Proposed Revised Total Coliform Rule

1. Proposed Revised Total Coliform Rule Proposed RTCR On July 14, 2010, EPA proposed the Revised Total Coliform Rule On July 14, 2010, EPA proposed the Revised Total Coliform Rule (RTCR). The RTCR is, at present time, still a proposed rule. Usually, there is a three year period after a rule is finalized that States and Public Water Systems have before they must be compliant with the regulation. Some estimates on a timeline have the final rule out in the fall of 2012 with implementation starting in 2015. Keep in mind that because this is still a proposed rule, everything in this presentation is subject to change.On July 14, 2010, EPA proposed the Revised Total Coliform Rule (RTCR). The RTCR is, at present time, still a proposed rule. Usually, there is a three year period after a rule is finalized that States and Public Water Systems have before they must be compliant with the regulation. Some estimates on a timeline have the final rule out in the fall of 2012 with implementation starting in 2015. Keep in mind that because this is still a proposed rule, everything in this presentation is subject to change.

2. Core Elements Assessments: Investigate and correct any sanitary defects found Sanitary defect: �a defect that could provide a pathway of entry for microbial contamination into the distribution system or that is indicative of a failure or imminent failure in a barrier that is already in place� Two levels of assessment depending on the severity and frequency of contamination. There are some major differences between the current Total Coliform Rule (TCR) and the Proposed RTCR. I am going to refer to these as the core elements of the RTCR. The first core element is that all water systems may be required to conduct assessments of the water system; source through distribution. If a sanitary defect is found during one of these assessments, it must be corrected in accordance with an approved timeline. The RTCR defines a sanitary defect as: �a defect that could provide a pathway of entry for microbial contamination into the distribution system or that is indicative of a failure or imminent failure in a barrier that is already in place�. There are two levels of assessments depending on the severity and frequency of contamination. I will discuss assessments in more detail in later slides.There are some major differences between the current Total Coliform Rule (TCR) and the Proposed RTCR. I am going to refer to these as the core elements of the RTCR. The first core element is that all water systems may be required to conduct assessments of the water system; source through distribution. If a sanitary defect is found during one of these assessments, it must be corrected in accordance with an approved timeline. The RTCR defines a sanitary defect as: �a defect that could provide a pathway of entry for microbial contamination into the distribution system or that is indicative of a failure or imminent failure in a barrier that is already in place�. There are two levels of assessments depending on the severity and frequency of contamination. I will discuss assessments in more detail in later slides.

3. No MCL/MCLG for TC: TC triggers assessment and corrective action (A/CA). Keeps E. coli with an MCLG of zero and MCL similar to current TCR Core Elements The Proposed RTCR suggests to no longer have a MCL/MCLG for Total Coliform. TC will not have a health based violation associated with it. Under the RTCR, TC is viewed as an indicator of possible contamination. This should make a lot of systems happy. No more violations for too many TC positives and that means there is no PN either. What is currently a TC MCL violation under the TCR will trigger, under the RTCR, the system to conduct an assessment and perform any corrective action required. The RTCR will keep the E. coli MCLG and MCL similar to the current TCR. So, in the RTCR there is no MCL Violation for TC but it does keep the current E. coli MCL violation.The Proposed RTCR suggests to no longer have a MCL/MCLG for Total Coliform. TC will not have a health based violation associated with it. Under the RTCR, TC is viewed as an indicator of possible contamination. This should make a lot of systems happy. No more violations for too many TC positives and that means there is no PN either. What is currently a TC MCL violation under the TCR will trigger, under the RTCR, the system to conduct an assessment and perform any corrective action required. The RTCR will keep the E. coli MCLG and MCL similar to the current TCR. So, in the RTCR there is no MCL Violation for TC but it does keep the current E. coli MCL violation.

4. Core Elements Monitoring requirements: Provides flexibility in the location of sites for repeat samples, and allows the use of dedicated sampling stations Eliminates additional routines for PWSs taking fewer than 5 routine samples The RTCR is less stringent than the TCR in two areas relating to monitoring. The proposed rule will allow for flexibility in the location of the sites systems can choose for repeat samples. The sites chosen to use for repeats can be more than 5 connections up or down stream of the original positive. The proposed rule also mentions dedicated sampling stations as approved collection sites. The RTCR also eliminates the additional routines for PWSs taking fewer than 5 routine samples monthly. This should simplify monitoring for small systems that taker fewer than 5 samples per month. They will no longer have to remember to take 5 samples the month following a positive sample.The RTCR is less stringent than the TCR in two areas relating to monitoring. The proposed rule will allow for flexibility in the location of the sites systems can choose for repeat samples. The sites chosen to use for repeats can be more than 5 connections up or down stream of the original positive. The proposed rule also mentions dedicated sampling stations as approved collection sites. The RTCR also eliminates the additional routines for PWSs taking fewer than 5 routine samples monthly. This should simplify monitoring for small systems that taker fewer than 5 samples per month. They will no longer have to remember to take 5 samples the month following a positive sample.

5. Core Elements Defines �seasonal systems�, requires start-up procedures: Seasonal PWS is defined as: a non-community system that operates 3 or fewer calendar quarters per year must demonstrate completion of a State approved start-up procedure The Proposed RTCR defines a seasonal system. The definition of a seasonal system is �a non-community system that operates 3 or fewer calendar quarters per year�. The proposed rule also requires these seasonal systems to demonstrate that they have completed a State approved start-up procedure before they can open to the public after their off season. The start-up procedure could require seasonal systems to perform maintenance on the plant and storage tanks. The start-up procedure could require hyperchlorination /disinfection of the plant and distribution system followed by flushing to bring the system back to an acceptable chlorine residual. It could also require the systems to perform microbiological testing to demonstrate that the system is free of contamination before the system opens to the public. The Proposed RTCR defines a seasonal system. The definition of a seasonal system is �a non-community system that operates 3 or fewer calendar quarters per year�. The proposed rule also requires these seasonal systems to demonstrate that they have completed a State approved start-up procedure before they can open to the public after their off season. The start-up procedure could require seasonal systems to perform maintenance on the plant and storage tanks. The start-up procedure could require hyperchlorination /disinfection of the plant and distribution system followed by flushing to bring the system back to an acceptable chlorine residual. It could also require the systems to perform microbiological testing to demonstrate that the system is free of contamination before the system opens to the public.

6. Assessments Level 1 vs. Level 2 Elements of Assessments Corrective Actions The major change when the RTCR is implemented is there will no longer be MCL violations associated with TC. Instead systems will be required to perform assessments in response to what was a TC MCL under the TCR. There are two levels of assessment. The level required is dependant on the severity and/or frequency of contamination. There is already a draft document that will help systems conduct these assessments. It is a checklist that covers the basic elements that EPA suggests systems assess. Once the assessment is complete, if anything was discovered, the required corrective actions will need to be completed according to an approved corrective action plan.The major change when the RTCR is implemented is there will no longer be MCL violations associated with TC. Instead systems will be required to perform assessments in response to what was a TC MCL under the TCR. There are two levels of assessment. The level required is dependant on the severity and/or frequency of contamination. There is already a draft document that will help systems conduct these assessments. It is a checklist that covers the basic elements that EPA suggests systems assess. Once the assessment is complete, if anything was discovered, the required corrective actions will need to be completed according to an approved corrective action plan.

7. Level 1 Assessments Triggers: If collect at least 40 samples per month, more than 5% of samples collected are TC (P) If collect fewer than 40 samples per month, more than one sample is TC (P) If the PWS fails to take every required repeat sample after any single routine TC (P) The triggers for a level one assessment are very similar to the current TCR TC MCL trigger: If collect at least 40 samples per month and more than 5% of samples collected are TC (P) If collect fewer than 40 samples per month and more than one sample is TC (P) If the PWS fails to take every required repeat sample after any single routine TC (P) The triggers for a level one assessment are very similar to the current TCR TC MCL trigger: If collect at least 40 samples per month and more than 5% of samples collected are TC (P) If collect fewer than 40 samples per month and more than one sample is TC (P) If the PWS fails to take every required repeat sample after any single routine TC (P)

8. Level 1 Assessments Assessment: Conducted by the PWS A basic examination of the source water, treatment, distribution system and relevant operational practices The level one assessment is a relatively basic examination of the source water, treatment, distribution system, and relevant operational practices. The level one assessment can be conducted by the PWS. Many water systems are currently conducting portions of this assessment when they respond to positive TC samples. Examples of statements I have heard from systems that call in about positive results are: the sampling location was not in good condition, or the building had recently had the plumbing worked on, or the sample site is on a dead end and it is not used enough to be a good representation of the distribution system. These are all examples of things that can be noted during an assessment.The level one assessment is a relatively basic examination of the source water, treatment, distribution system, and relevant operational practices. The level one assessment can be conducted by the PWS. Many water systems are currently conducting portions of this assessment when they respond to positive TC samples. Examples of statements I have heard from systems that call in about positive results are: the sampling location was not in good condition, or the building had recently had the plumbing worked on, or the sample site is on a dead end and it is not used enough to be a good representation of the distribution system. These are all examples of things that can be noted during an assessment.

9. Level 2 Assessments Triggers: Violation of the Proposed RTCR MCL for E. coli EC (P) RP following a TC(P) RT TC (P) RP following a EC (P) RT Fail to take all required RPs following an EC (P) RT Fail to test for EC when any RP is TC (P) Two level 1 triggers in a 12 month period Where the level one assessment is triggered by what is a TC MCL under the TCR, the level two assessment is triggered by having two level 1 triggers in a 12 month period or the violation of the proposed RTCR MCL for E. coli : EC (P) RP following a TC(P) RT TC (P) RP following a EC (P) RT Fail to take all required RPs following an EC (P) RT Fail to test for EC when any RP is TC (P)Where the level one assessment is triggered by what is a TC MCL under the TCR, the level two assessment is triggered by having two level 1 triggers in a 12 month period or the violation of the proposed RTCR MCL for E. coli : EC (P) RP following a TC(P) RT TC (P) RP following a EC (P) RT Fail to take all required RPs following an EC (P) RT Fail to test for EC when any RP is TC (P)

10. Level 2 Assessments Assessment: Conducted by the State or a party approved by the State A more in-depth examination of the system and its monitoring and operational practices The level two assessment is a more detailed review than what is required in the level one assessment. A level 2 is required to be conducted by the State or a party that is approved by the State. This approved party may be a water system employee/employees or a third party consultant. The person approved for a level two assessment must have an advanced understanding of the operations, treatment process, monitoring, simultaneous compliance, regulations, and the distribution system.The level two assessment is a more detailed review than what is required in the level one assessment. A level 2 is required to be conducted by the State or a party that is approved by the State. This approved party may be a water system employee/employees or a third party consultant. The person approved for a level two assessment must have an advanced understanding of the operations, treatment process, monitoring, simultaneous compliance, regulations, and the distribution system.

11. Elements of Assessments Atypical events that may affect distributed water quality or indicate that distributed water quality was impaired Changes in distribution system maintenance and operation that may affect distributed water quality, including water storage The different elements looked at during an assessment: Atypical events that may affect distributed water quality or indicate that distributed water quality was impaired Changes in distribution system maintenance and operation that may affect distributed water quality, including water storage The different elements looked at during an assessment: Atypical events that may affect distributed water quality or indicate that distributed water quality was impaired Changes in distribution system maintenance and operation that may affect distributed water quality, including water storage

12. Elements of Assessments Source and treatment considerations that bear on distributed water quality Existing water quality monitoring data Inadequacies in sample sites, sampling protocol, and sample processing Source and treatment considerations that bear on distributed water quality Existing water quality monitoring data Inadequacies in sample sites, sampling protocol, and sample processing Source and treatment considerations that bear on distributed water quality Existing water quality monitoring data Inadequacies in sample sites, sampling protocol, and sample processing

21. Corrective Action PWS must correct all sanitary defects found during the assessment Sanitary defects and corrective actions must be described in the assessment form the PWS must submit to the State within 30 days of the assessment trigger If there is a sanitary defect found during the assessment, the system must complete a corrective action. The sanitary defects and corrective actions must be described in the assessment form. The PWS is required to submit this to the State within 30 days of the assessment trigger.If there is a sanitary defect found during the assessment, the system must complete a corrective action. The sanitary defects and corrective actions must be described in the assessment form. The PWS is required to submit this to the State within 30 days of the assessment trigger.

22. Corrective Action A timetable for any corrective actions not already completed must also be in the form; the State will determine a schedule after consulting with the PWS The form may also indicate that no sanitary defects were found The State determines if the assessment is sufficient If the sanitary defect can be corrected during the assessment note on the assessment the corrective action completed. If the corrective action can not be completed during the assessment, a timetable must be submitted with the assessment form. The State will consult with the PWS to determine a schedule for completion. If the assessment is completed and there were no sanitary defects found; note on the assessment form that no sanitary defects were found. Once the State receives a copy of the assessment, it will be reviewed and the State will determine if it is sufficient.If the sanitary defect can be corrected during the assessment note on the assessment the corrective action completed. If the corrective action can not be completed during the assessment, a timetable must be submitted with the assessment form. The State will consult with the PWS to determine a schedule for completion. If the assessment is completed and there were no sanitary defects found; note on the assessment form that no sanitary defects were found. Once the State receives a copy of the assessment, it will be reviewed and the State will determine if it is sufficient.

23. Violations, PN, CCR Violation of the Proposed RTCR MCL for E. coli � Tier 1 PN Failure to take RPs following EC (P) RTs Fail to take all required RPs following an EC (P) RT Fail to test for EC when any RP is TC (P) EC (P) RP following a TC(P) RT TC (P) RP following a EC (P) RT The Proposed RTCR has closed some of the loopholes that TCR did not address. You can no longer get out of a possible MCL violation by not monitoring. The RTCR says that if you fail to monitor in a situation that has a potential to be a MCL violation, it is a Tier 1 MCL violation. The situations that cause a RTCR MCL for E. coli are: Failure to take RPs following EC (P) RTs Fail to take all required RPs following an EC (P) RT Fail to test for EC when any RP is TC (P) EC (P) RP following a TC(P) RT TC (P) RP following a EC (P) RT The Proposed RTCR has closed some of the loopholes that TCR did not address. You can no longer get out of a possible MCL violation by not monitoring. The RTCR says that if you fail to monitor in a situation that has a potential to be a MCL violation, it is a Tier 1 MCL violation. The situations that cause a RTCR MCL for E. coli are: Failure to take RPs following EC (P) RTs Fail to take all required RPs following an EC (P) RT Fail to test for EC when any RP is TC (P) EC (P) RP following a TC(P) RT TC (P) RP following a EC (P) RT

24. Violations, PN, CCR TT violation occurs when a PWS fails to conduct required A or CA � Tier 2 PN M&R violations � Tier 3 PN Fails to take all required TC samples Fails to analyze for EC following TC (P) RT sample Fails to submit monitoring reports Fails to submit a completed assessment form If water systems fail to conduct the required assessment or corrective actions, the RTCR requires that a tier 2 TT violation be issued. The tier 3 M&R violations proposed under the RTCR are: If a system fails to take all required TC samples If a system fails to analyze for EC following TC (P) RT sample If a system fails to submit monitoring reports If a system fails to submit a completed assessment formIf water systems fail to conduct the required assessment or corrective actions, the RTCR requires that a tier 2 TT violation be issued. The tier 3 M&R violations proposed under the RTCR are: If a system fails to take all required TC samples If a system fails to analyze for EC following TC (P) RT sample If a system fails to submit monitoring reports If a system fails to submit a completed assessment form

25. Violations, PN, CCR PN/CCR Language � TC health effects language changed to reflect failure to conduct A or CA The PNs and CCRs will change because, under the RTCR, there is no longer the MCL for TC. It will be replaced with language that reflects the failure to conduct an assessment or complete the required corrective actions.The PNs and CCRs will change because, under the RTCR, there is no longer the MCL for TC. It will be replaced with language that reflects the failure to conduct an assessment or complete the required corrective actions.

26. Analytical Methods Evaluation of currently-approved methods Concerns with EPA�s Alternate Test Procedure (ATP) process Method modification without EPA�s knowledge Reports of varying performance Manufacturer �product hold� and recall for reduced recovery of E.coli During the research and development of the RTCR, the Advisory Committee Agreement in Principal (AIP) recommended that the EPA evaluate the current methods and the Alternative Testing Procedure (ATP) for approving new methods. In the twenty years since the TCR was promulgated, many methods have been developed and approved for use. Most of the methods approved to support the current TCR were evaluated under the ATP. The ATP guidance document has been revised several times since it�s conception. As a result of different protocols being used to approve methods, the current set of approved methods have not been evaluated under identical conditions. EPA has also noted that there have been concerns that some of the approved methods may have been modified since approval without EPA�s knowledge. EPA is also aware of reports of varying performance of some enzyme-based methods. Questions about methods also arise because a manufacturer of an approved method placed a �product hold� and recall on the medium after the product was reported to be experiencing reduced recovery of E. coli.During the research and development of the RTCR, the Advisory Committee Agreement in Principal (AIP) recommended that the EPA evaluate the current methods and the Alternative Testing Procedure (ATP) for approving new methods. In the twenty years since the TCR was promulgated, many methods have been developed and approved for use. Most of the methods approved to support the current TCR were evaluated under the ATP. The ATP guidance document has been revised several times since it�s conception. As a result of different protocols being used to approve methods, the current set of approved methods have not been evaluated under identical conditions. EPA has also noted that there have been concerns that some of the approved methods may have been modified since approval without EPA�s knowledge. EPA is also aware of reports of varying performance of some enzyme-based methods. Questions about methods also arise because a manufacturer of an approved method placed a �product hold� and recall on the medium after the product was reported to be experiencing reduced recovery of E. coli.

27. Environmental Technology Verification Program Side-by-side method evaluation study Vendors can propose an equivalent alternative Not completed in time for final RTCR Independent regulatory actions Analytical Methods Because of the concerns raised in the AIP and known issues with methods, the EPA is considering a complete, side-by-side method evaluation study, whereby all methods are compared to each other under identical conditions, according to the same protocol. Vendors of all currently approved methods could voluntarily participate in the independent, third-party laboratory evaluation through EPA�s Environmental Technology Verification (EVT) Program. Vendors would fund the majority of the cost of their method evaluation. Based on the results of the EVT, EPA would judge the appropriateness of each method and determine which should continue to be approved for future monitoring. If the vendor does not choose to participate in the ETV Program, they can propose an equivalent alternative approach for method evaluation. The ETV is not anticipated to be completed and therefore could not be included in the final RTCR. Any changes in methods based on the EVT would be addressed in independent regulatory actions.Because of the concerns raised in the AIP and known issues with methods, the EPA is considering a complete, side-by-side method evaluation study, whereby all methods are compared to each other under identical conditions, according to the same protocol. Vendors of all currently approved methods could voluntarily participate in the independent, third-party laboratory evaluation through EPA�s Environmental Technology Verification (EVT) Program. Vendors would fund the majority of the cost of their method evaluation. Based on the results of the EVT, EPA would judge the appropriateness of each method and determine which should continue to be approved for future monitoring. If the vendor does not choose to participate in the ETV Program, they can propose an equivalent alternative approach for method evaluation. The ETV is not anticipated to be completed and therefore could not be included in the final RTCR. Any changes in methods based on the EVT would be addressed in independent regulatory actions.

28. Review of ATP 24 hour methods Elimination of fecal coliforms Analytical Methods The AIP recommended that EPA review the ATP. EPA suggests that the re-evaluation of the current methods under the ETV could serve as a basis for evaluating new methods. The study plan could be used as a model for a revised ATP protocol. The AIP also recommended that EPA consider approving methods that allow timely results for E. coli and TC. EPA is concerned that methods with 24 hour incubations may not be able to detect as many coliform bacteria as 48 hour methods. Many of the bacteria in a distribution system are stressed from the disinfection practices, and they may take longer to detect than 24 hours. The EPA may investigate the incubation time as part of or in addition to the ETV. The RTCR eliminates the use of fecal coliforms as substitute indicators for EC. This may be an issue in other states, but not so in Kentucky as we have been using EC as the indicator for fecal contamination. The fecal coliform group can contain bacteria not associated with fecal contamination and now there are many methods approved for EC.The AIP recommended that EPA review the ATP. EPA suggests that the re-evaluation of the current methods under the ETV could serve as a basis for evaluating new methods. The study plan could be used as a model for a revised ATP protocol. The AIP also recommended that EPA consider approving methods that allow timely results for E. coli and TC. EPA is concerned that methods with 24 hour incubations may not be able to detect as many coliform bacteria as 48 hour methods. Many of the bacteria in a distribution system are stressed from the disinfection practices, and they may take longer to detect than 24 hours. The EPA may investigate the incubation time as part of or in addition to the ETV. The RTCR eliminates the use of fecal coliforms as substitute indicators for EC. This may be an issue in other states, but not so in Kentucky as we have been using EC as the indicator for fecal contamination. The fecal coliform group can contain bacteria not associated with fecal contamination and now there are many methods approved for EC.

29. Other method issues Holding time Holding temperature Dechlorinating agent Filtration funnels Analytical Methods The EPA is proposing ,in the RTCR, some minor technical changes related to analytical methods. Many of these are practices already followed by PWSs and laboratories, and are consistent with the Manual for the Certification of Laboratories Analyzing Drinking Water, commonly called the Laboratory Certification Manual. The holding time is still 30 hours but the RTCR has a revised definition . It is �the time from sample collection to initiation of test medium incubation may not exceed 30 hours.� The systems are encouraged but not required to hold samples below 10 degrees C during transit. It is thought that maintaining the temperature below 10 degrees C serves to preserve the bacterial population by minimizing both cell death and cell multiplication. The RTCR also establishes a provision for use of a dechlorinating agent for sample preservation of chlorinated water supplies. �If chlorinated water is to be analyzed, sufficient sodium thiosulfate must be added to the sample bottle before sterilization to neutralize any residual chlorine in the water sample.� The EPA is proposing adding a footnote to the methods table that reads: �All filtration series must begin with membrane filtration equipment that has been sterilized by autoclaving. Exposure of membrane filtration equipment to UV light is not adequate to ensure sterilization. Subsequent to the initial autoclaving, exposure of the filtration equipment to UV light may be used to sanitize the funnels between filtrations within a filtration series.� The EPA is proposing ,in the RTCR, some minor technical changes related to analytical methods. Many of these are practices already followed by PWSs and laboratories, and are consistent with the Manual for the Certification of Laboratories Analyzing Drinking Water, commonly called the Laboratory Certification Manual. The holding time is still 30 hours but the RTCR has a revised definition . It is �the time from sample collection to initiation of test medium incubation may not exceed 30 hours.� The systems are encouraged but not required to hold samples below 10 degrees C during transit. It is thought that maintaining the temperature below 10 degrees C serves to preserve the bacterial population by minimizing both cell death and cell multiplication. The RTCR also establishes a provision for use of a dechlorinating agent for sample preservation of chlorinated water supplies. �If chlorinated water is to be analyzed, sufficient sodium thiosulfate must be added to the sample bottle before sterilization to neutralize any residual chlorine in the water sample.� The EPA is proposing adding a footnote to the methods table that reads: �All filtration series must begin with membrane filtration equipment that has been sterilized by autoclaving. Exposure of membrane filtration equipment to UV light is not adequate to ensure sterilization. Subsequent to the initial autoclaving, exposure of the filtration equipment to UV light may be used to sanitize the funnels between filtrations within a filtration series.�

30. Analytical methods table changes Organized by methodology E. coli methods included 18th and 19th edition of SM not approved Formulation of EC-MUG broth for 9222G.1a(2) Potassium dihydrogen phosphate, KH2PO4 must be 1.5g and 4-methylumbelliferyl-Beta-D-glucuronide must be 0.005g. Analytical Methods The EPA has proposed analytical methods table changes in the RTCR: The RTCR analytical methods table is organized by methodology category (e.g., lactose-fermentation methods vs. membrane filtration vs. enzyme-substrate methods). The table also includes the approved E. coli methods. This was not included in the TCR methods table. The 18th and 19th editions of the Standard Methods are no longer approved and have been removed. The addition of footnote 13 to the methods table clarifies the correct formulation for EC-MUG broth when used in conjunction with SM9222G.1a(2). Potassium dihydrogen phosphate, KH2PO4 must be 1.5g and 4-methylumbelliferyl-Beta-D-glucuronide must be 0.005g.The EPA has proposed analytical methods table changes in the RTCR: The RTCR analytical methods table is organized by methodology category (e.g., lactose-fermentation methods vs. membrane filtration vs. enzyme-substrate methods). The table also includes the approved E. coli methods. This was not included in the TCR methods table. The 18th and 19th editions of the Standard Methods are no longer approved and have been removed. The addition of footnote 13 to the methods table clarifies the correct formulation for EC-MUG broth when used in conjunction with SM9222G.1a(2). Potassium dihydrogen phosphate, KH2PO4 must be 1.5g and 4-methylumbelliferyl-Beta-D-glucuronide must be 0.005g.

31. Various methods removed/changed/approved The reference 9221A and 9222A are removed The reference 9221B is changed to 9221B.1, B.2 The reference 9221D is changed to 9221D.1, D.2 Allow 9221D in multiple tube format as in 9221B The citation for MI agar changed to EPA 1604 Clarifies that 9221 F.1 and 9222 G.1a(1),(2) may be used for E. coli analysis Approval of modified Colitag method for simultaneous detection of E. coli and other total coliforms Analytical Methods Various methods removed/changed/approved The reference 9221A and 9222A are removed (introduction section of the multiple-tube fermentation and membrane filter methods) The reference 9221B is changed to 9221B.1, B.2 (multiple-tube fermentation method presumptive or confirmed phase) The reference 9221D is changed to 9221D.1, D.2 (presence-absence (P-A) method presumptive or confirmed phase) The citation for MI agar changed to EPA Method 1604 for clarity and consistency The Standard Methods 9221 F.1 (EC-MUG medium following fermentation) and 9222 G.1a(1),(2) (E. coli partition method: (1) EC broth with MUG and (2) NA-MUG medium) may be used for E. coli analysis The approval of a modified Colitag method for the simultaneous detection of E. coli and other total coliforms Various methods removed/changed/approved The reference 9221A and 9222A are removed (introduction section of the multiple-tube fermentation and membrane filter methods) The reference 9221B is changed to 9221B.1, B.2 (multiple-tube fermentation method presumptive or confirmed phase) The reference 9221D is changed to 9221D.1, D.2 (presence-absence (P-A) method presumptive or confirmed phase) The citation for MI agar changed to EPA Method 1604 for clarity and consistency The Standard Methods 9221 F.1 (EC-MUG medium following fermentation) and 9222 G.1a(1),(2) (E. coli partition method: (1) EC broth with MUG and (2) NA-MUG medium) may be used for E. coli analysis The approval of a modified Colitag method for the simultaneous detection of E. coli and other total coliforms