Section 227.11(2), Wis. Stats., provides the department with the authority to promulgate rules that are necessary to administer the specific statutory directives in ch. 283, Wis. Stats.
4. Related Statutes or Rules:
These rules relate to surface water quality standards and the WPDES permit program. Related rules include chs. NR 102 and 104, Wis. Adm. Code, which comprise Wisconsin’s surface water quality standards, and chs. NR 200 to 299, Wis. Adm. Code., which comprise the WPDES permit program.
5. Plain Language Analysis:
The Clean Water Act (CWA) requires states to adopt water quality standards to protect recreation in and on the water. Water quality standards include a recreation designated use and water quality criteria that protect this use. In addition to the CWA requirements, the Beaches Environmental Assessment and Coastal Health (BEACH) Act requires States with coastal waters (e.g., the Great Lakes) to adopt new or revised criteria for pathogens (including bacteria) to protect recreation not later than three years after the United States Environmental Protection Agency (EPA) publishes revised criteria to maintain eligibility for grant funding for communities. The EPA published revised national recommended recreation water quality criteria for bacteria in 2012.
Human waste contains a number of pathogens that can be spread through water and cause a wide range of diseases. The EPA employs the pathogen indicator concept for these criteria in which the indicator does not itself cause disease, but instead signals the potential for illness caused by human fecal contamination. Pathogen indicators, such as certain bacteria, are used because they tend to be more numerous than pathogens in human fecal matter and are cheaper, safer, and easier to measure. In their 2012 recommended criteria, EPA provides a choice for states to use either E. coli or enterococci as their pathogen indicator.
The goals of this rule package are to adequately protect the public while recreating in and on Wisconsin’s waters; revise Wisconsin’s bacteria water quality criteria to be consistent with EPA’s latest recommendations; and update the permit requirements for sewage treatment works to ensure consistency with EPA’s policies. To accomplish these goals, the department proposes to revise the bacteria water quality criteria for recreation in ch. NR 102, Wis. Adm. Code, remove fecal coliform criteria for individual waters from ch. NR 104, Wis. Adm. Code, and revise the permit requirements for publicly owned and privately owned domestic sewage treatment works in ch. NR 210, Wis. Adm. Code.
Bacteria Water Quality Criteria for Recreation
In 2012, EPA recommended updates to bacteria criteria and provided states with a choice of criteria for E. coli and enterococci at two different risk levels. The department evaluated the pathogen indicator and risk level as well as the time frame of the criteria, which waters the criteria should apply to, and the frequency and duration of exceedances for assessment determinations. The department also added language to allow for the development of bacteria site-specific criteria and removed the fecal coliform “variance” criteria in ch. NR 104, Wis. Adm. Code.
EPA provided states two options for their pathogen indicator: E. coli or enterococci. Since the adoption of the BEACH Act in 2004, permittees in Wisconsin and the other Great Lake States have monitored for E. coli in the Great Lakes basin. As such, there is a large amount of data on E. coli levels in the Great Lakes. Additionally, the department has been assessing inland and Great Lakes beaches against EPA’s 1986 E. coli criteria. Given these reasons, the department chose to use E. coli as the pathogen indicator for the revised recreation criteria.
EPA recommends that states assess for their selected indicator using two methods: the geometric mean and the statistical threshold value. Use of both methods ensures that states not only assess the average over time (geometric mean, or GM), but also account for the frequency of bacterial level spikes (statistical threshold value, or STV).
Since 1986, EPA’s recommended bacteria water quality criteria for recreation have consisted of long-term and short-term criteria. In the 1986 recommendations, a GM was used as the long-term criterion and a single sample maximum (SSM) as the short-term criterion. In the 2012 recommendations, the same geometric mean is used as the long-term criterion. However, the recommendations for short-term criteria replace the SSM with a different approach, the statistical threshold value (STV). The SSM criterion from 1986 set a “do not exceed” threshold which limited the ability to account for natural variation. The 2012 STV criterion corresponds to the 90th percentile of the water quality distribution data. This is intended to allow for occasional, but not frequent, spikes in bacteria levels, reflecting the expected variability in water quality measurements.
Previously, when the department was using fecal coliform as the pathogen indicator, the criterion was only applied as a geometric mean. The revised rule for E. coli contains both GM and STV criteria.
EPA provided two illness rates for states to choose from: either 32 or 36 cases of gastrointestinal illness out of 1,000 primary contact recreation users. The department selected the criteria based on the higher illness rate of 36 per 1,000 users, given no known human health benefit of selecting the lower illness rate. The criteria based on the higher illness rate are consistent with the level of protection provided by the EPA’s previous criteria recommendations, and EPA concluded that criteria based on either of the illness rates would provide adequate human health protection. Criteria based on the lower illness rate would have been more stringent than criteria based on the higher illness rate. The department evaluated the impact of selecting the lower illness rate on permittees and impaired waters listings. Selecting the lower illness rate would unnecessarily require lower (more stringent) effluent limits for facilities and increase the number of impaired waters and beach advisories.
The revised rule includes a clause specifying that the bacteria criteria apply from May 1st to September 30th. Currently, disinfection is required from May 1st to September 30th to protect recreation, and beaches are assessed from May through September. As such, incorporation of this time frame into the criteria is not a change to the status quo, but an additional measure of transparency allowing the department to establish clear expectations for water quality assessments and permitting decisions.
A criterion’s duration is the time period over which the criterion is assessed. The department selected a duration of 90 days, which means that samples from throughout a 90-day time period would be used for calculating attainment of the criteria. The duration of 90 days is proposed for both Geometric Mean and Statistical Threshold Value criteria. It was selected to ensure adequate protection of the recreation designated use and to allow assessment of Wisconsin’s waters in a comprehensive and informative manner. This duration allows the department to assess more waterbodies and allows for a clear evaluation of the waterbody’s impairment status. The 90-day duration is consistent with a white paper produced by EPA clarifying that up to 90 days was determined to be an acceptable and scientifically defensible duration for E. coli criteria (U.S. EPA. 2015. Narrative justification for longer duration period for recreational water quality criteria).
Bacteria Site-Specific Criteria (SSC)
When numeric criteria are established, they must be based on EPA’s recommended water quality criteria, EPA’s recommended water quality criteria modified to reflect site-specific conditions, or other scientifically defensible methods. The EPA must review and approve a state’s criteria and does so only if the criteria are based on sound scientific rationale and contain sufficient parameters to protect the designated use. The EPA recognizes that there are sites where non-human and non-fecal sources may contribute to high bacteria levels while the probability of illness at these sites may be much lower than the probability of illness at sites with human sources. In such cases, the EPA allows for less-stringent site-specific criteria to be established if they are based on sound scientific rationale and contain sufficient parameters to protect the designated use.
This rule package includes language that allows the department to adopt bacteria SSC by rule for a specific waterbody. To ensure that bacteria SSC adopted by the state are appropriate, scientifically defensible and protective, the following conditions must be demonstrated: the proposed SSC were developed using an EPA approved method, procedure, or test, are based on sound scientific rationale, and the proposed SSC are as protective of the recreation use as the statewide E. coli criteria. For a less-stringent SSC, the request must also demonstrate that the predominant source of the bacteria must be non-human or non-fecal.
The existing language in ch. NR 104, Wis. Adm. Code, contains fecal coliform variance criteria for certain individual waters. As part of this rule package, the department removed all references to these variance criteria because they are outdated and not adequately protective. These criteria were based on recommendations by the National Technology Advisory Committee in 1968 for secondary contact recreation. Fecal coliform is no longer recommended as a pathogen indicator because studies conducted in the 1970-80s did not find a correlation between fecal coliform levels and the rate of gastrointestinal illness. Additionally, the EPA does not currently have criteria recommendations for secondary contact waters and the department does not have a designated use category for secondary contact waters. Furthermore, the variance criteria were intended to be temporary with an expectation that water meet these criteria by 1977 and the statewide criteria by July 1983.
In the existing language in ch. NR 210, Wis. Adm. Code, a fecal coliform limit of 400 cfu/100 mL applies to all facilities that are required to disinfect. This limit is a categorical limit (i.e., an effluent limit that applies to certain categories of wastewater dischargers) and not a water quality based limit (i.e., an effluent limit designed to meet a water quality standard in the receiving water). Facilities that are disinfecting should be able to maintain fecal coliform in their effluent below this level; however, this limit does not ensure that fecal coliform water quality criteria are met in the receiving water. The department replaced the fecal coliform limit with water quality based effluent limits (WQBELs) for E. coli.
Federal regulations require permit limits for publicly owned treatment works (POTWs) with continuous discharge to be expressed as average weekly and average monthly discharge limitations. The department elected to establish these limits using the procedures in EPA’s Technical Support Document for Water Quality-Based Toxics Control. In this approach, both short- and long-term limits are calculated from single duration expression of a criterion where the monthly limit is set equal to the geometric mean and a weekly geomean limit is derived from the monthly geomean limit. This approach was selected because it is consistent with federal regulations and is also used to establish Wisconsin’s short-term limits for toxic substances. In addition, this approach provides adequate protection while taking into consideration the variability in E. coli levels.
Repeal of Redundant Language on Compliance Schedules and Public Notice
The proposed rules repeal ch. NR 210.06 (4) to (6) as they are redundant with more recent codes that provide more detailed information. Language in sub. (4) on compliance schedules is repealed because general language allowing compliance schedules for any point source discharger and any substance is found in ch. NR 205.14, with specific requirements provided in ch. NR 106.117. Language in subs. (5) and (6) on tentative and final determinations related to the permit, public notice processes, and review procedures are repealed because this information is provided in detail for all facilities in ch. NR 203, “Wisconsin Pollutant Discharge Elimination System Public Participation Procedures,” which covers public noticing of permit applications received and tentative and final determinations. It also covers permit actions such as final determinations and modifications or reissuance of permits. Part of sub. (7) is repealed that required perpetual maintenance of the same WPDES permit conditions as were established in 1986, because it is appropriate that permit terms and conditions evolve over time as needed.
Update of tables with EPA-approved methodologies
Chapter NR 219 includes tables of EPA-approved methods for analyzing bacteria-related parameters. Portions of Table A and Table EM related to bacteria are updated to incorporate EPA’s most recent approved methods.
6. Summary of, and Comparison with, Existing or Proposed Federal Statutes and Regulations:
With the revisions contained in this rule package, the department rules will be consistent with the following federal regulations:
Clean Water Act section 303(c), which requires states to periodically review and modify or adopt, if necessary, water quality standards for protection and propagation of fish and shellfish and recreation in and on the water;
Clean Water Act section 303(i)(1)(B), which requires states to adopt water quality criteria for pathogens and pathogen indicators for coastal recreation waters based on federal criteria published by USEPA;
40 CFR 131.10 and 11, which require states to develop water quality standards comprised of uses and criteria to protect the uses, and requires that criteria be based on federal guidance, federal guidance modified to reflect site-specific criteria, or other scientifically-defensible methods;
40 CFR ss. 131.4 and 131.11, which allows states to adopt their own water quality criteria so long as these criteria are protective of human health or welfare, enhance the quality of the water, and serve the purposes of the Clean Water Act;
40 CFR 122.44(d), which provides that WQBELs must be derived from and comply with water quality standards and designated uses;
40 CFR 122.45(d), which requires that POTWs with continuous discharges receive limits expressed as monthly average and weekly average limits;
40 CFR 122.47, which specifies the protocols and restrictions for establishing compliance schedules in WPDES permits;
40 CFR Part 132, Appendix F, Procedure 9, which authorizes compliance schedule extensions within the Great Lakes Basin.
7. Comparison with Similar Rules in Adjacent States:
For this rule package, comparisons were made to the other states in EPA Region 5 (Illinois, Indiana, Michigan, Minnesota, and Ohio) and Iowa. All of the Region 5 states are subject to the Clean Water Act, BEACH Act, and EPA regulations. As Iowa does not have any coastal waters, they are not subject to the BEACH Act but are still subject to the Clean Water Act and EPA regulations. A brief comparison with these states is provided below on the key issues addressed in this rule package.
Bacteria Water Quality Criteria for Recreation
The other states have different criteria for each of their recreation use subcategories. Because Wisconsin has a single recreation use category, only the criteria for the “full contact” category were considered in this comparison. Because Illinois is currently revising its criteria for bacteria, they were not included in these comparisons.
All of the states that were used for this comparison, except Illinois, use E. coli as the pathogen indicator. Illinois is currently in the process of revising its criteria to use E. coli. In this rule package, the department selected E. coli as the pathogen indicator for Wisconsin’s criteria, consistent with these other states.
Indiana and Iowa have short- and long-term criteria based on EPA’s 1986 recommendations. Michigan also bases its criteria on EPA’s 1986 recommendations but uses single day GM instead of the SSM as its short-term criterion. Minnesota currently has criteria based on EPA’s 1986 recommendations. Ohio revised its criteria in 2016 based on EPA’s 2012 recommendations.
In this rule package, the department selected an approach that is consistent with Ohio. In the revised rule, EPA’s 2012 recommendations were used to establish Wisconsin’s criteria because they are based on the latest scientific knowledge and allow the natural variation in bacteria levels to be considered when assessing the waterbody.
In its 2012 recommendations EPA developed criteria based on two illness rates, with the higher illness rate corresponding with the level of protection provided by the EPA’s 1986 recommendations. Ohio’s criteria are based on the higher illness rate. A comparison to the other states was not made as their criteria were not based on the 2012 recommendations.
In this rule package, the department selected an approach that is consistent with Ohio. In the revised rule, the department selected the criteria based on the higher illness rate because selection of the lower illness rate would unnecessarily increase the number of impaired waters and beach advisories without any known human health benefits.
All of the other states have a specific time frame during which the bacteria criteria apply. This time frame ranges from March 15th – November 15th for Iowa to April 1st – October 31st for Minnesota and Indiana to May 1st – October 31st for Michigan and Ohio.
In this rule package, the department selected an approach that is consistent with the other states. The revised rule applies the bacteria criteria for recreation from May 1st – September 30th. This time frame was chosen because Wisconsin’s official beach season is Memorial Day to Labor Day (last weekend in May to first weekend in September), disinfection has historically been required from May 1st through September 30th to ensure adequate protection for beach use, and “full contact” recreation activities are not likely outside of this time frame due to low water temperatures.