Criteria Duration
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.
Variance Criteria
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. Permit Requirements
Effluent Limitations
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.
Pathogen Indicator
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.
Criteria Magnitude
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.
Illness Rate
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.
Time Frame
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.
Criteria Duration
All of the other states, except for Iowa, have duration specified as part of their criteria. Michigan, Minnesota, and Indiana’s criteria are based on EPA’s 1986 recommendations. Both Michigan and Indiana use a monthly duration for both the geometric mean (GM) and single sample maximum (SSM) criteria. Michigan uses geometric mean values for both its long- and short-term criteria and uses a duration of a month for the long-term criterion and a day for the short-term criterion. Ohio’s criteria are based on EPA’s 2012 recommendations and use a duration of 90 days for both its GM and statistical threshold value (STV) criteria.
In this rule package, the department selected an approach that is consistent with Ohio and is acceptable to EPA. The revised rule specifies a duration of 90 days for both the GM and STV criteria because it allows the department to adequately protect the recreation designated use while assessing Wisconsin’s waters in a comprehensive and informative manner.
Bacteria Site-Specific Criteria
None of the other states have language specific to the development of site-specific criteria for bacteria.
Variance Criteria
These variances, proposed for deletion, are specific to individual waterbodies in Wisconsin. A comparison to the other states was not conducted.
Permit Requirements
To ensure recreation is protected in Wisconsin’s waters, dischargers of treated human waste are required to meet effluent limits for bacteria. The requirements described in this section apply to facilities that are subject to ch. NR 210, Wis. Admin. code, including publicly owned treatment works and privately owned domestic sewage treatment works. Only the requirements for dischargers to “full contact” use waters were considered in this comparison as Wisconsin has a single recreation use category. Because Illinois is currently revising its permit requirements for bacteria, they were not included in these comparisons. Effluent Limitations
Effluent limits vary by state. For this comparison, only the limits that apply during the time frame in which the bacteria criteria apply were included. Minnesota and Michigan have effluent limits for fecal coliform that are based on EPA’s 1976 recommended criteria. Minnesota has a monthly limit equal to the geometric mean (GM) criterion and does not have specified monitoring requirements. Michigan has monthly and weekly limits, with the monthly limit equal to the GM criterion and the weekly limit equal to the “10% exceedance” criterion. Michigan requires a minimum of 5 samples for the monthly limit and 3 samples for the weekly limits.
Iowa and Indiana have effluent limits for E. coli that are based on EPA’s 1986 recommended criteria. Iowa has a monthly limit equal to the GM criterion and requires a minimum of 5 samples a month, with monitoring conducted for one month during each quarter of the recreation season. Indiana has both monthly and daily limits. The monthly limit equals the GM criterion and the daily limit equals the SSM criterion for designated bathing beaches. The daily limit only applies when 10 or more samples have been collected in a month. Indiana bases its minimum monitoring requirements on the average design flow of the facility. Small facilities are typically required to monitor only once a week while large facilities may be required to monitor daily.
Ohio has monthly and weekly effluent limits for E. coli. Limits for dischargers to the Ohio River are based on EPA’s 1986 recommended criteria while limits for dischargers to all other waters are based on EPA’s 2012 recommended criteria. These limits differ because of specific requirements from the Ohio River Valley Water Sanitation CommissionFor the Ohio River dischargers, the monthly limit equals the GM criterion (rounded) and the weekly limit equals the SSM criterion for designated bathing beaches (rounded). For dischargers to other Ohio waters, the monthly limit equals the GM criterion and the weekly limit is calculated using procedures in the U.S. EPA’s Technical Support Document for Water Quality-Based Toxics Control. Ohio bases its minimum monitoring requirements on the average design flow of the facility with very small facilities typically required to monitor only once per quarter and large facilities often required to monitor daily.
In this rule package, the department selected an approach for effluent limits that is consistent with Ohio’s approach for non-Ohio River waters. In the revised rule, Wisconsin’s monthly fecal coliform limit is replaced with monthly and weekly WQBELs for E. coli. The monthly limit equals the GM criterion and the weekly limit varies based on the number of samples collected in a month and is calculated using procedures in the U.S. EPA’s Technical Support Document for Water Quality-Based Toxics Control.
8. Summary of Factual Data and Analytical Methodologies Used and How Any Related Findings Support the Regulatory Approach Chosen:
The methodology identified in this rule package is based on Clean Water Act and Great Lake Initiative requirements and on EPA guidance including the U.S. EPA (March 1991) Technical Support Document for Water Quality-based Toxics Control. PB91-127415: Office of Water.
9. Analysis and Supporting Documents Used to Determine the Effect on Small Business or in Preparation of an Economic Impact Report:
This rule is expected to have minimal economic impact overall and for small businesses. The costs incurred will be due to changes in analytical methods associated with monitoring each type of bacteria. These changes solely pertain to facilities subject to ch. NR 210, Wis. Adm. Code (i.e., publicly owned treatment works, privately owned domestic sewage treatment works). We anticipate the total annual cost of compliance for 336 facilities to be $52,986. Cost savings for 20 facilities are estimated at $32,193. Taken together, the net annual cost of compliance is anticipated to be $20,793. The economic impact of alternative compliance methods is also presented.
