Update on Recreational Water Quality Criteria and Comparison to Colorado Standards. Jane Clary, Wright Water Engineers March 18, 2013

Transcription

1 Update on Recreational Water Quality Criteria and Comparison to Colorado Standards Jane Clary, Wright Water Engineers March 18, 2013

2 The Problem Top 10 Causes of Impairment in U.S. by # of 303(d) Listings What is the human health risk? Most strains of E. coli and enterococci do not cause human illness (that is, they are not human pathogens); rather, they indicate the presence of fecal contamination. Difficult to bring streams into compliance with standards--many of these listings are not due to sewage (untreated, CSO, or SSO). Source: EPA Accessed May 2012

3 Implications for Urban Areas Stormwater Managers/MS4s MS4 permit holders must address issue due to TMDLs FIB elevated in urban runoff Storm sewer system can be a source during dry weather, too

4 Overview of White Paper Summarizing CO Work Group Effort White Paper Topics Unresolved Issues (2009) 1. Regulatory Background 2. Colorado Case Studies 3. Sources of Bacteria 4. Monitoring and Assessment of Data 5. Best Management Practices (BMPs) 6. Unresolved Issues 2012: >65 stream segments listed in on CO 303(d) or M&E lists for E. coli in 2008: 22 segments listed as impaired) 1. Inland Flowing Waters and 1986 Criteria 2. Use of E. coli as Basis for Recreational Stream Standard 3. Wildlife/Environmental Contributions and Implications for TMDLs 4. Recreational Use Classifications: Primary vs. Not Primary 5. TMDL Endpoints

5 A Brief History and What s New: EPA s Recreational Water Quality Criteria 1960s-1976: U.S. PHS & EPA (Fecal Coliform) 1986: EPA s Ambient W.Q. Criteria (E. coli & Enterococci) 2000 & 2004: Beach Act & EPA actions : Major new research Dec. 2011: EPA draft update to recreational water quality criteria Feb. 2012: Public comment period closed December 2012: Final criteria issued EPA Water Quality Criteria lead to state water quality standards (don t become effective until adopted by states)

6 Criteria and Supporting Information

7 Recreational Water Quality Criteria Basics EPA required to publish water quality criteria under Section 304(a)(1) of the Clean Water Act. intended as guidance to states in developing water quality standards to protect swimmers from exposure to water that contains organisms that indicate the presence of fecal contamination. states have the discretion to adopt other scientifically defensible water quality criteria. designed to protect primary contact recreation, including swimming, bathing, surfing, water skiing, tubing, water play by children, and similar water contact activities where a high degree of bodily contact with the water, immersion and ingestion are likely.

8 EPA s 2012 Recreational Water Quality Criteria Frequency of Exceedances: 0 for geomean & 10% for STV Duration: 30- day assessment period A few highlights: Removes use intensity considerations at beaches. No national-level exclusion for natural sources. Tools for developing alternative RWQC on a site-specific basis (e.g., QMRA). Tools for assessing and managing recreational waters, such as predictive modeling and sanitary surveys. New rapid method for enterococci using qpcr method (helpful for beaches).

9 Understanding the STV

10 Some of What s New Two sets of recommended criteria Primary contact recreation is protected if either set of criteria recommendations are adopted into state water quality standards. 2 nd set appeared after comments on draft criteria Statistical Threshold Value (STV) to be used with GM 90th percentile of the water quality distribution; should not be exceeded in more than 10 percent of samples [essentially replace the single sample maximum in 1986 criteria; not all states adopted SSM] Duration EPA now specifically recommends a duration period 30 days should be explicitly included in the state's WQS as it is a component of the WQS Duration can be static or rolling. (EPA Jan 2013 webinar)

11 Current Colorado Recreational Water Quality Classifications and Standards E. Coli Numeric Standards CLASS E (Existing Primary Contact) & CLASS U (Undetermined Use) CLASS P (Potential Primary Contact Use) CLASS N (Not Primary Contact Use) (5 x Class E) 126/100 ml 205/100 ml 630/100 ml Allowed Frequency of Exceedances: None for 2-month geometric mean Duration: Attainment based on a 2-month geometric mean. No single-sample maximum. Primary Contact: Recreational activities where the ingestion of small quantities of water is likely to occur. Such activities include but are not limited to swimming, rafting, kayaking, tubing, windsurfing, water-skiing, and frequent water play by children.

12 Comparison of New EPA Criteria vs. Colorado Reg. for Primary Contact Rec. Magnitude: Same: Geometric Mean: 126/100 ml still consistent with EPA New: Statistical Threshold Value Duration: Different: CO uses 60-day assessment period; EPA recommending 30-day Frequency: Same: No exceedances allowed for geometric mean New: 10% allowed exceedance for STV Definition of Primary Contact: Waterplay by children considered primary contact for both EPA/CO. Use Intensity EPA silent on not primary contact

13 Use Intensity and Illness Rates Use Intensity: EPA is no longer utilizing the concept of use intensity as a basis for recommending multiple SSM criteria. EPA recommends instead that states adopt both the GM and STV into their WQS for all primary contact recreation waters. EPA does not provide recommendations for other uses (e.g., secondary contact) Illness rates: Based on NEEAR definition of gastrointestinal illness, which is not limited to illnesses which exhibit a fever (explains 32 illnesses/1000 in 2012 vs. 8 illnesses/1,000 in 1986)

14 Defining Illness: NGI vs. HCGI Because the NGI definition is broader than HCGI, more illnesses qualify to be counted as cases in the epidemiological studies than if the older HCGI definition were applied. Therefore, at the same level of water quality, more NGI will be observed than HCGI illnesses. The relative increase in rates of GI illness between the studies (i.e., HCGI versus NGI) is directly attributable to the changes in how illness was defined and not due to an actual increase in the incidence of illness among primary contact recreators at a given level of water quality.

15 Number of Samples Number of Samples The number of samples, to be collected by a state in determining if WQS have been exceeded, is not an approvable element of a WQS package (Florida Public Interest Research Group vs. EPA, 2007). Therefore states should not include a minimum sample size as part of their criteria submission. EPA is recommending that states conduct at least weekly sampling to evaluate the GM and STV over a 30-day period and encourages more frequent sampling at more densely populated beaches. The GM and STV would apply regardless of the number of samples. (from EPA Jan webinar)

16 Health Risk from Different Fecal Sources Human pathogens are often present in animal fecal matter, and thus, there are risks associated with recreating in animal-impacted waters...quantifying that level of risk associated with animal fecal material is difficult, and the methods necessary to distinguish between human and nonhuman fecal sources, with the appropriate level of confidence, are still under development. EPA is not developing recommendations that take source of fecal contamination into account. human health risk associated with exposure to waters impacted by animal sources can vary substantially. In some cases these risks can be similar to exposure to human fecal contamination, and in other cases, the risk is substantially lower. states interested in adopting different standards to address the variability in human health risks associated with different sources of fecal contamination on a site-specific basis should refer to methods for developing site-specific standards [in the new criteria].

17 QMRA Basics (Soller et al. 2010)

18 Changes Affecting Beach/Marine Criteria New Early Alert Tool (for beach goers) EPA is providing precautionary Beach Action Values (BAVs) for use in early alert notification programs. A Single Level of Beach Use The 1986 bacteria criteria document included four single sample maximum (SSM) values appropriate for different levels of beach usage (use intensities). Similar Protection for Fresh and Marine Waters NEEAR water quality data to refine the illness rate estimate for the recommended marine criterion for enterococci. The 2012 RWQC values now protect public health similarly in both marine and fresh waters.

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21 Inland Flowing Waters (a few selected notes) Few Epidemiological Studies EPA also evaluated the available epidemiological evidence in non-coastal waters. Only a handful of studies have been conducted in small lakes and even fewer in inland flowing waters Ohio Study: [epi. study of a] small inland lake in Ohio (Marion et al., 2010) concluded that E. coli was significantly associated with an elevated GI illness rate among swimmers compared to nonswimmers. The predicted illness rate increased among swimmers with increasing densities of E. coli. Not Enough Information for Different Criteria: Although some differences may exist between coastal and noncoastal waters, those differences were not significant enough to justify the development of different WQC recommendations for non-coastal waters.

22 Waterbody Type Differences exist in FIB loadings between waters that are WWTP-impacted and waters impacted by sources FIB survival compared to pathogen survival may differ between coastal and non-coastal waters. Some of the potential differences between coastal and non-coastal waters that may impact survival include extent of shading, hydrodynamics, potential for sedimentation, and microbial ecology. studies found the distinction of non-coastal waters versus coastal waters is of less importance than more fundamental variables, such as the source of fecal contamination, scale of the body of water, and the effects of sediment, which translate into differences in the densities, transport, and fate of indicators and pathogens (Dorevitch et al., 2010).

23 Alternate Water Quality Standards EPA recognizes that the NEEAR studies (i.e., waters primarily impacted by secondary-treated and disinfected POTW effluent) may not be representative of all possible fecal contamination combinations that could impact recreational bodies of water. Tools to support States considering alternate WQS: 1. Epidemiological studies Epidemiological studies are resource intensive and logistically difficult 2. QMRA [Quantitative Microbial Risk Assessment] Analogous to chemical risk assessment. Useful where nonhuman sources are predominant cause of fecal contamination. 3. Novel fecal indicators and analytical methods. If a consistent and predictable relationship exist between the enumeration methods and an established indicator-health relationship Look for TSMs on these topics and others.

24 Implementation Materials Weblink: lth/recreation/upload/2012-rwqc-implementation- Materials.pdf

25 January 30, 2013 EPA Webinar

26 Where from here? States with non-beach Act waters are encouraged to review and revise as appropriate their RWQS during their next triennial reviews. Next Colorado Basic Standards (Regulation 31) Rulemaking Issues Scoping: October 2014 Issues Formulation: November 2015 Rulemaking Hearing: 2016 TMDLs--E. coli listings are high priority on 303(d) List not dependent on new standards. Learn from new Technical Support Materials (TSMs) related to source identification and other topics. Innovative studies in Colorado--QMRA?

27 Questions? Jane Clary Wright Water Engineers See the EPA Website for complete information: EPA Webinar on January 30, 2013:

28 Additional Discussion from January 2013 E. coli Work Group Presentations (only if time allows)

29 Briefly Tools to Reduce Bacteria in Runoff & MS4s IDDE (Identify/Remove Illicit Discharges Infrastructure Repairs Other Source Controls (pets, urban wildlife, dumpsters) Passive Structural BMPs Active Treatment: Disinfection

30 International Stormwater BMP Database Statistical analysis updated April 2012 Includes new statistical characterizations Hypothesis testing FIB data set has grown E. coli Fecal coliform Enterococcus Still important to caveat findings based on # studies & # events

31 BMP # S, #E BR 3, 54 E. Coli Inflow-Outflow Boxplots BS 5, 39 DB 3, 32 GR 3, 39 RP 4, 69 WB 3,

32 Enterococcus Inflow-Outflow Boxplots BMP # S, #E BR 3, 49 MD-d 1,32 MD-ii 5,46 RP/WB 5,

33 General Conclusions Related to BMP Performance Data set remains limited for most BMP category-fib combinations. Results to date do not support attainment of numeric effluent limits for FIB in stormwater. Retention (wet) ponds appear to provide best performance on a density/concentration basis. Bioretention and other infiltration-oriented practices can reduce bacteria loads by reducing frequency and volume of runoff. Disinfection works at point of outfall, but not realistic in many contexts. Some BMP types appear to export bacteria.

34 Nebraska Case Study: Cost Estimates for E. coli TMDL 7.7 sq. mi. Antelope Creek Watershed, Lincoln Source load estimates by land use & BMP evaluation using WinSLAMM Curb-cut bioretention retrofits identified as a key BMP Est. Cost: $57 million over 40- year plan ($7.4 M/sq. mi.) City will start w/ source controls and pilot projects using 5-year plans

35 A few selected slides from E. coli Work Group Presentation.

36 Slide Source: Brandon Steets, Geosyntec Consultants, Santa Barbara, CA

37 Slide Source: Brandon Steets, Geosyntec Consultants, Santa Barbara, CA

38 Slide Source: Brandon Steets, Geosyntec Consultants, Santa Barbara, CA

39 Slide Source: Brandon Steets, Geosyntec Consultants, Santa Barbara, CA