Wisconsin Administrative Code
Department of Natural Resources
NR 200-299 - Environmental Protection - Wisconsin Pollutant Discharge Elimination System
Chapter NR 229 - Dental Offices
Section NR 229.03 - Pretreatment standards for existing sources
Universal Citation: WI Admin Code ยง NR 229.03
Current through August 26, 2024
No later than July 14, 2020, any existing source subject to this chapter shall achieve all of the following:
(1) Removal of dental amalgam solids from all amalgam process wastewater by one of the following methods:
(a) Installation, operation, and maintenance
of one or more amalgam separators that meet all of the following requirements:
1. The amalgam separator is compliant with
ANSI/ADA 108-2009 with the 2011 technical addendum, incorporated by reference.
Compliance shall be assessed by an accredited testing laboratory under ANSI's
accreditation program for product certification or a testing laboratory that is
a signatory to the International Laboratory Accreditation Cooperation's Mutual
Recognition Arrangement. The testing laboratory's scope of accreditation shall
include ANSI/ADA 108-2009 or ISO 11143.
Note: ANSI/ADA 108-2009 is the American National
Standards Institute/American Dental Association Specification for Amalgam
Separators, published in 2009. Copies of ANSI/ADA 108-2009 and the 2011
technical addendum are available at http://www.ada.org. Copies are also available
for inspection at the offices of the department of natural resources and the
legislative reference bureau. Note that ANSI/ADA 108-2009, along with the 2011
addendum, is identical to ISO 11143:2008, which is available at
2. The amalgam separator is sized to
accommodate the maximum discharge rate of amalgam process wastewater.
3. A dental discharger that operates an
amalgam separator that was installed at a dental facility prior to June 14,
2017, satisfies the requirements of subds. 1. and 2. until the existing
separator is replaced as described under subd. 5., or until June 14, 2027,
whichever is sooner.
4. The amalgam
separator is inspected in accordance with the manufacturer's operating manual
to ensure proper operation and maintenance of the separator and to confirm that
all amalgam process wastewater is flowing through the amalgam retaining portion
of the amalgam separator.
5. In the
event that an amalgam separator is not functioning properly, the amalgam
separator is repaired consistent with manufacturer instructions or replaced
with a unit that meets the requirements under subds. 1. and 2. as soon as
possible, but no later than 10 business days after the malfunction is
discovered by the dental discharger, or an agent or representative of the
dental discharger.
6. The amalgam
retaining unit is replaced in accordance with the manufacturer's schedule as
specified in the manufacturer's operating manual or when the amalgam retaining
unit has reached the maximum level, as specified by the manufacturer in the
operating manual, at which time the amalgam separator can perform to the
specified efficiency, whichever comes first.
(b) Installation, operation, and maintenance
of one or more amalgam removal devices other than an amalgam separator. The
amalgam removal device shall meet all of the following requirements:
1. The removal efficiency shall be at least
95 percent of the mass of solids from all amalgam process wastewater. The
removal efficiency shall be calculated in grams recorded to 3 decimal places,
on a dry weight basis. The removal efficiency shall be demonstrated at the
maximum water flow rate through the device as established by the device
manufacturer's instructions for use.
2. The removal efficiency shall be determined
using the average performance of 3 samples. The removal efficiency shall be
demonstrated using a test sample of dental amalgam that meets all of the
following particle size distribution specifications:
a. 60 percent by mass of particles that pass
through a 3,150 µm sieve but that do not pass through a 500 µm
sieve.
b. 10 percent by mass of
particles that pass through a 500 µm sieve but that do not pass through a
100 µm sieve.
c. 30 percent
by mass of particles that pass through a 100 µm
sieve.
2m. Each of the 3
particle size distributions specified under subd. 2. shall contain a
representative distribution of particle sizes.
3. The device shall be sized to accommodate
the maximum discharge rate of amalgam process wastewater.
4. The device shall be accompanied by the
manufacturer's manual providing instructions for use including the frequency
for inspection and collecting container replacement such that the unit is
replaced once it has reached the maximum filling level at which the device can
perform to the specified efficiency.
5. The device shall be inspected in
accordance with the manufacturer's operation manual to ensure proper operation
and maintenance, including confirmation that amalgam process wastewater is
flowing through the amalgam separating portion of the device.
6. In the event that a device is not
functioning properly, it shall be repaired consistent with manufacturer
instructions or replaced with a unit that meets the requirements under subds.
1. to 3. as soon as possible, but no later than 10 business days after the
malfunction is discovered by the dental discharger, or an agent or
representative of the dental discharger.
7. The amalgam retaining unit of the device
shall be replaced as specified in the manufacturer's operating manual, or when
the collecting container has reached the maximum filling level, as specified by
the manufacturer in the operating manual, at which time the amalgam separator
can perform to the specified efficiency, whichever comes first.
8. The demonstration of the device under
subds. 1. to 3. shall be documented in the one-time compliance report required
under s. NR 229.05.
(2) Implementation of all of the following best management practices:
(a) Waste amalgam
including dental amalgam from chair-side traps, screens, vacuum pump filters,
dental tools, cuspidors, or collection devices, may not be discharged to a
POTW.
(b) Dental unit water lines,
chair-side traps, and vacuum lines that discharge amalgam process wastewater to
a POTW may not be cleaned with oxidizing or acidic cleaners, including bleach,
chlorine, iodine, or peroxide that have a pH lower than 6 or greater than
8.
Disclaimer: These regulations may not be the most recent version. Wisconsin may have more current or accurate information. We make no warranties or guarantees about the accuracy, completeness, or adequacy of the information contained on this site or the information linked to on the state site. Please check official sources.
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