Winery Waste Discharge Requirements (WDRs)

Participating enrollees in Napa County's Winery Waste Discharge Program must continue to demonstrate compliance and submit required reports to remain in the program. Failure to comply will result in disqualification from the Napa County Program and the facility will need to enroll in the State program. 

Compliance and Reporting Requirements for enrollees in Napa County's Winery Waste Discharge Program: 

  • Facilities with ponds (above ground discharge systems) must submit reports quarterly (every 3 months) through the website.
  • Facilities with other systems (below ground discharge systems) must be serviced every six months by a qualified service provider and shall submit reports twice a year (every 6 months) through the website (typically, the service provider for the below ground facilities will fill out the OnlineRME report, however, it is still the responsibility of the facility to ensure Napa County is receiving these reports).

Wineries not enrolled in the Napa County Winery Waste Discharge Program, or those who do not maintain compliance, will be required to enroll in the new Statewide General Winery Discharge Program by January 20, 2024.  All winery facilities should have received a letter from the State of California regarding the new order; please keep that letter for future reference. For more information about the State program visit the State Water Board site.  


On January 20, 2021, the State Water Resources Control board adopted Resolution No. 2021-0001 for the California Environmental Quality Act Mitigated Negative Declaration for the Waste Discharge Requirements for Winery Process Water and associated General Order. The State Water Board has developed General Waste Discharge Requirements (WDRs), through adoption of Winery Order No. WQ 2021-0002-DWQ, for wineries and other similar facilities with activities related to producing wine that generate winery waste and discharge it to land for reuse or disposal. The ("Winery Order") is a set of requirements that protect water quality from the potential impacts of discharging winery waste to land. 

Winemaking generates process water that has the potential to degrade groundwater quality depending on winery-specific activities, size, and treatment processes. The primary concerns for winery process water that effects groundwater quality are nitrogen, salinity, and biochemical oxygen demand. The Winery Order is applicable statewide and includes requirements to ensure winery operations effectively mitigate adverse impacts to water quality.  This requires wineries producing 10,000 gallons or more per year of process waste that discharges to the land (surface or subsurface), without a separate WDR through Napa County, to enroll in the new Statewide General Winery Discharge by January 20, 2024.