Controlling aquatic plants and algae to support clean water – Washington State Department of Ecology (.gov)

Report on Proposed Updates to the Aquatic Plant and Algae Management General Permit

Introduction: Addressing Invasive Species to Advance Sustainable Development Goals

The proliferation of noxious aquatic weeds, legally defined as invasive, non-native plants, poses a significant threat to local ecosystems and agricultural production. The management of these species is critical for the achievement of several United Nations Sustainable Development Goals (SDGs), particularly those concerning water quality and biodiversity. This report outlines the proposed updates to Washington State’s Aquatic Plant and Algae Management General Permit, a regulatory instrument designed to mitigate the impact of these invasive species while safeguarding environmental health.

Regulatory Framework and Contribution to SDG 6 and SDG 14

The Washington State Department of Ecology administers a water quality permitting program to regulate the use of pesticides for controlling aquatic weeds. This program is mandated by state law (RCW 90.48.447) to protect the environmental, recreational, and aesthetic values of the state’s lakes, which are threatened by invasive plants and algae. The permit directly supports:

• SDG 6: Clean Water and Sanitation: By managing dense vegetation and harmful algae blooms, the program helps maintain water quality, which is essential for healthy ecosystems and human use.
• SDG 14: Life Below Water: The control of invasive species is vital for protecting native fish habitats and preventing the degradation of freshwater ecosystems.

The Aquatic Plant and Algae Management General Permit is a unified legal tool that regulates similar activities under a single framework, ensuring that all authorized actions adhere to strict environmental standards. The permit is reissued on a five-year cycle to incorporate new scientific data and stakeholder feedback, ensuring continuous improvement in environmental stewardship.

Permit Requirements and Alignment with Integrated Management Principles

Integrated Pest Management and SDG 12

The permit mandates an Integrated Pest Management (IPM) approach, requiring permittees to utilize management solutions with the least environmental impact among reasonably available options. This aligns with SDG 12: Responsible Consumption and Production by promoting the safe and minimized use of chemicals.

Management strategies under the permit include:

1. Non-Chemical Approaches: Prioritizing methods such as mechanical weed harvesters, bottom barriers, and public education programs like “Clean, Drain and Dry.”
2. Regulated Chemical Use: When necessary, the permit allows for the use of registered pesticides approved by the U.S. Environmental Protection Agency and the Washington State Department of Agriculture.

The permit establishes strict controls on chemical applications, including limitations on which chemicals can be used, where they can be applied, and requirements for public notification prior to treatment. This ensures that any chemical intervention is conducted in a manner that minimizes risks to non-target species and the broader aquatic environment.

Proposed Revisions for Enhanced Ecosystem Protection

The current draft of the reissued permit includes several key updates based on monitoring data and recent scientific findings to further strengthen protections for aquatic life and improve water quality management.

Flexible Herbicide Application Windows

To enhance the efficacy of plant management while protecting fish populations, the proposed updates introduce a new process for determining treatment timing. This data-driven approach, developed in collaboration with toxicologists and the Washington Department of Fish and Wildlife, allows for more effective control of invasive plants before they reproduce, directly contributing to the preservation of biodiversity as outlined in SDG 14 (Life Below Water) and SDG 15 (Life on Land).

Advanced Phosphorus Control and Monitoring

Excess phosphorus is a primary driver of aquatic plant overgrowth and harmful algae blooms. The permit regulates treatments, such as alum, designed to control phosphorus levels. To mitigate potential risks and improve outcomes, the proposed changes include:

• Enhanced Monitoring Requirements: Additional monitoring will be required for phosphorus control treatments to better understand their effects on lake ecosystems and prevent negative impacts.
• New Treatment Options: A new lanthanum-based product is proposed for inclusion, providing lake managers with more options to control phosphorus in both lakes and their tributary streams.

These revisions are aimed at improving water quality and preventing the ecological damage caused by eutrophication and toxic algae, reinforcing the commitment to SDG 6 (Clean Water and Sanitation).

Stakeholder Engagement and Collaborative Governance (SDG 17)

In alignment with SDG 17: Partnerships for the Goals, the Department of Ecology is conducting a public comment period for the draft permit from September 10 to October 24, 2025. This process invites feedback from permittees, Tribes, interested parties, and the general public. A series of online workshops and public hearings will be held to facilitate engagement and ensure a transparent and collaborative decision-making process.

Next Steps

Following the public comment period, all feedback will be reviewed and incorporated into the final permit as appropriate. A final decision on the permit reissuance is anticipated in early 2026, marking a continued commitment to the sustainable and science-based management of Washington’s vital freshwater resources.

Analysis of Sustainable Development Goals in the Article

1. Which SDGs are addressed or connected to the issues highlighted in the article?

The article on managing noxious aquatic weeds and algae in Washington’s water bodies connects to several Sustainable Development Goals (SDGs). The primary focus on water quality, ecosystem health, and pollution control directly addresses the following SDGs:

• SDG 6: Clean Water and Sanitation: The article is centered on maintaining and improving the quality of freshwater bodies like lakes. It discusses the management of pollution from pesticides and nutrients (phosphorus) to ensure water safety and usability.
• SDG 14: Life Below Water: By addressing threats to freshwater ecosystems, the article aligns with the principles of SDG 14. It discusses the protection of native fish habitats, the dangers of low oxygen levels from decomposing algae blooms, and the potential harm of chemical treatments to aquatic life, all of which are critical for preserving life below water.
• SDG 15: Life on Land: The core issue discussed is the management of “noxious weeds,” which are defined as “invasive, non-native plants that are so aggressive they harm local ecosystems.” This directly relates to protecting biodiversity and ecosystems on land and in inland freshwaters.

2. What specific targets under those SDGs can be identified based on the article’s content?

Based on the article’s discussion of water quality management, pollution control, and ecosystem protection, several specific SDG targets can be identified:

SDG 6: Clean Water and Sanitation

• Target 6.3: By 2030, improve water quality by reducing pollution, eliminating dumping and minimizing release of hazardous chemicals and materials, halving the proportion of untreated wastewater and substantially increasing recycling and safe reuse globally. The article directly addresses this by describing a water quality permitting program designed to control the use of “pesticides and other chemicals” and manage nutrient pollution from “excess phosphorus” to prevent water degradation.
• Target 6.5: By 2030, implement integrated water resources management at all levels, including through transboundary cooperation as appropriate. The permitting program described is a form of integrated management, involving state agencies (Ecology, Washington Department of Fish and Wildlife), local authorities (“irrigation district, municipality, or HOA”), and the public to manage aquatic ecosystems.

SDG 14: Life Below Water

• Target 14.1: By 2025, prevent and significantly reduce marine pollution of all kinds, in particular from land-based activities, including marine debris and nutrient pollution. Although the article focuses on freshwater, the principles are identical. It details efforts to control nutrient pollution (“Phosphorus is a nutrient that can boost the growth of aquatic plants and lead to more frequent algae blooms”) originating from land-based sources, which is a key aspect of this target.
• Target 14.2: By 2020, sustainably manage and protect marine and coastal ecosystems to avoid significant adverse impacts, including by strengthening their resilience, and take action for their restoration in order to achieve healthy and productive oceans. The article’s goal of controlling invasive plants that “harm local ecosystems” and “degrade water quality” is a direct effort to manage and protect aquatic ecosystems. The proposed changes to the permit aim to allow “more effective plant management can happen while also protecting fish.”

SDG 15: Life on Land

• Target 15.5: Take urgent and significant action to reduce the degradation of natural habitats, halt the loss of biodiversity and, by 2020, protect and prevent the extinction of threatened species. The article’s focus on controlling invasive weeds that “harm native fish habitat” is a clear action to reduce the degradation of natural habitats and protect the biodiversity within them.
• Target 15.8: By 2020, introduce measures to prevent the introduction and significantly reduce the impact of invasive alien species on land and water ecosystems and control or eradicate the priority species. The entire article is about this target. It describes a legal and regulatory framework (the “Aquatic Plant and Algae Management General permit”) specifically designed to control “invasive, non-native plants” referred to as “noxious weeds.”

3. Are there any indicators mentioned or implied in the article that can be used to measure progress towards the identified targets?

The article mentions and implies several indicators that can be used to measure progress towards the identified targets:

• Water Quality Monitoring Data: The article explicitly states, “for this permit we also review monitoring data.” This data can be used to track levels of pollutants, nutrients like phosphorus, and water clarity, serving as a direct indicator for Target 6.3.
• Monitoring of Treatment Effects: The proposal for “additional monitoring requirements to better understand the effects of these treatments [alum] and how to prevent problems” is a specific indicator. This helps measure whether actions taken to improve water quality are being implemented safely and effectively, relating to Targets 6.3 and 14.2.
• Frequency and Severity of Algae Blooms: The article notes that a goal of phosphorus control is “reducing plant growth and algae blooms.” Tracking the occurrence of toxic algae blooms that cause recreational closures is a clear indicator of water quality and ecosystem health (Targets 6.3 and 14.1).
• Oxygen Levels in Water: The article mentions that decomposing algae “lowers the oxygen levels in water, which can be dangerous for aquatic life.” Monitoring dissolved oxygen levels is a key scientific indicator of the health of an aquatic ecosystem (Target 14.2).
• Prevalence of Invasive Species: The effectiveness of the permit program can be measured by tracking the spread or reduction of noxious weeds like Hydrilla, Pondweed, and Loosestrife. This directly measures progress towards Target 15.8.
• Health of Native Species Populations: The article mentions protecting “native fish habitat” and “sensitive species.” Monitoring the population health and diversity of native fish and other aquatic life would serve as an indicator for the success of habitat protection efforts (Target 15.5).

4. SDGs, Targets and Indicators Table

Source: ecology.wa.gov