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The District's Pretreatment Program administers local, state, and federal regulations to control pollutants discharged from commercial and industrial customers that may disrupt the collection and treatment system.  The regulatory federal language refers to the collection system and treatment facilities as the "Publicly Owned Treatment Works" (POTW).  Our POTW consists of six wastewater facilities treating an average of approximately 100 million gallons per day, twenty-three pump stations, and over 2,100 miles of sanitary sewer collection pipelines. The Pretreatment Program administers and enforces the regulations in order to:  

  • Protect the District's wastewater collection systems, treatment plants, and employees
  • Allow the reclamation of treated effluent for irrigation and other uses
  • Maintain water quality in the Las Vegas Wash

POTWs are designed to treat typical household wastes and biodegradable commercial and industrial wastes. Commercial and industrial facilities that discharge toxic pollutants to the treatment plants may be very detrimental to treatment plant processes and the environment. Industrial and certain commercial customers that discharge pollutants into the POTW are required to install, operate, and adequately maintain pretreatment equipment to remove pollutants that could otherwise damage, obstruct, interfere with, or pass through the POTW. Examples of such pollutants include heavy metals, cyanides, toxic organics, and acidic or basic wastes from industrial operations. Heavy metals and some organic chemicals which cannot be treated by the biological treatment process can threaten the bacteria which are necessary to the treatment process at the wastewater treatment plants.

Wastewater from restaurants and other food service industries are often more problematic. This is due to the prevalence of conventional pollutants such as grease, organic matter and solids. Grease can clog and overload the sewer system. Processing these food contaminants raises the cost of treating wastewater. The installation and proper maintenance of grease interceptors are an important component of keeping grease out of the collection and treatment systems.

Our Pretreatment Program protects the treatment process and keeps costs down by working with local businesses to minimize pollutant discharges. Activities of the District's Pretreatment Program include the review of pretreatment designs, the issuance of permits, facility inspections, monitoring of facilities (wastewater sample collection), review of industry self-monitoring reports, and enforcement actions.


Dental Amalgam Certification

On June 14, 2017, the EPA implemented a new regulation, 40 CFR 441 – Dental Office Point Source Category, to reduce mercury discharges from dental facilities to the sewer and subsequently, local waterways. Clark County Water Reclamation District (CCWRD) is the Control Authority under which your facility is regulated. This regulation requires all dental offices submit a one-time compliance report to their local Control Authority.  

The one-time compliance report contains the following information: facility name, physical address, mailing address, contact information, name of the operator(s) 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, or certification statements regarding the amalgam separator, its maintenance, and the implementation of BMPs ensuring mercury-containing wastewater does not enter the POTW if the dental office does work with amalgam.

To be considered in compliance with the requirements of 40 CFR 441, a dental amalgam separator must be installed, and the certification must be submitted to CCWRD. The separator must be 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. A complete list of specifications can be found on the EPA website,, under the 40 CFR 441 regulations page.

Dental offices starting operations on or before July 14, 2017:

The sections that apply to existing dental facilities are as follows: 441.10 Applicability, 441.20 General definitions, 441.30 Pretreatment standards for existing sources (PSES), and 441.50 Reporting and recordkeeping requirements. Amalgam separator must be installed no later than July 14, 2020 and Compliance Report submitted no later than October 12, 2020.

Dental offices starting operations (or change of ownership) after July 14, 2017:

The sections that apply to new dental facilities are as follows: 441.10 Applicability, 441.20 General definitions, 441.40 Pretreatment standards for new sources (PSNS), and 441.50 Reporting and recordkeeping requirements. Amalgam separator must be installed, and Compliance Report submitted, no later than 90 days after the start of discharge to the local sewer.

If you have any questions please contact us at  (702) 668-8076 or email us at

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