Project Merrimack: Battling Combined Sewer Overflows in the Merrimack Valley

Project Merrimack: Battling Combined Sewer Overflows in the Merrimack Valley 

Throughout our beloved Merrimack Valley, where the Merrimack River meanders through picturesque towns and historic mill cities, a less glamorous but crucial issue often lurks beneath the surface: Combined Sewer Overflows (CSOs). While the Merrimack River is a vital resource, providing water for drinking, recreation, and wildlife, it faces the challenge of pollution due to CSOs.

Understanding Combined Sewer Overflows

CSOs occur in older urban areas where stormwater runoff and sewage are carried in the same pipes. These combined systems easily become overwhelmed during times of heavy rainfall or snowmelt. This leads to the creation of untreated wastewater, which is then discharged directly into nearby bodies of water - including the Merrimack River. This influx of pollutants, including bacteria, chemicals, and debris, poses significant environmental and public health risks.

The Merrimack Valley's Struggle

For the Merrimack Valley, CSOs represent a persistent challenge. While efforts are being made to upgrade infrastructure, the region continues to grapple with regular overflows, especially during extreme weather events. This not only tarnishes the water quality but also undermines recreational activities and harms aquatic ecosystems.

Addressing Current Challenges

One significant challenge facing residents in the Merrimack Valley is the difficulty of staying informed on when these CSO events occur. While treatment plants are required to send alerts notifying the public of CSO discharges, signing up for these notifications can be confusing due to the various systems used by each treatment plant and the various types of alerts received. This lack of streamlined communication leaves residents unaware of potential risks to water quality and public health, hindering their ability to take proactive measures.

Introducing Project Merrimack

In response to this ongoing issue, the Merrimack Company is launching "Project Merrimack," a new initiative aimed at alerting locals of CSO events and enhancing community awareness. At its core, Project Merrimack will provide simplified and centralized CSO notifications. Our alerts will strip away confusing technical jargon and provide a single update to inform residents and authorities when extra precautions need to be taken. It is advised to avoid contact with the water for 48 hours after a CSO event.

Key Features of Project Merrimack:

1. Easy Registration: Sign up for centralized alerts through a user-friendly online platform (

2. Receive Email Alerts: After registration, users will receive no more than one email per day when a CSO event occurs. While multiple events may occur daily, we believe one notification is sufficient for most people as it is advised to avoid contact with the river for 48 hours after an event (check your spam messages and approve to ensure you receive updates). 

3. Advocacy and Policy Support: The Merrimack Company collaborates with local environmental organizations to advocate for policies and investments that prioritize CSO mitigation and water quality protection. Project Merrimack serves as a catalyst for broader systemic change.

The Path Forward

Project Merrimack represents a significant and crucial step forward in the ongoing battle against CSOs in the Merrimack Valley. By harnessing the power of technology, community engagement, and advocacy, this initiative aims to not only mitigate immediate environmental threats but also foster a culture of environmental stewardship and resilience.

As we navigate the challenges of urbanization and climate change, initiatives like Project Merrimack remind us of the importance of collective action and innovation in safeguarding our precious natural resources. This is just the first step of many focused on improving the Merrimack River and the surrounding community.

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