The City of Arcata Wastewater Division is responsible for the monitoring, reporting, testing and treatment of all wastewater for the City of Arcata. The Arcata Wastewater Treatment Plant (AWWTP) uses mechanical and biological processes to treat wastewater to a quality that is acceptable for discharge into Humboldt Bay.

National Pollutant Discharge Elimination System

The City’s National Pollutant Discharge Elimination System (NPDES) permit prohibits excessive discharge of pollutants into Humboldt Bay. AWWTP can efficiently remove organic materials from the waste stream; however it is very difficult to remove some (inorganic) pollutants.

In order to prevent pollution the U.S. EPA and the State Water Resources Control Board require in the NPDES permit that the City have a Pretreatment Program for all industrial users that discharge wastewater to the City collection system.

Pretreatment Program

The Pretreatment Program is designed to prevent businesses from discharging pollutants to the collection (sewer) system. This makes it easier for the AWWTP to treat wastewater and reduces the risk of discharging pollutants into Humboldt Bay.

There are many pollutants that the City does not want in the waste stream. They range from grease produced at restaurants, to chemicals used at manufacturing facilities, to heavy metals from dental offices.

Pretreatment Program Categories

Each category of industrial users must meet different requirements to keep pollutants from the waste stream. The City currently has the following categories in its Pretreatment Program:
Check back with us in the future, we will be extending our program to the following:
  • Auto shops
  • Hospitals and Medical Facilities
  • Jewelry Making and more