Coliform Monitoring, Analyzing, and Reporting

1 TCEQ REGULATORY GUIDANCE Water Supply Division RG-421 Revised June 2021 Coliform Monitoring, Analyzing, and Reporting Public Water Supply Supervision Program Water Supply Division Texas Commission on Environmental Quality Coliform Monitoring, Analyzing, and Reporting Water Supply Division RG-421 June 2021 Published and distributedby theTexas Commission on Environmental Box 13087 Austin TX 78711-3087 Jon Niermann, ChairmanEmily Lindley, CommissionerBobby Janecka, CommissionerToby Baker, Executive DirectorWe authorize you to use or reproduce any original material contained in this publication that is, any material we did not obtain from other sources. Please acknowledge the TCEQ as your of this publication are available for public use through the Texas State Library, other state depository libraries, and the TCEQ Library, in compliance with state depository law.

2 For more information on TCEQ publications visit our website is an equal opportunity employer. The agency does not allow discrimination on the basis of race, color, religion, national origin, sex, disability, age, sexual orientation or veteran status. In compliance with the Americans with Disabilities Act, this document may be requested in alternate formats by contacting TCEQ at 512-239-0010 or 1-800-RELAY-TX (TDD), or by writing Box 13087, Austin, TX is our customer service? RG-421 Coliform Monitoring, Analyzing, and Reporting June 2021 Page ii Contents Glossary .. ivAcronyms .. xIntroduction ..1 TCEQ Publications ..2 Texas Rules Associated with This Guide ..2 Section 1. Background Information ..3 Revised Total Coliform Rule ..3 Revised Total Coliform Rule E. coli Maximum Contaminant Level Violations ..4 Groundwater Rule.

3 4 Types of Public Water Systems .. Noncommunity ..5 Transient Noncommunity ..6 Primary Water Source Types ..6 Texas Drinking Water Watch ..6 Section 2. Compliance Coliform Monitoring ..7 Types of Coliform Samples ..7 Routine Samples ..7 Repeat Samples ..9 Special Samples and Construction Samples .. 16 Monitoring Requirements and Procedures .. 16 Sample Siting Plans and Monitoring Plans .. 16 Selecting a Testing Laboratory .. 17 Sample Bottles and Documentation .. 18 Sample Collection .. 21 Delivery of the Sample(s) to the Laboratory for Analysis .. 25 Interpretation of Sample Results and Further Action .. 28 Section 3. Treatment Technique Triggers, Assessment, and Corrective Action .. 30 Revised Total Coliform Rule Treatment Technique Triggers .. 30 Level 1 Treatment Technique Triggers .. 30 Level 2 Treatment Technique Triggers.

4 30 Revised Total Coliform Rule Assessment and Corrective Action .. 32 Section 4. Groundwater Corrective Actions .. 33 Comprehensive Compliance Investigations and Significant Deficiencies .. 33 Corrective Action .. 34 Section 5. Reporting .. 35 TCEQ RG-421 Coliform Monitoring, Analyzing, and Reporting June 2021 Page iii Section 6. Compliance and Public Notification .. 36 Revised Total Coliform Rule Compliance Violations .. 37 Groundwater Rule Compliance Violations .. 38 Public Notice Tiers .. 39 Tier 1 .. 39 Tier 2 .. 40 Tier 3 .. 40 Public Notice Contents .. 41 Boil Water Notice .. 42 Consumer Confidence Reports .. 42 Appendix A. Microbial Reporting Form (10525) and Instructions .. 43 Appendix B. Rejection and Invalidation Codes Used by the Laboratory .. 45 Appendix C. Laboratory Positive Result Form (TCEQ-20894).

5 46 Tables 1. Sampling Frequency of Routine Samples Based on Population Served ..82. Revised Total Coliform Rule Reporting Requirements .. 353. Groundwater Rule Reporting Requirements .. 364. Revised Total Coliform Rule Violations and Reasons .. 375. Groundwater Rule Violations and Reasons .. 386. Tier 1 Public Notification .. 397. Tier 2 Public Notification .. 40 Figures 1. Repeat Sample Requirements for Positive Routine Distribution Sample Results .. 102. Raw Well Sample Requirements for Positive Routine Distribution Sample Results .. 133. GWR Triggered Source Water Monitoring Requirements for Consecutive andWholesale 144. Level 1 Assessment Trigger for Systems Collecting 40 or More 315. Level 1 Assessment Trigger for Systems Collecting Fewer than 40 Samples .. 32 TCEQ RG-421 Coliform Monitoring, Analyzing, and Reporting June 2021 Page iv Glossary Accredited laboratory: A laboratory that is accredited by TCEQ.

6 Analytical methods: Coliform analysis methods required by the US Environmental Protection Agency (EPA) and the National Primary Drinking Water Regulations as defined in 40 Code of Federal Regulations (CFR) Part 141 30 Texas Administrative Code (TAC) adopts these federally mandated methods by reference. Assessment source monitoring (ASM): Raw groundwater source monitoring required by TCEQ based on groundwater source susceptibility to fecal contaminants. Boil Water Notice (BWN): Issued as a precaution or notification to protect consumers from drinking water that may have been contaminated with disease-causing organisms. Boil Water Notices are typically issued when an unexpected condition has caused a potential for biological contamination of potable drinking water in a p ublic water system (PWS). Chain of custody (COC): An unbroken trail of accountability that ensures the physical security of samples from sample collection until analysis.

7 Code of Federal Regulations (CFR): The rules and regulations published in the Federal Register by the federal government. Compliance sample: Water samples collected to verify PWS adherence to the RTCR and the Groundwater Rule (GWR). Compliance samples associated with these rules include routine, repeat, and raw well source monitoring samples. Comprehensive Compliance Investigation (CCI): An onsite review (also known as a sanitary survey) of PWSs by field investigators in the TCEQ regional offices. CCIs are used to collect information on a PWS s capacity to produce and deliver safe drinking water on a sustainable basis. They are also used to prevent and correct physical and operational weaknesses. CCIs are a proactive public health measure that can identify deficiencies in PWSs before contamination of public drinking water occurs.

8 Contamination: The presence of any foreign substance (organic, inorganic, radiological or biological) in water that tends to degrade its quality. This may constitute a health hazard or impair the usefulness of water. Consecutive system: A PWS that receives some or all its raw water or finished water from one or more other PWSs. Disinfectant: A chemical or a treatment which is intended to kill or inactivate pathogenic microorganisms in water. Disinfection: A process which inactivates pathogenic organisms in the water by chemical oxidants or equivalent agents. Distribution system: A system of pipes that carries potable water from a treatment plant to consumers. The term includes pump stations, ground and elevated storage TCEQ RG-421 Coliform Monitoring, Analyzing, and Reporting June 2021 Page v tanks, potable water mains, and potable water service lines and all associated valves, fittings, and meters, but excludes potable water customer service lines.

9 Drinking water: All water distributed by any agency or individual, public, or private for human consumption. Entry Point: The point at which treated water enters the distribution system. Escherichia coli (E. coli or EC): One of several types of bacteria that normally inhabit the intestine of humans and animals. Some E. coli strains can cause disease under certain conditions. The presence of E. coli in drinking water indicates that potentially harmful bacteria may be present. Fecal indicator: Microorganisms used to indicate the presence of fecal contamination. Examples include coliphage, enterococci, and E. coli. Find and fix: Terminology applicable to the RTCR requiring PWSs to conduct Coliform monitoring to find microbial contamination and fix any maintenance or operational defect that could allow contamination of the system.

10 Groundwater system: For the purposes of compliance with the RTCR and the GWR, a groundwater system is a PWS that provides, uses, or distributes any groundwater except if the groundwater is combined with surface water (or with groundwater under the direct influence of surface water) prior to treatment. Groundwater corrective action plan: A plan approved by TCEQ documenting steps to address fecal contamination of a groundwater source or documenting steps to address a significant deficiency. Groundwater Rule (GWR): Regulation requiring raw water sampling, periodic sanitary surveys, and corrective action in response to detection of viral indicators or the identification of significant deficiencies. Groundwater system under the influence of surface water (GUI): A PWS that uses groundwater with some contact with surface water.