CII-Applicable Areas Have Changed Since Original Designation
Early workshops identified the Ports of Los Angeles (POLA) and Long Beach (POLB) as part of the watershed under the CII permit. However, the POLA and POLB were removed by EPA from the residual designation, which is reflected in the new GIS tool released by the water board.
Below, we highlight the key steps for determining applicability using the updated watershed boundaries.
CII Stormwater Permit Adopted: How Do I Determine Applicability
The stormwater Commercial, Industrial, and Institutional (CII) Permit becomes effective October 31, 2026, and applies to commercial, industrial, and institutional properties with at least five acres of impervious surface located within the Dominguez Channel/Greater Los Angeles and Long Beach Harbor Watershed and the Los Cerritos Channel/Alamitos Bay Watershed.
This includes properties like shopping centers, large office complexes, hotels, private schools, hospitals, churches, and portions of industrial facilities not otherwise regulated under the California Stormwater Industrial General Permit (IGP). For some of these facilities, the CII Permit represents the first time they will be subject to statewide industrial stormwater requirements, as they previously may not have been regulated under a State Water Resources Control Board stormwater permit.
To determine applicability, ask the following questions:
Is the property a privately owned parcel or contiguous parcels of land that are commercial, industrial, or institutional based on Los Angeles County Tax Assessor land use codes 1000 through 2900, 3000 through 3920, 6000 through 6910, 7000 through 7710, and 8100 through 8400?
Note: you can check by address or AIN using the LA County Assessor’s Portal: https://portal.assessor.lacounty.gov/.
Is the property located within the two watersheds covered by the CII Permit?
Note: the water board recently released a new GIS tool to aid in this determination: CII Permit GIS Tool.
Does the property have at least five acres of impervious surface that is not already regulated under another applicable stormwater permit (such as the Industrial General Permit)?
If applicable, determine who will be the responsible for compliance — the responsible discharger is either the property owner or operator, whoever has the authority and operational control to comply with all conditions of the CII permit.
Meet Key Compliance Deadlines
These CII permit deadlines are based on the permit's October 31, 2026, effective date:
Timeline | Requirement |
November 1, 2027 (Within 12 months) | Submit the Notice of Intent (NOI) and Stormwater Pollution Prevention Plan (SWPPP) via SMARTS as part of the Permit Registration Documents (PRDs) |
By May 1, 2028 (Within 18 months) | Complete initial stormwater sampling |
By May 1, 2030 (Within 3.5 years) | Submit selected compliance option documentation |
Annually by Dec. 15th | Submit Annual Report via SMARTS (after compliance option is selected). |
Annually | Pay permit fee via SMARTS |
How Ashworth Leininger Group (ALG) Can Help
The CII Permit creates new compliance obligations for subject properties, but early planning can help property owners and operators identify the most practical and cost-effective path forward.
Reach out to ALG is you need assistance with determining applicability, evaluating compliance strategies, training on the CII permit and sampling obligations, or preparing permit registration documents that includes the development and implementation of a SWPPP. Contact Mia Hill (mhill@algcorp.com) and Elliott Ripley (eripley@algcorp.com) to discuss if the CII Permit applies to your property and what actions may be needed to prepare for compliance.
