Yes, if the office places or removes amalgam fillings and drains to a public sewer. EPA's dental rule, 40 CFR Part 441, requires an amalgam separator meeting ISO 11143 or ANSI/ADA 108, set best management practices and a one-time compliance report. Some specialties and mobile units are exempt.
Who the rule covers, and who it doesn't
EPA's rule, 40 CFR Part 441, applies to a "Dental Discharger." That means "a facility where the practice of dentistry is performed" that sends wastewater to a publicly owned treatment works, or POTW. Offices, clinics, home offices and government facilities all count. In Phoenix, the POTW is the city's sewer system.
Section 441.10 carves out four groups:
- Specialists only. Offices that exclusively practice "Oral pathology, oral and maxillofacial radiology, oral and maxillofacial surgery, orthodontics, periodontics, or prosthodontics" are not covered.
- Mobile units. Wastewater from a mobile dental unit is not covered.
- No amalgam wastewater to the sewer. An office that collects all amalgam process wastewater for transfer to a centralized waste treatment facility is not covered.
- No amalgam work. Some offices never place amalgam. They remove it only in limited emergency or unplanned cases. Once they certify that to the Control Authority, the rest of the rule doesn't apply.
That last group still files paperwork. Phoenix's FAQ says exempt facilities "must still file a One-Time Compliance Report," certifying that no amalgam is placed and none is removed outside limited emergencies. Phoenix's flyer adds its own guidance on what counts. It points to offices that remove amalgam in fewer than five percent of procedures. It also warns that an office that stocks amalgam capsules "clearly intends to place amalgam."
Section 441.10 also says a covered dental office is not a Significant Industrial User or a categorical industrial user just because the rule applies, unless the Control Authority designates it. That keeps most offices out of the heavier permit process.
| Your practice | Separator required? | One-time report? |
|---|---|---|
| General dentistry that places or removes amalgam | Yes | Yes |
| Orthodontics, periodontics, prosthodontics, oral surgery, oral pathology or radiology only | No | Rule does not apply |
| Mobile dental unit | No | No, per Phoenix's flyer |
| Never places amalgam, removes it only in emergencies | No | Yes, certifying the exemption |
| All amalgam wastewater hauled to a treatment facility | No | Rule does not apply |
What the separator has to do
For a covered office, Section 441.30 sets the equipment standard. The separator must comply with ANSI/ADA 108 or ISO 11143, or a later version that still requires "at least a 95% removal efficiency." An accredited lab has to confirm that. The unit also "must be sized to accommodate the maximum discharge rate of amalgam process wastewater," so the chair count and vacuum system matter.
Section 441.30 also allows an amalgam removal device other than a separator. Under Section 441.30, that device must remove at least 95 percent of the mass of solids from all amalgam process wastewater, tested at the maker's maximum flow rate.
Upkeep is spelled out too:
- Inspection. The separator must be inspected as the maker's manual says. The check confirms that all amalgam wastewater flows through the part that traps the amalgam.
- Repair deadline. A separator that isn't working must be repaired or replaced "as soon as possible, but no later than 10 business days after the malfunction is discovered."
- Cartridge changes. The amalgam retaining unit gets replaced on the manufacturer's schedule, or when it reaches the maximum fill level, whichever comes first.
The rule adds two best management practices. Waste amalgam from chair-side traps, screens, vacuum pump filters, tools and cuspidors "must not be discharged to a POTW." And lines and traps that drain amalgam wastewater "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 6 or greater than 8." Phoenix's FAQ repeats both.
### The 2027 deadline for older separators
This is the date to watch. Some offices put in a separator before June 14, 2017. That unit meets the equipment standard "until the existing separator is replaced" or "until June 14, 2027, whichever is sooner." Phoenix calls this the grandfathering provision. A grandfathered unit also had to be "functioning properly" and not need replacement, per the city's FAQ.
So if your office still runs a pre-2017 unit, plan its replacement now. The new unit must meet ISO 11143 or ANSI/ADA 108, be sized for your chairs, and be in place by June 14, 2027.
Reports, records and who checks them in Phoenix
The rule's paperwork runs through the "Control Authority." Phoenix's FAQ says it's "The local wastewater utility, which is the City of Phoenix," and reports go to the Water Services Department's Environmental Services Division at 2474 S 22nd Ave. The city's flyer lists 602-495-7412 or 602-495-5926 for questions.
The one-time compliance report has firm deadlines under Section 441.50:
- 1Existing offices had to file by October 12, 2020.
- 2New offices, meaning those whose first discharge came after July 14, 2017, file within 90 days of first sending wastewater to the sewer.
- 3New owners file a new report within 90 days of the transfer. Phoenix's notification flyer says every practice must file one, including after ownership changes.
The report lists your total chairs and the chairs where amalgam may be present. It gives the make, model and year of each separator. It also names the outside service company that maintains it, if you use one. A responsible corporate officer, partner, proprietor or authorized representative signs it.
Keep records for at least three years. Section 441.50 lists them. Log each separator inspection with its date, who did it and the results. Log each cartridge change. Record each date amalgam was picked up or shipped for disposal, and the facility that got it. Log each repair or replacement too. Keep the manufacturer's manual for the current unit on hand, and keep the compliance report for as long as you operate or until ownership changes.
Phoenix also treats dental offices as a pretreatment use during development. Its due diligence guide lists dental offices among the businesses where "Wastewater pretreatment devices (such as interceptors for grease, oil, & sand) are required." A new build-out should show the separator on the plans.
Common situations in Valley practices
Buying a practice. The 90-day clock for a new report starts at the transfer. Check the separator's age too, since a grandfathered unit runs out in June 2027.
Opening a new general dentistry office. You must comply from your first discharge and file within 90 days. Put the separator in the build-out drawings. For the broader build-out, see commercial tenant improvement plumbing.
A specialty office adding general dentistry. Once the office no longer practices only the listed specialties, the rule applies.
Moving into a former retail suite. A new clinic use can also trigger new backflow requirements; see when a new tenant or change of use needs a backflow assembly.
Full cartridges are recycled or disposed of through an amalgam recycler or waste company, not down the drain and not by a plumber.
HQ Plumbing & Air installs and repairs commercial drain piping and separators for Valley dental offices, with free estimates and upfront pricing.
Water-side rules for dental offices are in whether a dental office needs a backflow preventer.