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 EPA’s recommended approach of applying both the geometric mean and statistical threshold value criteria to the end-of-pipe discharge. The monthly geometric mean is used by several states. States use a wide variety of approaches to the short-term limit. The statistical threshold value (one type of short-term limit) is not currently applied by Wisconsin’s neighboring states. However, EPA states that the “end-of-pipe” approach selected by Wisconsin “is considered to be the simplest and most common method to develop the effluent limits for pathogens and pathogen indicators.” (U.S. EPA. 2015. FAQ: NPDES Water-Quality Based Permit Limits for Recreational Water Quality Criteria.)
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. The department’s initial rule revision proposal included creation of a minimum twice-a-week monitoring requirement for all facilities. However, after review of comments on the original Economic Impact Assessment, review of current code, and consultations with department wastewater staff, it was determined that current regulations provide sufficient flexibility for facilities to select a monitoring frequency that reflects variability in their samples. Removing this requirement greatly reduced the anticipated fiscal burden for most facilities and in particular small facilities, some of which may be small businesses.
Facilities that may experience an increased cost associated with the revisions to this rule are those that are currently monitoring for fecal coliform and will be required to switch to monitoring for E. coli. Facilities may also incur increased costs associated with purchasing equipment to analyze E. coli samples using a defined substrate method if they choose to use that analytical technique. To estimate costs associated with this rule, the department looked both at costs for facilities to send samples to an external certified lab for analysis, and at an alternative of conducting analysis in-house if the facility has a certified lab.
The department obtained quotes from several commercial labs in the state for both fecal coliform and E. coli monitoring (per sample, E. coli: $25; fecal coliform: $19). This information, along with monitoring requirements in current permits, was used to estimate facilities’ current cost of monitoring. Projected costs were then calculated assuming facilities will monitor for only E. coli at their current monitoring frequency from May 1 through September 30, and send samples to an external lab for analysis (Table 1). For facilities currently monitoring for a longer time frame, the same monitoring time frame currently being used by the facility was used in the analysis.
Table 1. Cost Estimates Due to Changes in Monitoring and Analysis: Using External Lab |
Proposed Change | Number of Facilities | Estimated Annual Change per Facility ($) | Total Annual Costs ($) |
Switch indicator from fecal coliform to E. coli; External lab analysis | 336 | 158 | 52,986 |
Facilities with a certified lab in-house can determine whether it is more cost-effective for them to send their samples to an external lab or do the analysis in-house. If doing in-house analysis, facilities may use membrane filtration methods or defined substrate methods. Most facilities are already doing membrane filtration for fecal coliform. If they continue with membrane filtration for E. coli, cost per sample would be generally equivalent. Some facilities may wish to instead purchase equipment to convert to defined substrate analysis, which can save staff time and may be more efficient in the long-term. The department obtained cost estimates from a defined substrate test manufacturer (IDEXX) for upfront capital costs as well as ongoing annual costs for facilities that choose to begin analyzing E. coli using a defined substrate method rather than a membrane filtration method (Table 2). Costs shown in Table 2 are optional and would be in place of costs from Table 1 for facilities selecting this option.
Table 2. Cost Estimates Due to Changes in Monitoring and Analysis: In-house Lab Analysis with Defined Substrate Methods |
Proposed Change | Number of Facilities | Estimated Annual Change per Facility ($) | Total Annual Costs
over 10 years ($) |
Switch indicator from fecal coliform to E. coli; Purchase defined substrate analytical equipment (optional) | 102* | First year** | 5000 | 51,000 |
| | Subsequent years** | 140 | 14,280 |
* represents 50% of facilities that have a laboratory certification ** first year costs represent basic equipment; subsequent year costs represent UV bulb replacement |
For some facilities, changes to the monitoring requirements will reduce costs. There are 20 municipal wastewater treatment facilities that are monitoring for both fecal coliform and E. coli. These facilities may see an economic benefit from this rule as they will no longer have to monitor for fecal coliform (Table 3). Each of these 20 facilities is estimated to save $1,610 annually, for a total of $32,193 combined annual savings.
Table 3. Savings Estimates Due to Changes in Monitoring Requirements | |
Proposed Change | Number of Facilities | Estimated Annual Change per Facility ($) | Total Annual Savings ($) |
Drop fecal coliform indicator; continue monitoring E. coli | 20 | -1,610 | -32,193 |
Revisions to the water quality criteria and effluent limits are likely to lead to improved water quality and reduced risk of illness in people recreating in Wisconsin’s waters. While these benefits are hard to quantify, they are likely to result in an overall benefit to the citizens of Wisconsin.
10. Effect on Small Business (initial regulatory flexibility analysis):
Seven of the identified facilities may be small businesses, such as mobile home parks or nursing homes. Costs for small businesses were estimated in the same way as described above, but using just the subset of these seven facilities. Annual costs for switching from monitoring wastewater for fecal coliform to monitoring E. coli are projected to be approximately $132 per facility. Total costs for these seven facilities combined are estimated at $924 annually.
11. Agency Contact Person: Kristi Minahan, Wisconsin Department of Natural Resources, Bureau of Water Quality WY/3, P.O. Box 7921, Madison, WI 53707-7921;
12. Place where comments are to be submitted and deadline for submission:
Written comments may be submitted at the public hearings, by regular mail or email to:
Kristi Minahan
Wisconsin Department of Natural Resources
Bureau of Water Quality WY/3
