&EPA United States Environmental Protection Agency I * Comprehensive Surface Water Treatment Rules Quick Reference Guide: Systems Using Conventional or Direct Filtration r Overview of the Rules Title* Purpose General Description Surface Water Treatment Rule (SWTR) - 40 CFR 141 .70-141 .75 Interim Enhanced Surface Water Treatment Rule (IESWTR) - 40 CFR 141 .170-141.175 Filter Backwash Recycling Rule (FBRR) 40 CFR 141 .76 Long Term 1 Enhanced Surface Water Treatment Rule (LT1 ESWTR) - 40 CFR 1 41 .500-1 41 .571 Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) - 40 CFR 1 41 .700-1 41 .722 Improve public health protection through the control of microbial contaminants, particularly viruses, Giardia lamblia, and Cryptosporidium. The Surface Water Treatment Rules: >• Applies to all public water systems (PWSs) using surface water or ground water under the direct influence of surface water (GWUDI), otherwise known as "Subpart H systems." >• Requires all Subpart H systems to disinfect. >• Requires Subpart H systems to filter unless specific filter avoidance criteria are met. >• Applies a treatment technique requirement for control of microbials. This document provides a summary of federal drinking water requirements; to ensure full compliance, please consult the federal regulations at 40 CFR 141 and any approved state requirements. Overview of Requirements The purpose of this table is to show how the requirements for the IESWTR, FBRR, LT1ESWTR and LT2ESWTR build on the existing requirements established in the original SWTR. APPLICABILITY: PWSs that use surface water or GWUDI (Subpart H systems) that practice conventional or direct filtration. Population Served Regulated Pathogens Residual Disinfection Requirements Source Water Monitoring Requirements and Bin Classification Turbidity Performance Standards Disinfection Profiling and Benchmarking Sanitary Surveys (state requirement) Finished Reservoirs/ Water Storage Facilities > 10,000 < 10,000 99.99% (4-log) removal/ inactivation of viruses 99.9% (3-log) removal/ inactivation of Giardia lamblia 99% (2-log) removal of Cryptosporidium Entrance to distribution system (> 0.2 mg/L) Detectable in the distribution system Monitoring to calculate Cryptosporidium and determine appropriate bin classification for each plant required to monitor Combined Filter Effluent Individual Filter Effluent Systems must profile inactivation levels and generate benchmark, if required CWS**: Every 3 years NCWS**: Every 5 years All new facilities constructed must be covered Uncovered facilities must be covered or discharge treated Final Rule Dates SWTR 1989 ^ ^ ^ ^ ^ •/ * ~ Operated by Qualified Personnel as Specified by State | * IESWTR 1998 ^ For sanitary survey provisions only Regulated under SWTR Regulated under SWTR ^ Regulated under SWTR Regulated under SWTR ^ ^ ^ ^ ^ Regulated under SWTR LT1 ESWTR 2002 ^— ^^^M ^ Regulated under SWTR Regulated under SWTR * Regulated under SWTR Regulated under SWTR *< * * Regulated under IESWTR * "• Regulated under SWTR LT2ESWTR 2006 •/ * Regulated under SWTR Regulated under SWTR Additional treatment may be required Regulated under SWTR Regulated under SWTR \/ Regulated under SWTR, IESWTR and LT1 ESWTR Regulated under IESWTR and LT1 ESWTR ^ Regulated under IESWTR Regulated under LT1 ESWTR \/ Regulated under SWTR FBRR 2001 ** *S Regulated under SWTR Regulated under SWTR Regulated under IESWTR and LT1 ESWTR Regulated under SWTR Community water system (CWS), Noncommunity water system (NCWS) ------- Turbidity Compliance with turbidity provisions is measured at the Combined Filter Effluent (CFE) and Individual Filter Effluent (IFE). The CFE turbidity results may mask the performance of an individual filter since the individual filter may have a turbidity spike of a short duration not detected by 4 hours CFE readings. IFE performance is measured in systems using conventional or direct filtration. The performance of each individual filter is critical to controlling pathogen breakthrough. The IESWTR and LT1ESWTR created more stringent CFE turbidity standards and established a new IFE turbidity monitoring requirement to address Cryptosporidium. These new turbidity standards assure conventional and direct filtration systems will be able to provide 2-log Cryptosporidium removal. Subpart H systems using the Treatment Performance Toolbox option under the LT2ESWTR must meet the more stringent CFE and IFE turbidity monitoring levels in order to receive additional Cryptosporidium log credit. Turbidity: Monitoring and Reporting Requirements Turbidity Type and Reporting Requirements (Reports due by the 10th day of the following month the system serves water to the public.) CFE 95% Value Report total number of CFE measurements and number and percentage of CFE measurements s 95th percentile limit CFE Maximum Value Report date and time of any CFE measurement that exceeds CFE maximum limit IFE Monitoring Report IFE monitoring conducted and any follow-up actions Monitoring/ Recording Frequency At least every 4 hours* At least every 4 hours* Monitor continuously every 15 minutes SWTR As of June 29, 1993 <0.5 NTU 5NTU Contact state within 24 hours None IESWTR > 10,000 people As of January 1, 2002 < 0.3 NTU 1 NTU Contact state within 24 hours LT1ESWTR < 10,000 people As of January 1, 2005 < 0.3 NTU 1 NTU Contact state within 24 hours Monitor-exceedances require follow-up action. Systems with 2 or fewer filters may monitor CFE continuously in lieu of IFE. 'Monitoring frequency may be reduced by the state to once per day for systems serving fewer than 500 people. IFE Turbidity: Follow-Up and Reporting Requirements Condition 2 consecutive recordings > 0.5 NTU taken 15 minutes apart at end of first 4 hours of continuous filter operation after backwash/offline: 2 consecutive recordings > 1 .0 NTU taken 15 minutes apart: 2 consecutive recordings > 1 .0 NTU taken 15 minutes apart at the same filter for 3 months in a row: 2 consecutive recordings > 2.0 NTU taken 15 minutes apart at the same filter for 2 months in a row: IESWTR (> 10,000) Action Produce filter profile within 7 days (if unknown cause). Produce filter profile within 7 days (if unknown cause). Conduct filter self-assessment within 14 days. Arrange for Comprehensive Performance Evaluation (CPE) within 30 days & submit report within 90 days. Report *• Filter* >• Turbidity value >• Date >• Cause (if known) or report profile was produced >• Filter* ^ Turbidity value >• Date >• Cause (if known) or report profile was produced >• Filter* ^ Turbidity value >• Date >• Report filter self-assessment produced *• Filter* ^ Turbidity value >• Date Submit CPE report By 10th of the following month 10th of the following month 10th of the following month 10th of the following month 90 days after exceedance LT1ESWTR(<1 0,000)** Action Conduct a filter self-assessment within 14 days Systems with 2 filters that monitor CFE in lieu of IFE must do both filters. Arrange for CPE within 60 days & submit CPE report within 120 days. Report >• Filter* ^- Turbidity value > Date ^- Cause (if known) Date filter assessment triggered & completed Date CPE triggered Submit CPE report By 10th of the following month 10th of the following month (or within 14 days of filter self- assessment being triggered if triggered in last 4 days of the month). 10th of the following month 120 days after exceedance ** Systems serving fewer than 10,000 people had to begin complying with these requirements beginning January 1, 2005. ------- Filter Backwash Recycling Rule The FBRR applies to Subpart H systems that practice conventional or direct filtration, and recycle spent filter backwash, thickener suernatant, or liquids from dewatering processes. The FBRR requires systems that recycle to return specific recycle flows through all processes of the system's existing conventional or direct filtration system or at an alternate location approved by the state. The FBRR was developed to improve public health protection by assessing and changing, where needed, recycle practices for improved contaminant control, particularly microbial contaminants. Systems were required to submit recycle notification to the state by December 8, 2003. By June 8, 2004, systems were required to return recycle flows through the processes of a system's existing conventional or direct filtration system or an alternate recycle location approved by the state and collect recycle flow information and retain on file. Any system making capital improvements to modify the recycle return location was given until June 8, 2006, to complete the improvements. All new systems must abide by these requirements. Disinfection Disinfection must be sufficient to ensure that the total treatment process (disinfection plus filtration) of the system achieves at least: >• 99.9% (3-log) inactivation and/or removal of Giardia lamblia. >• 99.99% (4-log) inactivation and/or removal of viruses. Subpart H systems using chlorine dioxide, ozone, or ultraviolet (UV) disinfection may achieve additional Cryptosporidium log credit by using the Inactivation Toolbox option under the LT2ESWTR. Systems must also comply with the maximum residual disinfectant level (MRDL) and maximum contaminant level (MCL) requirements specified in the Stage 1 Disinfectants and Disinfection Byproducts Rule (Stage 1 DBPR) and Stage 2 Disinfectants and Disinfection Byproducts Rule (Stage 2 DBPR). Residual Disinfectant Monitoring and Reporting Requireme Location Concentration Monitoring Frequency Reporting (Reports due 10th of the following month) Entry to distribution system. Residual disinfectant concentration cannot be < 0.2 mg/L for more than 4 hours. Continuous, but states may allow systems serving < 3,300 to take grab samples from 1 to 4 times per day, depending on system size. Lowest daily value for each day, the date and duration when residual disinfectant was < 0.2 mg/L, and when state was notified of events where residual disinfectant was < 0.2 mg/L. Distribution system - same location as total coliform sample location(s). Residual disinfectant concentration cannot be undetectable in greater than 5% of samples in a month, for any 2 consecutive months. Heterotrophic plate count (HPC) < 500/mL is deemed to have detectable residual disinfectant. Same time as total coliform samples. Number of residual disinfectant or HPC measurements taken in the month resulting in no more than 5% of the measurements as being undetectable in any 2 consecutive months. LT2ESWTR Source Water Monitoring and Bin Classification Bin concentration is calculated by averaging individual sample results from 1 or more years of monitoring (specific procedures vary by frequency and duration of monitoring). A combined distribution system (CDS) is an interconnected distribution system consisting of the distribution systems of the wholesale system and of the consecutive systems that receive finished water from that wholesale system. Under the LT2ESWTR, wholesale systems in a CDS must comply with the LT2ESWTR based on the population of the largest system in their CDS. EPA has established four schedule categories based on system size to simplify the discussion of the LT2ESWTR monitoring requirements. Schedule 1 applies to systems that serve 100,000 or more people or in a CDS that largest system serves 100,000 people. Schedule 2 applies to systems that serve 50,000 to 99,999 people or in a CDS that largest system serves 50,000 to 99,999 people. Schedule 3 applies to systems that serve 10,000 and 49,999 people or in a CDS that largest system serves 10,000 and 49,999 people. Schedule 4 applies to systems that serve less than 10,000 people. Source water monitoring requirements are as follows: >• Large systems (> 10,000 people served) must sample for Cryptosporidium, E.coli and turbidity at least monthly for 2 years. >• Small systems (< 10,000 people served) must initially sample for E.coli at least once every 2 weeks for 1 year. Cryptosporidium monitoring is only required if E. coli levels are above certain levels based on the water source type. >• All systems must begin a second round of monitoring 6 years after initial bin classification. Bin Classification and Additional Treatment Requirements Bin Bin1 Bin 2 Bin 3 Bin 4 Cryptosporidium Bin Concentration Less than .075 oocysts/ L ** .075 oocysts/L or higher, but less than 1 .0 oocysts/L 1 .0 oocysts or higher, but less than 3.0 oocysts/L 3.0 oocysts or higher Additional Treatment Requirements* Conventional Filtration No additional treatment 1-log treatment*** 2-log treatment*** 2.5 log treatment*** Direct Filtration No additional treatment 1 .5-log treatment*** 2.5-log treatment*** 3-log treatment*** Requirements in addition to those met in full compliance with SWTR, IESWTR, and LT1ESWTR * Or Subpart H systems not required to monitor for Cryptosporidium ** Removal or inactivation ------- Microbial Toolbox: Inactivation Options, Credits and Criteria The Microbial Toolbox provides a list of the tools that systems can use, and receive treatment credits for, in order to meet additional treatment requirements of LT2ESWTR. The toolbox provides systems with the flexibility to use any combination of applicable treatment options as long as the systems are in compliance with design, operational, and performance criteria which are not detailed in this document. The toolbox options and credits available for Subpart H systems are divided into five categories: >• Source protection and management: watershed control program (0.5-log), alternative source/intake management (no prescribed credit). >• Prefiltration: presedimentation basin with coagulation (0.5-log), two-stage lime softening (0.5-log), bank filtration (0.5- or 1-log). >• Treatment performance: combined filter performance (0.5-log), individual filter performance (0.5-log), demonstration of performance (log credit variable). >• Additional filtration: bag and cartridge filters individual (up to 2-log), bag and cartridge filters in series (up to 2.5-log), membrane filtration (log credit variable), second stage filtration (0.5-log), slow sand filters (2.5- to 3-log). >• Inactivation: chlorine dioxide (log credit variable), ozone (log credit variable), UV (log credit variable). Disinfection Profiling and Benchmarking Requirements A disinfection profile is the graphical representation of a system's microbial inactivation over 12 consecutive months. A disinfection benchmark is the lowest monthly average microbial inactivation value. The disinfection benchmark is used as a baseline of inactivation when considering changes in the disinfection process. Disinfection Profiling and Benchmarking Requirements The purpose of disinfection profiling and benchmarking is to allow systems and states to assess whether a change in disinfection practices reduces microbial protection. Systems must develop a disinfection profile that reflects Giardia lamblia and viruses inactivation, calculate a benchmark (lowest monthly inactivation) based on the profile, and consult with the state prior to making a significant change to disinfection practices. Requirement Affected Systems: Begin Profiling By: Frequency & Duration: States May Waive Disinfection Profiling Requirements If: Disinfection Benchmark Must be Calculated If: IESWTR Community water systems (CWS), nontransient noncommunity water systems (NTNCWS), and transient noncommunity water systems (TNCWS) > 10,000. April 1 , 2000 Daily monitoring for 12 consecutive calendar months to determine the total logs of Giardia lamblia inactivation (and viruses, if necessary) for each day in operation. TTHM annual average < 0.064 mg/L and HAAS annual average < 0.048 mg/L: ^ Collected during the same period. ^ Annual average is arithmetic average of the quarterly averages of 4 consecutive quarters of monitoring. >• At least 25% of samples at the maximum residence time in the distribution system. >• Remaining 75% of samples at representative locations in the distribution system. >• Systems required to develop a disinfection profile and are considering making a significant changes in disinfection practice*. >• Systems must consult the state prior to making any modifications to disinfection practices. LT1ESWTR CWS and NTNCWS <1 0,000 only. >• July 1 , 2003, for systems serving 500-9,999 people. >• January 1 , 2004, for systems serving < 500 people. Weekly inactivation of Giardia lamblia (and viruses, if necessary), on the same calendar day each week over 12 consecutive months. One TTHM sample < 0.064 mg/L and one HAAS sample < 0.048 mg/L: >• Collected during the month of warmest water temperature; AND ^ At the maximum residence time in the distribution system. Samples must have been collected after January 1, 1998. Same as IESWTR, and systems must obtain state approval prior to making any modifications to disinfection practices. LT2ESWTR Any CWS, NTNCWS or TNCWS that proposes to make a significant change in disinfection practice*. ^ Upon completion of initial round of source water monitoring, AND >• 1 2 consecutive months prior to making the proposed change. At least weekly inactivation of Giardia lamblia and viruses, for at least 1 year. May use data collected for profile under IESWTR or LT1 ESWTR. ^ The system has an existing disinfection profile for both Giardia lamblia and viruses, and has neither made a significant change to its treatment practices nor changed sources since the profile was developed; OR, ^ The system has at least 1 year of existing data that can be used to complete a disinfection profile, and has neither made a significant change to its treatment practice nor changed sources since the data were collected. Complete disinfection profile and benchmark for viruses and Giardia lamblia. *A significant change in disinfection practice is defined as (1) change in the point of disinfection, (2) change to the type of disinfectant, (3) change to the disinfection process, or (4) any other modification designated by the state. Office of Water (4606M) EPA 816-F-10-074 http://water.epa.gov/drink August 2010 ------- |