Frequently Asked Questions for Control Authorities on the Dental Rule (40 CFR Part 441)

United States
Environmental Protection
\r ^1 # ^Agency
Office of Water
EPA 800-F-18-002
May 2018
Frequently Asked Questions for Control Authorities on the Dental Rule (40 CFR Part 441)
1. Does the dental office category rule apply to dental facilities that discharge to publicly owned
treatment works (POTWs) (e.g., municipal sewage system) that have a dental amalgam reduction
program?
Yes. The federal rule applies to dental dischargers irrespective of any state or local dental amalgam reduction
program.
2. Is a dental discharger considered an "industrial user"?
Yes. An "industrial user" is a nondomestic source of indirect discharge into a POTW. Dental dischargers are
therefore considered industrial users under the general pretreatment regulations in 40 CFR part 403; see:
https://www.federalregister.gOv/d/2017-12338/p-110. This rule does not alter that status. However, this rule
established that dental dischargers are not significant industrial users (SlUs) or categorical industrial users
(ClUs) as defined in 40 CFR part 403 unless designated as such by the control authority.
3. Are control authorities required to identify all dental dischargers?
Because dental dischargers are industrial users as explained in question two, the requirements in 40 CFR §403
and §122, which pertain to control authority identification and oversight of all industrial users, continue to
apply. Because dental dischargers are generally neither SlUs nor ClUs per 40 CFR §441.10(b). they are not
required, under 40 CFR §403, to be individually identified in the POTW's annual report or National Pollutant
Discharge Elimination System (NPDES) permit application, unless otherwise required under state or local
authorities.
4. As a control authority, what are my oversight and enforcement responsibilities regarding dental
dischargers?
As noted in section VI.D.4 of the Preamble to this rule, "Control Authorities have discretion under the final rule
to determine the appropriate manner of oversight, compliance assistance, and enforcement." (82 FR
27164). However, while dental dischargers are not ClUs or SlUs, they continue to be industrial users (lUs) -
defined broadly at 40 CFR §403.3 as a "source of Indirect Discharge." 40 CFR §403.8(f) directs POTWs to
establish procedures and standards to identify all lUs, including dental dischargers, to ensure compliance with
the general and specific prohibitions in order to protect against pass through and interference. Control
authorities, however, have discretion and flexibility on what those requirements should be for dental
dischargers. As a POTW's procedures are tailored to the capacity and capability of each POTW, as well as the
NPDES permit requirements for the individual receiving water body, they will be different for each control
authority. Refer to your program's procedures and NPDES permit conditions to understand your requirements
as they relate to industrial users. If necessary, control authorities have the option to modify their program to
adapt their otherwise applicable procedures to dental dischargers. In some circumstances, this may be
considered a substantial modification, which has special requirements described in 40 CFR §403.18. Control

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authorities may work with their approval authority for assistance with questions on handling specific
oversight, enforcement or program modification questions.
5.	What are the recordkeeping requirements for the dental office category rule for a control authority?
The rule does not impose additional recordkeeping requirements on a control authority. See the
recordkeeping requirements for a control authority found in 40 CFR §403.12(o).
6.	Does a dental discharger that places or removes amalgam and submitted a one-time compliance report
need to submit another one-time compliance report if there are changes to the information provided on
the report (e.g., I replace my amalgam separator or change the total number of chairs in my facility)?
No. If, however, a dental discharger transfers ownership of the facility, the new owner must submit a new
one-time compliance report. In addition, if a dental discharger submits a one-time compliance report under 40
CFR §441.50(a)(3)(i) certifying that the dental discharger does not place or remove dental amalgam except in
limited circumstances but the dental discharger changes the practice such that the certification is no longer
accurate, a new one-time compliance report should be submitted that includes the information required for
dental dischargers subject to the standards of Part 441 (see 40 CFR §441.50(a)(3)(ii)).
7.	Can control authorities modify the language in the sample one-time compliance report that EPA posted?
Yes. The sample form for the one-time compliance report developed by EPA contains the minimum
information that dental facilities must submit in a one-time compliance report to comply with §441.50.
Control authorities may request additional information on their one-time compliance report in accordance
with the provisions of their pretreatment program's legal authority, or in accordance with any related state or
local laws. EPA recommends that control authorities cite the authority under which they are requesting this
additional information, should they choose to do so. A sample one-time compliance report is available for
download on EPA's website here: https://www.epa.gov/eg/dental-effluent-guidelines
8.	Does the 2015 NPDES Electronic Reporting Rule (40 CFR Part 127) require dentists to electronically
submit their one-time compliance reports?
No. The 2015 NPDES Electronic Reporting Rule ("NPDES eRule") does not require electronic submission of the
one-time compliance report because it is not listed in Table 1 of Appendix A of the NPDES eRule (40 CFR
§127).
9.	Can a control authority set up an electronic reporting system to collect the one-time compliance
reports?
The dental office category rule does not preclude control authorities from collecting their reports
electronically. Note: If a control authority establishes an electronic reporting system, it must be CROMERR-
compliant (Cross-Media Electronic Reporting Rule, 40 CFR §3).
10. Does the dental office category rule apply to septage haulers who service the septic tanks of dental
facilities?
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No. The dental office category rule applies only to dental dischargers - i.e. a facility where the practice of
dentistry is performed that discharges wastewater to publicly owned treatment works (40 CFFR 441.20(e)). It
does not apply to dental discharges to septic systems.
Note: dental discharges to septic systems would be subject to regulation under the Safe Drinking Water Act
Underground Injection Control Program, which may be implemented by EPA or the State depending on
whether the State has primary enforcement responsibility. Other state and local regulations regarding the
disposal of nondomestic wastewater to septic systems may also apply. Also note that control authorities may
impose controls on the receipt of hauled nondomestic septage under federal Clean Water Act authorities.
11. There is a dental facility that collects all amalgam process wastewater in a wastewater retaining tank,
which is then pumped out of the tank and transferred to a privately owned wastewater treatment
facility (a Centralized Waste Treatment, or CWT, facility as defined in 40 CFR Part 437). The CWT does
not discharge the dental amalgam process wastewater to a POTW. Are these dentists subject to the rule
and thereby required to submit a one-time compliance report?
No. See §441.10(e). Dental facilities that do not discharge amalgam process wastewater to a POTW are not
subject to this rule. As EPA noted in the preamble to the final rule, "[djental offices using wastewater
retention tanks must ensure that all amalgam process wastewater is collected by the wastewater retention
tanks. Any uncollected amalgam process wastewater that is discharged to the POTW is subject to this rule."
82 FR 27160, footnote 4.
12. Are there any requirements in the dental office rule that apply to POTWs that discharge to a water body
listed as impaired on the State's CWA 303(d) list due to mercury?
No. Discharge limits for a direct discharger, such as a POTW, are established in the NPDES permit for the
facility by the NPDES permitting authority. These requirements are separate from the pretreatment
requirements for dental dischargers established in part 441, which are self-implementing. Additionally, as
dental dischargers are neither ClUs or SlUs, they do not need to be identified in the NPDES permit or
application per the NPDES application requirements at 40 CFR 122.21(j)(6).
13. What are the regulatory consequences for dental dischargers that fail to comply with Part 441?
Part 441 contains Pretreatment Standards and Requirements applicable to specific industrial users of a POTW
(dental dischargers). Pursuant to Section 307(d) of the Clean Water Act, a failure to comply with such
applicable standards and requirements would constitute a violation of the Clean Water Act and potentially
therefore subject the industrial user, in this case the dental discharger, to federal civil and criminal penalties
under Section 309 of the Clean Water Act, and to civil and criminal penalties under state and local law
implementing the CWA pretreatment program.
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