SWTR FACT SHEET - EPA Region 8Requirements for Filtered Public Water Systems under the following regulations:Surface Water Treatment Rule (SWTR) - 40 CFR Part 141, Subpart HFilter Backwash Recycling Rule (Recycle provisions within Subpart H)Interim Enhanced SWTR (IESWTR) - 40 CFR Part 141, Subpart PLong Term 1 Enhanced SWTR (LT1ESWTR) - 40 CFR Part 141, Subpart TLong Term 2 Enhanced SWTR (LT2) – 40 CFR Part 141, Subpart WGENERAL INFORMATIONThe following requirements apply to Subpart H systems (those using a surface water source, or thosethat have been notified by EPA Region 8 that they are using a source determined to beGroundwater Under the Direct Influence of Surface Water (GWUDISW)). EPA may designate agroundwater system as GWUDISW at any date, based upon new information. At that point, EPA willnotify the system when the requirements outlined in this Fact Sheet begin (typically within 18 months ofthe GWUDISW determination).The original SWTR of 1989 addressed the pathogens Giardia lamblia and viruses. The SWTR was latermodified with additional requirements to address Cryptosporidium, through the Interim EnhancedSWTR (IESWTR) for systems serving at least 10,000 people, and the Long Term 1 EnhancedSWTR (LT1ESWTR) for systems serving less than 10,000 people. The main compliance dates forthe new treatment technique requirements of the IESWTR and LT1ESWTR were January 1, 2002 andJanuary 1, 2005, respectively.The LT2 Enhanced Treatment for Cryptosporidium regulation was finalized in 2006. It applies to ALLSubpart H systems. This rule requires an initial and second round of source water monitoring for eachplant that treats a SW or GWUDISW source. Based upon the monitoring results, additional treatmentfor Cryptosporidium may be required. The Subpart H, P, and T requirements discussed in this FactSheet remain in effect with the LT2 rule. For additional information on LT2, please contact EPARegion 8.The following information in this Fact Sheet deals with the ongoing requirements of these rules forsystems that filter: operating personnel, treatment technique requirements, monitoring and test methods,equipment calibration, public notice, and reporting. Note that there are additional, specificrequirements in the SWTRs (such as for unfiltered systems meeting avoidance criteria, for disinfectionprofiling, and for recordkeeping of backwash recycle rates). Please refer to the specific rules for theserequirements, or contact EPA Region 8 with questions.1

PERSONNELQualified operators Every public water system using a surface water or GWUDISW must be operatedby a qualified operator.Wyoming Public Water Systems: EPA Region 8 considers an operator qualified ifthey are certified according to Wyoming Department of Environmental Quality(WDEQ) requirements. Contact the WDEQ at (307) 777-7594 or 777-6128 oremail [email protected] for operator certification requirements and procedures.Tribal Public Water Systems: EPA Region 8 considers an operator qualified ifthey are certified at the appropriate level under an approved program operated byone of the states in Region 8 or through the EPA National Operator CertificationProgram.Approved partiesOn-site measurements of certain water quality parameters (e.g. turbidity, pH,disinfectant residual, temperature) may be made by an approved party; this issomeone under the supervision of a certified operator, who has been adequatelytrained to use the equipment needed for testing.TREATMENT TECHNIQUESObjectivesAt least 99.9% (3-log) removal and/or inactivation of Giardia lamblia cystsANDAt least 99.99% (4-log) removal and/or inactivation of viruses.The above treatment objectives can be met by combining filtration andinactivation (disinfection) barriers. You can add up the logs achieved from eachbarrier to get the total treatment for that micro-organismANDAt least 99% (2-log) removal of CryptosporidiumNote that for Cryptosporidium, the IESWTR and LT1ESWTR require that 2-logremoval be achieved by the filters; inactivation of Cryptosporidium is not creditedfor compliance with these two rules. Additional removal and/or inactivation ofCryptosporidium based on LT2ESWTR monitoring results or commitment toinstall maximum treatment may apply. Exact level of additional treatmentrequired is system specific.2

Treatment CreditWell operated/maintained filtration is granted removal credit for Giardia lamblia,viruses, and Cryptosporidium.Inactivation (disinfection) credit can be determined by CT (concentrationx time) values (or IT (intensity x time) values for ultraviolet radiation(UV)).CT is calculated by multiplying C (the concentration of free chlorine or otherdisinfectant in mg/L) by T (the disinfection contact time in minutes, at or beforethe first service connection.)Calculate CT based on your specific treatment parameters.Adequate CT should be maintained daily to consistently meet the treatmenttechnique requirements, although EPA does not require filtered water systems toprovide daily calculations. A calculator spreadsheet for daily or weeklycalculations of inactivation for Giardia and virusus can be provided upon request.UV dose values for logs inactivation by ultraviolet radiation (UV) are found in theLT2ESWTR at 40 CFR 141.720(d).Filtration Removal CreditPlease see EPA Region 8 policy SWTR #2 revised May 17, 2004 for a discussionof the various types of filtration which are acceptable for SWTR compliance, andthe associated microbial pathogen removal credits associated with each type offiltration. This information is summarized in Table 1, taken from policy SWTR#2, which indicates for each filtration type the expected log removal credits forCryptosporidium, Giardia and viruses, and the necessary remaining disinfection(inactivation) credits to achieve the treatment technique requirements. Theseremoval credits are based upon filtration systems meeting the operational anddesign requirements specified in policy SWTR #2, and consistently meeting thespecified, combined filter effluent (CFE) and individual filter effluent (IFE)turbidity requirements.Note that for Cryptosporidium, the IESWTR and LT1ESWTR require that 2log removal be achieved by the filters; inactivation of Cryptosporidium is notcredited for compliance with those rules.3

Table 1FILTRATION CREDITS FOR MICROBIAL REMOVAL, TO MEET SWTR, IESWTR andLT1ESWTR**(systems consistently meeting the CFE turbidity limits in the table below, and the operational and design requirementsoutlined in policy SWTR #2, are granted the Logs removal credit in the table below.)FILTRATIONTREATMENTTECHNOLOGYCOMBINEDFILTER EFFLUENT(CFE) TURBIDITY(95%MNTHLY/MAX)ntuMAXIMUM LOGS OF CREDIT FORPHYSICAL REMOVALMINIMUM LOGS OFINACTIVATIONNEEDED VirusesConventional*** 0.3/1***0.3/1 Sand1/5 Earth1/5 Osmosis0.3/1 2 2 2 3.0004.0Microfiltration0.3/1 2 3.0004.0Pretreatment plusBag or Cartridge(B/C) on followed by(B/C)* See policy for description of adequate pretreatment for SW and for GWUDISW using B/C Filtration2.0** Additional types of alternative filtration should be evaluated on a case-specific basis. 95th percentile and maximumturbidity values will be no more than 1 NTU and 5 NTU, respectively, for all alternative filtration technologies, unlessdifferent site specific values are assigned. All NTU rounding shall be in accordance with EPA established policy. Also,these filtration credits do not apply to point-of-use devices, which are not compliant with the SWTRs.*** Conventional, direct, and membrane filtration also have requirements for monitoring of individual filter effluentturbidity (IFE). See IESWTR and LT1ESWTR.4

MONITORING REQUIREMENTSMonthly reporting is required under the SWTRs. These reports and instructions can befound at ms-and-instructions-reportingforms. Please note that the report you should use depends upon your type of filtration andpopulation served.Public Notice requirements for the violations discussed in each section below may be found forms-and-instructions-public-notification.(I) Turbidity - REPORT TO EPA IN MONTHLY REPORTContinuous monitoring of effluent from individual filters (IFE) is required for systems usingconventional or direct filtration, as well as individual membrane units. Monitoring ofthe combined effluent from all filters (CFE) is required for every regulated filteredsystem. The CFE turbidimeter must be sited at a sampling location which is representativeof the filtered water. The CFE turbidity is most representative of filtered water turbidity inthe pipe where the individual filter effluents first combine, or near a clearwell inlet.Measuring turbidity at locations further downstream (after pumping operations or afterstorage tanks) may result in inaccurate readings due to air entrainment, particle resuspension,etc. For a further discussion on appropriate turbidimeter locations, please see EPA Region 8policy SWTR #5, dated June 30, 2003.The turbidity limits depend upon the type of filtration:Conventional and direct filtration: The turbidity level of representative samples of CFE must be less than or equal to0.3 NTU in at least 95% of the measurements taken each month. The maximum level of turbidity of the CFE must not exceed 1 NTU at any time.Since CFE may meet the regulatory requirements even though one filter is producinghigh turbidity water, the IFE must also be measured to help the operators assessindividual filter performance. IFE turbidity must be monitored continuously andrecorded at least every 15 minutes. This IFE turbidity data is kept on-site, onlysummarized results and corrective actions are reported monthly to EPA. If you havetwo or fewer filters, you can conduct the continuous monitoring of the CFE instead.Certain follow-up actions are required if the IFE turbidity (or CFE turbidity if youhave 2 filters) exceeds certain levels, typically 0.5 NTU. These followup actions caninclude additional reporting, filter profiles or self-assessments, and/or comprehensiveperformance evaluations. If you use conventional or direct filtration, PLEASEreview the regulations for these specific requirements.5

Slow sand and diatomaceous earth (DE) filtration: The turbidity level of representative samples of CFE must be less than or equal to1 NTU in at least 95% of the measurements taken each month. The maximum level of turbidity of the CFE must not exceed 5 NTU.Alternative technologies (other than conventional, direct, slow sand or DE): Operational and design requirements for alternative filtration are discussed inEPA Region 8 policy memo SWTR #2. In general, the water system mustdemonstrate that the filtration combined with disinfection consistently meets thetreatment technique requirements; specific turbidity limits for maintaining thisperformance may be set from performance demonstration data. The turbiditylimits for alternative filtration are also shown in Table 1. For membranetechnologies, the turbidity level of representative samples of CFE must be lessthan or equal to 0.3 NTU in at least 95% of the measurements taken each month;for bag or cartridge (B/C) filtration this limit is 1 NTU. Membrane systems mustcontinuously monitor filtrate turbidity from each unit/skid, and record the valuesonce/15 minutes. Membranes also have requirements for direct integrity testingof each unit. The maximum level of turbidity of the CFE must not exceed 1 NTU formembrane filtration and 5 NTU for B/C filtration.The frequency of CFE turbidity monitoring depends on the system size and type offiltration:All SystemsTurbidity must be monitored on representative samples of the CFE every 4 hours thatthe system serves water to the public.A public water system can substitute continuous CFE turbidity monitoring for 4-hourgrab samples. You must record the current CFE turbidity value at equal intervals of 4hours. Averaging of 4 hours of data, or monitoring at any other intervals longer than4 hours, is not permitted, except as discussed below.Systems serving populations 500If approved by EPA, they have the option of reducing CFE turbidity monitoringfrequency to one per day regardless of the type of treatment.6

Systems using acrylamide or epichlorohydrinMust provide annual written certification (third party or manufacturer’s certification)to EPA. The combination/product of dose and monomer level dose cannot exceed thefollowing levels:Acrylamide 0.05% dosed at 1 ppm, or equivalentEpichlorohydrin 0.01% dosed at 20 ppm, or equivalentWhat you must know about violationsA treatment technique violation results when a system cannot meet the turbiditycriteria outlined above. Public notice is required; the type of notification dependsupon the type of treatment technique violation:If at any time the CFE turbidity exceeds 5 NTU (or 1 NTU for conventional ordirect filtration, or membrane systems, pursuant to the IESWTR orLT1ESWTR), the system must inform EPA within 24 hours after learning of theviolation. EPA will consult with the system to determine if Tier 1 (24 hour) publicnotice is needed; Tier 1 is mandatory if the system does not consult with EPA within24 hours. Also, if it appears that a waterborne disease outbreak has occurred resultingfrom the water system, EPA must be notified as soon as possible, but no later than bythe end of the next business day. In this case, Tier 1 public notice is required.For other turbidity treatment technique violations, Tier 2 (30 day) public notice isneeded. For monitoring and testing procedure violations, Tier 3 (within 1 year)public notice is required.(II) Disinfection - - REPORT TO EPA IN MONTHLY REPORTDisinfectant levels must be measured at BOTH (i) the entry point to the distributionsystem and (ii) within th