli.5
Fecal indicator: E. coli, and/or enterococci, and/or coliphage Untreated Water from a Ground Water Source TT No fecal indicator in samples collected from raw source water from a ground water source.6 A TT violation occurs when a raw water sample is positive for the fecal indicator contaminant and system does not provide and document, through process compliance monitoring, 4-log virus treatment during peak flow at first customer. If repeat sampling of the raw water is directed by the State and all additional samples are negative for fecal indicator, there is no TT violation.6
  1. A public water system must comply with the MCL for total coliform each month the system is required to monitor for total coliform.
  2. All samples collected in accordance with Table 11 footnotes 1 and 2 and Table 11B of this section and samples collected in accordance with section 5-1.51(g) of this Subpart shall be included in determining compliance with the MCL unless any of the samples have been invalidated by the State.
  3. For notification purpose, an E. coli MCL violation in the distribution system is a public health hazard reqioromg Tier 1 notification.
  4. See Table 13 for public notification requirements.
  5. If any total coliform or E. Coli sample is positive, repeat samples must be collected in accordance with Table 11B of this section.
  6. If raw water source sample is fecal indicator positive, the water system, in consultation with the State, may collect an additional 5 samples within 24 hours at each source that tested fecal indicator positive. If none of the additional samples are fecal indicator positive, then there is no TT violation. Note that Tier 1 notification must be made after the initial raw water fecal indicator positive sample, even if it is not confirmed.
Table 7. Radiological Maximum Contaminant Level Determination1
Contaminant MCL Type of Water System Determination of MCL Violation2
Combined radium-226 and radium-228

Gross alpha activity (including radium-226 but excluding radon and uranium)

5 picocuries per liter

 
15 picocuries per liter

Community A violation occurs when a sample or the annual average of samples at any sampling point exceeds the MCL3,4,5,6,7.
Uranium 30 micrograms per liter Community A violation occurs when a sample or the annual average of samples at any sampling point exceeds the MCL3,4,5,6,7.
Beta particle and photon radioactivity from manmade radionuclides Four millirems per year as the annual dose equivalent to the total body or any internal organ8. Community Water Systems designated by the State as vulnerable A violation occurs when a sample or the annual average of samples at any sampling point exceeds the MCL3,4,5,7,9,10.
Community systems designated by the State as utilizing waters contaminated by effluents from nuclear facilities. A violation occurs when a sample or the annual average of samples at any sampling point exceeds the MCL3,4,5,7,9,10.
  1. The Radionuclides Rule including the MCLs and minimum monitoring requirements applies only to community water systems.
  2. To judge compliance with the maximum contaminant levels, averages of data shall be used and shall be rounded to the same number of significant figures as the maximum contaminant level for the substance in question.
  3. For systems monitoring more than once per year, compliance with the MCL is determined by a running annual average at each sampling point. If the average of any sampling point is greater than the MCL, then the system is out of compliance with the MCL.
  4. For systems monitoring more than once a year, if any sample result will cause the running average to exceed the MCL at any sample point, e.g., a single sample result is greater than four times of the MCL, the system is out of compliance with the MCL immediately.
  5. If a system does not collect all required samples when compliance is based on a running annual average of quarterly samples, compliance will be based on the running average of the samples collected.
  6. If a sample result is less than the detection limit, zero will be used to calculate the annual average, unless a gross alpha particle activity is being used in lieu of radium-226 and/or uranium. If the gross alpha particle activity result is less than detection and is substituted for radium-226 and/or uranium, 1/2 the detection limit will be used to calculate the annual average.
  7. If the MCL for radionuclides in this Table is exceeded, the community water system must give notice to the State.
  8. A system must determine compliance with the MCL for beta particle and photon radioactivity by using the calculation described below:

    pCi/L found in sample (from laboratory results) divided by the pCi/L equivalent of 4 mrem of exposure equals the fraction of the maximum 4 mrem/year exposure limit

  9. To determine compliance with the MCL, a system must monitor at a frequency as described in Table 12.
  10. If the results show an MCL violation for any of the constituents, the system must conduct monthly monitoring for all species at any sampling point that exceeds the MCL. Monitoring must be conducted in accordance with Table 12 in this section. A system can resume quarterly monitoring if the rolling average of three months of samples is at or below the MCL.
Table 8A. Inorganic Chemicals and Physical Characteristics
Minimum Monitoring Requirements for Asbestos
Contaminant Type of water system Initial frequency by source type5 Repeat sampling and compliance
Groundwater only Surface Only or Surface and Groundwater
Asbestos1 Community and NTNC One sample at entry point by 12/31/95 2,3,4 One sample at entry point by 12/31/95 2,3,4 If GT MCL, one sample quarterly. 6,7

If LT MCL, one sample every nine years.

GT = Greater Than
LT = Less Than

  1. If a system is not vulnerable to asbestos contamination, either at its source or due to corrosion of asbestos cement pipe, it is not required to monitor if granted a waiver by the State. The waiver must be renewed by the State every nine years. The basis for a waiver must include the following:
    1. Lack of potential asbestos contamination of the water source
    2. No use of asbestos cement pipe for finished water distribution and noncorrosive nature of the water.
  2. If asbestos monitoring data collected after January 1, 1990 are consistent with the requirements of this table, the State may allow systems to use that data to satisfy the initial monitoring requirement beginning January 1, 1993.
  3. If a system is vulnerable to asbestos contamination due to source water and corrosion of asbestos cement pipe or solely to corrosion of asbestos cement pipe, it shall take one sample at a tap served by asbestos cement pipe and under conditions where asbestos contamination is most likely to occur.
  4. If a system is vulnerable to asbestos contamination due to source water only, monitoring shall be conducted as follows:
    • Groundwater - Collect a minimum of one sample at every entry point to the distribution system representative of each well after treatment.
    • Surface water - Collect a minimum of one sample at each entry point to the distribution system after any application of treatment or in the distribution system at a point which is representative of each source after treatment.
  5. For both types of water sources the system shall take each sample at the sample sampling point unless conditions make another sampling point more representative of each source or treatment plant. If a system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions when water is representative of all sources.
  6. A system which exceeds the MCL for asbestos shall monitor quarterly beginning in the next quarter after the violation occurred.
  7. State may decrease the quarterly monitoring requirement to the initial sampling requirement provided that the State has determined that the system is reliably and consistently below the MCL on the basis of a minimum of two quarterly groundwater samples and a minimum of four quarterly samples for surface water.
Table 8B. Inorganic Chemicals and Physical Characteristics
Minimum Monitoring Requirements
Contaminant Type of water system Initial frequency of source type3 Accelerated sampling7
Groundwater Only Surface Only or Surface and Ground Water
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Cyanide
Mercury
Nickel
Selenium
Thallium
Fluoride
Community and NTNC1,2,6 One sample per entry point every 3 years by 12/31/958 One sample per entry point per year9 If GT MCL, one sample quarterly. 4,5

If LT MCL, maintain initial frequency.
Transient noncommunity State discretion10 State discretion10 State discretion10
Bromate11 Community and NTNC using ozone for disinfection or oxidation One sample per month at each entry point13, 17 One sample per month at each entry point13, 17 State discretion10
Chlorite12 Community and NTNC using chlorine dioxide for disinfection or oxidation Daily samples at each entry point. Additional three-sample set monthly in the distribution system14, 15, 16, 17 Daily samples at each entry point. Additional three-sample set monthly in the distribution system14, 15, 16, 17 State discretion10
GT = Greater Than
LT = Less Than
  1. A waiver from the required initial monitoring frequencies may be granted by the State, based upon the following conditions:
    1. A minimum of one sample shall be collected while the waiver is effective.
    2. Surface water systems must have monitored annually for at least three years and groundwater systems must have conducted a minimum of three rounds of monitoring with at least one sample taken since January 1, 1990.
    3. All results must be less than the MCL.
    4. New sources are not eligible for a waiver until completion of three rounds of sampling
    5. Waivers issued by the State shall be made in writing, shall cite the basis for determination and shall not exceed a maximum of nine years.
  2. To determine the appropriate reduced monitoring frequency, the State shall consider:
    1. Reported concentrations from all previous monitoring
    2. Variations in reported concentrations; and
    3. other factors which may affect contaminant concentrations such as changes in groundwater pumping rates, changes in the system's configuration, operating procedures, stream flows or other characteristics
  3. For all types of water sources the system shall take each sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant. If a system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions when water is representative of all sources, or separately at the individual sources. The State may allow systems to composite samples in accordance with the conditions in Appendix 5-C. All samples taken and analyzed in accordance with the monitoring plan must be included in determining compliance, even if the number is greater than the minimum required.
  4. The State may decrease the quarterly monitoring requirement to the initial sampling requirement provided that it is determined that the system is reliably and consistently below the MCL on the basis of a minimum of two quarterly groundwater samples and a minimum of four quarterly samples for surface water.
  5. If concentrations of a listed contaminant exceed the MCL, the Department requires the collection of an additional sample as soon as possible but not to exceed two weeks.
  6. The State may require or the water system may request more frequent monitoring frequencies than is minimally required. The State, at its discretion, may require confirmation samples for positive and negative results.
  7. The average of the initial and confirmation sample contaminant concentration at each sampling point shall be used to determine compliance with the MCL.
  8. Systems with fewer than 150 service connections may postpone initial monitoring for antimony, beryllium, cyanide, nickel and thallium until 1998, but no later than three years after conducting its last result set of analysis for arsenic, barium, cadmium, mercury, selenium and fluoride.
  9. Systems with fewer than 150 service connections may postpone initial monitoring for antimony, beryllium, cyanide, nickel and thallium until 1996.
  10. State discretion shall mean requiring monitoring when the State has reason to believe the MCL has been violated, the potential exists for an MCL violation or the contaminant may present a risk to public health.
  11. Community and nontransient noncommunity systems using ozone for disinfection or oxidation must comply with the bromate monitoring requirement. Systems using surface water or ground water under the direct influence of surface water and serving 10,000 or more people must comply by January 1, 2002. Systems using surface water or ground water under the direct influence of surface water and serving fewer than 10,000 people, or systems using ground water must comply by January 1, 2004.
  12. Community and nontransient noncommunity systems using chlorine dioxide as a disinfectant or oxidant must comply with the chlorite monitoring requirement. Systems using surface water or ground water under the direct influence of surface water and serving 10,000 or more people must comply by January 1, 2002. Systems using surface water or ground water under the direct influence of surface water and serving fewer than 10,000 people, or systems using ground water must comply by January 1, 2004.
  13. Systems required to analyze for bromate may reduce monitoring from monthly to once per quarter, if the system demonstrates that the average source water bromide concentration is less than 0.05 mg/L based on representative monthly bromide measurements for one year. A system may remain on reduced bromate monitoring until the running annual average source water bromide concentration, computed quarterly, is equal to or greater than 0.05 mg/L. If the average bromide concentration is equal to or greater than 0.05 mg/L, the system must resume routine monthly bromate monitoring.
  14. On each day following a sample result that exceeds the chlorite MCL at the entrance to the distribution system, the system must take three chlorite distribution system samples at the following locations: as close to the first customer as possible, in a location representative of average residence time, and in a location representative of maximum residence time. The samples comprising the three-sample set required for routine monitoring must be collected at the same three locations in the distribution system that are used when following up on a daily MCL exceedance at the entry point. The system may use results of additional monitoring, conducted as the result of an entry point MCL exceedance, to meet the requirement for routine monthly monitoring.
  15. Daily chlorite monitoring at the entrance to the distribution system may not be reduced. Monthly chlorite monitoring in the distribution system may be reduced to one three-sample set per quarter after one year of monitoring where no individual chlorite sample taken in the distribution system has exceeded the chlorite MCL. If the system has had to conduct distribution system monitoring as a result of an MCL exceedance at the entry point, the system cannot reduce monitoring. The system may remain on a reduced monitoring schedule until either any of the three individual chlorite samples taken quarterly in the distribution system exceeds the chlorite MCL or the system is required to conduct distribution system monitoring because of an entry point chlorite MCL exceedance.
  16. A system must monitor according to its monitoring plan as described in section 5-1.51(c) of this Subpart. Failure to monitor in accordance with the monitoring plan is a monitoring violation.
  17. Failure to monitor will be treated as a monitoring violation for the entire period covered by an annual average where compliance is based on an annual average of monthly or quarterly samples or averages and a system's failure to monitor makes it impossible to determine MCL compliance.
Table 8C. Inorganic Chemicals and Physical Characteristics
Minimum Monitoring Requirements - Nitrates, Nitrites
Contaminant Type of water system Initial frequency of source type1,6 Accelerated sampling7
Groundwater Only Surface Only or Surface and Ground Water
Nitrate Community and Noncommunity2 One sample per entry point per year One sample per entry point quarterly For Groundwater: if equal to or GT 50 percent MCL, quarterly for one year3

For Surface Water: If LT 50 percent MCL, one sample per year3,4
Nitrite Community and Noncommunity One sample per entry point by 12/31/95 One sample per entry point by 12/31/95 If equal to or GT 50 percent MCL, repeat quarterly for at least one year3,4

If LT 50 percent MCL, sample frequency at State discretion5
GT = Greater Than
LT = Less Than
  1. The State may require, or the water system may request, more frequent monitoring frequencies than is minimally required. The State at its discretion may require confirmation samples for positive and negative results.
  2. Noncommunity water systems must sample annually beginning 1/1/93 regardless of the water source.
  3. The frequency may be reduced to annual if the State determines the systems contaminant concentration is consistently and reliably less than the MCL and annual samples are collected during the quarter(s) having the highest analytical results.
  4. A surface water shall return to quarterly monitoring if any one sample is GT 50 percent of MCL.
  5. State discretion shall mean requiring monitoring when the State has reason to believe the MCL has been violated, the potential exists for an MCL violation or the contaminant may present a risk to public health.
  6. For both types of water sources the system shall take each sample at the same sampling point unless conditions make another sampling point more representative of each source or treatment plant. If a system draws water from more than one source and the sources are combined before distribution, the system must sample at an entry point to the distribution system during periods of normal operating conditions when water is representative of all sources.
Table 8D. Inorganic Chemicals and Physical Characteristics
Minimum Monitoring Requirements - Other Chemicals
Contaminant Type of water system Initial frequency of source type Sampling and compliance
Groundwater Only Surface Only or Surface and Ground Water
Chloride


Iron
Manganese
Silver
Sodium1
Sulfate
Zinc
Color
Odor
Community and NTNC State discretion2 State discretion2 State discretion2
  1. All community systems with sodium levels exceeding 20 mg/l will be required to sample for sodium analysis.
  2. State discretion shall mean requiring monitoring when the State has reason to believe the MCL has been violated, the potential exists for an MCL violation or the contaminant may present a risk to public health.
Table 9A. Organic Chemicals - Disinfection Byproducts
Minimum Monitoring Requirements
Surface Water Systems, Ground Water Systems Under the Direct Influence of Surface Water, or Combined Surface and Ground Water Systems
Contaminant Type of Water System Routine Monitoring Frequency1 Reduced Monitoring Frequency Sample Locations in the Distribution System1
Total Trihalomethanes

Haloacetic Acids

Community and NTNC serving at least 10,000 persons2 Four samples per quarter per treatment plant 3,4 One sample per quarter per treatment plant.3,4,5 At least 25% of all samples collected each quarter at locations representing maximum residence time. Remaining samples taken at locations representative of at least average residence time in the distribution system and representing the entire distribution system.6 If monitoring has been reduced, sample must be collected at location reflecting maximum residence time.
Community and NTNC serving 500 to 9,999 persons7 One sample per quarter per treatment plant 3,4 One sample per year per treatment plant during month of warmest water temperature.5 Location representing maximum residence time.6
Community and NTNC serving fewer than 500 persons7 One sample per year per treatment plant collected during the month of warmest water temperature. If the sample (or average of annual samples, if more than one sample is taken) exceeds the MCL, system must increase monitoring to one sample per treatment plant per quarter Cannot reduce monitoring. Location representing maximum residence time.6
Transient Noncommunity State discretion8 State discretion8 State discretion8
Community and NTNC using chemical disinfectant and serving at least 10,000 persons One sample per quarter per treatment plant.3,4,10 One sample per year per treatment plant during month of warmest water temperature.9,10 Locations representing maximum residence time.6
Community and NTNC using chemical disinfectant and serving fewer than 10,000 persons7 One sample per year per treatment plant during month of warmest water temperature.10 If the sample (or average of annual samples, if more than one sample is taken) exceeds the MCL, system must increase monitoring to one sample per treatment plant per quarter, taken at a point reflecting the maximum residence time in the distribution system. One sample every three years per treatment plant.11 Sample must be collected during month of the year with the warmest water temperature. Locations representing maximum residence time.6
Transient Noncommunity State discretion8 State discretion8 State discretion8
  1. A system must monitor according to its monitoring plan as described in section 5-1.51 (c) of this Subpart. Failure to monitor in accordance with the monitoring plan is a monitoring violation.
  2. Effective January 1, 2002.
  3. Failure to monitor will be treated as a monitoring violation for the entire period covered by an annual average where compliance is based on an annual average of monthly or quarterly samples or averages and a system's failure to monitor makes it impossible to determine MCL compliance. If a system fails to complete four consecutive quarters of monitoring, compliance with the MCL will be based on an average of the available data.
  4. If, during the first year of monitoring, any individual quarter's average will cause the annual average of that system to exceed the MCL the system is out of compliance at the end of that quarter.
  5. System may reduce monitoring if at least one year of samples have been collected and the annual average of total THMs is less than or equal to 0.040 mg/L and the annual average of haloacetic acids is less than or equal to 0.030 mg/L. In order to be eligible for reduced monitoring, the source water annual average total organic carbon (TOC) level, before any treatment, must be less than or equal to 4.0 mg/L. Systems on a reduced monitoring schedule may remain on that reduced schedule as long as the average of all samples taken in the year is no more than 0.060 mg/L and 0.045 mg/L for total trihalomethanes and haloacetic acids, respectively. Systems that exceed these levels must resume monitoring at the routine frequency in the quarter immediately following the exceedance.
  6. If a system elects to sample more frequently than the minimum required, at least 25% of all samples collected each quarter (including those taken in excess of the required frequency) must be taken at locations that represent the maximum residence time of the water in the distribution system. The remaining samples must be taken at locations representative of at least average residence time in the distribution system. A system must sample at locations identified in a monitoring plan approved by the State.
  7. Effective January 1, 2004. Until then, monitoring of these systems is at State's discretion.
  8. State discretion shall mean requiring monitoring when the State has reason to believe the MCL has been violated, the potential exists for an MCL violation or the contaminant may present a risk to public health.
  9. System may switch from routine monitoring to reduced monitoring if at least one year of samples have been collected and the annual average of total THMs is less than or equal to 0.040 mg/L and the annual average of haloacetic acids is less than or equal to 0.030 mg/L. Systems on a reduced monitoring schedule may remain on that reduced schedule as long as the result of the sample for the year is no more than 0.060 mg/L and 0.045 mg/L for total trihalomethanes and haloacetic acids, respectively. Systems that exceed these levels must resume quarterly monitoring in the quarter immediately following the exceedance.
  10. The State may allow multiple wells drawing water from a single aquifer to be considered one treatment plant for determining the minimum number of samples required.
  11. System may reduce monitoring if at least one year of samples have been collected and the annual average of total THMs is less than or equal to 0.040 mg/L and the annual average of haloacetic acids is less than or equal to 0.030 mg/L for two consecutive years, or if the annual average of total THMs is less than or equal to 0.020 mg/L and the annual average of haloacetic acids is less than 0.015 mg/L for one year. If a system qualifies for reduced monitoring, the three-year cycle will begin on January 1 following the quarter in which the system qualifies. Systems on a reduced monitoring schedule may remain on that reduced schedule as long as the result of the last sample is no more than 0.060 mg/L and 0.045 mg/L for total trihalomethanes and haloaceteric acids, respectively. Systems that exceed these levels must resume yearly monitoring in the year immediately following the exceedance.
Table 9B. Organic Chemicals - POCs, Vinyl Chloride, Methyl-tertiary-butyl-ether (MTBE), UOCs, Propylene Glycol
Minimum Monitoring Requirements
Contaminant Type of Water System Initial Requirement1 Continuing Requirement Where Detected1 Continuing Requirement Where not Detected and Vulnerable to Contamination1 Continuing Requirement Where not Detected and Invulnerable to Contamination1
Principal Organic Contaminants listed on Table 9D and Vinyl chloride and Methyl-tertiary-butyl-ether (MTBE)7 Community and Nontransient Noncommunity serving 3,300 or more persons If not sampled between 1/1/88 and 1/1/92, quarterly sample per source for one year.5 Quarterly2 Annually3 Once every six years4for groundwater sources. State discretion6 for surface water sources.
Community and Nontransient Noncommunity serving fewer than 3,300 persons If not sampled between 1/1/88 and 9/30/93, quarterly sample per source for one year.5 Quarterly2 Annually3 Once every six years4for groundwater sources. State discretion6 for surface water sources.
Noncommunity excluding NTNC State discretion6 State discretion6 State discretion6 State discretion6
Unspecified Organic Contaminants and other POCs not listed on Table 9C or 9D and Propylene glycol Community and Noncommunity State discretion6 State discretion6 State discretion6 State discretion6
  1. The location for sampling of each groundwater source of supply shall be between the individual well and at or before the first service connection and before mixing with other sources, unless otherwise specified by the State to be at the entry point representative of the individual well. Public water systems which rely on a surface water shall sample at points in the distribution system representative of each source or at an entry point or points to the distribution system after any water treatment plant.
  2. The State may decrease the quarterly monitoring requirement to annually provided that the system is reliably and consistently below the MCL based on a minimum of two quarterly samples from a groundwater source and four quarterly samples from a surface water source. Systems which monitor annually must monitor during the quarter which previously yielded the highest analytical result.
  3. The State may reduce the frequency of monitoring of a groundwater source to once every three years for a public water system which has three consecutive annual samples with no detection of a contaminant.
  4. The State may determine that a public water system is invulnerable to a contaminant or contaminants after evaluating every three years the following factors:
    1. Knowledge of previous use (including transport, storage, or disposal) of the contaminant within the watershed or zone of influence of the system. If a determination by the State reveals no previous use of the contaminant within the watershed or zone of influence, a waiver can be granted.
    2. If previous use of the contaminant is unknown or it has been used previously, then the following factors shall be used to determine whether a waiver can be granted.
      1. Previous analytical results.
      2. The proximity of the system to a potential point or nonpoint source of contamination. Point sources include spills and leaks of chemicals at or near a water treatment facility or at manufacturing, distribution, or storage facilities, or from hazardous and municipal waste landfills and other waste handling or treatment facilities.
      3. The environmental persistence and transport of the contaminants.
      4. The number of persons served by the public water system and the proximity of a smaller system to a larger system.
      5. How well the water source is protected against contamination, such as whether it is a surface or groundwater system. Groundwater systems must consider factors such as depth of the well, the type of soil, and wellhead protection. Surface water systems must consider watershed protection.
  5. The State may reduce the initial monitoring requirement to one sample if the State determines that the system is invulnerable in accordance with footnote 4.
  6. State discretion shall mean requiring monitoring when the State has reason to believe the MCL has been violated, the potential exists for an MCL violation or the contaminant may present a risk to public health.
  7. The initial requirement does not apply to MTBE monitoring
Table 9C. Organic Chemicals - Pesticides, Dioxin, PCBs
Minimum Monitoring Requirements
Contaminant Type of Water System Initial Requirement1,2 Continuing Requirement Where Detected2,3,9,10 Continuing Requirement Where not Detected2
Group 1 Chemicals

Alachlor
Aldicarb
Aldicarb sulfoxide
Aldicarb sulfone
Atrazine
Carbofuran
Chlordane
Dibromochloropropane
2,4-D
Endrin
Ethylene Dibromide
Heptachlor
Heptachlor epoxide
Lindane
Methoxychlor
Polychlorinated
biphenyls
Pentachlorophenol
Toxaphene
2,4,5-TP (Silvex)
Group 2 Chemicals

Aldrin
Benzo(a)pyrene
Butachlor
Carbaryl
Dalapon
Di(2-ethylhexyl)adipate
Di(2-ethylhexyl)phthalate
Dicamba
Dieldrin
Dinoseb
Diquat
Endothall
Glyphosate
Hexachlorobenzene
Hexachlorocyclopentadiene
3-Hydroxycarbofuran
Methomyl
Metolachlor
Metribuzin
Oxamyl vydate
Picloram
Propachlor
Simazine
2,3,7,8-TCDD (Dioxin)
Community and Nontransient Noncommunity serving 3,300 or more persons9 Quarterly sample per source, for one year by 12/31/934 Quarterly One sample every eighteen months per source5,6,7
Community and Nontransient Noncommunity serving fewer than 3,300 persons and more than 149 service connections Quarterly samples per entry point, for one year by 12/31/945,6,7 Quarterly Once per entry point every three years5,6,7
Community and Nontransient Noncommunity serving fewer than 3,000 persons and fewer than 150 service connections Quarterly samples per entry point for one year by 12/31/95 for Group 1 and 12/31/98 for Group 25,6,7 Quarterly Once per entry point every three years5,6,7
Noncommunity excluding NTNC State discretion8 State discretion8 State discretion8
  1. If monitoring data collected after January 1, 1990 are consistent with the requirements of Appendix 5-C then the State may allow systems to use that data to satisfy the initial requirement. Systems serving a population of less than 3,300 persons shall not be required to collect additional quarterly monitoring for a specific contaminant or contaminants, if monitoring for only one quarter prior to October 1, 1993 did not detect the presence of such contaminant or contaminants.
  2. The location for sampling of each groundwater source of supply shall be between the individual well and at or before the first service connection and before mixing with other sources, unless otherwise specified by the State to be at the entry point representative of the individual well. Public water systems which take water from a surface water body or watercourse shall sample at points in the distribution system representative of each source or at entry point or points to the distribution system after any water treatment plant.
  3. The State may decrease the quarterly monitoring requirement to annually provided that system is reliably and consistently below the MCL based on a minimum of two quarterly samples from a groundwater source and four quarterly samples from a surface water source. Systems which monitor annually must monitor during the quarter that previously yielded the highest analytical result. Systems serving fewer than 3,300 persons and which have three consecutive annual samples without detection may apply to the State for a waiver in accordance with footnote 6.
  4. The State may allow a system to postpone monitoring for a maximum of two years, if an approved laboratory is not reasonably available to do a required analysis within the scheduled monitoring period.
  5. The State may waive the monitoring requirement for a public water system that submits information every three years to demonstrate that a contaminant or contaminants was not used, transported, stored or disposed within the watershed or zone of influence of the system.
  6. The State may reduce the monitoring requirement for a public water system that submits information every three years to demonstrate that the public water system is invulnerable to contamination. If previous use of the contaminant is unknown or it has been used previously, then the following factors shall be used to determine whether a waiver is granted.
    1. Previous analytical results.
    2. The proximity of the system to a potential point or nonpoint source of contamination. Point sources include spills and leaks of chemicals at or near a water treatment facility or at manufacturing, distribution, or storage facilities, or from hazardous and municipal waste landfills and other waste handling or treatment facilities. Nonpoint sources include the use of pesticides to control insect and weed pests on agricultural areas, forest lands, home and gardens, and other land application uses.
    3. The environmental persistence and transport of the pesticide or PCBs.
    4. How well the water source is protected against contamination due to such factors as depth of the well and the type of soil and the integrity of the well casing.
    5. Elevated nitrate levels at the water supply source.
    6. Use of PCBs in equipment used in production, storage or distribution of water.
  7. The State may allow systems to composite samples in accordance with the conditions in Appendix 5-C of this Title.
  8. State discretion shall mean requiring monitoring when the State has reason to believe the MCL has been violated, the potential exists for an MCL violation or the contaminant may present a risk to public health.
  9. If a contaminant is detected, repeat analysis must include all analytes contained in the approved analytical method in Appendix 5-C of this Title for the detected contaminant.
  10. Detected as used in the table shall be defined as reported by the State approved laboratory to be greater than or equal to the method detection levels as specified in Appendix 5-C of this Title.
Table 9D. Organic Chemicals - POCs
Minimum Monitoring Requirements
Contaminant Specific Contaminants for analysis
POCs Benzene1
Bromobenzene
Bromochloromethane
Bromomethane
N-Butylbenzene
Sec-Butylbenzene
Tert-Butylbenzene
Carbon Tetrachloride1
Chlorobenzene
Chloroethane
Chloromethane
2-Chlorotoluene
4-Chlorotoluene
Dibromomethane
1,2-Dichlorobenzene1
1,3-Dichlorobenzene
1,4-Dichlorobenzene1
Dichlorodifluoromethane
1,1-Dichloroethane
1,2-Dichloroethane1
1,1-Dichloroethene1
cis-1,2-Dichloroethene1
trans-1,2-Dichloroethene1
1,2-Dichloropropane1
1,3-Dichloropropane
2,2-Dichloropropane
1,1-Dichloropropene
cis-1,3-Dichloropropene
Trans-1,3-Dichloropropene
ethylbenzene1
hexachlorobutadiene
Isopropylbenzene
p-Isopropyltoluene
Methylene Chloride1
n-Propylbenzene
Styrene1
1,1,1,2-Tetrachloroethane
1,1,2,2-Tetrachloroethane
Tetrachloroethene1
Toluene1
1,2,3-Trichlorobenzene
1,2,4-Trichlorobenzene1
1,1,1-Trichloroethane1
1,1,2-Trichloroethane1
Trichloroethene1
Trichlorofluoromethane
1,2,3-Trichloropropane
1,2,4-Trimethylbenzene
1,3,5-Trimethylbenzene
m-Xylene1
o-Xylene1
p-Xylene1
  1. Notification must contain mandatory health effect language.
Table 10. Turbidity
Minimum Monitoring Requirements1
Contaminant Source Type Surface Only, Surface and Groundwater
or Groundwater Directly Influenced
by Surface Water
Type of Water System Groundwater Only
Entry point turbidity Community State discretion2 Collect and analyze one sample per day from each entry point. All results must be recorded to two significant figures.
Noncommunity State discretion2 Collect and analyze one sample annually. Monitoring requirement may be increased at State discretion.2
Distribution point turbidity Community State discretion2 Five distribution samples each week unless otherwise determined by the State. No two samples may be obtained on the same day and no two samples are to be collected from the same distribution point during the week.
Noncommunity State discretion2 State discretion2
  1. The requirements of this table apply to unfiltered systems that the State has determined, in writing pursuant to section 5-1.30 of this Subpart, must install filtration. These requirements only apply until filtration is installed.
  2. State discretion shall mean requiring monitoring when the State has reason to believe the MCL has been violated, the potential exists for an MCL violation or the contaminant may present a risk to public health.
Table 10A. Turbidity
Minimum Monitoring Requirements1
Contaminant Type of water system Source type
Groundwater Surface Water1
Filtered Water Turbidity Community and Noncommunity Not applicable Continuous monitoring for composite filter effluent and individual filters.2,3,4,5
Raw water turbidity Unfiltered surface: Community and Noncommunity Not applicable Every four hours or continuous monitoring. 5
Distribution point turbidity Community State discretion 6 Five distribution samples each week unless otherwise determined by the State. No two samples may be obtained on the same day and no two samples are to be collected from the same distribution point during the same week.
Noncommunity State discretion 6 State discretion 6
  1. Surface water sources or groundwater sources directly influenced by surface water.
  2. Effective January 1, 2002 systems serving 10,000 or more people must record the results of individual filter monitoring every fifteen minutes, and combined filter effluent every four hours. Effective January 14, 2005 systems serving fewer than 10,000 persons must record the results of individual filter monitoring every fifteen minutes, and combined filter effluent every four hours. Until January 14, 2005, systems serving fewer than 10,000 persons must continuously monitor the composite filter effluent turbidity, or record the turbidity every four hours. The state may allow systems with two filters to monitor the combined filter effluent continuously (recording every 15 minutes) in lieu of monitoring individual filter turbidity. Results of individual filter monitoring must be maintained for at least three years.
  3. If there is a failure in the continuous turbidity monitoring equipment, the system must conduct grab sampling every four hours instead of continuous monitoring, but for no more than five working days following the failure of the equipment.
  4. For systems using slow sand filtration or filtration treatment, other than conventional treatment, direct filtration or D.E. filtration, the State may reduce sampling frequency to once per day if it determines that less frequent monitoring is sufficient to indicate effective filtration performance.
  5. If a system uses continuous monitoring, it must use the turbidity values recorded every four hours to determine if a treatment technique violation occurs, unless the State has approved in writing a different time interval.
  6. State discretion shall mean requiring monitoring when the State has reason to believe the MCL has been violated, the potential exists for an MCL violation or the contaminant may present a risk to public health.
Table 11 Microbiological
Minimum Monitoring Requirements (Refer to Table 11B following any positive samples) 1,2,3,4
Contaminant Type of water system Number of samples based on population
Population Served Minimum Number of
Samples per Month4
Population Served Minimum Number of Samples per Month4
Total coliform in distribution system5 Community Up to 1,0006 1 59,001 to 70,000 70
1,001 to 2,500 2 70,001 to 83,000 80
2,501 to 3,300 3 83,001 to 96,000 90
3,301 to 4,100 4 96,001 to 130,000 100
4,101 to 4,900 5 130,001 to 220,000 120
4,901 to 5,800 6 220,001 to 320,000 150
5,801 to 6,700 7 320,001 to 450,000 180
6,701 to 7,600 8 450,001 to 600,000 210
7,601 to 8,500 9 600,001 to 780,000 240
8,501 to 12,900 10 780,001 to 970,000 270
12,901 to 17,200 15 970,001 to 1,230,000 300
17,201 to 21,500 20 1,230,001 to 1,520,000 330
21,501 to 25,000 25 1,520,001 to 1,850,000 360
25,001 to 33,000 30 1,850,001 to 2,270,000 390
33,001 to 41,000 40 2,270,001 to 3,020,000 420
41,001 to 50,000 50 3,020,001 to 3,960,000 450
50,001 to 59,000 60 3,960,001 or more 480
Noncommunity using surface water or groundwater directly influenced by surface water All Same as community    
Noncommunity using only groundwater not directly influenced by surface water ≤1,000 Quarterly    
>1,000 Same as community
Escherichia coli(E. coli) Community and Noncommunity All Any routine or repeat samples that are Coliform positive must be analyzed for E. coli.4    
Fecal Indicator in Raw Source Water7 All ground water systems unless providing 4-log virus treatment and process compliance monitoring All State discretion8    
  1. Public water supply systems must collect total coliform samples at sites which are representative of water throughout the distribution system and throughout the reporting period according to a written monitoring plan which is subject of State review and revision as described in subdivision 5-1.51(c) of this Subpart.
  2. Public water systems using surface water or groundwater directly influenced by surface water, and which do not provide filtration, must collect and analyze at least one sample for total coliforms near the first service connection each day the turbidity level of the raw water exceeds 1.49 NTU. This sample shall be collected within 24 hours. Results of this sample must be included in determining compliance with the Maximum Contaminant Level (MCL) of total coliforms in Table 6 of this section.
  3. Samples taken to determine disinfection practices after pipe repair, replacement, etc. are not to be used for determining MCL compliance for total coliforms in Table 6 of this section.
  4. See Table 11B for repeat sampling requirements following any total coliform or E. Coli positive samples.
  5. If chlorine or chloramines are used as the disinfectant, a chlorine residual determination shall be made at the same time and location that the sample is collected for total coliform analysis. Monitoring for heterotrophic bacteria may be substituted for free chlorine residuals. A heterotrophic plate count result equal to or less than 500 colonies per milliliter is considered to be equivalent to a measurable free chlorine residual.
  6. The State may, in writing, reduce the monitoring frequency to quarterly for a community water system serving 1,000 or fewer persons if the system has no history of total coliform contamination and a sanitary survey conducted in the past five years shows that the system is supplied solely by a protected groundwater source and the system and groundwater source are free of sanitary defects. Systems that have been granted a disinfection waiver are not eligible for reduced monitoring frequency.
  7. Fecal indicators include Escherichia coli (E. coli), enterococci, and coliphage. Only E. coli testing will be required, unless otherwise directed by the State.
  8. State discretion shall mean that monitoring is required when the State has reason to believe the Maximum Contaminant Level or Treatment Technique (MCL/TT) has been violated, the potential exists for an MCL/TT violation or the contaminant may present a risk to public health.
Table 11A. Microbiological/Filtration Avoidance Criteria
Minimum Monitoring Requirements1
Contaminant2 Type of Water System Population Served Minimum Number
of Samples
per Week3,4
Raw water fecal or total coliform Community and Noncommunity Up to 500
501 to 3,300
3,301 to 10,000
10,001 to 25,000
25,001 or more
1
2
3
4
5
  1. The monitoring requirement applies to surface water sources and groundwater sources directly influenced by surface water.
  2. Either fecal or total coliform density measurements are acceptable. If both analyses are performed, the fecal coliform results will take precedence.
  3. Monitoring sampling must be performed on separate days.
  4. Samples must be taken and analyzed every day the system serves water to the public and the turbidity of the raw water exceeds 1.49 NTU. The samples count toward the weekly sampling requirement.
Table 11B Repeat Microbiological Sampling Requirements following Total Coliform Positive and/or Fecal Indicator Positive Sample(s)1
Type of Positive Sample Type of Water System/Source System Size Number of Repeat Samples Required within 24 hours of notification Sampling Location Required action for positive repeat samples
Routine total coliform sample(s) from distribution system positive Surface water, GWUDI2, or ground water performing 4-log virus treatment and process compliance monitoring More than one service connection Four distribution system samples The same sampling site where the original coliform-positive sample was collected, one sample within five service connections upstream, one sample within five service connections downstream and one sample taken at random in the distribution system. Distribution sampling must be repeated until total coliform is not detected in repeat samples or it is determined that the MCL has been violated.3
One service connection One distribution system sample4 Original sampling location
Ground water system or ground water source not providing (or not documenting) 4-log virus treatment5 Population >1,000 Four distribution system samples and source water sample(s) collected in accordance with a State-approved sampling plan6 The same distribution system sampling site where the original coliform-positive sample was collected, one sample within five service connections upstream, one sample within five service connections downstream and one sample taken at random in the distribution system. An additional sample must be collected from each raw water source or according to State approved sampling plan.6,7 Distribution sampling must be repeated until total coliform is not detected in repeat samples or it is determined that the MCL has been violated.3
Population ≤1,000 and more than one service connection Four samples, three at specified locations in the distribution system and one sample to characterize raw water quality. Additional raw water samples according to approved sampling plan if multiple sources are in use. 5,8 The same distribution system sampling site where the original coliform-positive sample was collected, one sample within five service connections upstream, and one sample within five service connections downstream. A fourth sample can be taken at random in the distribution system or collected from a single raw water source. An additional sample must be collected from each raw water source or according to State approved sampling plan.6,7,8
One service connection One distribution system sample and source water sample(s) in accordance with a State-approved sampling plan4,6,8 Original sampling location. An additional sample must be collected from each raw water source or according to State approved sampling plan.6,7,8
Wholesale System of any size After notification by consecutive system of total coliform-positive sample6,7,9,11 Collect one raw water sample at each source or in accordance with a State-approved sampling plan.6,7,9 As directed by State10
Source water sample(s) fecal indicator positive7, 10 Ground water system or ground water source not providing or not documenting 4-log virus treatment All Five raw water samples for fecal indicator or immediate corrective action as directed by State6, 9, 11 Fecal indicator sampling from source or sources with initial fecal indicator positive samples6, 7 As directed by State10, 11
  1. After any total coliform positive sample from the distribution system, the system must collect repeat samples on the same day and within 24 hours of being notified.
  2. GWUDI = Ground Water Under the Direct Influence of surface water
  3. The month following repeat sample collection, the system must collect a minimum of five routine distribution system samples. The State may waive, in writing, the requirement to collect five routine samples the next month the system provides water to the public, if the State carries out an onsite visit before the end of the next month and the State determines why the sample was total coliform positive and establishes that the system has corrected the problem. The State cannot waive the requirement to collect five routine samples solely on the basis that all the repeat samples were total coliform negative. Before the end of the next month the system serves water to the public, at least one routine sample to determine compliance with the MCL must be collected by the system as required in Table 11. If the State determines that the system has corrected the problem that allowed the total coliform contamination and if all repeat samples were total coliform negative, only the routine samples will be required the following month.
  4. The sample may be collected in four (4) bottles of equal sample volume taken consecutively from the same tap, or a single bottle four (4) times the minimum sample volume. If E. coliis used as the fecal indicator at a ground water system, a single sample of three (3) times the minimum sample volume or three (3) bottles of minimum required sample volume may be collected consecutively from the tap and the fourth sample collected from the raw water source. This source water sample result must be used to determine compliance with all Table 6 requirements.
  5. If a consecutive system purchasing (or otherwise obtaining) ground water from a wholesale system has a total coliform-positive sample from the distribution system, the system must notify the wholesale system and collect distribution system repeat samples as specified in Table 11B within 24 hours. The wholesale system must collect raw source water sample(s) unless the system provides 4-log virus treatment at peak flow before or at the first customer as confirmed through process compliance monitoring.
  6. Sampling plan requirements are given in subdivision 5-1.51 (c) of this Subpart.
  7. Fecal indicators include E. coli, enterococci and coliphage. Sampling for fecal indicators other than E.coli is at State discretion.
  8. A system with a single well may collect a single raw water sample to serve as both a distribution repeat sample to replace the "at random" location sample and a raw water sample taken following a routine total coliform positive sample, if E. coli is used as the fecal indicator. If this dual-purpose source water sample is collected, the sample result must be used to determine compliance with all Table 6 requirements.
  9. Wholesale system source water sampling requirements are in addition to distribution system sampling requirements for consecutive systems.
  10. In the event of a fecal indicator positive sample from the raw source water, the state must be notified immediately and may require immediate corrective action. In no case will notification be later than 24 hours as described in paragraph 5-1.78(d)(4) of this Subpart.
  11. If a ground water wholesale system does not perform 4-log virus treatment and process compliance monitoring, and has a fecal indicator positive sample from a raw source water, the system must notify any consecutive systems as well as any of its own customers.
Table 12 Radiological Minimum Monitoring Requirements
Contaminant Type of water system Monitoring Requirement1
Initial Reduced Monitoring2,3
Combined Ra-226 and Ra-228, uranium and gross alpha particle activity Community Four consecutive quaterly samples at every entry point before December 31, 2007.4,5,6

One sample every nine years at every entry point when monitoring results are below the detection limit.7,8

One sample every six years at every entry point when monitoring results are at or above the detection limit but below half of the MCL.7,8

One sample every three years at every entry point when monitoring results are above half of the MCL but at or below the MCL.7,8

Noncommunity Not applicable
Beta particle and photon radioactivity from manmade radionuclides Community systems designated by the State as vulnerable9 Quarterly samples for beta particle and annual samples for tritium and Sr-90, beginning within one quarter after being notified by the State.10,11 If the gross beta particle activity minus the naturally occurring K-40 beta particle activity at a sampling point has a running annual average (computed quarterly) less than or equal to 50 pCi/L (screening level), the State may reduce the frequency of monitoring at that sampling point to once every 3 years.14,15
Community systems designated by the State as utilizing waters contaminated by effluents from nuclear facilities9 Quarterly samples for beta emitters and I-131 and annual samples for tritium and Sr-90, beginning within one quarter after being notified by the State.10,11,12,13 If the gross beta particle activity minus the naturally occurring K-40 beta particle activity at a sampling point has a running annual average (computed quarterly) less than or equal to 15 pCi/L (screening level), the State may reduce the frequency of monitoring at that sampling point to once every 3 years.14,15
  1. All radiological samples must be collected at every entry point to distribution systems (EPTDS).
  2. The State may allow systems to reduce the frequency of monitoring based on initial monitoring or historical results as noted in footnote 4 below.
  3. Systems on a reduced monitoring schedule must perform quarterly sampling if a sample result exceeds the MCL.
  4. The State may allow historical monitoring data collected between June 2000 and December 8, 2003 for systems with:

    (1) only one entry point to the distribution system;

    (2) multiple entry points and having appropriate historical monitoring data for each entry point to the distribution system;

    (3) appropriate historical data for a representative point in the distribution system, provided that the State finds that the historical data satisfactorily demonstrate that each entry point to the distribution system is expected to be in compliance based upon the historical data and reasonable assumptions about the variability of contaminant levels between entry points.

  5. The State may waive the final two quarters of initial monitoring for a sampling point if the results of the samples from the previous two quarters are below the detection limit.
  6. If the average of the initial monitoring results for a sampling point is above the MCL, the system must collect and analyze quarterly samples at the sampling point until the system has results from four consecutive quarters that are at or below the MCL.
  7. A gross alpha particle activity measurement may be substituted for the required radium-226 measurement provided that the measured gross alpha particle activity does not exceed 5 pCi/L. A gross alpha particle activity measurement may be substituted for the required uranium measurement provided that the measured gross alpha particle does not exceed 15 pCi/L. The gross alpha measurement shall have a confidence interval of 95% (1.65σ, where σ is the standard deviation of the net counting rate of the sample) for radium-226 and uranium. When a system uses a gross alpha particle activity measurement in lieu of a radium-226 and/or uranium measurement, the gross alpha particle activity analytical result will be used to determine the future monitoring frequency for radium-226 and/or uranium. If the gross alpha particle activity result is less than detection, 1/2 the detection limit can be used to substitute to radium-226 and determine compliance for future monitoring frequency.
  8. Radium-228 measurement can not be substituted by the gross alpha particle activity result.
  9. For systems in the vicinity of a nuclear facility, the State may allow the CWS to utilize environmental surveillance data collected by the nuclear facility in lieu of monitoring the systems entry point(s), where the State determines that such data is applicable.
  10. Systems already designated by the State must continue to sample until the State reviews and either reaffirms or removes the designation.
  11. Quarterly monitoring for gross beta particle activity shall be based on the analysis of monthly samples or the analysis of a composite of three monthly samples.
  12. Annual monitoring for Sr-90 and tritium shall be conducted by means of the analysis of a composite of four consecutive quarterly samples or analysis of four quarterly samples.
  13. For iodine-131, a composite of five consecutive daily samples shall be analyzed once each quarter. As ordered by the State, more frequent monitoring shall be conducted when iodine-131 is identified in the finished water.
  14. Systems must collect all samples for beta emitters, tritium and strontium-90 during the reduced monitoring period.
  15. A system that exceeds the gross beta particle activity minus the naturally occurring potassium-40 beta particle screening level (50 pCi/L for vulnerable systems or 15 pCi/L for systems utilizing waters contaminated by effluents from nuclear facilities), must further analyze the sample for the major radioactive constitutents. The potassium-40 beta particle activity must be calculated by multiplying elemental potassium concentrations in mg/L by a factor of 0.82.
Table 13 - Required Notifications
Contaminant/Situation (Subpart 5-1 citations) Single Sample Exceeds MCL/MRDL MCL/MRDL/TT1 violation Failure to Meet Monitoring Requirements and/or Failure to use Applicable Testing Procedure
Public Health Hazard (section 5-1.1(bc))2 Not applicable State State
Tier 1 Tier 1
Escherichia coli (E. coli)in distribution system (section 5-1.52 tables 6, 11 and 11B) State3 State State
Not applicable, or Tier 14 Tier 1 Tier 35, or Tier 1
E. coli or other fecal indicator detected in ground water source at system not providing both 4-log virus treatment and process compliance monitoring (section 5-1.52 tables 6, 11 and 11B) Tier 12,3,5,6 Tier 16 State
Tier 32,5,7, or Tier 1
Total coliform in distribution system (section 5-1.52 tables 6, 11 and 11B) Not applicable State8 State
Tier 29, or Tier 1 Tier 3, or Tier 2 as directed by State
Entry Point Turbidity monthly average (section 5-1.52 tables 4 and 10) State10 State State
Tier 2 Tier 3
Entry Point Turbidity two day average (section 5-1.52 tables 4 and 10) State State State
Tier 211, or Tier 1 Tier 3
Raw Water Turbidity (subdivision 5-1.30(d) and section 5-1.52 table 10A) State State State
Tier 211, or Tier 1 Tier 3
Filtered Water Turbidity Single exceedance of the maximum allowable Turbidity level (section 5-1.52 tables 4A and 10A) State State State
Tier 211, or Tier 1 Tier 3
Filtered Water Turbidity Treatment Technique violation (section 5-1.52 tables 4A and 10A) Not applicable State State
Tier 2 Tier 3
Distribution Point Turbidity (section 5-1.52 tables 5, 10 and 10A) Not applicable State State
Tier 2 Tier 3
Treatment Technique violations other than turbidity (subdivisions 5-1.12, 5-1.30 and 5-1.71(d))12,13 Not applicable State State
Tier 22,13, or Tier 1 Tier 313
Free chlorine residual less than 0.2 mg/L at the entry point (subdivision 5-1.30(d))14 Not applicable State Not applicable
Free chlorine residual less than required minimum for a ground water system or ground water source required to provide 4-log virus treatment (subdivision 5-1.30(a))15 Not applicable State Tier 2
Tier 29, or Tier 1
Inorganic chemicals and physical characteristics listed in Tables 8A and 8B (section 5-1.52 tables 1, 8A, and 8B) State State State
Tier 2 Tier 3
Chloride, iron, manganese, silver, sulfate, and zinc (section 5-1.52 tables 1 and 8D) Not applicable State State
Tier 3 Tier 3
Sodium (section 5-1.52 tables 1 and 8D) State if the level exceeds 20 mg/L Tier 2 if the level exceeds 270 mg/L Tier 3
Nitrate, Nitrite, Total Nitrate and Nitrite (section 5-1.52 tables 2 and 8C) State State State
Tier 1 Tier 116, or Tier 3
Lead and Copper (sections 5-1.40 to 1.49) Not applicable State State
Tier 2 Tier 3
Organic Chemicals Group 1 and 2 (section 5-1.52 table 9C) State State State
Tier 2 Tier 3
Principal Organic Contaminants, Unspecified Organic Contaminants, Total POCs and UOCs (section 5-1.52 tables 3, 9B and 9D) State State State
Tier 2 Tier 3
Radiological Contaminants (section 5-1.52 tables 7 and 12) State State State
Tier 2 Tier 3
Monitoring and Control of Disinfection Byproduct Precursors (section 5-1.60 to 5-1.64) Not applicable State State
Tier 2 Tier 3
Disinfectant residuals Chlorine and Chloramine (section 5-1.52 tables 3A and 15) State State State
Tier 2 Tier 3
Disinfectant residual Chlorine dioxide At entry point (section 5-1.52 tables 3A and 15) State State State
Tier 2 Tier 317, or Tier 2
Disinfectant residual Chlorine dioxide In distribution system (section 5-1.52 tables 3A and 15) State State State
Tier 118 Tier 118
Disinfection byproducts Trihalomethanes Haloacetic acids (section 5-1.52 tables 3 and 9A) and Bromate and Chlorite (section 5-1.52 tables 1 and 8B) Not applicable State State
Tier 2 Tier 3
Acrylamide and Epichlorohydrin (subdivision 5-1.51(j)) Not applicable State Not applicable
Tier 2
Operation under a variance or exemption Not applicable Tier 3 Not applicable
Violation of conditions of a variance or exemption Not applicable State Not applicable
Tier 2
Disruption of water service of four hours or more (subdivision 5-1.23(b)) Not applicable State19 Not applicable
  1. MCL-maximum contaminant level, MRDL-maximum residual disinfectant level, TT-treatment technique.
  2. Community systems must describe in their annual water supply statement (5-1.72(e)), prepared in accordance with section 5-1.72(f), any Public Health Hazard that is determined to be a violation, or any uncorrected significant deficiency, and indicate whether corrective action is completed. This notice must be repeated every year until the annual report documents that corrective action is completed in accordance with section 5-1.22 of this Subpart.
  3. State notification must be made by the supplier of water within 24 hours of learning of an E. coli positive sample.
  4. Public notification normally does not have to be issued for an E. coli positive sample prior to the results of the repeat samples. However, there may be situations where the State determines that a Tier 1 notification is necessary to protect the public health. The supplier of water must provide the Tier 1 notification no later than 24 hours after learning of the State's determination.
  5. Failure to test for E. coli requires a Tier 1 notification if testing is not done after any repeat sample tests positive for coliform. All other E. coli monitoring and testing procedure violations require Tier 3 notification.
  6. At a ground water system, Tier 1 notification is required after initial detection of E. coli or other fecal indicator in raw source water, if system does not provide 4-log virus treatment and process compliance monitoring. Confirmation of E. coli or other fecal indicator in the source water requires Tier 1 notification. Failure to take confirmatory samples may be a public health hazard requiring Tier 1 notification.
  7. Notice of the fecal indicator positive raw water sample must be made in the annual water supply statement (5-1.72(e)), until the annual report documents that corrective action is completed.
  8. State notification must be made by the supplier of water within 24 hours of learning of the violation.
  9. Tier 2 notification is normally required, however, there may be situations where the State determines that a Tier 1 notification is necessary to protect the public health. The supplier of water must provide the Tier 1 notification no later than 24 hours after learning of the State's determination.
  10. If the daily entry point analysis exceeds one NTU, a repeat sample must be taken as soon as practicable and preferably within one hour. If the repeat sample exceeds one NTU, the supplier of water must make state notification.
  11. Systems must consult with the State within 24 hours after learning of the violation. Based on this consultation, the State may subsequently decide to elevate the violation from a Tier 2 to a Tier 1 notification. If consultation does not take place within the 24-hour period, the water system must distribute a Tier 1 notification no later than 48 hours after the system learns of the violation.
  12. These violations include the following: failure to comply with the treatment technique or monitoring requirements in section 5-1.30(a), (b), (c), and (g) of this Subpart; failure to comply with the avoidance criteria in section 5-1.30(c) of this Subpart; and failure to install filtration or disinfection treatment facilities required by section 5-1.30 of this Subpart; failure to report to the state information required in section 5-1.72(c)(3) of this Subpart; and failure to maintain records required in section 5-1.72(c)(7) of this Subpart.
  13. Any significant deficiency that is not corrected or where correction has not begun according to a State-approved corrective action plan within 120 days, or as directed by the State, is a treatment technique violation and must be addressed in accordance with the requirements in section 5-1.12. If the deficiency is a public health hazard, the deficiency must be addressed as directed by the State and Tier 1 notification is required.
  14. Applies to systems that have surface water or groundwater directly influenced by surface water as a source and use chlorine. The system must make State notification whether the residual was restored to at least 0.2 mg/L within four hours.
  15. Required minimum chlorine residual at point that demonstrates adequate CT for disinfected water from ground water sources at first customer.
  16. Failure to take a confirmation sample within 24 hours for nitrate or nitrite after an initial sample exceeds the MCL requires a Tier 1 notification. Other monitoring violations for nitrate or nitrite require a Tier 3 notification.
  17. Failure to monitor for chlorine dioxide at the entrance to the distribution system the day after exceeding the MRDL at the entrance to the distribution system requires a Tier 2 notification. Other monitoring violations for chlorine dioxide at the entrance to the distribution system require a Tier 3 notification.
  18. If any daily sample taken at the entrance to the distribution system exceeds the MRDL for chlorine dioxide and one or more samples taken in the distribution system the next day exceed the MRDL, Tier 1 notification is required. Failure to take the required samples in the distribution system the day after the MRDL is exceeded at the entry point also triggers Tier 1 notification.
  19. Tier 1 notification is required if the situation meets the definition of a public health hazard.
Table 14A
CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia Lamblia Cysts
by Free Chlorine at 0.5 Degrees Celsius or Lower1
Free chlorine
residual (mg/L)
PH
<=6.0 6.5 7.0 7.5 8.0 8.5 <=9.0
<=0.4 137 163 195 237 277 329 390
0.6 141 168 200 239 286 342 407
0.8 145 172 205 246 295 354 422
1.0 148 176 210 253 304 365 437
1.2 152 180 215 259 313 376 451
1.4 155 184 221 266 321 387 464
1.6 157 189 226 273 329 397 477
1.8 162 193 231 279 338 407 489
2.0 165 197 236 286 346 417 500
2.2 169 201 242 297 353 426 511
2.4 172 205 247 298 361 435 522
2.6 175 209 252 304 368 444 533
2.8 178 213 257 310 375 452 543
3.0 181 217 261 316 382 460 552
  1. These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature, and at the higher pH.
Table 14B
CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia Lamblia Cysts
by Free Chlorine at 5.0 Degrees Celsius1
Free chlorine
residual (mg/L)
PH
<=6.0 6.5 7.0 7.5 8.0 8.5 <=9.0
<=0.4 97 117 139 166 198 236 279
0.6 100 120 143 171 204 244 291
0.8 103 122 146 175 210 252 301
1.0 105 125 149 179 216 260 312
1.2 107 127 152 183 221 267 320
1.4 109 130 155 187 227 274 329
1.6 111 132 158 192 232 281 337
1.8 114 135 162 196 238 287 345
2.0 116 138 165 200 243 294 353
2.2 118 140 169 204 248 300 361
2.4 120 143 172 209 253 306 368
2.6 122 146 175 213 258 312 375
2.8 124 148 178 217 263 318 382
3.0 126 151 182 221 268 324 389
  1. These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature, and at the higher pH.
Table 14C
CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia Lamblia Cysts
by Free Chlorine at 10.0 Degrees Celsius1
Free chlorine
residual (mg/L)
PH
<=6.0 6.5 7.0 7.5 8.0 8.5 <=9.0
<=0.4 73 88 104 125 149 177 209
0.6 75 90 107 128 153 183 218
0.8 78 92 110 131 158 189 226
1.0 79 94 112 134 162 195 234
1.2 80 95 114 137 166 200 240
1.4 82 98 116 140 170 206 247
1.6 83 99 119 144 174 211 253
1.8 86 101 122 147 179 215 259
2.0 87 104 124 150 182 221 265
2.2 89 105 127 153 186 225 271
2.4 90 107 129 157 190 230 276
2.6 92 110 131 160 194 234 281
2.8 93 111 134 163 197 239 287
3.0 95 113 137 166 201 243 292
  1. These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature, and at the higher pH.
Table 14D
CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia Lamblia Cysts
by Free Chlorine at 15.0 Degrees Celsius1
Free chlorine
residual (mg/L)
PH
<=6.0 6.5 7.0 7.5 8.0 8.5 <=9.0
<=0.4 49 59 70 83 99 118 140
0.6 50 60 72 86 102 122 146
0.8 52 61 73 88 105 126 151
1.0 53 63 75 90 108 130 156
1.2 54 64 76 92 111 134 160
1.4 55 65 78 94 114 137 165
1.6 56 66 79 96 116 141 169
1.8 57 68 81 98 119 144 173
2.0 58 69 83 100 122 147 177
2.2 59 70 85 102 124 150 181
2.4 60 72 86 105 127 153 184
2.6 61 73 88 107 129 156 188
2.8 62 74 89 109 132 159 191
3.0 63 76 91 111 134 162 195
  1. These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature, and at the higher pH.
Table 14E
CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia Lamblia Cysts
by Free Chlorine at 20.0 Degrees Celsius1
Free Chlorine
Residual (mg/L)
PH
<=6.0 6.5 7.0 7.5 8.0 8.5 <=9.0
<=0.4 36 44 52 62 74 89 105
0.6 38 45 54 64 77 92 109
0.8 39 46 55 66 79 95 113
1.0 39 47 56 67 81 98 117
1.2 40 48 57 69 83 100 120
1.4 41 49 58 70 85 103 123
1.6 42 50 59 72 87 105 126
1.8 43 51 61 74 89 108 129
2.0 44 52 62 75 91 110 132
2.2 44 53 63 77 93 113 135
2.4 45 54 65 78 95 115 138
2.6 46 55 66 80 97 117 141
2.8 47 56 67 81 99 119 143
3.0 47 57 68 83 101 122 146
  1. These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature, and at the higher pH.
Table 14F
CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia Lamblia Cysts
by Free Chlorine at 25.0 Degrees Celsius and Higher1
Free chlorine
residual (mg/L)
PH
<=6.0 6.5 7.0 7.5 8.0 8.5 <=9.0
<=0.4 24 29 35 42 50 59 70
0.6 25 30 36 43 51 61 73
0.8 26 31 37 44 53 63 75
1.0 26 31 37 45 54 65 78
1.2 27 32 38 46 55 67 80
1.4 27 33 39 47 57 69 82
1.6 28 33 40 48 58 70 84
1.8 29 34 41 49 60 72 86
2.0 29 35 41 50 61 74 88
2.2 30 35 42 51 62 75 90
2.4 30 36 43 52 63 77 92
2.6 31 37 44 53 65 78 94
2.8 31 37 45 54 66 80 96
3.0 32 38 46 55 67 81 97
  1. These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. CT values between the indicated temperatures of different tables may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature, and at the higher pH.
Table 14G
CT Values (CT99.9) for 99.9 Percent Inactivation of Giardia Lamblia Cysts
by Chlorine Dioxide and Ozone1,2
  Degrees Celsuis
<=1 5 10 15 20 >=25
Chlorine dioxide 63 26 23 19 15 11
Ozone 2.9 1.9 1.4 0.95 0.72 0.48
  1. These CT values achieve greater than a 99.99 percent inactivation of viruses. CT values between the indicated pH values may be determined by linear interpolation. If no interpolation is used, use the CT99.9 value at the lower temperature for determining CT99.9 values between indicated temperatures.
  2. The use of these alternative disinfectants shall be approved in accordance with the provisions of section 5-1.22 of this Section.
Table 15. Entry Point Disinfectant Monitoring Frequency for Systems Using Chemical Disinfection1
Water System Source Type Population served Samples per day2
Surface Water or Ground Water under the Direct Influence of Surface Water (GWUDI)2, 3 Up to 500 1
501 - 1,000 2
1,001 - 2,500 3
2,501 - 3,300 4
> 3,300 Continuous monitoring required5
Ground Water System or ground water source required to provide 4-log virus treatment and process compliance monitoring 6, 7, 8 ≤ 3,300 19
> 3,300 Continuous monitoring required5
Ground Water System or ground water source with other than 4-log virus treatment Any 19
  1. See also Table 15A for distribution system disinfectant residual sampling locations and frequency depending on disinfectant used.
  2. If at any time chlorine residual concentration falls below 0.2 mg/L at the entry point for a surface water or GWUDI system, the system must collect and analyze a grab sample every four hours until the chlorine residual concentration is again equal to or greater than 0.2 mg/L.
  3. Entry point samples collected at Surface Water or GWUDI systems
  4. The day's grab samples may not be conducted at the same time.
  5. If there is a failure in the continuous monitoring equipment, grab samples, every four hours, may be conducted in lieu of continuous monitoring, but for no more than five working days (fourteen working days for ground water systems) following the failure of the equipment.
  6. If at any time the disinfectant concentration at a ground water system falls below the minimum required in the process compliance monitoring plan approved by the State, the system must collect and analyze a grab sample every four hours until the disinfectant residual concentration is again at or above minimum required levels, without exceeding other applicable concentration requirements in Table 3A.
  7. Any ground water system required to provide 4-log virus treatment because of fecal contamination of the source or because of significant deficiencies in system operation, and using chemical disinfection, must demonstrate minimum disinfectant residual at a location that demonstrates adequate concentration to provide the required treatment at the first customer during peak flow according to the sampling plan developed for the system. These samples to confirm the minimum disinfection residual are to be collected at the frequency in this table.
  8. Lowest daily concentration must be recorded on operation report.
  9. A minimum of one disinfectant residual concentration must be recorded on operation report every day.
Table 15A. Disinfectant Residual Minimum Distribution System Monitoring Requirements for Systems Using Chemical Disinfection
Disinfectant Type of Water System Routine Monitoring
Chlorine/Chloramines Community and Nontransient Noncommunity Sample at the same time and same points in the distribution system as total coliform sampling1
Chlorine Dioxide2 Community, Nontransient Noncommunity and Transient Noncommunity Daily sample at the entrance to the distribution system3
  1. Community Water Systems using surface water or ground water under the direct influence of surface water may use heterotrophic plate count results of equal to or less than 500 colonies per milliliter as equivalent to a free chlorine residual as outlined in table 11, footnote 5, in lieu of taking separate samples for disinfection residuals
  2. Monitoring is required if chlorine dioxide is used for either oxidation or disinfection.
  3. If the Maximum Residual Disinfectant Level (MRDL) of 0.8 mg/L is exceeded, the system must take three samples in the distribution system on the following day. If chlorine dioxide or chloramines are used to maintain a disinfectant residual in the distribution system, or if chlorine is used and there are no rechlorination stations, the system must take 3 samples as close to the first customer as possible, at intervals of at least 6 hours. If chlorine is used and there is a rechlorination station, the system must take one sample as close to the first customer as possible, one sample representing average residence time, and one sample representing maximum residence time.
Table 16. Additional Contaminants for which Reporting is Required Pursuant to 5-1.72 (e)-(h) of this Subpart
Contaminant Name
2,4-dinitrotoluene
2,6-dinitrotoluene
DCPA monoacid
DCPA di acid
4,4'-DDE
EPTC
Molinate
MTBE
Nitrobenzene
Terbacil
Acetochlor
Perchlorate
Diuron
Linuron
Prometon
2,4,6-trichlorophenol
2,4-dichlorophenol
2,4-dinitrophenol
2-methyl-1-phenol
Alachlor ESA
1,2-diphenylhydrazine
Diazinon
Disulfoton
Fonofos
Terbufos
Aeromonas Hydrophilia
Polonium-210
RDX
Algae and toxins
Echoviruses
Coxsackie viruses
Helicobacter pylori
Microsporidia
Caliciviruses
Adenoviruses
Lead – 210
Napthalene
Table 17. Information Collection Rule Contaminant Reporting Requirements
Contaminant Reporting Requirements for Finished Water
Total Trihalomethanes (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) Report as a group if detected
Haleocetic Acids (mono-, di-, and trichloroacetic acid, and mono- and di-bromoacetic acid) Report as a group if detected
Haloacetilenitriles (dichloro-, trichloro-, bromochloro-, and dibromoacetonitrile) Report as a group if detected
Haloketones (1,1-dichloropropanone and 1,1,1-trichloropropanine) Report as a group if detected
Chloropicrin Reporting required if detected
Chloral Hydrate Reporting required if detected
Total Organic Halides Reporting required if detected
Disinfectant Residual Reporting required if detected
Cyanogen Chloride Report if detected and treatment plant uses Chloramines
Chlorate Report if detected and treatment plant uses Hypochlorite Solutions
Bromate, Aldehydes Report if detected and treatment plant uses Ozone
Chlorine Dioxide residual, Chlorite, Chlorate, Bromate, Aldehydes Report if detected and treatment plant uses Chlorine Dioxide
Total Coliforms Report if detected
Fecal Coliforms or Giardia Lamblia Report if detected
Giardia Report if detected
Total Culturable Viruses Report if detected