Wastewater Operator Certification Program


Wastewater Treatment Plant Classification

Section 13626 of the California Water Code gives the Wastewater Operator Certification Program (WWOCP) responsibility for classifying all publicly owned wastewater treatment plants and private plants regulated by the Public Utility Commission or issued a waste discharge requirement by the State Water Board one of the nine Regional Water Boards.

The owner or Chief Plant Operator (CPO) acting on behalf of the owner of a Wastewater Treatment Plant (WWTP) is required to submit a wastewater plant classification form at least 60 days before the plant begins operations and at least within 30 days of changes to the plant (including closure). The wastewater plant classification form along with an organization chart, flow diagram of the plant, job descriptions for all personnel classifications and duty rosters must be submitted to the WWOCP. Once the WWOCP reviews the information, the CPO will be sent a letter indicating the classification and appropriate operator grades. The WWOCP does not specify how many operators must be employed at each grade; however, the CPO’s certification grade level must be equal to or higher than the WWTP’s classification. The Designated Operator-In-Charge (DOIC) must meet the minimum grade level according to the WWTP classification.  Please see the table listed below.

Wastewater Treatment Plant Classification Minimum Grade Level of Chief Plant Operator Minimum Grade Level of Designated Operator-in-Charge
I I I
II II I
III III II
IV IV III
V V III

Wastewater Treatment Plant Exemption

An owner of a Class I WWTP may apply for an exemption if:

  1. It has been classified as a Class I WWTP.
  2. The WWTP could not, due to operator error, violate water quality objectives.

Questions or Comments?

If you have additional questions, please contact the Plant Classifications Analyst, Neal Funston by email at: wwopcertprogram@waterboards.ca.gov or by phone at (916) 341-5909.