EPA United States Environmental Protection Agency *: • Comprehensive Surface Water Treatment Rules Quick Reference Guide: Systems Using Conven tional or Direct Filtration 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 (LT1ESWTR) - 40 CFR 141.500-141.571 Improve public health protection through the control of microbial contaminants, particularly viruses, Giardia, 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 ail Subpart H systems to disinfect. >• Requires Subpart H systems to filter unless specific filter avoidance criteria are met. >• Requires individual filter monitoring and establishes combined filter effluent (CFE) limits. >• Applies a treatment technique requirement for control of microbials. Overview of Requirements The purpose of this table is show how the requirements for the IESWTR and LT1 ESWTR build on the existing requirements established in the original SWTR. APPLICABILITY: PWSs that use surface water or ground water under the direct influence of surface water (Subpart H) that practice conventional or direct filtration. Population Served Regulated Pathogens Residual Disinfectant Requirements Turbidity Performance Standards Disinfection Profiling & Benchmarking Sanitary Surveys (state requirement) >1 0,000 < 10,000 99.99% (4-log) removal/inactivation of viruses 99.9% (3-log) removal/inactivation of Giardia lamblia Final Rule Dates SWTR 1989 V •/ V •/ 99% (2-log) removal of Cryptosporidium Entrance to distribution system (>0.2 mg/L) Detectable in the distribution system Combined Filter Effluent Individual Filter Effluent V •/ V m IESWTR 1998 V N/A (except for sanitary survey provisions) Regulated under SWTR Regulated under SWTR ' Regulated under SWTR Regulated under SWTR •/ V Systems must profile inactivation levels and generate 1 ^ benchmark, if required H H CWS: Every 3 years NCWS: Every 5 years Covered Finished Reservoirs/Water Storage Facilities (new construction only) Operated by Qualified Personnel as Specified by State - •/ •/ V Regulated under SWTR LT1 ESWTR 2002 •/ Regulated under SWTR Regulated under SWTR V Regulated under SWTR Regulated under SWTR FBRR 2001 V •/ Regulated under SWTR Regulated under SWTR Regulated under IESWTR & LT1 ESWTR I ' •/ Regulated under IESWTR V Regulated under SWTR Regulated under SWTR (CWS) Community Water System (NCWS) Non-community Water System ------- Turbidity There are two ways turbidity is measured: Combined Filter Effluent (CFE) and Individual Filter Effluent (IFE). Turbidity 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 < 95th % limit. CFE Maximum Value Report date and value of any CFE measurement that exceeded 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 5 NTU 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 Monitor-exceedances require follow-up action 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 500 or fewer people. IFE Follow-Up and Reporting Requirements Condition 2 consecutive recordings >0.5 NTU taken 15 minutes apart at the end of the 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 2 consecutive recordings > 2.0 NTU taken 15 minutes apart at the same filter for 2 months in a IESWTR (> 10,000) Action Produce filter profile within 7 days (if cause not known) Produce filter profile within 7 days (if cause not known) Conduct filter self-assessment within 14 days Arrange for CPE within 30 days & submit report within 90 days Report >. Filter* > Turbidity value >. Date > Cause (if known) or report profile >. 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 LT1ESWTR(< 10,000)** Action 1 0th of the I following month 10th of the month 1 0th of the following month 1 0th of the following month 90 days after exceedance Conduct a filter self -assessment within 14 days. Systems with 2 filters that monitor CFE in do both filters. Arrange for CPE within 60 days & report within 120 days Report >. Filter # >. Turbidity value >. Date >. Cause (if known) >. Date filter self- assessment triggered & completed >. Date CPE triggered Submit CPE report By 1 0th of the following month 1 0th of the following month (or within 14 days of filter self -assessment being triggered if triggered in last 4 days of the month) 1 0th of the following month 120 days after exceedance ** Systems serving fewer than 10,000 people must begin complying with these requirements beginning January 1, 2005. ------- IFE performance is measured in systems using conventional or direct filtration. The performance of each individual filter is critical to controlling pathogen breakthrough. 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 hour CFE readings. 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. 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. Cryptosporidium must be removed by filtration and no inactivation credits are currently given for disinfection. Systems must also comply with the maximum residual disinfectant level (MRDL) requirements specified in the Stage 1 Disinfectants/ Disinfection Byproducts Rule (Stage 1 DBPR). Residual Disinfectant Monitoring and Reporting Requirements 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 or fewer persons 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. ------- 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 Under IESWTR & LT1ESWTR The purpose of disinfection profiling and benchmarking is to allow systems and states to assess whether a change in disinfection practices creates a microbial risk. Systems should develop a disinfection profile that reflects Giardia lamblia inactivation (systems using ozone or chloramines must also calculate inactivation of viruses), 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 IESWTR LT1ESWTR AFFECTED SYSTEMS: Community, non-transient non-community, and Community and non-transient non-community systems only. BEGIN PROFILING BY: April 1,2000 > July 1, 2003 for systems serving 500-9,999 people. > January 1, 2004 for systems serving fewer than 500 people. FREQUENCY & DURATION: 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. Weekly inactivation of Giardia lamblia (and viruses, if necessary), on the same calendar day each week over 12 consecutive months. STATES MAY WAIVE DISINFECTION PROFILING REQUIREMENTS IF: TTHM annual average <0.064 mg/L and HAA5 annual average <0.048 mg/L: > Collected during the same period. > Annual average is arithmetic average of the quarterly averages of four 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. One TTHM sample <0.064 mg/L and one HAA5 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. DISINFECTION BENCHMARK MUST BE CALCULATED IF: Systems required to develop a disinfection profile and are considering any of the following: > Changes to the point of disinfection. > Changes to the disinfectant(s) used. > Changes to the disinfection process. > Any other modification identified by the state. Systems must consult the state prior to making any modifications to disinfection practices. Same as IESWTR, and systems must obtain state approval prior to making any modifications to disinfection practices. Filter Backwash Recycling Rule The FBRR applies to PWSs that use surface water or ground water under the direct influence of surface water, practice conventional or direct filtration, and recycle spent filter backwash, thickener supernatant, or liquids from dewatering pro- cesses. 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. Filter Backwash Critical Deadlines and Requirements June 8, 2004 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 (a 2-year extension is available for systems making capital improvements to modify the recycle return location). Collect recycle flow information and retain on file. June 8, 2006 Complete all capital improvements associated with relocating recycle return location (if necessary). Office of Water (4606) EPA816-F-04-003 www.epa.gov/safewater August 2004 ------- |