The bill creates a new statutory section in chapter 90.48 RCW that establishes a presumption that holders of the state industrial stormwater general permit are in compliance with water quality standards when they meet specified conditions. Those conditions are being in full compliance with all permit conditions (planning, sampling, monitoring, reporting, recordkeeping, and deadlines) and fully implementing stormwater best management practices (BMPs) in department-approved stormwater technical manuals or demonstrably equivalent practices. A permittee can regain the presumption by notifying the Department of Ecology in writing within 30 days of becoming aware, based on credible site-specific information, that a discharge caused or contributed to a potential violation; the notice must include required minimum information and a single notice covers ongoing discharges. The department may require additional actions and must notify the permittee in writing; the presumption resumes after corrective actions required by the permit and deadlines are completed, unless the potential violation is already addressed by a total maximum daily load (TMDL), another enforceable cleanup plan, or other permit requirements. The bill also changes sampling and waiver procedures: stormwater sampling at marine/transportation facilities is not required until the Department determines sampling can be done without endangering the health and safety of people conducting sampling; when reviewing sampling waiver applications the department must assess safety and may modify sampling requirements to ensure safety; and sampling is not required while a waiver under the industrial stormwater general permit is under department consideration or appeal. The act names the Department of Ecology, cites the federal Clean Water Act, references former RCW 90.48.555, and includes an emergency clause so it takes effect immediately. This is a procedural statutory change rather than a new crime or listed penalty change: it creates a legal presumption of compliance for certain permittees and alters notification, sampling, and waiver procedures. The extracted text does not provide the exact new RCW section number, the full content or detailed requirements of the industrial stormwater general permit or the department-approved stormwater technical manuals, nor does it supply standards for evaluating waiver applications beyond the health and safety consideration, so those specifics are uncertain from the provided material.

If enacted, industrial facilities covered by the state's stormwater general permit will generally face less immediate enforcement and litigation risk when they follow their permit terms and use the department-approved stormwater manuals or equivalent practices, because they would be treated as meeting water quality standards while those conditions are met. Marine and transportation facilities and the people who collect samples will likely see fewer immediate sampling requirements and lower sampling costs and safety risks, since sampling can be delayed until the department determines it can be done safely and sampling is paused while a waiver is under review or appeal. The Department of Ecology will need to spend more time reviewing waiver requests, safety issues, and written notices from permittees and must tell permittees in writing if further action is required, which could increase administrative workload but reduce enforcement actions. Important details are missing that affect how big these changes will be in practice: the bill does not include the text of the industrial permit or the stormwater manuals, it does not set specific standards for evaluating waivers beyond safety, and it does not specify the exact new RCW section number.