INDUSTRIAL
PRETREATMENT
The Industrial Pretreatment Program is an essential component of the National Pollutant Discharge Elimination System (NPDES) and water reclamation process. The national pretreatment program is designed to protect the public wastewater collection systems and treatment facilities from industrial discharges of concern. According to the U.S. Environmental Protection Agency (EPA), the national pretreatment program is responsible for a 50% decrease in pollutants transferred to public wastewater treatment facilities since 1987.
The public collection system and treatment facilities are designed to treat domestic wastewater. Because industrial wastewater differs significantly from domestic wastewater, it must be monitored and regulated through an industrial pretreatment program. Each establishment that discharges non-domestic wastewater is subject to the industrial pretreatment program and may be required to obtain a discharge permit. The types of processes performed at the facility, the pollutants that may be discharged, and the quantity of water sent to the collection system by the facility will all be considered when determining whether a permit is required.
Certain substances and quantities of specific pollutants cannot be discharged into the collection system. The City of Little Rock Pretreatment Ordinance gives further details on what these prohibitions are:
The initial step in determining whether a facility needs a permit is for pretreatment staff to assess the information provided on an industrial user survey form. More information may be required through a phone call, an on-site visit, or by reviewing the SDSs of the materials used at the facility.
One of the first steps in the industrial user permitting process is for the facility to complete an Industrial User Survey form. Here, Cornelius Jones, Pretreatment/Sampling Coordinator, answers questions about the form and how to complete it.
There are fees for new permits, permit modifications or transfers, annual permits, permit renewals, noncompliance inspections and monitoring, late reporting, and special discharge inspections and monitoring. These fees are found in the Consolidated Fee Schedule.
Additionally, there are surcharges associated with extra-strength wastewater: TSS, COD, and Oil & Grease (O&G). The surcharge rates can be found in the City of Little Rock Sewer Rate Ordinance.
Some wastewater may be hauled in and discharged at the Adams Field Water Reclamation Facility. Depending on the source and composition of the wastewater, the discharger may be required to have an Industrial Pretreatment Permit.
EPA has promulgated pretreatment standards to reduce discharges of mercury from dental offices into publicly owned treatment works. Amalgam separators are a practical, affordable and readily available technology for capturing mercury and other metals.
- Ensure the removal of dental amalgam solids from all amalgam process wastewater via amalgam separator(s) or equivalent device(s) that meet the standard of the final rule. See §441.30(a) (1-2) for an existing source and §441.40 for a new source.
- Implementation of two best management practices. See § 441.30(b) for an existing source and §441.40 for a new source.
- Comply with reporting requirements. See §441.50(a).
- Maintain and make available for inspection certain records documenting compliance. See §441.50(b). They are discharged into sewers. Dental Office Category requirements are summarized as follows:
