Navigating California’s waste discharge requirements for wineries

The California Statewide General Waste Discharge Requirements (WDR) for Winery Process Water — commonly known as the general winery order — is creating significant compliance challenges statewide. Adopted by the State Water Resources Control Board in January 2021, the order regulates the discharge of processed wastewater and solids to land, requiring eligible wineries to obtain coverage and meet monitoring, reporting, and operational standards. Understanding the most common compliance hurdles and how to address them is essential for wineries to maintain compliance.

Approximately 1,500 wineries statewide are expected to be permitted under the order, yet many still lack coverage. The original deadline for wineries without existing WDRs was January 2024, and although Regional Water Quality Control Boards have been working with wineries to achieve compliance, wineries that continue to defer compliance may risk formal notices of violation and, eventually, penalties under state law of up to $5,000 per day. The San Francisco Bay Regional Board has prepared a streamlined enrollment process for wineries currently enrolled in Napa County’s Winery Waste Discharge Program, which is scheduled to sunset on January 20, 2027.

Common compliance challenges

• Water softener brine separation. The order requires wineries to separate water softener brine from processed wastewater within 90 days of receiving their Notice of Applicability (NOA). This has proven to be one of the most burdensome requirements, particularly for existing facilities not designed with separate conveyance in mind.
• Monitoring requirements. The monitoring and reporting requirements are extensive, especially during harvest, when winery staff are already stretched thin. The extent of monitoring is dependent on each winery’s tier. For example, Tier 2 wineries must collect samples bi-weekly during crush and Tier 4 wineries face weekly sampling obligations.
• Pond lining and hydraulic conductivity. Tier 3 and Tier 4 wineries must demonstrate that ponds are either lined or meet the hydrologic conductivity standard and perform leak testing every five years using an appropriate performance test method. For older wineries, determining whether an existing clay-lined or unlined pond meets the hydraulic conductivity standard can be challenging, and lining ponds may require costly planning.

Practical tips for getting started

• Determine eligibility, tier, and system needs. Wineries must identify their tier based on the volume of wastewater generated. If flow meter readings are not available, some wineries may estimate the volume of wastewater using a general rule-of-thumb of six gallons of wastewater per one gallon of wine produced. Invest in a flow meter, and start to compile treatment, pond, land application, and disposal information.
• Collect baseline samples. Sample your source water, winery effluent, ponds, and land-applied water to understand how you compare against permit limits before formal reporting begins, and to avoid compressed response timelines if lab results are delayed.
• Develop a compliance schedule. Wineries are not required to be in full compliance before obtaining coverage. The order allows wineries to submit a justified compliance schedule subject to the Regional Board’s review.
• Engage with the regulators. Staff at both the State Board and Regional Boards have been willing to discuss issues, set up calls, and develop workable solutions. Proactive communication can ease the path to compliance.

For updates, wineries should monitor the State Board’s Statewide General WDRs for Wineries web page and stay engaged through their trade organizations.

The Statewide Winery Order is not going away, and the window for cooperative engagement with regulators will not remain open indefinitely. The most cost-effective strategy for most wineries is to begin now: gather data, engage consultants and State Board/Regional Board staff, and use the compliance schedule provisions built into the order.

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