Section NR 229.03 - Pretreatment standards for existing sources 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 http://webstore.ansi.org.
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.Wis. Admin. Code Department of Natural Resources NR 229.03
Adopted by, CR 21-063: cr. Register April 2022 No. 796, eff. 5/1/2022