Response: EPA does not take the position that nonhuman and human sources are equal in health risk. Section 3.5 indicates that waters impacted by nonhuman sources may carry risks. Because these risks are possible under some situations, national criteria for nonhuman sources are not appropriate. The site-specific nature of nonhuman sources is one reason EPA is developing tools to assist states that want to adopt site-specific alternative WQC to take into account the variation in risk from nonhuman sources. The final RWQC text has been edited accordingly.

Agree with EPA Approach to Apply Criteria to All Sources

Comment: Commenters agreed with EPA that the risk presented by fecal contamination from nonhuman sources varies and has been shown in some cases to be potentially less significant than the risk presented by fecal contamination from human sources; they also agreed that not all animal fecal material presents the same level of risk.

Response: Thank you for your comment.

Comment: Commenters agreed with EPA's efforts in developing criteria that consider all fecal sources as a potential human health risk rather than advocating for the development of separate national criteria for nonhuman sources of fecal contamination of recreational waters.

Response: EPA thanks the commenters for their support and agrees that it is appropriate for national criteria recommendations to consider all fecal sources at this time. In addition, EPA believes that site-specific alternative WQC might be appropriate for some waterbodies.

Comment: Commenters thought that Soller et al. (2010) indicates that only bird guano has the potential to generate false positives. Feces from cow, pig, etc. are high in pathogens and people should not be exposed to them.

Response: EPA acknowledges that animal wastes from many different animal sources may contain zoonotic pathogens. The research the commenter mentions has been continued and expanded to other animals. Soller et al (2010) indicates that cattle under certain scenarios (e.g., accounting for fecal loading, diet, and shedding status) can result in risks similar to human fecal material.

Comment: Commenters asked that EPA consider requiring proof of the nonhuman source (i.e., birds) as the primary cause of high Enterococcus spp. concentrations.

Response: EPA expects that its TSM for site-specific alternative WQC will include details on demonstrating the predominance of a nonhuman source. Case studies may also be included to show users how the support for site-specific criteria may be built and documented.

Comment: Commenters thought that there is insufficient data to allow development of criteria for situations where fecal contamination is primarily from nonhuman sources.

Response: EPA believes that there is insufficient data available at this time to develop national criteria for situations where fecal contamination is primarily from nonhuman sources. However, EPA believes that site-specific alternative criteria might be appropriate for some waterbodies.

Issue 3.6 Expression of Criteria

Support for Continuing with 1986 Values

Comment: Commenters expressed support for the use of the GM for expression of WQC, and for this draft RWQC carrying the same level of protection forward and adopted criteria values for the culture methods as the 1986 criteria values. They supported the rationale and science that this recommendation is based upon and urged EPA to expand the explanation and rationale for keeping the 1986 values.

Response: Based on EPA's review of public comments and further scientific analyses, EPA has decided to modify the criteria as explained in section 3.6.2 of the RWQC document.

Issue 3.6.1 Use of the STV for Beach Notification

Support for STV Approach for Beach Notification

Comment: Commenters expressed support for the concept of a STV (formerly SSM) as part of the recommended criteria for marine and fresh waters. They agreed that the use of the 25% excursion allowance of the STV makes sense when one considered the statistical distribution of bacteria water quality. They also expressed anticipation that the additional clarity provided by EPA in using the STV (as a replacement for SSM) will reduce inconsistencies in interpretation of SSM values and implementation of the bacteria criteria. Commenters supported EPA's clarification in the draft RWQC that the interpretation of SSM values as not-to-be exceeded values effectively creates a WQS that is more stringent than is needed to be protective of primary contact recreation. They agreed that 25% excursion allowance of the STV is more scientifically correct than a "never to exceed" value.

Response: Based on EPA's review of public comments and further scientific analyses, EPA has decided to modify the criteria as explained in section 3.6.2 of the final RWQC document. The STV is based upon the 90[th] percentile of the water quality distribution. EPA has determined that a maximum 10% frequency of excursions (ambient conditions worse than those described by the combination of the criterion magnitude and criterion frequency) is consistent with full support of primary contact recreation.

When to Apply STV

Comment: Commenters thought that the GM and STV concepts are inconsistent and urged EPA to apply the GM whenever more than one sample is available and the STV when only one sample is available.

Response: EPA disagrees that the GM and STV concepts are inconsistent. These concepts are consistent with water quality observations, and accurately describe, in a statistical sense, conditions which will be protective of the designated use of primary contact recreation. EPA guidance regarding monitoring and assessment of waterbodies for 303(d) listing and 305(b) reporting purposes appears in the Agency's Integrated Reporting Guidance (IRG) (U.S. EPA, 2006). Commenters may find the sections on data set size and the degree to which certain sampling data is likely representative of WQC-relevant waterbody conditions to be of particular interest.

Comment: Commenters requested explicit recognition of "uncontrollable sources" and site-specific STV calculations to account for "uncontrollable sources."

Response: Section 6 of the RWQC document describes tools for managing and assessing waters on a site-specific basis. The term "uncontrollable sources" is not well defined enough to be sure what sources the commenters are including. EPA is not providing national criteria for different sources.

Comment: Commenters suggested that EPA explicitly recommend the use of the STV (75th percentile) in waters of all states, including waterbodies receiving predominantly urban runoff.

Response: Based on EPA's review of public comments and further scientific analyses, EPA has decided to modify the RWQC as explained in section 3.6.2 of the final RWQC document. The STV is based upon the 90[th] percentile of the water quality distribution. EPA has determined that a maximum excursion rate of 10% (frequency = 10%) is consistent with full support of primary contact recreation. The recommended RWQC (including the GM and STV) are recommended for all U.S. waters regardless of source.

Comment: Commenters asked EPA to clarify that the STV is generally applicable to (and protective of) both wet and dry weather, flowing streams and beaches, marine and fresh water, urban runoff, and WWTP-impacted waters.

Response: The final RWQC are protective of the designated use of primary contact recreation for U.S. waters. This statement applies to flowing streams and beaches, marine and fresh water, and WWTP-impacted waters.

Comment: Commenters asked that EPA clarify that the STV is protective of urban runoff beaches (if that is the case) based on epidemiological data that were considered.

Response: The final RWQC are protective of the designated use of primary contact recreation in all waters regardless of source. EPA's perspective is consistent with the available epidemiological data which were considered in the development of the final RQWC.

Comment: Commenters indicated that the FR notice should indicate that the excursion rate of 25 percent applies for CWA purposes other than beach notifications.

Response: Based on EPA's review of public comments and further scientific analyses, EPA has decided to modify the RWQC as explained in section 3.6.2 of the final RWQC document. The STV is based on the 90[th] percentile of the water quality distribution with 10% frequency of excursions allowed.

Suggested Changes to STV

Comment: Commenters suggested that EPA retain and/or expand the use of a SSM criteria and offered options that included daily excursions, weather-adjusted excursions, and changing the maximum excursion rate from 25 to 10 percent, or in other comments, to 0 percent. Commenters noted that the STV as defined as the 75th percentile concentration seems to be grandfathered in from the original 1986 document that defined a SSM as the 75th percentile concentration. However, the 75th percentile concentration seems to be arbitrary. These commenters thought that there was a lack of scientific evidence from epidemiological studies that the 75th percentile concentration was based on any cause-effect relationships between Enterococcus spp. distributions and illness rates. They asked what the justification was for using this percentile.

Response: Based on EPA's review of public comments and further scientific analyses, EPA has decided to modify the criteria as explained in section 3.6.2 of the final RWQC. The STV is based upon the 90[th] percentile of the water quality distribution. EPA has determined that a maximum 10% frequency of excursions (ambient conditions worse than those described by the combination of the criterion-magnitude and criterion frequency) is consistent with full support of primary contact recreation. Please see section 3.6.2 of the final RWQC for additional discussion.

Comment: Commenters suggested EPA maintain the SSM approach and/or strengthen the STV or even withdraw it. They argued that the STV has little statistical value, and that the SSM approach is an invaluable tool for public health protection and risk management (beach closures and postings), as well as a regulatory tool to ensure that beneficial uses are protected.

Response: EPA is not recommending an SSM value, as explained previously. The STV approximates the 90th percentile of the water quality distribution and is intended to be a value that should not be exceeded by more than 10 percent of the samples used to calculate the GM. For the STV, EPA selected the estimated 90th percentile to take into account the expected variability in water quality measurements, while limiting the number of excursions above the STV, and to encourage additional monitoring. In addition, EPA is providing BAVs as an option for states to use for beach notification purposes (such as advisories and closings), see section 5.1 of the final RWQC document.

Comment: Commenters suggested that an STV that allows up to a 25 percent excursion rate for beaches has the potential to permanently mask chronically polluted beaches, and is therefore inappropriate. They suggested that the GM and STV together should be used to make beach management decisions. These commenters urged EPA to provide additional analyses to substantiate the 104 cfu per 100 mL SSM criteria regarding the association between an FIB SSM and adverse health effects. They suggested that EPA complete a more thorough analysis of existing epidemiological data to determine the SSM enterococci density associated with the health risk based on EPA's determined acceptable risk.

Response: Based on EPA's review of public comments and further scientific analyses, EPA has decided to modify the criteria as explained in section 3.6.2 of the final RWQC document. The STV is based upon the 90[th] percentile of the water quality distribution. EPA has determined that a maximum 10 percent frequency of excursions (ambient conditions worse than those described by the combination of the criterion-magnitude and criterion frequency) is consistent with full support of primary contact recreation. Both the GM and STV apply independently and would need to be evaluated to determine whether or not water quality in a given waterbody meets the WQS for primary contact recreation. EPA believes that a shorter duration (30 days), coupled with limited excursions above the STV, allows for the detection of transient fluctuations in water quality in a timelier manner than over a greater period of time (e.g., a recreational season). EPA is also providing BAVs as an option for states to use for beach notification purposes (such as advisories and closings).

Document is Not Clear on Applications to Different CWA Programs

Comment: Commenters indicated that the document does not distinguish between criteria for recreational water monitoring programs and other programs (use attainment, 303(d), etc.)

Response: The final RWQC specifically specify levels of water quality that are protective of the designated use of primary contact recreation. Please see section 5.1 of the final RWQC for discussion of BAVs for beach notification and section 3.6 for discussion of other CWA programs.

Support for Retaining the SSM

Comment: Commenters thought that the SSM was intended to be applied as a value not to be exceeded and applied in that way is neither restrictive nor overprotective. They supported the use of a SSM rather the STV for identifying, tracking, and posting chronically polluted beaches to EPA's 303(d) list.

Response: EPA is providing an STV as one component of the recommended criteria. If adopted in a State standard, the GM and the STV together would be the applicable WQS for CWA programs such as listing and NPDES permits. Additionally, EPA is proving BAVs as a precautionary tool for states to use for beach notification purposes (such as advisories and closings).

Comment: Commenters argued that the proposed STV runs contrary to the November 2004 WQS for Coastal and Great Lakes Recreation Waters where EPA indicated that single samples were only necessary for beach closure/notification purposes.

Response: EPA has clarified the use of STV criteria value and the BAVs in the final RWQC document. Please see sections 3.6 and 4.0.

Comment: Commenters argued that the STV is simply the upper bound confidence level around the GM; hence, it has no scientific meaning and is a policy statement.

Response: The STV represents an upper percentile of the water quality distribution that, when used in conjunction with the GM, is protective of the designated use of primary contact recreation.

Comment: Commenters suggested EPA maintain the reliance on the GM as providing the intended level of health protection and leave any use of the STV to the discretion of the states.

Response: The GM and the STV serve two different purposes. The GM protects the long-term health of the waterbody, while the STV catches short-term excursions. The STV ensures that the variance of the water quality distribution in a waterbody is consistent with the water quality that is protective of the designated use of primary contact recreation. States do have the flexibility to adopt WQS that are more stringent than the recommended final RWQC.

Site-specific Standard Deviations to Determine STV

Comment: Commenters asked EPA to clarify whether states could use their own site-specific data distributions (standard deviations) to determine their own STVs, particularly for inland waters. They requested the criteria incorporate site-specific standard deviation (variability) for calculation of the STV because the costs may be difficult for states to justify without new data for inland waters.

Response: As discussed previously, states may adopt WQC into their WQS that differ from EPA's recommended WQC. EPA would evaluate any such criteria to determine whether they are scientifically defensible and protective of the primary contact recreation use.

Other Comments

Comment: Commenters indicated that a 90-day period is necessary to correctly evaluate compliance with the STV.

Response: Based on EPA's review of public comments and further scientific analyses, EPA has decided to modify the criteria as explained in section 3.6.2 of the RWQC document. An averaging duration of 30 days is recommended for computing GMs and STVs for decisions relating to use attainment.

Comment: Commenters urged EPA to clarify the appropriate application and intent of the revised recommendations, because the use of the averaging period and STV differ for beach notifications versus CWA §303(d) listing purposes.

Response: Beach notification decisions can be made using the same data that are collected for §303(d) listing purposes. See section 3.6 in the final RWQC document for information on GM and STV for CWA purposes and section 5.1 for BAVs for beach notification.

Comment: Commenters urged EPA to define "single sample". Some states take multiple (3) samples at a beach on a given day to gain more confidence in determining the indicator density for that beach at the time of sampling. They calculate an average or mean of the results and compare that number with the 75th percentile SSM (STV) to make a beach management decision. Within this context, commenters asked how EPA would interpret `single sample.' A commenter asked for clarification about how to handle duplicate or triplicate samples.

Response: FIB can be highly variable even over short time periods. The GM and STV are used to describe a water quality distribution that would be protective of primary contact recreation use. For computation of the 30-day GM and comparison to the STV, each of the samples should be treated independently so that each sample can be used to most accurately estimate the water quality distribution at that location. For daily beach notification decisions, if multiple samples are available for a particular site, the best estimate of the water quality is the GM. Therefore, if multiple daily samples are available for a particular site, the daily GM for those samples can be compared to the BAV.

Comment: Commenters suggested that the title of the section include `and GM,' unless the STV concentration is identical to the GM concentration. Commenters recommended that EPA set the SSM or STV at the GM level and guide states to close or issue advisories for recreational waters when single samples exceed the STV for acute contamination. Based on program experience, a commenter argued for use of short-term GM (as opposed to STV values) in making beach postings or closure decisions when using culturable methods. Commenters asked for clarification regarding EPA's allowance of short-term GM use for beach advisories (for manager use or for Healthy Beaches program).

Response: EPA is offering BAVs that can be used as a threshold for beach notification decisions based on individual samples.

Comment: Commenters disagreed with EPA's suggested use of the actual detection limits for the GM calculation for observations reported below the detection limit, and recommended that instead the non-detects be replaced with the median value of the observed samples.

Response: EPA guidance regarding monitoring and assessment of waterbodies for CWA §303(d) listing and §305(b) reporting purposes appears in the Agency's IRG (U.S. EPA, 2006). Commenters may find the sections on data screening to be of particular interest.

Comment: Commenters thought that the use of the STV may result in more beach closures than are necessary based on the epidemiological data.

Response: Beach notifications will occur only when there are excursions of the STV. EPA believes that the STV is protective of the recreational use.

Comment: Commenters suggested that EPA not rely on states to implement more conservative standards than what is recommended.

Response: The CWA allows states to adopt standards that are more stringent than the EPA's recommendations, should they deem that appropriate.

Comment: Commenters asked why both the GM and STV must be included if they are equivalently stringent.

Response: Based on EPA's review of public comments and further scientific analyses, EPA has decided to modify the draft RWQC as explained in sections 3.6.2, 4.0, and 4.1 of the final RWQC document. The GM and STV serve two different purposes. The GM protects the longer-term health of the waterbody, while the STV with ten percent allowable excursion frequency catches short-term fluctuations. Either measure alone is not sufficient to protect the primary contact recreation designated use. Statistically the GM indicates where the water quality distribution lies on the X-axis and the STV indicates the width of the WQ distribution (i.e., how spread out the data are around the GM).

Lognormal Distribution and Standard Deviation of Water Quality Data

Comment: Commenters argued with numerical and visual examples that beach water data quality results do not generally fit a lognormal distribution.

Response: Actual water quality at a beach tends to be log-normally distributed, based on the fact that water quality data typically span many orders of magnitude and that the distributions are right skewed since they are bound by zero on the left. General environmental sampling data tend to follow log-normal distributions, a phenomenon discussed by Esmen and Hammad (1977). The use of the GM for recreational WQC is discussed in detail and further justified by Wymer and Wade (2007). Additionally, the GM has been used by numerous researchers to discuss the central tendency of water quality at beaches (for examples, see Boehm et al., 2009 and Whitman et al., 2004). Importantly, the GM was used for the draft RWQC because the GM at the NEEAR beaches is linked to health effects.

The commenters present a valid point  -  that data sets from some beaches may not fit a log-normal distribution. However, based on data from the NEEAR beaches, and studies from the literature, if enough data are collected and the samples below the detection limit are treated in statistically rigorous manner, the log-normal distribution tends to be a good fit for most data sets. For example, WHO based their recreational water Guidelines (WHO, 2003) on a lognormally distributed dataset from the E.U. from over 11,000 bathing locations and over 121,000 enterococci observations (Kay, et al. 2004). In addition, even in cases where beach water quality is not log-normally distributed, application of the recommended RWQC, if attained, should provide protection consistent with full support of primary contact recreation. Martinez et al. (2010) examined data sets from beaches in the European Union and found beach classification for beaches with data that were not log-normally distributed was generally unchanged when using parametric methods versus non-parametric methods to estimate percentiles.

Comment: Commenters also argued that beach water data quality results do not generally have the same log10 standard deviation as those assumed by the proposed criteria and pointed out that yearly variations exist. In view of site-specific variations, the commenters urged EPA to permit each jurisdiction to establish its own site-specific standard deviation values, and thus allow site-specific STV value for a universal GM limit.

Response: The commenters are correct that there is variation in the log10 standard deviation. The recommended final RWQC is based on a standard deviation of 0.44. Higher variances than this may give rise to more illnesses than deemed tolerable, even if the beach meets the GM. Together, the recommended GM and the STV describe waterbodies that would protect the designated use of primary contact recreation. The STV value ensures that even when a waterbody meets the GM criteria, its variability is constrained, such that high values would be captured.

Comment: Commenters pointed out that if the bacteria sample results follow a lognormal distribution, the sample median can be used as an estimate of the sample GM.

Response: The commenters point out the fact that for a true lognormal distribution, the median is indeed equal with the GM. EPA has historically used the GM and the log10 standard deviation to describe the water quality distribution associated with the recommended RWQC protective of the designated use of primary contact recreation. At this time, EPA does not see a marked advantage to using the median in the expression of the criteria.

Issue 3.6.2 Criteria Magnitude, Duration, and Frequency

Issue <IP_ADDRESS> Criteria Magnitude

Agree with Criteria Magnitude for Beach Notification

Comment: Commenters agreed that numeric endpoints for FIB that are expressed in the draft RWQC are likely very conservative and sufficient for making beach management decisions while maintaining at least the same level of protection as the previous criteria. Commenters supported the use of a GM of 35 cfu per 100 mL for enterococci for beach management as being protective of public health and pointed out a lack of evidence that more stringent values are significantly more protective.

Response: Based on EPA's review of public comments and further scientific analyses, EPA has decided to modify its recommendations as explained in sections 3.6.2 and 4.0 of the RWQC document. In addition, the BAVs provided for beach notification purposes (section 5.1). The final RWQC are based on the latest science and provide improved public health protection and flexibility to states.

Want Lower Illness Rate

Comment: Commenters thought that the illness rate of 1 in 28 is too high.

Response: Based on EPA's review of public comments and further scientific analyses, EPA has decided to modify its recommendations as explained in sections 3.2.4, 3.6.2 and 4.0 of the final RWQC document. The illness rates associated with the final RWQC recommendations are approximately 32 cases of NGI per 1,000 primary contact recreators for a culturable enterococci GM criteria of 30 cfu per 100 mL (corresponds to 1 in 31 NGI) and 36 cases of NGI per 1,000 primary contact recreators for a culturable enterococci GM criteria of 35 cfu per 100 mL (corresponds to 1 in 28 NGI), in both marine and fresh water.

Want Flexibility to Lower Magnitude

Comment: Commenters urged EPA to amend the draft RWQC to permit each jurisdiction to easily determine its own WQC at a given risk level.

Response: The 304(a) RWQC are national recommendations; they are not regulations. As described in 40 C.F.R. 131.11, states may adopt and submit to EPA for approval WQC that is not based on EPA's criteria recommendations. EPA would evaluate the WQC to determine whether they are scientifically defensible and protective of primary contact recreation. Also, as recognized by §510 of the CWA, states may develop more stringent WQS than those recommended in EPA's 304(a) criteria.

Comment: Commenters asked EPA to lower the SSM/STV as justified by a smaller confidence interval, and the acknowledged larger health risk to the public.

Response: Based on EPA's review of public comments and further scientific analyses, EPA has decided to modify its recommendations as explained in sections 3.6.2 and 4.0 of the RWQC document. EPA is recommending an STV criterion associated with the 90[th] percentile of the water quality distribution.

Comment on how GM is Calculated

Comment: Commenters indicated that there are apparent inconsistencies in the recommendations for the use of STV of 235 cfu per 100 mL in fresh waters. If used as a "never to be exceeded" value, the GM of that waterbody would need to meet 28 cfu per 100 mL GM (not the 126 cfu per 100 mL GM proposed based on data that did not include inland waters).

Response: EPA disagrees that there are inconsistencies in the RQWC document. The commenter is referring to the statement in the draft RQWC document that indicates that "if 235 cfu per 100 mL value is interpreted to be `never to be exceeded' values for assessing a waterbody, the resulting water-quality standard is much more stringent than needed to protect the designated use of primary contact recreation if the GM were used. For example, in fresh water, if the STV of 235 cfu per 100 mL is used as a `never to be exceeded' value, the GM of that waterbody would need to meet 28 cfu per 100 mL." The final RWQC document explains that EPA believes that concentrations of FIBs can go above STV concentrations ten percent of the time in a waterbody, and said waterbody will be able to fully support primary contact recreation. In the past, many states treated the SSM values in the 1986 criteria as "never to exceed values," which did result in inconsistencies in terms of public health protection between the GM and SSM components of the criteria. The current approach with the STV resolves these issues. EPA has decided to modify the STV as explained in sections 3.6.2 and 4.0 of the final RWQC document.

Comment: Commenters noted that when determining compliance with the GM, background levels of indicator bacteria are not considered.

Response: Compliance issues are beyond the scope of the RWQC.

Comment: Commenters urged EPA to update the magnitude of the GM and SSM to reflect new scientific information about GI illness rates.

Response: Based on EPA's review of public comments and further scientific analyses of the NEEAR study, EPA has decided to modify the criteria as explained in sections 3.2.4, 3.6.2, and 4.0 of the RWQC document. EPA believes the criteria are based on the latest scientific information.

Comment: Commenters asked that the RWQC document include guidance and methodology to determine the GM, including for Enterococcus spp. using qPCR.

Response: Section 3.6 discusses how to calculate a GM. Further guidance on the Enterococcus spp. qPCR Method 1611 (U.S. EPA, 2012) will be provided in upcoming TSM.

Issue <IP_ADDRESS> Criteria Duration

Support for 90-Day Average

Comment: Commenters supported the flexibility of the recommended duration of 30 to 90 days because as the sample size increases, the chance of misclassification errors with respect to attainments status decreases.

Response: EPA is recommending a 30-day averaging period. See section 3.6.2 in the final RWQC document for additional discussion. EPA guidance regarding monitoring and assessment of waterbodies for 303(d) listing and 305(b) reporting purposes appears in the Agency's IRG (U.S. EPA, 2006). Commenters may find the sections on data set size/quantity to be of particular interest.

Want 30-Day Average

Comment: Commenters supported the GM being calculated over a shorter (30-day) time period. They thought that a 30-day or rolling 30-day GM is more protective and argued that EPA should mandate the use of a 30-day GM, coupled with the continued use of a SSM `never to be exceeded' standard that, if exceeded, results in a regulatory response and compliance measures that will improve water quality. Commenters argued that extending the GM period beyond a 30-day mean will only add more uncertainty and decrease public health protection. Commenters suggested that increasing the allowed duration/averaging period for the GM WQC from 30 days to 90 days with no corresponding decrease in the concentration significantly weakens beach warning/closing policy and increases the risk of illness to swimmers, surfers, kayakers, and boaters. Commenters argued that EPA did not provide data to demonstrate that 90-day evaluation time frame is indeed safe.

Response: EPA is recommending a 30-day averaging period. See section 3.6.2 in the final RWQC document for additional discussion.

Comment: Commenters indicated that seasonal GMs allow combined sewer overflows (CSO) to continue.

Response: Based on EPA's review of public comments and further scientific analyses of the NEEAR study data, EPA has decided to modify the final RWQC as explained in sections 3.2.4, 3.6.2, and 4.0 of the final RWQC document. EPA is also now recommending a 30-day averaging period, which EPA believes will be more effective in dealing with wet weather events.

Comment: Commenters asked EPA to define `short-term GM' and how it can be useful in beach advisory context.

Response: EPA is providing BAVs for beach notification purposes (such as advisories and closings). See section 5.1 of the final RWQC. The term "short-term GM" has been removed from the final RWQC document.

Want Seasonal Average

Comment: Commenters disagreed with EPA that the averaging period be limited to 90 days. They asked for justification as to why the averaging period was reduced from seasonal average to 90 day average, and asked EPA to allow states to select an averaging period that coincides with their recreational season and beyond to protect public health. Commenters thought that rolling GMs should not be used and rather seasonal GMs should be used. They asked EPA to provide guidance as to the appropriate seasonal duration (which could be more than 90 days in certain regions) and the number of samples and spacing of samples during the sampling interval (of 30 to 90 days) so that it is clearly understood whether the samples should be evenly distributed.

Response: The final RWQC recommend an averaging duration of 30 days for determining GMs and STVs to support impairment decisions. EPA believes that a 30-day averaging duration is effective at identifying short-term fluctuations in water quality. More frequent evaluations can allow some pollution problems to be identified sooner so that they may be addressed in a timely manner.

Other Comments

Comment: Commenters thought that the draft RWQC allow states far too much flexibility.

Response: CWA §304(a) criteria are recommendations, not binding requirements. The CWA and EPA's implementing regulations provide states with the flexibility to adopt WQC that are different from EPA's criteria recommendations.

Comment: Commenters pointed out that GM and STV determinations based on data over a duration of 30 to 90 days would be meaningless for streams that are monitored at a much lower frequency.

Response: EPA is recommending a 30-day averaging period. See section 3.6.2 of the final RWQC document. Regardless of the number of samples, the GM and STV are recommended for primary contact designated waters.

Comment Commenters had reservations regarding adopting criteria studied and developed for one purpose (beach management) for other, completely different purposes, without further scientific study.

Response: EPA disagrees that the criteria were developed for only beach management. The applications of the final RWQC for various CWA purposes are discussed in section 3.6.3. In addition, the BAVs are provided for beach notification purposes.

Comment: Commenters noted that there is inadequate assessment, notification, and protection for offseason recreational water use and a lack of guidance during this time period.

Response: States establish WQS to protect designated uses. EPA is recommending the RWQC specifically to be protective of the designated use of primary contact recreation. The RWQC apply to all waters that are designated for primary contact recreation. If states have different uses for specific waterbodies during specific time periods, then the applicable WQS would apply during those time periods. It is beyond the scope of the RWQC to discuss how states determine which designated use applies.

Comment: Commenters asked EPA to revise the RWQC so that the GM can be utilized only for long-term permit limits, and for short-term permit limits, only the STV should be used.

Response: Application of the RWQC to establishing permit limits is beyond the scope of the RWQC.

Comment: Commenters stated that using all of the data in the recreation season would provide the best representation of the GM and the STV and recommended use of the STV on a daily basis for appropriate notification of the public of potentially unsafe conditions.

Response: States determine the appropriate monitoring frequency for their beaches. The BAVs are provided for beach monitoring purposes.

Comment: Commenters commented that for infrequently monitored waters, the GM could become the defacto single sample limit, and that this should be corrected.

Response: Monitoring strategies and the implications of them are beyond the scope of the RWQC.

Issue <IP_ADDRESS> Frequency (see Issue 3.6.1 for `Other STV Frequency Comments')

Support for 25 percent Allowable Excursion Frequency

Comment: Commenters supported EPA's shift to the STV with an allowable excursion frequency of 25 percent.

Response: Based on EPA's review of public comments and further scientific analyses, EPA has decided to modify the criteria as explained in section 3.6.2 of the final RWQC document.

A 25 percent Allowable Excursion is Too High

Comment: Commenters suggested that converting the 75th percentile SSM value into an allowable excursion frequency would be difficult to justify statistically or from a public health protection perspective. They believed that the criterion of an excursion rate of up to 25 percent of the STV is too high. Commenters supported the use of a ten percent allowable SSM excursion frequency as a more protective value with respect to public health than the 25 percent frequency.

Response: Based on EPA's review of public comments and further scientific analyses, EPA has decided to modify the criteria as explained in section 3.6.2 of the final RWQC document. The STV is based upon the 90[th] percentile of the water quality distribution. An excursion frequency of ten percent is allowable for decisions relating to use attainment.

Allow Site-Specific Frequencies

Comment: Commenters asked EPA to allow calculation of site-specific excursion frequencies.

Response: The final RWQC document explains that only a specific portion of samples should be higher than the STV values to prevent inconsistencies between the GM and STV. EPA believes that the STV set at the 90[th] percentile with a ten percent allowable excursion frequency is protective of the primary contact designated use.

Comment: Commenters recommend that GM exceedances be allowed based on local reference systems where naturally generated bacterial sources are known to cause or contribute to exceedances. Commenters asked that EPA acknowledge that the use of the reference watershed approach would be a valid application of the criteria. The reference watershed approach uses the water quality objective exceedance probabilities in a reference/background system to calculate a number of allowable excursion days for impaired watersheds.

Response: The final RWQC provide a series of tools and flexibilities for waterbodies whose predominant source of contamination is different than those upon which the RWQC are based. EPA is familiar with the reference watershed approach that is used in various locations throughout California. Use of the reference watershed approach should become unnecessary because the RWQC clearly indicate that waterbodies protect the recreational use (provided that the GM is at or below the recommended value) as long as no more than ten percent of all samples are higher than the STV. California and a number of other states interpreted the (previously recommended) SSM as a value which was not to be exceeded. This interpretation led to the need for the "reference watershed approach," referred to by the commenter. EPA anticipates that the final RWQC could help to resolve the need for use of the reference system watershed approach. If a waterbody is found to be impacted by nonhuman sources, EPA has provided a series of tools and flexibilities to derive scientifically defensible site-specific criteria values.

Other Comments

Comment: Commenters noted that only where primary contact occurs (i.e., designated bathing beaches) should the STV be employed as it is more restrictive than the GM when no STV excursions are allowed.

Response: The GM and the STV are set such that they are equivalently protective. EPA determined that both are necessary to control the central tendency and the variance of FIB in waters designated for primary contact recreation. Note that the STV is allowed an excursion frequency of ten percent

Comment: Commenters requested guidance on sample size for evaluation of waterbodies relative to the STV.

Response: EPA is not recommending a specific sampling size.

Issue <IP_ADDRESS> Using Criteria Derived For Beaches for NPDES

Comment: A number of comments were received regarding implementation of the RWQC in NPDES permits.

Response: These comments are beyond the scope of the RWQC.

Issue <IP_ADDRESS> CWA §303(d) Impaired List

Comment: Several comments were received regarding implementation of the RWQC for 303(d) listings.

Response: Implementation of the RWQC for 303(d) listings is beyond the scope of the criteria.

Issue 3.6.3 Practical Considerations for Applying the Criteria

Concerns with Sampling Frequency and Magnitude

Comment: Commenters expressed concern regarding why sampling frequency is not considered by EPA to be an approvable element of a WQS. Commenters asked EPA to give states more intense monitoring requirements at high-use beaches and weekly sampling when recreational use is high. Commenters also requested clarification on allowing states to use less than weekly sampling, even over 90 days, and asked that EPA recognize the benefit in better temporal distribution of the same sample size. Commenters asked for justification to support the conclusion that only 4 samples in 30-day or 12 in a 90-day consecutive period is acceptable.

Response: Design of monitoring programs is beyond the scope of the RWQC. See section 3.6.5 for discussion of impact of number of samples.

Issue 4.0 Recreational Water Quality Criteria

Comments on the RWQC are included in Issue 3 and sub-issues below.

Issue 4.1 qPCR As Part of Recreational Water Quality Criteria

qPCR Should Not Be Included In The RWQC

Comment: Commenters supported EPA's decision not to include qPCR values as a part of the RWQC. They argued that rapid testing does little to increase protection of public health because of issues including low variability at most beaches, site-specific inhibition, low correlations between culture and qPCR methods when Enterococcus spp. concentrations are below the SSM/STV of 104 cfu, and usefulness in calculating a GM (i.e., data collected below 104 cfu). Commenters expressed a lack of support for qPCR because of its associated costs.

Response: While EPA's overall testing of qPCR in ambient waters has been limited, EPA continues to support the use of rapid methods such as qPCR where they are effective and where states have developed the capacity to use those methods. See section 5.2 of the final RWQC for a discussion of qPCR.

Comment: Commenters pointed out specific limitations that a state like Alaska may encounter in using qPCR, such as difficult environmental conditions that would impact qPCR performance, in addition to limited and difficult access to facilities, laboratories, and the high-level skilled staff.

Response: EPA appreciates the issues raised by the commenter and acknowledges that qPCR is not appropriate for all waters.

Comment: Commenters agreed with EPA that qPCR results should not be incorporated into the NPDES and TMDL programs under the CWA.

Response: Thank you for your comment.

Comment: Commenters suggested that EPA wait until a standardized method has been shown to work in most of all types of U.S. waters before recommending the methodology.

Response: EPA acknowledges that there is limited information on the performance of the Enterococcus spp. qPCR method in all types of waters. However, there is evidence from the NEEAR study that the Enterococcus spp. qPCR method may offer advantages compared to the culture method including rapidity and stronger and more sensitive health relationships. EPA therefore continues to support the use of rapid methods such as qPCR where they are effective and where states have developed the capacity to use those methods.

Comment: Commenters requested that EPA evaluate the role of interference in analytical results before recommending the method. The commenters also suggested that EPA would place an unrealistic and undue burden on states to refine and evaluate a new method.

Response: As stated in the RWQC document, EPA will provide guidance on how to evaluate performance with respect to sample interference at a particular site at a later date. Despite the potential for sample interference and the lack of complete data on the performance of the method in all types of waters, EPA believes there is sufficient evidence that the Enterococcus spp. qPCR Method 1611 (U.S. EPA, 2012) may offer potential benefits compared to the culture method including rapidity and stronger and more sensitive health relationships. EPA therefore continues to support the use of rapid methods such as qPCR where they are effective and where states have developed the capacity to use those methods.

Rapid Methods, Including qPCR, Should be Required for Beach Monitoring Purposes

Comment: Commenters pointed out that one major goal for EPA during the development of the draft RWQC was to create WQC based on rapid methods in order to provide timely water quality results and increase public health protection for those recreating in and around coastal waters. They supported the required use of rapid based methods, including qPCR, nationally at high-use beaches and areas with known pollution problems by a specific date (i.e., no later than 2015). Commenters expressed disappointment with EPA for not requiring the use of qPCR or other rapid methods for analyzing recreational water samples and thought that the criteria did not properly emphasize that qPCR methods are faster and have been consistently shown to have a stronger correlation to health effects and thus are more accurate than the culture methods.

Response: While EPA's overall testing of qPCR in ambient waters has been limited, EPA continues to support the use of rapid methods such as qPCR where they are effective and where states have developed the capacity to use those methods. See section 5.2 of the final RWQC for a discussion of qPCR.

Comment: Commenters supported use of Enterococcus spp. qPCR and suggested that the qPCR method act as a replacement for cultural methods, where appropriate to detect and quantify enterococci for beach monitoring.

Response: The text in the RWQC has been edited to clarify that qPCR can replace culture methods.

Base qPCR Criteria on Epidemiology

Comment: Commenters asked that EPA base rapid method criteria on the best and most current epidemiological data. They thought that EPA should develop rapid method criteria for qPCR based on current epidemiological data and a criterion that is independent from culture-methods. They asked EPA to analyze all current qPCR epidemiological data, including the Doheny SCCWRP study, to determine the lowest value associated with health risk, in order to scientifically determine a SSM and GM.

Response: See Issue 3.2.3 for response regarding the use of non-EPA epidemiological data.

Other Comments

Comment: Commenters expressed concern that EPA has included a potential disincentive for deploying qPCR in their monitoring programs: an as yet undefined, but potentially multi-year period during which both qPCR and current cultural methods must both be utilized.

Response: The RWQC provides states information for using rapid methods such as qPCR in the development of criteria based on such methods. The potential disincentive described is not in the RWQC.

Comment: Commenters requested that EPA analyze waters, apart from epidemiological studies, to see if the qPCR methodology was applicable to all or most areas.

Response: EPA does not have the resources to further analyze the qPCR method in most or all types of waters. In addition, qPCR provides the most benefit in waters that have high daily usage. Therefore it's best for states to determine which waterbodies would benefit most from qPCR.

Comment: Commenters asked for clarity on why qPCR was included in the RWQC when EPA stated earlier in the criteria document that culture methods are adequate for measuring FIB for beach monitoring purposes.

Response: Despite the potential for sample interference and the lack of complete data on the performance of the Enterococcus spp. qPCR method in all types of waters, EPA believes there is sufficient evidence that the Enterococcus spp. qPCR method may offer potential benefits compared to the culture method including rapidity and stronger and more sensitive health relationships. EPA therefore continues to support the use of rapid methods such as qPCR where they are effective and where states have the capacity to use those methods. EPA reiterates that states may choose not to adopt WQS based on a qPCR method.

Issue 4.2 Use Intensity

Support of the Elimination of Use Intensity

Comment: Commenters supported the elimination of use intensity values and a tiered approach to criteria based on use intensity. They acknowledged that this was likely a policy decision to create uniformity and consistency between regions of the country.

Response: Thank you for the comment.

Comment: Regarding the removal of the tiered approach, commenters requested EPA proactively give states more intense monitoring requirements (such as higher sampling frequency) where warranted.

Response: EPA is not recommending specific monitoring requirements. Regardless of sample size, EPA is recommending that states calculate a GM over a 30-day period. See section 3.6.3.

Against The Elimination of Use Intensity

Comment: Commenters disagreed with the elimination of multiple use intensity values (with different STVs for different levels of recreational contact) and found their elimination to be scientifically unjustified. They argued that this policy decision is best addressed by the appropriate state agency, at the local level and that use intensity allows states the flexibility in assessing and prioritizing beach monitoring programs for high-use beaches as well as when developing WQS that are most protective of public health. Commenters suggested that elimination of use intensity values might divert limited monitoring resources to areas that are not frequently used by human bathers. Commenters thought that the elimination of use intensity values would impact recreational use UAA efforts for developing realistic recreational use expectations. Commenters expressed concern with the effect of eliminating use intensity on the perceived illness rate for a waterbody. Commenters were concerned that the modifications to the E. coli criteria take away some of the methodological flexibilities present in the 1986 criteria (e.g., the application of multiple illness rates for GM data, and multiple confidence levels for SSM data [now STV]). Commenters noted that intensity values "had some merit; a waterbody could conceivably meet the requirements of the CWA but at the same time not have the same strict discharge restrictions on waterbodies that are infrequently used for primary contact." Commenters requested EPA strengthen its justification for elimination of use intensity, especially in the context of the failure of some studies to show associated high risk with indicator occurrences.

Response: EPA's previously recommended multiple use intensity values, as laid out in the 1986 criteria, should not be interpreted as recommending differing risk levels for different intensities of use. Instead, the multiple use intensity values represented alternative levels of statistical confidence at the same level of risk, with the highest level of statistical confidence reserved for the greatest intensity of use. In no longer recommending multiple use intensity values, EPA is recommending the use of the same level of statistical confidence for all intensities of use. EPA expects this recommendation to increase national consistency across bodies of water and ensure equivalent public health protection in all waters. EPA reiterates that intensity of use in this context refers to the frequency at which a body of water is used for full body primary contact recreation; it does not refer to secondary contact uses. EPA believes that discharges should be managed regardless of likelihood of exposure.

These RWQC are for the primary contact designated use. States determine the designated use if applicable. State standards must be sufficient to protect the use and must be scientifically defensible. Therefore any submitted state standards must include documentation that shows that the WQS is protective of the use and based on sound science.

The draft and final RWQC state that EPA is no longer recommending multiple "use intensity" values, in an effort to increase national consistency across bodies of water and ensure equivalent public health protection in all waters.

Issue 5.0 Tools  -  Managing and Alternate Criteria

Site-Specific Standards Add Flexibility and Better Quantify the Level of Health Risk

Comment: Commenters expressed support for the increased discretion and flexibility in developing site and state-specific standards where the data and information defend such action (such as for waterbodies which are believed to be predominantly impacted by nonhuman sources). Another commenter supported the use of STV (75th percentile) and site-specific criteria, pointing out that this will allow better allocation of resources to waterbodies posing the highest risks for human health. One commenter stated that site-specific tools do not "relax" WQS, but instead serve to quantify the actual level of health risk for watersheds based on unique, site-specific conditions, and thereby improve water quality and public health protection programs. Another commenter pointed out that the site-specific tools highlighted by EPA will be valuable for many municipalities that would like to improve their ability to predict recreational health risks and develop health-effective strategies for implementing best management practices.

Response: Thank you for your comments.

Concerns with the Use of Site-Specific Criteria

Comment: A commenter expressed concern that site-specific criteria requirements are too stringent and fail to complement existing infrastructure. A commenter expressed concern regarding EPA's lack of research and studies in areas and on waters where a new standard might be applicable. This questions EPA's ability to provide accurate, science-based guidance for states.

Response: EPA's primary concern is the protection of public health. Although the RWQC include a wide range of tools for states and tribes to develop site-specific criteria, EPA expects that sufficient information and technical documentation would be needed to support the appropriateness of site-specific criteria at any given location. Moreover, EPA will issue a series of TSM that will help to explain how site-specific criteria may be developed.

Issue 5.1 Tools for Assessing and Managing Recreational Waters

Combined Use of Sanitary Surveys and QMRA

Comment: A commenter supported the use of sanitary surveys and QMRA to fully assess exposure risk, particularly if the concern is over exposure to human sewage versus other sources of FIB. A commenter suggested that additional development to merge sanitary surveys with pathogen monitoring is necessary to fully exploit the power of QMRA.

Response: The forthcoming TSM will describe in detail the synergy EPA anticipates with respect to compilation of information from sanitary surveys as input to QMRA for recreational waters.

Recommendations for Other Efforts and Additional Data Collection

Comment: A commenter suggested that EPA support a microbial transport and fate program, including an improved understanding of molecular marker transport and degradation.

Response: EPA will consider this suggestion as one component of future work.

Comment: A commenter recommended that EPA accept sanitary surveys, regional and watershed scale assessments, existing permitting information, and local knowledge as guidance as to the appropriate level of contact and risk to the general populace. Previously collected data should also be applicable to determine a scientifically supported confidence level (i.e., 90% confidence level). Another commenter suggested that pollution reduction efforts need to be emphasized more and that the sentence at lines 2036-2037 in the draft RWQC should be expanded to: "This section discusses tools that states can use to reduce sources of pollution and enhance public health protection." Another commenter requested that TMDLs, enforcement of stormwater regulations, or other mechanisms to reduce sources be described in this section.

Response: These comments are beyond the scope of the RWQC.

Issue 5.1.1 Sanitary Survey

Support for the Use of Sanitary Survey

Comment: A commenter expressed support for the inclusion of information on tools such as sanitary surveys to support states and tribes manage recreational waters. Sanitary surveys help identify pollution sources and provide data to develop predictive models, while also providing data to assess beach health and identify problem spots.

Response: Thank you for your comment.

Widen the Scope of Sanitary Survey

Comment: A commenter expressed disappointment that sanitary surveys were relegated to section 5 of the draft RWQC ("Tools to Consider Alternate Indicators...") and not an integral part of the criteria themselves (section 4) for BEACH Act purposes (designated bathing beaches).

Response: EPA agrees that sanitary surveys are an important component of beach water quality protection. However, EPA does not consider sanitary surveys part of the numerical WQC.

Comment: A commenter pointed out that the document has a narrow focus on bathing beach applications, and suggested that this section 5.1.1 in the draft RWQC be expanded to discuss the use of sanitary surveys in the context of watersheds.

Response: The nationally recommended criteria apply to all waters of the United States with a primary contact recreation designated use. Sanitary surveys are usually conducted at the beach, but can be extended into nearby watersheds. States may consider using sanitary surveys in conjunction with other watershed assessment tools.

Guidance Is Needed

Comment: A commenter urged EPA to expedite the development of tools for conducting sanitary surveys and if possible, publish them simultaneously with the final RWQC.

Response: The sanitary survey tool for the Great Lakes is online (U.S. EPA, 2008). The marine sanitary survey tool will be issued in early 2013.

Comment: A commenter suggested that EPA provide updated guidance on source tracking methods to identify fecal pollution sources, such as EPA's April 2011 document "Using Microbial Source Tracking for TMDL Development and Implementation" (U.S. EPA, 2011) as part of this section or as a new section.

Response: Fecal source tracking is a rapidly evolving field. As indicated previously, guidance on specific aspects of implementation of these criteria will be provided separately as TSM documents. EPA will provide in one of the TSM documents a summary of a case study for site-specific criteria that includes use of fecal source tracking as one component of the site-specific criteria development considerations.

Comment: A commenter asked for clarification regarding whether sanitary surveys could be used instead of routine water quality monitoring for a recreational beach, or if they are to only be used to direct the sampling to the best locations as implied on line 2065 of the draft RWQC.

Response: EPA considers sanitary surveys to be a tool to be used in addition to monitoring of water quality since the surveys do not provide numerical values for indicator organisms. Sanitary surveys help to provide the context for the monitoring results. Sanitary surveys can help refine the risk characterization and priorities for beach monitoring programs.

Issue 5.1.2 Predictive Models

Utility of Predictive Models

Comment: Commenters expressed support for the inclusion of information on real time predictive modeling for recreational waters to supplement culture-based sampling methods, until such a time when sampling rates and testing ability allows real time decisions on actual data. Another commenter encouraged EPA to support the use of predictive modeling especially in those areas where it will allow the agency to better define the proper and improper implementation of the primary contact recreation standard to waters where it is inappropriately applied today. Another commenter noted the usefulness of this tool for known contamination events and areas with reoccurring problems, such as for provisional rainfall closures. Finally, a commenter suggested that predictive models should only be used for supplemental purposes as indicated and should not replace sampling and monitoring programs that actually detect the presence of fecal contamination.

Response: Thank you for your comments.

Guidance is Needed

Comment: A commenter urged EPA to expedite the development of tools for performing predictive modeling, and if possible, publish them simultaneously with the final RWQC.

Response: EPA has released Predictive Modeling at Beaches Volume I: Review and Technical Protocol (U.S. EPA, 2010d) and Predictive Modeling at Beaches Volume II: Predictive Tools for Beach Notification (U.S. EPA, 2010e).

Issue 5.2 Tools for Use in Developing Alternative RWQC

Utility of Tools for Use in Developing Alternative RWQC

Comment: A commenter expressed agreement that it is important to be able to use tools such as QMRA or epidemiological studies to assess the relative significance of regularly elevated FIB concentrations at locations known to have natural sources of bacteria reservoirs and for areas with existing best management practices in place.

Response: Thank you for your comment.

Suggested Requirements for Alternative RWQC

Comment: Commenters asked that any alternative RWQC be demonstrated to be at least as protective as EPA's RWQC.

Response: Alternative site-specific criteria must be scientifically defensible and protective of the primary contact designated use.

Support for the Development of Site-Specific Criteria

Comment: A commenter expressed support for EPA providing additional flexibilities including tools for developing site-specific criteria.

Response: Thank you for your comment.

Concerns Associated With the Development of Site-Specific Criteria

Comment: A commenter argued that application of site-specific criteria is dangerous for public health. It was suggested that this theory is not supported by epidemiological research conducted over decades (lack of studies showing enterococci is from nonhuman sources and causes beaches to appear noncompliant when there is no health risk (false-positive), and a plethora of positive-positive studies). The commenter noted that the most appropriate levels (bacterial and risk) for the criteria are those reported in the study where no significant associated risk was measureable.

Response: The revised RWQC values are based on water quality from the epidemiological studies and are the lowest values which exhibit a statistically significant difference between swimmers (above and below specific water quality values). Those FIB levels represent conditions in wastewater impacted areas. Current research indicates that the levels of indicators and pathogens vary widely depending on the source of contamination. EPA disagrees that application of site-specific criteria is dangerous for public health because alternative criteria must be scientifically defensible and protective of the primary contact recreation designated use.

Comment: Commenters suggested EPA make the requirements for site-specific criteria very tight, considering issues such as: no exemption if an outfall is within a generous distance (based on volume and level of treatment), or if a beach has a certain level of attendance; an exemption if treated sewage discharge volume is large; the requirement for states to perform epidemiological studies if they plan to use QMRA at beach with visitors; and the requirement of proof of nonhuman source as the primary cause for enterococci concentration.

Response: EPA does not intend to establish additional requirements for site specific criteria beyond those in 40 C.F.R. Part 131. EPA plans to issue TSM to help states that want to perform either QMRAs or epidemiological studies to support site-specific criteria.

Guidance/Clarification is Needed

Comment: Commenters asked EPA to provide eligibility guidance for when and how (specific steps) site-specific criteria can or should be developed, and what scientific evidence or testing is required to justify development of alternative criteria.

Response: Refer to RTC Issue 6.0 for response regarding timing of TSM.

Comment: A commenter suggested that the draft RWQC, TSM, and guidance state whether the reference watershed approach is a viable tool for implementing RWQC and suggested that this approach could be a viable alternative to expensive QMRA studies for hundreds of watersheds to account for bacteria sources and transport characteristics.

Response: EPA is familiar with the reference watershed approach that is used in various locations throughout California. Use of the reference watershed approach should become unnecessary because the RWQC clearly indicate that waterbodies protect the recreational use (provided that the GM is at or below the recommended value) as long as no more than 10% of all samples are higher than the STV. California and a number of other states interpreted the (previously recommended) SSM as a value which was not to be exceeded. This interpretation led to the need for the "reference watershed approach," referred to by the commenter. EPA anticipates that the final RWQC could help to resolve the need for use of the reference system watershed approach. If a waterbody is found to be impacted by nonhuman sources, EPA has provided a series of tools and flexibilities to derive scientifically defensible site-specific criteria values.

Comment: Commenters suggested that based on previous discussions, EPA gave the impression that site-specific criteria could only be developed under narrow conditions, such as at remote beaches with no known FIB sources, or very simple land uses such as open space or agricultural drainages.

Response: The forthcoming TSM will provide detailed information about the recommended approach for considering whether site-specific criteria are appropriate for a particular location or not.

Comment: Commenters urged EPA to provide clarification regarding the development of site-specific criteria, particularly when background bacteria indicator levels are high, for areas where the risk from exposure to pathogens and illness incidence is low, or for waters impacted by nonhuman fecal contamination.

Response: The forthcoming TSM will provide information about the recommended approach for considering whether site-specific criteria are appropriate for a particular location. EPA does not intend to limit site-specific criteria development to areas such as remote beaches with no known FIB sources, or very simple land uses such as open space or agricultural drainages.

Other Comments

Comment: A commenter applauded EPA on its skepticism of the science behind "natural sources" of Enterococcus spp.

Response: Thank you for your comment.

Comment: A commenter suggested EPA should provide considerably more discretion to the states on the development of watershed level recreation standards, and it should accept standards developed using other scientifically defensible methods including geographic information system modeling.

Response: States have substantial flexibility to adopt criteria in their WQS that differs from EPA's recommendations, including, but not limited to site-specific criteria. EPA would review them to determine whether they are scientifically defensible and protective of the use.

Issue 5.2.1 Epidemiological studies

Support for the Use Of Site-Specific Epidemiological Studies

Comment: A commenter strongly supported EPA's allowance of site-specific criteria using epidemiological studies because these studies are particularly needed in areas where most waterbodies are impacted by urban runoff but without influence from wastewater treatment plant effluent. The commenter asked EPA to consider local, site-specific epidemiological studies when allowing states to develop site-specific criteria.

Response: As indicated in the RWQC document, local, site-specific epidemiological studies can be used as a basis of site-specific criteria that are scientifically defensible and protective of the use.

Feasibility and Practicality of States' Ability to Conduct Epidemiological Studies

Comment: Commenters expressed concern that EPA's expectation that states to carry out epidemiological studies is unrealistic, since these studies are costly and have uncertain outcomes (especially with small population sizes), leading states to default to EPA criteria.

Response: States interested in developing site-specific alternative criteria may choose to conduct epidemiological studies. However, EPA is also providing other tools and flexibilities to support site-specific alternative criteria. No additional studies are needed for states to adopt and implement WQC in their WQS based on the final RWQC.

Comment: A commenter suggested that removal of differential percentile STVs for different use intensities interferes with state's flexibility in assessing and prioritizing beach monitoring programs based on high use intensity and makes epidemiological studies impractical.

Response: EPA believes that the final RWQC, with a GM and an STV at the 90[th] percentile of water quality, provides a health protective approach to protecting the designate use of primary contact recreation. BAVs reflecting a 75[th] percentile value have been provided for beach notification purposes (such as advisories and closings).

Need for Guidance

Comment: A commenter suggested EPA provide specific implementation guidance for urban runoff-impacted beaches, and urgently support epidemiological and QMRA studies at such beaches so that protective yet scientifically-defensible and achievable criteria are developed for these particular streams and beaches given their unique FIB sources and levels of recreational illness risk.

Response: EPA conducted an epidemiological study at an urban runoff-impacted site in South Carolina in 2009 as part of the critical path science plan underlying the final RWQC. Although the results of that epidemiological study were ambiguous compared to the studies conducted at human impacted beaches, EPA is currently collaborating with SCCWRP to evaluate the use of sanitary surveys, fecal source tracking and QMRA to develop site-specific criteria at an urban runoff impacted beach in Southern California. The results of this work will be provided in TSM upon completion of the study and could serve as the basis for similar consideration in other locations.

Comment: A commenter suggested EPA provide clarification on the source of EPA's uncertainty regarding the use of epidemiological study designs other than the prospective cohort study design, and whether this uncertainty extended to any alternative criteria, not just site-specific criteria.

Response: Review of the epidemiological literature indicates that both designs have been implemented successfully. However, guidelines and criteria values based on these two different study designs are derived differently. There are substantial differences in the experimental designs of both types of studies which preclude a direct comparison of the results. The RWQC are based on prospective cohort study results, and thus, uncertainty would exist in deriving any alternative criteria based on study designs other than the prospective cohort study design, site-specific or otherwise. A WQS submission derived from a site-specific epidemiological study should demonstrate the scientific defensibility and protection of the designated use. The uncertainty in how to compare non- prospective cohort study results to those underlying the RWQC may preclude both of these requirements until the state of the science allows for a better comparison among different types of epidemiological studies.

Other Comments

Comment: A commenter urged EPA to acknowledge in section 5.2.1 the lack of significant correlations with culture methods in the nine study sites in the U.S. EPA's NEEAR Water Study, although the number of participants was quite large.

Response: This information is covered in section 3.2.4 of the final RWQC.

Comment: Commenters thought that EPA needs to specify the level or risk deemed acceptable, and that site-specific criteria must be at least as protective as EPA's national criteria.

Response: Site-specific criteria could be based on one of the illness rates associated with the final national recommended RWQC, regardless of the source of contamination. In addition, states may choose another illness rate if it would protect the designated use of primary contact recreation. EPA would evaluate it as part of the state's submission in such a situation.

Issue 5.2.2 QMRA and Sanitary Survey

Support for QMRA

Comment: Commenters expressed support for the development of site-specific criteria using QMRA for waterbodies believed to be predominantly impacted by nonhuman sources. A commenter suggested EPA continue to perform studies such as QMRA, and collect information regarding the risk for human health at waterbodies predominantly impacted by nonhuman sources.

Response: Thank you for your comment.

Limitations of QMRA

Comment: A commenter emphasized that QMRA's potential for site-specific criteria would only be applicable at beaches impacted by birds.

Response: EPA agrees that beaches impacted predominantly by birds may be good candidates for site-specific criteria development, but disagrees that the scope of the candidate waters would be limited to beaches predominantly impacted by birds. There is additional information that may support relative risk differences with other nonhuman sources of fecal contamination.

Comment: A commenter thought that site-specific QMRA studies might require extensive species-level testing to properly characterize the composition of bacteria in a waterbody, and many states lack resources for these kinds of analyses.

Response: EPA emphasizes that states always have the option of adopting the nationally recommended criteria. EPA believes that the final RWQC are appropriate for most sites in the country. Where states opt to pursue alternative or site-specific criteria for specific waters, additional information (e.g., other studies) would be submitted with a state's WQS package. EPA agrees that site-specific QMRA studies might call for collecting additional evidence to demonstrate the sources of fecal contamination at a specific site (e.g., using MST markers). EPA is currently collaborating with SCCWRP to evaluate the use of sanitary surveys, fecal source tracking and QMRA to develop site-specific criteria at an urban runoff impacted beach in Southern California. EPA plans to provide the results of this work in TSM.

Comment: A commenter expressed that QMRA should not be used for site-specific criteria development at frequently visited beaches and beaches in urbanized or mixed land-use areas, unless the resulting WQS are more strict and protective than the national criteria. The commenter's concern is that urban runoff is complex and variable, making QMRA difficult. Commenters urged EPA to wait for the science of QMRA to become more developed before recommending QMRA implementation at locations with limited historical monitoring data.

Response: EPA and other federal agencies use risk assessment to make a wide range of decisions to protect public health. The science that underpins QMRA is sound and extensively documented in the scientific literature. QMRA supplements the currently available epidemiological data and allows for prediction of risks in locations where existing epidemiological studies may not accurately predict precise illness rates for recreators. EPA is currently developing 1) case-studies to show how QMRAs relate to available epidemiologic data and 2) TSM for states wanting to implement QMRA on a site-specific basis. QMRA will be especially useful for waterbodies not predominantly impacted by human fecal contamination. The forthcoming TSM will provide detailed information about the recommended approach for considering whether site-specific criteria are appropriate for a particular location or not.

Broaden the Scope of Applicability

Comment: Commenters suggested EPA broaden its discussion of the applicability of QMRA to include locations and sources different than those observed during the NEEAR study, such as flowing fresh water (river and creeks) and/or sites with human fecal sources, since in certain states the criteria developed based on the frequency of use are applied to inland surface waters where the frequency of use is significantly below bathing beaches.

Response: QMRA may be useful for consideration of site-specific criteria in waters that are predominantly impacted by sources other than human fecal contamination. In waters that are predominantly impacted by human fecal contamination, EPA believes that the nationally recommended criteria are protective and appropriate. EPA has recommended these criteria in all U.S. waters that have the primary contact recreation designated use, regardless of the source and of how intensely waters are used  -  thus, all recreators are provided with the same level of protection.

Comment: Commenters proposed that EPA encourage and/or support additional QMRA studies at urban runoff-impacted waterbodies to strengthen the pathogen monitoring and site-specific criteria datasets and to allow evaluation of different water body types (e.g., open marine beaches and flowing fresh water creeks/streams).

Response: EPA is collaborating with SCCWRP to evaluate the use of sanitary surveys, fecal source tracking and QMRA to develop protective yet scientifically-defensible and achievable site-specific criteria at an urban runoff impacted beach in Southern California. The results of this work will be provided in TSM upon completion of the study and could serve as the basis for similar consideration in other locations.

Comment: Commenters suggested EPA incorporate flexibility that provides for regional, statewide, or multistate QMRA analyses as this could allow states to prioritize site-specific efforts on waters which are more likely to pose pathogen-associated human health risks.

Response: Pursuant to EPA's implementing regulations at 40 C.F.R. Part 131.11(b), states have the flexibility to adopt alternative WQC state wide, or on a site specific basis.

Comment: A commenter suggested EPA clarify whether states may consider use intensity when characterizing site-specific waters using a QMRA approach. The concern here was that elimination of designated uses will result in implementation of permit limitations in areas where there is little potential for human health risk.

Response: EPA is recommending the final RWQC criteria in all U.S. waters that have been designated as primary contact recreation, regardless of how intensely those waters are used  -  thus, all recreators are provided with the same level of protection. Site-specific criteria, whether derived via QMRA or other means must be scientifically defensible and protective of the use.

Need for Guidance and Models

Comment: Commenters suggested that EPA provide clear implementation guidelines and eligibility requirements for QMRA. Commenters expressed concern regarding the TSM release timeframe that includes additional guidance on conducting QMRA.

Response: EPA is currently developing 1) case-studies to show how QMRAs relate to available epidemiologic data and 2) TSM for states wanting to implement QMRA on a site-specific basis. EPA anticipates that QMRA will be especially useful waterbodies that are impacted predominantly by nonhuman sources.

Comment: A commenter asked that EPA provide additional QMRA models for the states to use that characterize additional fecal sources (e.g., sources other than agricultural animals and gulls, such as wildlife and nonfecal sources) and additional exposure scenarios (e.g., exposure scenarios other than agricultural runoff).

Response: EPA will consider this recommendation as one potential area of future research.

Comment: A commenter suggested that EPA provide clarification on what standards will be used for QMRA, and that these analyses be allowed only where enhanced sanitary surveys and comprehensive MST studies have been conducted and have concluded that there is no possibility of human sources other than individual recreational users. Thus, eligibility must be specific and allowed only in limited circumstances.

Response: EPA does not agree with the comment because recent research indicates that small amounts of human contamination are not associated with illness rates that are above the illness rates associated with the nationally recommended RWQC. And the nationally recommended RWQC are protective of the primary contact designated use.

Comment: A commenter remarked that EPA also needs to specify whether the QMRA tool will be developed sufficiently to address issues with natural sources of fecal indicators such as wildlife and endemic non fecal derived FIB.

Response: The TSM for QMRA will specifically include how states can include various FIB sources such as wildlife and environment in QMRA modeling.

Issue 5.2.3 Other/New Methods and Indicators

Support for New Methods

Comment: Commenters supported EPA's accepting new or alternative indicator and/or enumeration method combinations, and explicitly including some flexibility in the draft RWQC for implementing superior tools in the near future.

Response: Thank you for your comment.

Comment: A commenter suggested states could develop alternative criteria using the qPCR method for Enterococcus spp.

Response: The RWQC provides a GM and STV for use with EPA Enterococcus spp. qPCR Method 1611 (U.S. EPA, 2012). For other methods, see section 6.2 of the RWQC for a discussion of how to proceed.

Microbial Source Tracking and Fate and Transport

Comment: Commenters proposed MST as a relevant tool for determining the origin of fecal pollution in waterbodies or for determining the extent of human pollution before initiating QMRA studies. MST should be added to the final RWQC document and described in detail as a useful tool for determining the sources of fecal pollution in waterbodies.

Response: MST can be used as part of the weight of evidence approach needed to justify the use of site-specific criteria for a particular waterbody. EPA is collaborating with SCCWRP to evaluate the use of sanitary surveys, fecal source tracking including MST and QMRA to evaluate the development of protective yet scientifically-defensible and achievable site-specific criteria at an urban runoff impacted beach in Southern California. The results of this work will be provided in TSM upon completion of the study and could serve as the basis for similar consideration in other locations.

Comment: A commenter urged EPA to support a microbial transport and fate program, including an improved understanding of molecular marker transport and degradation. A commenter proposed the development and use of community fingerprint approaches which will aid in source identification and ultimately quantitative source allocation, which will impact TMDL implementation programs.

Response: Thank you for the comment. EPA will consider these recommendations as potential areas of future research.

Models

Comment: A commenter expressed hope that EPA's new or alternative indicator and/or enumeration method combinations would include the development of models to better indicate the geographic extent of primary contact waters.

Response: States determine designated uses for waterbodies, so this suggestion is beyond the scope of the RWQC.

Comparative Analysis

Comment: A commenter recommended EPA conduct or fund E. coli culture Method 1603 and E. coli qPCR side-by-side monitoring studies in a variety of fresh waters to determine qPCR GM and STV values equivalent to the acceptable culture-based values.

Response: E. coli qPCR could be a candidate for alternative site-specific criteria for alternative indicator/methods. EPA will provide TSM to help states conduct studies such as the one suggested.

Comment: A commenter encouraged comparative analyses prior to considering implementation of either alternative indicators or methods.

Response: The TSM for alternative indicator/methods will include steps for conducting comparative analyses.

Uncertainty Surrounding the Use of New Methods and Indicators

Comment: A commenter cautioned against EPA's allowing the use of "new technologies" for quantifying fecal pathogens or fecal contaminant indicators that have not been validated for the ambient waters or wastewaters for which they might be applied.

Response: Pursuant to EPA's implementing regulations at 40 C.F.R. Part 131.11(b), states have the flexibility to adopt alternative WQC state-wide, or on a site specific basis. WQC in a State WQS using a different indicator or analytical method that is different from the final RWQC would need to be scientifically defensible and protective of the designated use. EPA would review technical information provided by the state with any WQS submission. Information on demonstrating the relationship between two-indicator method combinations can be found in TSM.

Comment: A commenter expressed concern that allowing the use of "any other equivalent method" will cause difficulties for laboratories and laboratory auditors as they will need to review additional quality control data to ensure that methods utilized meet the quality control requirements of the "lab-approved" method. The commenter urged EPA to include a procedure to determine equivalency for the option of "any equivalent method" to result in data meeting 40 CFR Part 136 Measurement Quality Objectives. A commenter suggested that EPA provide clear requirements and guidelines on new and equivalent methods, performance standards, method verification and expectations for approval, especially given that timeline of the TSM for this topic is not clear.

Response: At the current time, because no qPCR method is approved in 40 CFR Part 136, stakeholders may use any equivalent method. EPA does not currently have an alternative test procedures protocol (which would only apply to approved methods) for genetic methods which would specify how side-by-side testing should be completed, but may develop one in the future. The upcoming TSM will detail how to demonstrate a consistent and predictable relationship between methods with one being an EPA recommended method.

Need for Guidance

Comment: A commenter suggested it is not clear from the draft RWQC how a state might utilize other indicators and/or test methods.

Response: EPA is developing TSM on alternative indicators and methods.

Issue 6.0 Implementation

Concerns with when TSM will be issued to Users

Comment: A commenter expressed concern that the guidance and TSMs would not be published until after the final RWQC. Commenters requested that guidance be published within the comment period for the RWQC. They argued that it was difficult to assess the new criteria while lacking guidance about implementation. Commenters requested that guidance be published concurrently with the final RWQC, to aid in the implementation of the new criteria and ensure that it is adopted uniformly between states. Waiting until late 2013 to release these documents will lead to confusion, inconsistencies, and misinterpretation of RWQC. A commenter suggested EPA should delay adoption until the criteria are revised (to allow exceedances due to uncontrollable sources, calculation of site-specific exceedance frequencies, until clarification is provided regarding how WQS can be implemented during wet weather conditions, and consideration of use intensity).

Response: EPA is developing a number of technical tools and documents to aid states implement the final RWQC. EPA plans to provide information on sanitary surveys, development of site-specific criteria, EPA's qPCR method and other topics in its upcoming beach guidance and other TSM documents. Once completed, EPA will make the TSM documents available on the EPA RWQC web site. EPA must publish the final RWQC by November 30, 2012, so RWQC cannot be delayed to wait for the TSM documents.

Issue 6.1 Current State Standards - Implications

No comments were associated with this issue.

Issue 6.2 Beach Grant Issues

Comment: Commenters raised concerns about beach grant funding and implementation.

Response: Implementation of beach grants is beyond the scope of the RWQC.

Issue 6.3 Monitoring/Sampling Concerns

Concerns with Costs

Comment: Commenters expressed concern over the monitoring, monitoring plans, and sampling cost of transitioning to and implementing the new criteria, especially in light of the end of funding from the Beach grants program.

Response: Monitoring, monitoring plans, and cost implications for transitioning and implementing the new criteria are beyond the scope of the criteria.

Need for Guidance

Comment: Commenters questioned how they should interpret samples from urban runoff and storm water.

Response: The final RWQC recommendations are applicable to all waterbodies designated for primary contact recreation without regard to source.

Issue 6.4 Public Notification/Risk Communication

Suggestions for a Revised Public Notification System

Comment: Commenters expressed dissatisfaction with the current public notification system. Commenters suggested a national notification system, including input from local agencies and the public. Another commenter requested a simpler (binary) system, and another commenter requested a more nuanced approach that included warning levels at a beach that was still "open."
One commenter requested that primary water contact recreational areas (that are not beaches) also have public notification systems.

Response: These comments are beyond the scope of the RWQC.

Improving Risk Communication

Comment: A commenter requested that risk information be available in multiple languages and formats to reach more of the public.

Response: This comment is beyond the scope of the RWQC.

Need for Guidance/Clarification

Comment: Commenters expressed confusion over beach status decision-making criteria.

Response: This comment is beyond the scope of the RWQC.

Issue 6.5 qPCR Method  -  Guidance (Inhibition Concerns)

Guidance on Establishing Method Equivalency

Comment: Commenters supported the use of qPCR but requested clear guidance for establishing qPCR method competency while recognizing that qPCR may not be appropriate for use at some beaches. Therefore, these commenters requested that EPA add clarity on what constitutes "equivalency" between methods and establish clear guidance for appropriate use of qPCR for recreational water quality monitoring. Allowing replacement of methods at appropriate beaches should be a high priority.

Response: EPA has provided a discussion of how to use new analytical methods in section 6.2 of the RWQC. EPA also intends to provide TSM on this topic.

Guidance on Implementation and Training

Comment: Commenters thought that EPA did not provide a clear path to facilitate implementation of qPCR in the current RWQC and that more guidance will needed on implementation and training. Another commenter noted that guidance on evaluating results with respect to interference is needed before states attempt to implement qPCR technologies and that this guidance is needed in the very near future (e.g., 2013).

Response: In addition to posting Enterococcus spp. qPCR Method 1611 (U.S. EPA, 2012), EPA intends to issue several documents to facilitate qPCR use. EPA intends to issue a tool to convert machine results (i.e., CT) to reporting unit results (cce per 100 mL) at the same time as the final RWQC and a troubleshooting guide in 2013. Training is also being developed. Finally, the revised beach guidance is expected to discuss considerations for use of qPCR in beach programs.

Comment: A commenter recommended that a laboratory be properly evaluated before using qPCR for compliance monitoring and some commenters asked EPA to be more descriptive with their implementation timeline.

Response: EPA does not certify or evaluate laboratories. EPA relies on the user to closely adhere to the method, including the performance acceptance criteria.

Comment: A commenter specifically requested guidance on implementing qPCR during the peak swimming season, implementing qPCR at heavily-used beaches, using qPCR after a rainfall and after a sewage spill to potentially open a beach to the public sooner, and recommendations for appropriate locations where qPCR should be used (e.g., populated beaches, beaches that are not remote).

Response: Implementation issues are beyond the scope of the RWQC.

qPCR Inhibition

Comment: A commenter thought that site-specific inhibition is too problematic for confidence in qPCR at this time and therefore did not support the recommendation to incorporate rapid testing methods for measuring water quality.

Response: EPA has provided information on qPCR, but has not included it in the recommended criteria.

Comment: Commenters pointed out that EPA did not cite any studies that show problems with qPCR technology, or examples of waterbody types in which qPCR has been found to be ineffective and asked EPA to conduct their own assessment of the benefits of adopting qPCR for evaluating the RWQC.

Response: The final RWQC discusses the problems with interference that EPA encountered at Boquerón, Puerto Rico.

Issue 6.6 qPCR Related Costs of Implementation

qPCR is a Burden To States

Comment: Commenters cited budget concerns and found that the use of side-by-side testing (i.e., qPCR and culture) both methods would cause a financial burden to states. A commenter theorized that a period of eight to 12 weeks of running simultaneous culture and qPCR methods would be adequate for determining how the two methods compare. This could be viewed as a potential disincentive for deploying qPCR in their monitoring programs because states will be responsible for costs associated with rapid methods and costs associated with the routine use of standard methods.

Response: The RWQC does not establish side by side testing as a prerequisite to the use of qPCR in beach notification programs or adoption into state standards. Overall testing of the qPCR method with different types of ambient waters, and by different laboratories, remains limited and EPA anticipates that there may be situations at some locations where the performance of the qPCR method may be inconsistent. Therefore, EPA suggests that states evaluate the qPCR method with respect to laboratory performance and sample interference in their prospective waters prior to prior to use in a beach notification program or adoption of WQS based on the method.

Issue 6.7 Other Costs of Implementation

Comment: Commenters were concerned about the costs of implementing and transitioning to the new criteria and thought that cost should be considered in the process of developing new criteria. In particular, commenters mentioned the cost to WWTPs for changing the indicator of effluent quality. The new standards could change impairment levels. Commenters requested funding for infrastructure upgrades to assist in compliance with the new criteria. In particular, commenters were concerned about old sewer systems. They requested flexible criteria to allow site-specific implementation and to take into account use levels of different waterbodies so as to prioritize spending (within and between states) to maximize public health benefit, and expressed concerned with false negatives or false positives regarding actual risk, from affects such as storm water runoff or warm climates. Finally, commenters expressed concern over the cost of QMRA and epidemiological studies.

Response: The final RWQC indicators (E. coli and enterococci) have not changed since the 1986 recommended criteria. The approved analytical test methods for these indicators in 40 CFR Part 136 would still be the relevant test methods if states revise their WQS based on EPA's RWQC recommendations. Thus, there would be no additional cost to dischargers to monitor for these fecal indicators assuming that the applicable WQS includes WQC for E. coli or Enterococcus spp. as measured by a culture method. EPA does acknowledge that the adopted recommended criteria could change §303(d) listings for some state surface waters because EPA's recommended criteria include both GM and STVs, and if adopted in state standards, both values would be relevant components of the applicable WQS, which is used in §303(d) listing.
References:

Bartram, J., Rees, G., editors. 2000. Monitoring bathing waters. Lopdon: E & F N Spon. http://www.who.int/water_sanitation_health/bathing/monbathwat.pdf

Boehm, A.B., Ashbolt, N., Colford, J., Dunbar, L., Fleming, L., Gold, M., Hansel, J., Hunter, P.R., Ichida, A., McGee, C., Soller, J.A., Weisberg, S.B. 2009. A Sea Change Ahead for Recreational Water Quality Criteria. Journal of Water and Health 7(1): 9-20.

Cabelli, V.J., Dufour, A.P., McCabe, L.J., Levin, M.A. 1982. Swimming Associated Gastroenteritis and Water Quality. American Journal of Epidemiology 115: 606-616.

Cabelli, V.J. 1983. Health Effects Criteria for Marine Recreational Waters, Technical Report. U.S. Environmental Protection Agency, Health Effects Research Laboratory: Research Triangle Park, NC. EPA 600/1-80-031.

Cheung, W.H.S., Chang, K.C.K., Hung, R.P.S., Kleevens, J.W.L. 1990. Health Effects of Beach Water Pollution in Hong Kong. Epidemiology and Infection 105(1): 139-162.

Dorevitch, S., Ashbolt, N.J., Ferguson, C.M., Fujioka, R., McGee, C.D., Soller, J.A., Whitman, R.L. 2010. Meeting Report: Knowledge and Gaps in Developing Microbial Criteria for Inland Recreational Waters. Environmental Health Perspectives 118(6): 871-876.

Dufour, A.P. 1984. Health Effects Criteria for Fresh Recreational Waters. EPA 600/1-84-004.

Esmen, N., Hammad, Y. 1977. Lognormality of environmental sampling data. Journal of Environmental Science and Health, 29-41.

Fleisher, J.M., Fleming, L.E., Solo-Gabriele, H., Kish, J.K., Sinigalliano, C.D., Plano, L., Elmir, S.M., Wang, J.D., Withum, K., Shibata, T., Gidley, M.L., Abdelzaher, A., He, G., Ortega, C., Zhu, X., Wright, M., Hollenbeck, J., Backer, L.C. 2010. The BEACHES Study: Health effects and exposures from non-point source microbial contaminants in subtropical recreational marine waters. International Journal of Epidemiology, 1-10.

Kay, D., Bartram, J., Prüss, A., Ashbolt, N., D. Wyer, M.D., Fleisher, J.M., Fewtrell, L., Rogers, A., Rees, G. 2004. Derivation of numerical values for the World Health Organization guidelines for recreational waters. Water Research, 38(5): 1296-1304.

Kinzelman, J. 2012. Personal communication.

Lavender, J. S., Kinzelman, J.L. 2009. A cross comparison of qPCR to agar-based or defined substrate test methods for the determination of Escherichia coli and enterococci in municipal water quality monitoring programs. Water Research 43: 4967-4979.

Marion, J.W., Lee, J., Lemeshow, S., Buckley, T.J. 2010. Association of Gastrointestinal Illness and Recreational Water Exposure at an Inland U.S. Beach. Water Research 44(16): 4796-4804.

Noble, R.T., Blackwood, A.D., Griffith, J.F., McGee, C.D., and Weisberg, S.B., 2010. Comparison of Rapid Quantitative PCR-Based and Conventional Culture-Based Methods for Enumeration of Enterococcus spp. and Escherichia coli in Recreational Waters. Applied and Environmental Microbiology 76(22): 7437-7443.

Prüss, A. 1998. Review of Epidemiological Studies on Health Effects from Exposure to Recreational Water. International Journal of Epidemiology 27(1): 1-9.

Soller, J.A., Schoen, M.E., Bartrand, T., Ravenscroft, J., Wade, T.J. 2010. Estimated Human Health Risks from Exposure to Recreational Waters Impacted by Human and Non-Human Sources of Faecal Contamination. Water Research 44(16): 4674-4691.

U.S. EPA 1978. Microbiological Methods for Monitoring the Environment: Water and Wastes. U.S. Environmental Protection Agency, Office of Research and Development: Cincinnati, OH. EPA 600-8-78-017.

U.S. EPA 1986. EPA's Ambient Water Quality Criteria for Bacteria  -  1986. U.S. Environmental Protection Agency: Washington, DC. EPA440/5-84-002.

U.S. EPA 2002. National Beach Guidance and Required Performance Criteria for Grants. EPA -823-B-02-004. Available at: http://water.epa.gov/grants_funding/beachgrants/guidance_index.cfm

U.S. EPA 2006. 2006 Integrated Report Guidance. Available at: http://water.epa.gov/lawsregs/lawsguidance/cwa/tmdl/2006IRG_index.cfm

U.S. EPA 2008. Great Lakes Beach Sanitary Survey Manual. Available at: http://water.epa.gov/type/oceb/beaches/sanitarysurvey_index.cfm

U.S. EPA 2010a. A Study of the Various Parameters that Affect the Performance of the New Rapid U.S. Environmental Protection Agency Quantitative Polymerase Chain Reaction (qPCR) Method for Enterococcus Detection and Comparison with Other Methods and Pathogens in Treated Wastewater Mixed with Ambient Water. EPA 600-R-10-149.

U.S. EPA 2010b. Evaluation of the Suitability of Individual Combinations of Indicators and Methods for Different Clean Water Act Programs. EPA 823-R-10-004.

U.S. EPA 2010c. Applicability of Great Lakes NEEAR Dataset to Inland Recreational Water Criteria; Summary of Key Studies. EPA-823-R1-0002.

U.S. EPA 2010d. Predictive Tools for Beach Notification Volume I: Review and Technical Protocol. EPA-823-R-10-003. Available at: http://water.epa.gov/scitech/swguidance/standards/criteria/health/recreation/upload/P26-Report-Volume-I-Final_508.pdf

U.S. EPA 2010e. Predictive Modeling at Beaches Volume II: Predictive Tools for Beach Notification. EPA-600-R-10-176. Available at: http://water.epa.gov/scitech/swguidance/standards/criteria/health/recreation/upload/P23-25-Report-Volume-II-Final_508.pdf

U.S. EPA 2011. Using Microbial Source Tracking for TMDL Development and Implementation. Available at: http://www.epa.gov/region10/pdf/tmdl/mst_for_tmdls_guide_04_22_11.pdf

U.S. EPA 2012. Method 1611: Enterococci in Water by TaqMan(R) Quantitative Polymerase Chain Reaction (qPCR) Assay. EPA-821-R-12-008.

Wade, T.J., Pai, N., Eisenberg, J.N.S., Colford, J.M., Jr. 2003. Do U.S. Environmental Protection Agency Water Quality Guidelines for Recreational Waters Prevent Gastrointestinal Illness? A Systematic Review and Meta-Analysis. Environmental Health Perspectives 111(8): 1102-1109.

WERF 2009. Report on the Expert Scientific Workshop on Critical Research and Science Needs for the Development of Recreational Water Quality Criteria for Inland Waters. PATH4W09.

WERF 2008. Disinfection of Wastewater Effluent: Comparison of Alternative Technologies. Report Number 04-HHE-4.

Whitman, R.L., Nevers, M.B., Korinek, G.C., Byappanahalli, M.N. 2004. Solar and Temporal Effects on Escherichia coli Concentration at a Lake Michigan Swimming Beach. Applied and Environmental Microbiology, 70(7): 4276-4285.

WHO 2003. Guidelines for Safe Recreational Water Environments: Volume 1 Coastal and Fresh Waters. Available at: http://www.who.int/water_sanitation_health/bathing/srwe1/en/

Wiedenmann, A., Krüger, P., Dietz, K., López-Pila, J.M., Szewzyk, R., Botzenhart, K. 2006. A Randomized Controlled Trial Assessing Infectious Disease Risks from Bathing in Fresh Recreational Waters in Relation to the Concentration of Escherichia coli, Intestinal Enterococci, Clostridium perfringens, and Somatic Coliphages. Environmental Health Perspectives 114(2): 228-236.

Wyer M.D., Kay, D., Fleisher, J.M., Salmon, R.L., Jones, F., Godfree, A.F., Jackson, G., Rogers. A. 1999. An experimental health-related classification for marine waters. Water Research 33: 715 - 22.

Wymer, L.J., Wade, T.J. 2007. Chapter 6: The lognormal distribution and use of the geometric mean and the arithmetic mean in recreational water quality measurement. Statistical Framework for Recreational Water Quality Criteria and Monitoring. Edited by Wymer, L.J. John Wiley and Sons.