WSACC is required by its NPDES permit to implement and enforce a Pretreatment Program for the Rocky River Regional Wastewater Treatment Plant and Muddy Creek Wastewater Treatment Plant. The purpose of the Pretreatment Program is to protect the treatment plants and the environment from damage that may occur when hazardous or toxic wastes are discharged into the wastewater treatment system. The program prevents problems such as upsets or interference with the operation of the wastewater treatment plants, pass-through of pollutants into the receiving waters, sludge contamination, and exposure of workers to chemical hazards. The program also ensures industries comply with the local Sewer Use Ordinance and state and federal regulations.
The Pretreatment Program issues industrial user permits, conducts wastewater monitoring, on-site inspections, and industrial surveys, as well as implements the surcharge program and septage hauler program.
Overall, the Pretreatment Program helps WSACC provide high-quality wastewater treatment services to the jurisdictions we serve.
On June 14, 2017, the USEPA promulgated pretreatment standards (40 CFR 441) to reduce discharges of mercury from dental offices into municipal sewage plants known as Publicly Owned Treatment Works (POTWs). The final rule requires dental offices to use amalgam separators and Best Management Practices (BMPs) recommended by the American Dental Association. As the local Control Authority, the Water and Sewer Authority of Cabarrus County (WSACC) is required to implement and enforce the regulation.
The regulation is applicable to all dental dischargers that remove or replace amalgam. It does not apply to dental dischargers that exclusively practice one or more of the following dental specialties: oral and maxillofacial surgery, orthodontics, periodontics, or prosthodontics. Also excluded are mobile units and those practices that only remove or place amalgam in limited emergency or unplanned circumstances. Key points to the standard are:
- All amalgam process wastewater must be treated prior to discharge to the POTW utilizing an amalgam separator meeting specific performance standards outlined in the regulation.
- For existing sources, including those facilities that do not place or remove amalgam, a One-Time Compliance Report must be submitted to WSACC no later than October 12, 2020, or no later than 90 days after a transfer of ownership. WSACC will work with these facilities to ensure the report is submitted by the deadline established by EPA.
- Any new dentist/dental practice that opens on or after July 14, 2017 is considered a “new source” and must comply with the Rule (amalgam separator, BMPs, record keeping) prior to discharging dental wastewater to a POTW.
- “New Sources” must comply immediately with all of the requirements upon opening the practice and do not get the 3-year compliance period allowed for an “existing source.”
- The New Source One-Time Compliance Report is due no later than 90 days following the introduction of wastewater into a POTW.