- As of June 18, 2025, vessels must exchange ballast water taken from areas with salinity below 18 ppt before discharging in California’s fresh or brackish waters.
- The regulation aims to block invasive freshwater species from entering and damaging California’s marine ecosystems.
- Shipping operators must now include offshore ballast exchanges in their voyage planning for calls to California ports.
On June 18, 2025, the California State Lands Commission enacted an emergency amendment to its ballast water regulations, specifically Article 4.7 of Chapter 1, Division 3, Title 2 of the California Code of Regulations, reports Safety4sea.
This new rule requires vessels that carry ballast water sourced from areas with salinity levels below 18 parts per thousand (ppt) to perform a ballast water exchange before discharging in California’s fresh or brackish waters. This measure is in addition to the state’s existing ballast water discharge performance standards.
California updates ballast rules
The regulatory update is driven by California’s ongoing effort to protect its aquatic ecosystems from invasive species. Low-salinity ballast water is considered a significant vector for transporting freshwater and brackish organisms, which, when introduced to California’s unique marine environments, can cause ecological harm and economic disruption. By mandating an exchange of low-salinity ballast water offshore—where organisms are less likely to survive—California aims to minimize this risk and add an extra level of protection beyond federal standards.
For vessel operators, this change means adjusting voyage planning and ballast water management protocols. Any ship arriving at a California port with ballast water from low-salinity sources must now schedule an exchange before reaching the state’s internal waters. This exchange must be conducted offshore and in compliance with the new rule, regardless of whether the vessel already meets federal discharge standards.
The emergency rule came into immediate effect on June 18, 2025, without any grace period or phased implementation. As a result, shipowners and operators must comply with the regulation now or risk enforcement actions, including fines or other penalties, as administered by the State Lands Commission.
In summary, California’s revised ballast water regulation represents a significant step in its broader environmental protection strategy. By targeting discharges from low-salinity areas, the state reinforces its commitment to preventing biological invasions and ensuring long-term marine ecosystem health. Vessels operating along the Pacific Coast should review their ballast procedures carefully to remain in compliance.
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Source: Safety4sea
