(d) Other toxic pollutants; compliance within 3 years after limitations are established. Compliance with effluent limitations under par. (b) with respect to all toxic pollutants included on the list promulgated under s. 283.21 (1) (a) but which are not included in the table referred to under par. (c) not later than 3 years after the date the effluent limitations are established.” Section 283.21, Wis. Stats., establishes effluent standards for pretreatment of wastewater and the discharge of toxic pollutants. This section requires the department to establish a list of toxic pollutants, promulgate effluent standards for those pollutants, and establish pretreatment standards for pollutants introduced into publicly owned treatment works that would ordinarily not be treated or would have a negative effect on the facility.
(b) Effluent standards. The department may promulgate by rule an effluent standard, which may include a prohibition, establishing requirements for a toxic pollutant which, if an effluent limitation is applicable to a class or category of point sources, is applicable to that category or class of point sources only if this effluent standard imposes more stringent requirements than are imposed under s. 283.13 (2) (b). An effluent standard promulgated under this section shall take into account the toxicity of the pollutant, its persistence, degradability, the usual or potential presence of affected organisms in any waters, the importance of affected organisms, the nature and extent of the effect of the toxic pollutant on these organisms and the extent to which effective control is being or may be achieved under other regulatory authority.” Section 283.21 (2) (a) reads: “The department shall by rule promulgate pretreatment standards to regulate the introduction into publicly owned treatment works of pollutants which are not susceptible to treatment by such treatment works or which would interfere with the operation of such treatment works.” 4. Related Statutes or Rules: Chapters NR 211, 215, 661, and 662, Wis. Adm. Code. Chapter NR 211, Wis. Adm. Code, establishes requirements for POTWs and point source dischargers of pollutants to POTWs to prevent the discharge of pollutants that would interfere with the operation of the treatment works, pass through treatment works insufficiently treated, or impair the use or disposal of the sludge generated by treatment works. Chapter NR 215, Wis. Adm. Code, is the list of toxic, conventional, and nonconventional pollutants required under s. 283.21, Wis. Stats. Mercury, which is a significant component of dental amalgam, is included on that list under s. NR 215.03 (6) (j), Wis Adm. Code. Chapter NR 220, Wis. Adm. Code, establishes a list of industrial categories for which effluent limitation guidelines and/or pretreatment standards apply and provides for the incorporation of effluent limitations into discharge permits. Chapters NR 221-297, Wis. Adm. Code, contain effluent limitation guidelines for industrial categories of dischargers, just as this proposed rule will for dental offices. Effluent limitation guidelines are typically promulgated by the U.S. Environmental Protection Agency (EPA) and adopted into this range of administrative code chapters, just as is the case with this proposed rule. Chapter NR 661, Wis. Adm. Code, in part identifies solid wastes subject to regulation as hazardous wastes under ch. NR 662, Wis. Adm. Code. Mercury is specifically listed in ch. NR 661 Appendix VIII, HAZARDOUS CONSTITUENTS. Chapter NR 662, Wis. Adm. Code, establishes requirements for storage, transport, disposal, and recordkeeping related to hazardous wastes. Mercury collected in an amalgam separator is classified as a solid hazardous waste under ch. NR 661, Wis. Adm. Code. 5. Plain Language Analysis: The proposed rule requires dental offices to control the discharge of mercury and other metals in dental amalgam to POTWs based on the best available technology or best available demonstrated control technology. Specifically, the requirements are based on the use of amalgam separators and best management practices recommended by the American Dental Association (ADA). The best management practices (BMPs) are:
—prohibiting the discharge of waste (or “scrap”) amalgam; and
—prohibiting of the use of line cleaners that are oxidizing or acidic and that have a pH higher than 8 or lower than 6.
Amalgam separators are a practical, affordable, and readily available technology for capturing mercury and other metals before they are discharged into sewers that drain to POTWs. The mercury collected by these separators can be recycled. This rule also includes a provision to significantly reduce and streamline the oversight and reporting requirements in pretreatment regulations that would otherwise apply as a result of this rulemaking. The rule requires dental offices to meet a performance standard that includes BMPs and the use of an amalgam separator(s) compliant with the 2008 International Organization for Standardization (ISO) 11143 standard (ISO, 2008), or the American National Standards Institute (ANSI)/ADA Specification 108 for Amalgam Separators (2009) with Technical Addendum (2011), (ANSI/ADA, 2009; ANSI/ADA, 2011). ISO, a voluntary standard setting organization, established a standard for measuring amalgam separator efficiency by evaluating the retention of amalgam solids using specified test procedures in a laboratory setting. In order to meet the ISO standard, a separator must achieve 95 percent removal or greater of total solids. The standard also includes requirements for instructions on the use, operation, and maintenance of amalgam separators (see proposed s. NR 229.03 (a) (1) 4., Wis. Adm. Code). The rule also includes a provision such that the performance standard can be met with the use of an amalgam removing technology other than an amalgam separator (equivalent device). This provision was included to incorporate future technologies that achieve comparable removals of pollutants from dental discharges as amalgam separators, but that may not fall under the amalgam separator classification.
Because the rule does not include a numerical limit, the performance standards also specify certain operation and maintenance requirements for the amalgam separator(s) or comparable device to ensure they are operated optimally. In addition to installing one or more amalgam separators compliant with the ISO 11143 standard (or its equivalent) and implementing the required BMPs, the pretreatment standards specify certain operating and maintenance requirements for the amalgam separator. These requirements include:
—documented amalgam separator inspection as specified by the manufacturer’s user manual to ensure the separator is performing properly and to confirm that all amalgam process wastewater is flowing through the amalgam retaining portion of the separator;
—replacement of the amalgam retaining unit of the device in accordance with the manufacturer’s schedule or when the amalgam retaining unit has reached the maximum level, whichever comes first; repair/replacement as needed; and
—recycling/disposal of amalgam waste.
Reporting requirements include a One-time Compliance Report.
The rule allows dental offices to continue to operate amalgam separators installed prior to publication of this rule for the equipment lifetime or ten years (whichever comes first), as long as the dental discharger complies with the other rule requirements including the specified BMPs, operation and maintenance, reporting, and recordkeeping requirements.
Once the separator needs to be replaced or the ten-year period has ended, whichever comes first, dental offices will need to replace the amalgam separator with one that meets the requirements of the final rule.
Dental offices that do not place amalgam, and do not remove dental amalgam except in limited emergency or unplanned, unanticipated circumstances are exempt from any further requirements as long as they certify such in their One-time Compliance Report.
Application of typical categorical discharger oversight and reporting requirements to all of the dental offices in the state would require a large amount of additional staff time. Because of this, the rule minimizes the administrative burden on dental offices subject to the rule, as well as the department and local regulatory authorities (Control Authorities) responsible for oversight and enforcement of the new standard. This is appropriate because dental office discharges differ from other industries for which categorical pretreatment standards have been established. Both the volume of wastewater discharged and the quantity of pollutants in the discharge on a per facility basis are significantly less than other industries for which categorical pretreatment standards have been established.
Accordingly, this rule exempts dental offices from the oversight and reporting requirements of categorical pretreatment standards, reflecting the department’s recognition that the otherwise-applicable regulatory framework for categorical dischargers would be unlikely to have a significant positive impact on overall compliance with the rule across the dental industry, while imposing a substantial burden on state and local regulating authorities.
In order to simplify implementation and compliance for the dental offices and the regulating authorities, the rule establishes that dental dischargers are not Significant Industrial Users (SIUs) or Categorical Industrial Users (CIUs) as defined in ch. NR 211, Wis. Adm. Code, and are not “industrial users subject to categorical pretreatment standards” as those terms and variations are used in the administrative code, unless designated as such by the Control Authority. While this rule establishes pretreatment standards that require dental offices to reduce dental amalgam discharges, the rule does not require Control Authorities to implement the traditional suite of oversight requirements in ch. NR 211, Wis. Adm. Code. This significantly reduces the reporting requirements for dental dischargers that would otherwise apply by instead requiring them to demonstrate compliance with the performance standard and BMPs through a One-Time Compliance Report to their Control Authority. This regulatory approach also eliminates the additional oversight requirements for Control Authorities that are typically associated with SIUs, such as permitting and annual inspections of individual dental offices. It also eliminates additional reporting requirements for the Control Authorities typically associated with CIUs, such as identification of CIUs in their annual pretreatment reports. At the same time, the rule recognizes the Control Authority’s discretionary authority to treat a dental discharger as an SIU and/or CIU if, in the Control Authority’s judgement, it is necessary.
6. Summary of, and Comparison with, Existing or Proposed Federal Statutes and Regulations: This rule is a direct adoption of 40 CFR Part 441, with only small, non-substantive changes in some terms to comply with Wisconsin legislative drafting style these changes do not change the requirements of the rule. 7. Summary of Comments Received on the Statement of Scope and How the Agency Took Those Comments into Account in Drafting the Proposed Rule: The department received one written comment from Milwaukee Metropolitan Sewerage District in support of the statement of scope. The department received one comment from a private citizen that stated they felt a rule was not necessary. There were no attendees at the public hearing for the statement of scope.
8. Comparison with Similar Rules in Adjacent States: Adjacent states have not enacted similar rules and are instead applying 40 CFR 441. Pretreatment programs in Illinois are directly administered by Region 5 of the EPA, so 40 CFR 441 is being used directly. Under s. NR 211.34 (2), Wis. Adm. Code, the department is required to adopt pretreatment standards or requirements as soon as possible after the promulgation of any federal regulation establishing pretreatment standards or requirements. The same rule promulgation requirement is also found in s. 283.11 (1), Wis. Stats. (see item 2., above). 9. Summary of Factual Data and Analytical Methodologies Used and How Any Related Findings Support the Regulatory Approach Chosen: Dental offices discharge mercury present in amalgam used for fillings. Amalgam separators are a practical, affordable, and readily available technology for capturing mercury and other metals before they are discharged into sewers that drain to POTWs. Once captured by a separator, mercury can be recycled.
EPA first identified the dental industry for study in its 2006 Effluent Guidelines Plan (71 FR 76644) as part of the health services industry. In 2008, EPA published its results from the detailed study in the technical report, Health Services Industry Detailed Study: Dental Amalgam (U.S. EPA, 2008). For that report, EPA compiled and summarized information on mercury discharges from dental offices, BMPs, and amalgam separators. Regarding amalgam separators, EPA examined their frequency of use, their effectiveness in reducing mercury discharges to POTWs, and the capital and annual costs of their installation and operation. The detailed study report also included a preliminary industry profile that provided the number of dental offices, the number of small businesses, discharge information, financial characteristics of the industry, and a description of the national, state, and local mandatory and voluntary programs to reduce mercury wastewater discharges from dental offices. EPA documented its findings in the August 2008 technical report, Health Services Industry Detailed Study: Dental Amalgam (EPA-821-R-08-014).
EPA Region 8 developed a draft Mercury Control Strategy to help POTWs control mercury pollution problems from commercial and smaller industrial users, including dental offices. This draft Strategy included detailed information on the development of BMPs, amalgam separators, and other removal and filtration devices, as well as other background information regarding dental amalgam control approaches
EPA reviewed literature and collected data on various aspects of the dental industry, amalgam separators, and mercury discharges, including:
—Current, relevant technical publications that describe the sources and generation of mercury wastes at dental offices and the discharge of mercury and other amalgam filling metals (i.e., copper, silver, tin, and zinc) to POTWs.
—Current information on possible treatment solutions (i.e., amalgam separators) for dental offices to reduce mercury in the wastewater and their effectiveness.
—Current implementation costs for technologies to reduce mercury and other metal discharges at dental offices.
EPA participated in several meetings with stakeholders including the Environmental Council of the States (ECOS), Association of Clean Water Act Administrators (ACWA), environmental organizations, the American Dental Association (ADA), the National Association of Clean Water Agencies (NACWA), and various environmental organizations.
It is important to note that many dental offices in Wisconsin have already installed the technology necessary to come into compliance with the proposed rule, as use of dental amalgam separators is required by many municipal wastewater treatment plants (POTWs) that administer mercury pollutant minimization plans.
10. Analysis and Supporting Documents Used to Determine the Effect on Small Business or in Preparation of an Economic Impact Report:
American Dental Association:
—“An Economic Study of Expanded Duties of Dental Auxiliaries in Colorado” (ADA, 2009).
—“2009 Survey of Dental Practice: Income from the Private Practice of Dentistry” (ADA, 2010).
EPA:
—EPA-821-R-16-005 -Technical and Economic Development Document for the Final Effluent Limitations Guidelines and Standards for the Dental Category (US-EPA, 2016).
11. Effect on Small Business (initial regulatory flexibility analysis): DNR anticipates that the majority of entities (if not all) impacted by this rule are small businesses. As a result, the impact of this rule to small businesses will be the same as the broader impact of the rule to the business sector provided in section #14 of the Fiscal Estimate and Economic Impact Analysis, form DOA-2049 (attached).
The economic impact on dental entities, local government units, and small businesses, per year, is estimated at $1.2 M. The analysis considered that 60% of the dental facilities in Wisconsin (an estimated 2,061 facilities) did not have the technology and equipment required, and as a result would have to install the required equipment to meet the federal regulations, which brought the cost to an estimated $909,847.97. An estimated 40% of the 2,061 dental entities with already installed technology would spend an estimated $314,338.99, which brings the annual total to $1,224,186.96.
12. Agency Contact Person: Richard Douglas; Department of Natural Resources, 101 S. Webster Street, Madison, WI 53707; Richard.Douglas@wisconsin.gov; (608) 267-6822
