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Long-Term 2 ESWTR

Long Term 2 Enhanced Surface Water Treatment Rule Bruce Macler USEPA Region 9 415 972-3569 macler.bruce@epa.gov. Long-Term 2 ESWTR. Provides for additional disinfection to control Cryptosporidium Will require extensive initial Cryptosporidium and E. coli monitoring in sources

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Long-Term 2 ESWTR

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  1. Long Term 2 Enhanced Surface Water Treatment RuleBruce MaclerUSEPA Region 9415 972-3569macler.bruce@epa.gov

  2. Long-Term 2 ESWTR • Provides for additional disinfection to control Cryptosporidium • Will require extensive initial Cryptosporidium and E. coli monitoring in sources • Monitoring results will determine additional treatment requirements beyond IESWTR/ LT1ESWTR • Disinfection profiling for all systems • All finished water reservoirs must be covered • Rule proposed August 11, 2003 • Federal Register v. 68, n.154, pp47639-47688 • Final Rule expected December 15, 2005*

  3. *Regulatory Schedule • LT2 ESWTR expected to be signed by EPA Administrator on December 15th • Publication in Federal Register is official “promulgation” date- January? • 60-day Congressional review hold • Rounded to beginning of following month for “effective” date • April 1, 2006 starts the ball rolling

  4. Applicability and Purpose • Applies to all systems using surface water, or ground water under the direct influence of surface water • Purpose is to provide additional health protection from pathogenic microorganisms, especially Cryptosporidium • Supplements existing regulations by focusing on systems with higher risk • Filtered systems with high source water occurrence • All unfiltered systems

  5. Existing Regulations • IESWTR and LT1 ESWTR • Require 99% (2-log) removal of Cryptosporidium in all filtered systems • Do not require treatment for Cryptosporidium in unfiltered systems, except through watershed control • Do not require existing finished water reservoirs to be covered

  6. New Data on Cryptosporidium • Occurrence • Source water occurrence overall is lower than previously thought • However, relatively high levels for some filtered systems • Finished water occurrence relatively higher in unfiltered systems • Infectivity greater than previously estimated • New treatment technologies available • UV light

  7. Crypto monitoring Treatment installation Possible extension Crypto monitoring 1 1 Crypto monitoring Treatment installation Possible extension Crypto Monitoring 2 2 Crypto monitoring Treatment installation Possible extension Crypto Monitoring 3 3 E. coli 4 4 Crypto E. coli Treatment installation Possible extension Crypto Crypto Monitoring E. coli Treatment installation Possible extension Crypto Implementation Schedule 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 >100,000 50K-100K 10K-100K <10,000

  8. Monitoring Requirements • Details very specific to system type • Filtered systems serving 10,000 or more people monitor for Cryptosporidium, E. coli and turbidity • At least monthly for 24 months • Filtered systems serving <10,000 monitor initially only for E. coli • Biweekly for 12 months • If above benchmarks, then must do Cryptosporidium twice a month for 12 months • No monitoring for filtereds if 5.5-log treatment • All unfiltered systems monitor for Cryptosporidium • 10,000 or more: monthly for 24 months • <10,000: twice a month for 12 months • No monitoring if 3.0-log Crypto inactivation in place

  9. Source Water Monitoring at Large Filtered Systems (100,000 People) • Turn in sampling plan by June 30, 2006 • Does not need to be approved • Sample at least monthly for Cryptosporidium, E. coli, and turbidity for 24 months beginning October 1, 2006 • Begin second round of monitoring six years after bin classification • Exempt if system provides at least 5.5 log Cryptosporidium treatment

  10. Monitoring for Other Larger Systems • Same requirements, different start times • 50,000-99,999 people served • Monitoring plan in by December 31, 2006 • Begin monitoring April 1, 2007 • 10,000-49,000 people served • Monitoring plan in by September 30, 2007 • Begin monitoring January 1, 2008

  11. Bin Classification for Large Filtered Systems • Determination of bin assignment depends on number of samples taken • For systems conducting monthly sampling, calculate running annual averages for Cryptosporidium, and use the highest of these averages • For systems conducting semi-monthly (or more frequent) monitoring, calculate the mean concentration of all 48 (or more) samples

  12. Source Water Monitoring at Small Filtered Systems (<10,000 People) • Initial E. coli screening analysis to determine if Cryptosporidium monitoring is required • Bi-weekly E. coli sampling for one year • If mean E. coli exceeds trigger value, then semi-monthly Cryptosporidium sampling for one year • Mean E. coli > 10/100 mL for lake/reservoir sources • Mean E. coli > 50/100 mL for flowing stream sources • Bin classification based on mean Cryptosporidium concentration • Systems below E. coli trigger levels incur no additional monitoring or treatment requirements

  13. Filtered System* Bin Classification and Treatment

  14. *Filtered System Bin Classification and Treatment • Treatment requirements listed in table apply to systems using conventional, slow sand, or diatomaceous earth filtration • Based on assumption of 3 log average removal • Direct filtration systems must provide an additional 0.5 log Cryptosporidium treatment for Bins 2-4 (i.e., 1.5, 2.5, and 3.0 log) • Alternative filtration systems must provide totalCryptosporidium treatment of 4.0, 5.0, and 5.5 log in Bins 2-4 as determined by State

  15. Source Water Monitoring at Unfiltered Systems • Large systems (>10,000) monitor Cryptosporidium monthly for 24 months • All small systems monitor Cryptosporidium semi-monthly for 12 months • E. coli and turbidity monitoring not required • Already required, actually • Exempt if system currently provides at least 3 log Cryptosporidium inactivation

  16. Initial Monitoring: Unfiltered > 10,000 • Monitor: • Crypto • Frequency: • Monthly for 24 months • Already monitor for E. coli and turbidity for other SWTRs • Continue this monitoring

  17. Treatment by Unfiltered Systems • All unfiltered systems must provide Cryptosporidium inactivation • If mean Cryptosporidium concentration is >0.01 oocysts/L, systems must provide at least 3 log Cryptosporidium inactivation • Otherwise must provide at least 2 log Cryptosporidium inactivation • Must use chlorine dioxide, ozone, or UV for Cryptosporidium inactivation • Must use two disinfectants for overall Cryptosporidium, Giardia, and virus inactivation

  18. More Monitoring Details • Submit sampling plan with schedule 3 months before beginning monitoring • Schedule must specify calendar date when each sample will be collected • Does not have to be approved • Collect sample within 2 days of the dates on the schedule • If system cannot sample on scheduled date due to dangerous or unforeseen conditions, then sample as close to date as feasible • If method requirements are violated, then collect replacement sample within 14 days of notification

  19. Analytical Method for Cryptosporidium • EPA Method 1622 or 1623 • Sample volume analyzed must be at least 10 L or packed pellet volume of at least 2 mL or volume passed through 2 filters • QC criteria include analysis of matrix spike samples initially and after every 20 samples from a given plant • Labs must be certified by EPA or equivalent State program

  20. Calculation of Sample Concentration • Individual sample concentrations based on total number of oocysts counted in each sample (unadjusted for recovery), including empty oocysts and other oocysts that may not be viable • In samples where no oocysts are detected, concentrations are assigned a value of 0 oocysts/L

  21. Sampling Location Requirements • Samples must be taken at intake prior to any treatment (except as described below) • Systems that add chemicals at intake must sample as close to intake as possible, at similar depth and distance • Special directions for systems using bank filtration, off-stream storage, presedimentation, or multiple sources

  22. Source Water Sampling Location for Bank Filtration Processes If the system does not have a treatment plant following bank filtration, then sample at the source of the water* Treatment Plant Well If the system has a treatment plant following bank filtration, then take sample after well and prior to the next treatment application Riverbank Filtration *Systems using GWUDI that meet the filtration avoidance criteria (i.e., are unfiltered systems) must sample the well

  23. Source Water Sampling for Raw Water Storage or Presedimentation Processes River Raw Water Storage or Presedimentation Basin Treatment Plant Collect sample at effluent of storage or presedimentation basin or as close to it as possible. Sample must be collected before start of any other treatment (e.g., sedimentation tank, disinfectant addition)

  24. Source Water Sampling for Multiple Sources • Must sample where the sources are combined, if sample tap is available • If combined source tap is not available then sample each source separately and determine a weighted average concentration using one of two methods (see next slide)

  25. Sampling for Multiple Sources Separately 2 MGD 1 MGD River Lake 1) Combine into one sample, proportional to flows. Analyze combined sample. + = 3.33 L River Sample 10 L Combined Sample 6.67 L Lake Sample 2) Analyze sample from each source. Calculate a flow-weighted average. 1 oocyst/10 L = 0.1 oocysts/L x = 0.067 oocysts/L 10 L Lake Sample + = 0.133 oocysts/L 10 L River Sample 2 oocysts/ 10 L = 0.2 oocysts/L x = 0.067 oocysts/L

  26. Grandfathering Monitoring Data for Bin Classification • Existing Cryptosporidium data may be used for bin classification if approved by EPA • Data must meet same conditions as data collected under LT2ESWTR (i.e., same method, sampling frequency, sampling location, volume analyzed) • Systems with less than 2 years of existing data may use these data for bin classification but must conduct additional monitoring until they have a total of 2 years of data

  27. EPA Implementation Support • Large systems will report initial sampling schedule and monitoring results to EPA • Data system for electronic reporting and review of monitoring results • States will have full access to their systems’ data • Guidance manuals and help line will address sampling and analysis questions • Draft guidance available with proposal • Results from small system and from 2nd round of monitoring will be reported to States • Ongoing EPA laboratory certification program for Cryptosporidium analysis

  28. UV Light Pre-sedimentation basin Ozone Chlorine dioxide River bank filtration Slow sand filters Manage timing or level of withdrawal Lower finished water turbidity Membranes Bag and cartridge filters Intake relocation Microbial Toolbox Watershed Control Program Inactivation Demonstration of Performance Improved Treatment Alternative Source Pre-treatment • Options can be used singly or in combination to meet treatment requirements • Systems must meet criteria specific to each option to be granted treatment credit

  29. Source Toolbox Options

  30. Pre-Filtration Toolbox Options

  31. Treatment Performance Toolbox Options

  32. Additional Filtration Toolbox Options

  33. Additional Filtration Toolbox Options (cont.)

  34. Inactivation Toolbox Options

  35. Additional Requirements for Unfiltered Systems • Systems using chlorine dioxide or ozone may not fail to achieve required Cryptosporidium inactivation more than one day a month • Systems using UV must meet required Cryptosporidium inactivation for at least 95 percent of water delivered to public each month

  36. Uncovered Finished Water Reservoirs • Compliance options (to be in place 36 months after promulgation) • Cover • Treat to achieve at least 4 log virus inactivation • Implement State-approved risk mitigation plan addressing access and site security, surface water runoff, animal waste, and ongoing water quality assessment

  37. Disinfection Profiling and Benchmarking • Systems must monitor weekly for 12 months during peak hourly flow to determine Giardia and virus inactivation profiles • Existing profiles and historical operational data may be used, if disinfection practices have not changed • Transient noncommunity systems are exempt • Small systems may be exempt, based on disinfection byproduct levels and E. coli monitoring results

  38. Disinfection Profiling and Benchmarking (cont.) • Systems that plan to make a significant change in their disinfection practice must calculate a disinfection benchmark (from data collected during profiling) and notify State • Benchmarks are defined as the lowest mean monthly values of Giardia and virus inactivation

  39. Related State Requirements • Records kept by states • E. coli and Cryptosporidium monitoring results • Bin classification for each filtered system • Determination of whether each unfiltered system is above 0.01 oocysts/L • The treatment measures systems use to meet Cryptosporidium treatment requirements under the LT2ESWTR

  40. Related State Requirements • Reports by States • Bin classification for each filtered system • Determination of whether each unfiltered system is above 0.01 oocysts/L • Special Primacy Conditions • How states will assess significant changes in the source water as part of the sanitary survey and determine appropriate follow-up actions by systems

  41. Related State Requirements • Records kept by states • A list of systems required to cover or treat the effluent of an uncovered finished water reservoir • A list of systems for which the state has waived the requirement to cover or treat an uncovered finished water reservoir and documentation of the risk mitigation plan

  42. Implications for R9 DW Systems • Monitoring will be expensive and a nuisance • With respect to monitoring results and treatment, probably little • Source waters appear to be low for Crypto • Most utilities should have no additional treatment • Sources with dairy or animal husbandry may be impacted

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