Our ocean is not a dumping ground. Yet 70-80% of global wastewater enters the environment untreated, poisoning coral reefs and coastal communities. At the 2025 UN Ocean Conference, the Ocean Sewage Alliance (OSA) and partners confronted this crisis head-on through two action-driven sessions, and launched the Global Action Platform to End Sewage Pollution.

The Action Platform calls for:

✅ Global monitoring to track pollution

✅ Stronger regulations for microplastics, chemicals & nutrients

✅ Nature-based solutions at scale

✅ Innovative financing for wastewater systems

You may have spotted our flyers at the conference (yes, even in the toilet stalls) because this invisible emergency demands visible solutions. Together, these session discussions revealed a clear path forward: solving the wastewater crisis requires breaking silos, smart investment, and replicating what already works. Read the key takeaways below and visit links to resources.

Session I: Building Coastal and Ocean Resilience Through Cross-Sector Wastewater Pollution Action

Wastewater pollution remains one of the ocean's most pervasive yet overlooked threats, with untreated sewage and agricultural runoff devastating coastal communities and coral reefs worldwide. At our UN Ocean Conference side event, experts moved beyond diagnosis to deliver actionable solutions—revealing why progress has stalled, where breakthroughs are emerging, and how we can finally turn talk into measurable action.

1. The Problem: Wastewater Pollution Is a Silent Crisis

• Untreated sewage, agricultural runoff, and industrial waste are devastating coral reefs, coastal ecosystems, and human health.
• Many regions lack even basic monitoring, making it impossible to manage pollution effectively.
• Economic and ecological costs are staggering, yet systemic action lags behind.

Michelle Devlin (Cefas) emphasized:

"We can’t manage what we don’t measure. We need strategic data collection in critical areas — where people swim, where tourism thrives, and where ecosystems like seagrass and corals are most vulnerable."

2. Solutions Exist—But Deployment Is the Challenge

Amelia Wenger (Wildlife Conservation Society) highlighted:

"The issue isn’t a lack of technology—it’s about context and implementation. We need actionable strategies, not just awareness."

• Pollution Solutions Initiative: A new platform to help decision-makers choose the right wastewater interventions for their specific needs.
• Community engagement is critical — people won’t support solutions they don’t understand or trust.

Manuel Mejia (Coral Reef Alliance) shared a success story from Honduras:

"After upgrading wastewater systems, a bay once polluted is now swimmable, fishable, and supports healthy biodiversity. The biggest hurdle? Funding not just infrastructure but long-term maintenance."

3. Blended Finance: Unlocking Investment in Wastewater

Melanie Mayfield (Healthy Reefs for Healthy People) discussed the Global Fund for Coral Reefs (GFCR) approach:

• Blended finance (mixing grants, loans, and private capital) helps de-risk investments in small-scale wastewater projects.
• Example: A $100,000 loan supported decentralized sewage treatment in Mexico, with potential for replication.

Challenges?

• Private investors often expect high returns, while wastewater projects need low-interest, long-term funding.
• Solution: Grants and concessional loans can bridge the gap.

4. Replicating Success: The Power of Aggregation

Mehrnaz Ghojeh (Okhtapus) argued that innovation isn’t the bottleneck — deployment is:

"We don’t need more pilots — we need to scale what already works. The problem? Projects are often too small to attract traditional financing."

• Okhtapus’ model matches innovators, local enablers, and financiers to replicate proven solutions.
• Example: Aggregating small wastewater projects into a portfolio makes them more attractive to investors.

5. Nature-Based Solutions: Beyond Pilot Projects

Maxence Prat (French Development Agency - AFD) shared lessons from the Pacific:

• Watershed restoration (tree planting, sustainable farming) reduces runoff into oceans.
• Mainstream nature-based solutions into larger infrastructure projects to ensure scalability.

6. Why an Alliance? Collaboration Is Non-Negotiable

Jasmine Fournier (Ocean Sewage Alliance) noted:

"We’re a small community working on sewage—if we don’t collaborate, we’ll keep reinventing the wheel. Engineers, policymakers, financiers, conservationists, and local communities must work together."

• ‍OSA’s Action Platform to End Sewage Pollution in the Ocean seeks global commitments on wastewater regulation and funding.

Session II: Wastewater Pollution Management To Boost The Climate Resilience Of Coral Reefs

Wastewater pollution doesn't just damage coral reefs—it erodes their ability to survive climate change. But proven solutions are being implemented from Honduras to Hawaii. This UNOC session cut through the noise with two panels: first exposing the real-world challenges of implementation, then revealing how innovative finance and nature-based solutions can scale impact.

Panel I: Implementation & Lessons from the Ground

1. Regional Collaboration is Key

Christopher Corbin (UNEP Cartagena Convention) highlighted the power of regional alliances in tackling wastewater pollution:

 "We bring together 28 Caribbean nations to harmonize policies, mobilize resources, and engage non-traditional sectors like tourism and fisheries."

Key Insight:

• Harmonized standards prevent a "checkerboard" of water quality regulations.
• Cross-sector partnerships (e.g., tourism operators funding wastewater upgrades) accelerate progress.

2. Breaking Silos Between Public Health & Conservation

Amelia Wenger (Wildlife Conservation Society) shared a success story from Fiji:

• Linking wastewater pollution to human health risks (e.g., waterborne diseases) drove policy action.
• A Bloomberg Philanthropies-funded project reduced disease risks in communities while protecting reefs.

Lesson:

• Conservationists must collaborate with public health experts—pollution impacts both ecosystems and people.

3. On-the-Ground Success: 98% Drop in Coral Disease

Manuel Mejia (Coral Reef Alliance) showcased real-world wins:

• Honduras: A wastewater treatment plant prevented 34 million gallons of raw sewage from entering the ocean annually.
• Hawaii: After upgrades, one bay now has the highest coral cover in the state.
• Unexpected Challenge? Coordination takes time—engaging communities, governments, and funders early is critical.

Biggest Lesson? Manuel reiterated: 

"Budget not just for infrastructure — but long-term operations and maintenance."

4. Measuring Pollution: A Toolkit for Action

Many regions don’t monitor or measure wastewater pollution.

• Amelia Wenger’s team developed ‘A guide for pollution assessment and monitoring in coastal ecosystems’ to help communities assess pollution and ‘A Guide for Integrated Conservation and Sanitation Programs and Approaches’  that help the conservation and sanitation sectors on how working in partnership.
• Takeaway: "You can’t manage what you don’t measure."

Panel II: From Declarations to Delivery: Nature-based solutions, finance strategies, and private sector engagement

1. The Private Sector’s Role: Why Should Businesses Care?

Stewart Sarkozy-Banoczy (World Ocean Council) made the case:

"If you find the economic, social, and health intersections—like tourism, fisheries, and insurance—businesses will invest. Clean water means thriving coastal economies."

Example: In coastal areas with proper sewage treatment, seagrass beds and marine life rebound—directly supporting tourism, real estate, and fisheries.

Key Insight:

• Corporations must see the ROI—whether through risk reduction (e.g., fewer beach closures) or brand value (sustainability commitments).

2. Nature-Based Solutions: Beyond "Gray Infrastructure"

Maxence Prat (French Development Agency - AFD) explained:

• Nature-based solutions (NbS) (mangroves, wetlands, forest buffers) can filter pollutants, stabilize land, and reduce runoff—often cheaper and more resilient than traditional "gray" systems.
• But they’re not a silver bullet: In dense urban areas, hybrid systems (NbS + engineered infrastructure) are essential.

Success Story:

• Mangrove restoration in the Pacific reduced pollution while boosting climate resilience.

3. Blended Finance: The Key to Scaling Solutions

Yabanex Batista (Global Fund for Coral Reefs - GFCR) shared lessons from Kenya:

• Problem: Coastal towns like Malindi lack sewage pipes—waste flows straight into the ocean.
• Solution: GFCR is financing a social enterprise building decentralized wastewater plants.
• Innovation: Using concessional loans (not just grants) to make projects bankable.

Why It Matters? Yabanex noted:

"Grants alone won’t solve this — we need private capital. But first, we must de-risk investments."

4. Insurance & Risk-Sharing: The Missing Link

Chip Cunliffe (Ocean Risk and Reseililence Action Alliance - ORRAA) highlighted:

• $550 billion/year could flow into ocean resilience—if barriers are removed.
• Solution: Blended finance tools (e.g., guarantees, first-loss capital) help mobilize private investors.

Example:

• The "Blue Alliance Marine Protected Areas" (a $22M fund) supports reef-positive businesses in the Philippines and Indonesia.
• The Outrigger Impact Fund (targeting $35M) focuses on SMEs in small island states.

Biggest Barrier? Chip highlighted:

"’Financial ocean literacy’ — many investors don’t understand blue economy opportunities.”

5. Policy & Governance: The Make-or-Break Factor

Yabanex Batista (GFCR) warned:

"Private capital won’t flow where policies are unstable."

• Unclear regulations kill innovation. Example: In Mexico, sargassum seaweed (which smothers reefs) isn’t classified as waste or resource—blocking companies that want to upcycle it.
• GFCR’s approach: Every project must address policy gaps, not just funding.

The evidence is clear and the solutions are within reach. From Honduras’ dramatic coral recovery to Kenya’s innovative decentralized treatment systems, we have both the knowledge and the tools to address sewage and wastewater pollution. What remains missing is the collective will to implement these solutions at scale. 

The Global Action Platform to End Sewage Pollution provides the comprehensive framework needed to drive this transformation through four critical pathways: establishing global monitoring systems, strengthening regulatory standards, advancing nature-based solutions, and mobilizing innovative financing mechanisms.

We invite governments, businesses, research institutions and civil society organizations to join this vital effort. By signing onto the Action Platform, your organization can help turn isolated successes into systemic change.

(This blog synthesizes key insights from the side-event panels. Quotes edited for clarity.)

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SIGN THE ACTION PLATFORM TO END SEWAGE POLLUTION IN THE OCEAN