D.C. Mun. Regs. tit. 21, r. 21-1520

Current through Register Vol. 71, No. 49, December 6, 2024

Rule 21-1520 - DENTAL AMALGAM PRETREATMENT STANDARDS

1520.1

Except as provided in 21 DCMR §§ 1520.2 and .3, the requirements of this section shall not apply to the following exempt Dental Dischargers that:

(a) Exclusively practice one or more of the following dental specialties: Oral pathology, oral and maxillofacial radiology, oral and maxillofacial surgery, orthodontics, periodontics, or prosthodontics;

(b) Discharge wastewater from a mobile unit operated by a dental practitioner; or

(c) Do not discharge any amalgam process wastewater to the District's wastewater system, such as Dental Dischargers that collect all dental amalgam process wastewater for transfer to a Centralized Waste Treatment facility as defined in 40 CFR part 437.

1520.2

All active facilities that practiced dentistry in the District of Columbia on or before July 14, 2017, shall submit a Dental Discharge Questionnaire to DC Water by July 16, 2018.

(a) The Dental Discharge Questionnaire, as provided by DC Water, shall include: the facility name, physical address, mailing address, contact information, name of all dental practitioners and owners, type of dental facility, current dental amalgam placement and removal information, discharge information, and signature.

(b) The Dental Discharge Questionnaire and all other records and documents shall be submitted to:

District of Columbia Water and Sewer Authority

Wastewater Treatment/Pretreatment Program Manager

5000 Overlook Avenue, S.W.

Washington, D.C. 20032

1520.3

Dental Dischargers that do not place dental amalgam, and do not remove amalgam except in limited emergency or unplanned, unanticipated circumstances, and submit the required One-Time Compliance Report to DC Water as required in 21 DCMR § 1520.6(c)(1), are exempt from any further requirements of this section.

1520.4

Any Existing Dental Discharger subject to the requirements of this section shall achieve the following pretreatment standards by July 14, 2020, except as provided in 21 DCMR §§ 1520.4(a)(1) (iii) and (v), and (2)(vi):

(a) Removal of dental amalgam solids from all amalgam process wastewater by one of the following methods:

(1) Installation, operation, and maintenance of one or more amalgam separators that meet the following requirements:

(i) Compliant with either the American National Standards Institute (ANSI) American National Standard/American Dental Association (ADA) Specification 108 for Amalgam Separators (2009) with Technical Addendum (2011) or the International Organization for Standardization (ISO) 11143 Standard (2008) or subsequent versions so long as that version requires amalgam separators to achieve at least a 95% removal efficiency. Compliance must 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 must include ANSI/ADA 108-2009 or ISO 11143.

(ii) The amalgam separator(s) must be sized to accommodate the maximum discharge rate of amalgam process wastewater.

(iii) A Dental Discharger that operates an amalgam separator that was installed at a dental facility prior to June 14, 2017, satisfies the requirements of paragraphs 1520.4(a)(1)(i) and (ii) of this section until the existing separator is replaced as described in paragraph 1520.4(a)(1)(v) of this section or until June 14, 2027, whichever is sooner.

(iv) The amalgam separator(s) must be inspected in accordance with the manufacturer's operating manual to ensure proper operation and maintenance of the separator(s) and to confirm that all amalgam process wastewater is flowing through the amalgam retaining portion of the amalgam separator(s).

(v) In the event that an amalgam separator is not functioning properly, the amalgam separator must be repaired consistent with manufacturer instructions or replaced with a unit that meets the requirements of paragraphs 1520.4(a)(1)(i) and (ii) of this section as soon as possible, but no later than ten (10) business days after the malfunction is discovered by the Dental Discharger, or an agent or representative of the Dental Discharger.

(vi) The amalgam retaining units must be 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 the amalgam separator can perform to the specified efficiency, whichever comes first.

(2) Installation, operation, and maintenance of one or more amalgam removal device(s) other than an amalgam separator. The amalgam removal device must meet the following requirements:

(i) Removal efficiency of at least ninety- five percent (95%) of the mass of solids from all amalgam process wastewater. The removal efficiency must be calculated in grams recorded to three decimal places, on a dry weight basis. The removal efficiency must be demonstrated at the maximum water flow rate through the device as established by the device manufacturer's instructions for use;

(ii) The removal efficiency must be determined using the average performance of three (3) samples. The removal efficiency must be demonstrated using a test sample of dental amalgam that meets the following particle size distribution specifications: sixty percent (60%) by mass of particles that pass through a 3150 µm sieve but which do not pass through a 500 µm sieve, ten percent (10%) by mass of particles that pass through a 500 µm sieve but which do not pass through a 100 µm sieve, and thirty percent (30%) by mass of particles that pass through a 100 µm sieve. Each of these three specified particle size distributions must contain a representative distribution of particle sizes;

(iii) The device(s) must be sized to accommodate the maximum discharge rate of amalgam process wastewater;

(iv) The devices(s) must 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;

(v) The device(s) must 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(s);

(vi) In the event that a device is not functioning properly, it must be repaired consistent with manufacturer instructions or replaced with a unit that meets the requirements of paragraphs 1520.4(a)(2)(i) through (iii) of this section as soon as possible, but no later than ten (10) business days after the malfunction is discovered by the Dental Discharger, or an agent or representative of the Dental Discharger;

(vii) The amalgam retaining unit(s) of the device(s) must 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 the amalgam separator can perform to the specified efficiency, whichever comes first; and.

(viii) The demonstration of the device(s) under paragraphs 1520.4(a)(2)(i) through (iii) of this section must be documented in the One-Time Compliance Report.

(b) Implementation of the following best management practices (BMPs):

(1) Waste amalgam including, but not limited to, dental amalgam from chairside traps, screens, vacuum pump filters, dental tools, cuspidors, or collection devices, must not be discharged to the District's wastewater system;

(2) Dental unit water lines, chair-side traps, and vacuum lines that discharge amalgam process wastewater to the District's wastewater system must not be cleaned with oxidizing or acidic cleaners, including, but not limited to bleach, chlorine, iodine and peroxide that have a pH lower than six (6) or greater than eight (8);

(3) Dental chairside traps, vacuum screens, and amalgam separator equipment must not be rinsed in a sink, toilet or into any other sanitary discharge connection;

(4) Dental Discharge facility staff must be trained in the handling and disposal of mercury amalgam materials and waste. Training shall be completed within one year for new hires and all staff shall be retrained once every three (3) years; and

(5) The storage, handling and disposal/recycling of all amalgam waste must be in accordance with District of Columbia, state and federal requirements.

1520.5

Effective July 14, 2017, any New Dental Discharger subject to the requirements of this section must comply with the requirements of 21 DCMR §§ 1520.4(a) and (b) and the reporting and recordkeeping requirements of 21 DCMR §§ 1520.6 and .7.

1520.6

Dental Dischargers subject to the requirements of this section must comply with the following reporting requirements:

(a) One-Time Compliance Report deadlines:

(1) For an Existing Dental Discharger, a One-Time Compliance Report must be submitted to DC Water no later than October 12, 2020, or ninety (90) calendar days after a transfer of ownership.

(2) For a New Dental Discharger, a One-Time Compliance Report must be submitted to DC Water no later than ninety (90) calendar days following the first introduction/discharge of wastewater into the District's wastewater system.

(b) Signature and Certification. The One- Time Compliance Report must be signed and certified by a responsible corporate officer, a general partner or proprietor if the Dental Discharger is a partnership or sole proprietorship, or a duly authorized representative as defined in 21 DCMR § 1599.

(c) The contents of the One-Time Compliance Report shall be as follows:

(1) The One-Time Compliance Report, as provided by DC Water, for Dental Dischargers subject to t he requirements of this section that do not place or remove dental amalgam as described at 21 DCMR § 1520.3 must include: facility name, physical address, mailing address, contact information, name of the operator(s) (dental practitioners) and owner(s); and a certification statement that the Dental Discharger does not place dental amalgam and does not remove amalgam except in limited circumstances.

(2) The One-Time Compliance Report, as provided by DC Water, for Dental Dischargers subject to the requirements of this section must include:

(A) The facility name, physical address, mailing address, and contact information;

(B) Name(s) of the operator(s) (Dental practitioners) and owner(s);

(C) A description of the operation at the dental facility including: The total number of chairs, the total number of chairs at which dental amalgam may be present in the resulting wastewater, and a description of any existing amalgam separator(s) or equivalent device(s) currently operated to include, at a minimum, the make, model, year of installation;

(D) Certification that the amalgam separator(s) or equivalent device is designed and will be operated and maintained to meet the requirements specified in 21 DCMR § 1520.4(a);

(E) Certification that the Dental Discharger is implementing BMPs specified in 21 DCMR § 1520.4(b) and will continue to do so;

(F) The name of the third-party service provider that maintains the amalgam separator(s) or equivalent device(s) operated at the dental office, if applicable. Otherwise, a brief description of the practices employed by the facility to ensure proper operation and maintenance in accordance with 21 DCMR § 1520.4(a).

(d) Replacement of amalgam separator or equivalent device. Existing and New Dental Dischargers shall submit an amended One-Time Compliance Report to DC Water no later than ninety (90) days after replacement, if the amalgam separator or equivalent device is replaced after the submittal of the One-Time Compliance Report.

(e) Transfer of ownership notification. If a Dental Discharger transfers ownership of the facility, the new owner must submit a new One-Time Compliance Report to DC Water no later than ninety (90) days after the transfer.

1520.7

Dental Dischargers subject to the requirements of this section must comply with the following document retention requirements:

(a) As long as a Dental Discharger subject to this section is in operation, or until ownership is transferred, the Dental Discharger or an agent or representative of the Dental Discharger must maintain the One-Time Compliance Report required in Subsection 1520.6 of this section and make it available for inspection in either physical or electronic form.

(b) Dental Discharger or an agent or representative of the Dental Discharger must maintain and make the following documents available for inspection in either physical or electronic form, for a minimum of three (3) years or until updated, whichever is longer:

(1) Documentation of the date, person(s) conducting the inspection, and results of each inspection of the amalgam separator(s) or equivalent device(s), and a summary of follow- up actions, if needed.

(2) Documentation of amalgam retaining container or equivalent container replacement (including the date, as applicable).

(3) Documentation of all dates that collected dental amalgam is picked up or shipped for proper disposal in accordance with 40 CFR § 261.5(g)(3) (Special requirements for hazardous waste generated by conditionally exempt small quantity generator) and 20 DCMR § 4261.7, and the name of the permitted or licensed treatment, storage or disposal facility receiving the amalgam retaining containers.

(4) Documentation of any repair or replacement of an amalgam separator or equivalent device, including the date, person(s) making the repair or replacement, and a description of the repair or replacement (including make and model).

(5) The manufacturers operating manual for the current device.

(6) Documentation of staff training and retraining, including the name of the staff person and date of training.

D.C. Mun. Regs. tit. 21, r. 21-1520

Final Rulemaking published at 64 DCR 447 (1/19/2018)