Our Work / Stewardship

Sagg Pond Watershed


This critical research and remediation work is only possible because of the passion and generosity of the Sagg Pond community. We’re so grateful for your support!

Thanks to you, we have already raised an initial $250,000 towards our $465,000 2023 goal! With your help, we can fund the important work of Cornell Cooperative Extension (CCE) and the Center for Clean Water Technology (CCWT) as they begin field piloting work and laboratory research.

To sustain this critical research and remediation work, we need to raise $465,000 by December 31, 2023. If you have not done so already, please help us reach this goal by giving today!

Working with the team at CCE, CCWT, and other partners, your support will allow us to:

  • Begin installing permeable reactive barriers in key areas around the pond. They will break down excessive nutrients and harmful chemicals before they reach the pond.
  • Educate watershed residents about nitrogen-reducing I/A septic systems and turf management practices.
  • Support further research and development, like the purchase of an auger to enable larger test wells to document results.
  • Work with a septic systems manager from the Center for Clean Water Technology to install I/A septic systems affordably with public subsidies.
  • Sustain the Trust’s coordinating role in this crucial work.
  • Leverage private dollars to unlock public funding earmarked for water quality improvement projects.
  • Inform future remediation work across the East End and beyond.

Thanks again to the scientists, students, neighbors, donors, and supporters who have already committed so much to Sagg Pond's restoration. You're making a lasting impact on the future of Sagg Pond - both now and for future generations. Thank you!

On October 26, 2023, residents of the Sagg Pond watershed, along with project supporters, public partners, and other community members, were invited to join Trust President John v.H. Halsey and our partners from Cornell Cooperative Extension to learn more about recent remediation work on the shores of Sagg Pond. Molly Graffam, PhD, and Ron Paulsen, PG, shared an update on the installation of Sagg Pond’s first permeable reactive barrier (PRB) and previewed the next phase of this restoration project.

To learn more about this restoration effort, and to find out how you can lead the charge for a cleaner, safer Sagg Pond, watch the recording below!

Project History

Like many of our ponds and bays, Sagg Pond has suffered from the effects of excessive nutrient loading from various sources. In 2019, Peconic Land Trust began building a coalition of partners committed to studying the root causes of algae blooms that plague the pond and to finding solutions to improve the resilience of this fragile, and precious, place.

That year, in partnership with the New York State Center for Clean Water Technology and Stony Brook University's Dr. Christopher Gobler, we launched a 4-year project to study the causes of these blue-green algal blooms. The results of this research will help the Southampton Town Trustees prepare a Sagg Pond Revitalization and Management Plan.

The preliminary findings confirmed that an over-abundance of nitrogen and other nutrients in the water leads to harmful algal blooms in Sagg Pond. The likely sources of nitrogen include fertilizers from farms and lawns, aging septic systems, and (to a lesser degree) atmospheric deposition.

In 2021, with the cause of the algae blooms identified, scientists with Cornell Cooperative Extension’s (CCE) Marine program initiated research to pinpoint the locations of nitrogen-rich groundwater seepage into the pond and potential remediation methods to filter out nitrogen before it reaches the pond.

CCE groundwater team collecting porewater and surface water samples

CCE groundwater team collecting porewater and surface water samples

Molly and Ron in front of the Cornell boat

Molly Graffam, PhD: Water Resource Geochemical Specialist (left) and Ronald J. Paulsen PG: Hydrogeologist/Groundwater Specialist (right)

Molly Graffam, PhD, Ron Paulson, PG, and CCE Marine program staff conducted site characterization studies along the Trust's Smith Corner Preserve and nearby properties. The water samples they collected allowed them to quantify nitrogen in Sagg Pond and in the groundwater that discharges into the pond along the shoreline.

In addition to quantifying nitrogen levels in the water, site characterization was used to evaluate the soil characteristics of the ground underneath and around Sagg Pond. This required the installation of wells that allow for testing of groundwater conditions and borings to evaluate soil characteristics. Using hydraulic drilling equipment such as a Geoprobe(TM), CCE staff strategically drilled wells with minimal temporary disruptions or disturbances to the property.

What's Next

Once the sources of groundwater seepage have been identified, we will know where to deploy remediation methods that break down nitrogen and other nutrients before they reach the pond.

One method being studied by the CCE team is the use of permeable reactive barriers (PRBs). This sub-surface green infrastructure provides passive remediation, does not require extensive maintenance, and has the potential to remain effective for decades.

PRBs have been used extensively in the Midwest to treat agricultural tile drainage runoff. In nearby Hampton Bays, a PRB installed by CCE behind a bulkhead has successfully reduced nitrogen levels in the mixing zone between groundwater and the sea. The team anticipates that PRBs will be an important tool in limiting excess nitrogen and other nutrients from entering the pond.

The team is also looking at the potential for biochar to increase the effectiveness of PRBs. Produced from solid waste generated on farms, biochar is a carbon-rich material used to improve soil health. Its use, in combination with woodchips, as a filtering media for PRBs would help reduce agricultural waste, enhance soil health, and improve groundwater remediation. With an ancient history and the added benefit of carbon sequestration, biochar presents exciting new opportunities to enhance the sustainability of this project.

Permeable reactive barrier graphic

Schematic from Cornell Cooperative Extension of a PRB at the edge of a farm field adjacent to an impaired waterbody.

With proper stewardship, the land itself can be an effective means of limiting nitrogen-rich groundwater from entering the pond. A new initiative involves the Trust, working with CCE, Southampton Town, and the Friends of the Long Pond Greenbelt to create a demonstration project on 8.3 acres of Town-owned farmland adjacent to Poxabogue Pond.

Located within the Sagg Pond watershed, this proposed demonstration project will showcase vegetative buffers for use on shorelines to curb nutrient-rich surface water runoff into both Poxabogue and Sagg Ponds. In addition, we will demonstrate regenerative agricultural practices that improve soil health and the ability of the land to absorb nitrogen and other nutrients before they enter the groundwater.

By reducing surface water runoff, vegetative buffers will improve the pond’s water quality in more ways than one. In 2019, one of Gobler’s initial research questions was to understand the source of pathogenic bacteria in Sagg Pond. Using microbial source tracking, they found that the major source of fecal contamination came from dogs and small mammals, most likely carried to the pond via surface runoff.

In addition to the use of PRBs, another important tool for limiting nitrogen from entering the pond is to upgrade antiquated septic systems. There is significant public funding available, in the form of rebates from the Town, County and State, to assist homeowners to replace their traditional septic systems with Innovative/Alternative Systems (I/A systems). However, few homeowners have made the switch so far. The major obstacle is that the criteria for selecting among the available I/A systems is complex. Also, the regulatory process of getting one installed is complicated.

To accelerate the upgrading of septic systems within both the Sagg Pond and Georgica Pond communities, the New York State Center for Clean Water Technology at Stony Brook University (CCWT) has hired a manager to help. Tom Varley, the new hire, will help homeowners navigate the unwieldy process of upgrading their systems. The Trust is funding the position for CCWT using funds raised from the community. Homeowners can reach out to Tom Varley at thomas.varley@stonybrook.edu


You can make a difference. Here’s how.

Small changes in how we care for our lawns, gardens, and houses can make a lasting impact in the health and vitality of this place we call home. Here are just a few ways you can make the Sagg Pond watershed a healthy place to live!

  • Reduce or eliminate chemical inputs into the soil from landscaping
  • Maintain and upgrade your home septic system
  • Share what you learned with your friends and neighbors
  • Support this work with a donation to the Sagg Pond Restoration Fund

Meet with Bruce! Bruce Horwith, the Trust's Natural Resource Consultant is offering free, at-home consultations to homeowners in the watershed. Email Bruce to schedule a consultation today! This is a great opportunity to review on-site methods to help restore the pond's water quality.

Meet with Tom! Tom Varley can help homeowners navigate the unwieldy process of upgrading their septic systems. For more information and to set up a call, email Tom at thomas.varley@stonybrook.edu

Stay in the loop! Sign up for our quarterly emails to stay informed about this ongoing work and to learn how you can make a difference.

Perfect Earth Project:

Perfect Earth Project promotes toxin-free lawns and landscapes for the health of people, their pets, and the planet. Visit their website for links to resources and information on lawn and landscape care: www.perfectearthproject.org

Peconic Land Trust Connections:

Sign up to receive our Connections email and flyer for upcoming programs, many of which provide information on sustainably managing lands, water quality improvement, growing food, and more. Check out our Lawn and Landscaping Advice page for how to videos along with Zoom programs on planting for a healthier environment.

Cornell Cooperative Extension of Suffolk County:

Check out CCE's Groundwater Program website page for more information on the causes of pollution in our bays and ponds, the impacts, and the various solutions -- including Permeable Reactive Barriers.


Cornell Cooperative Extension of Suffolk County:

  • Deborah Aller, PhD: Agricultural Stewardship Specialist (bio)
  • Ronald J. Paulsen PG: Hydrogeologist/Groundwater Specialist (bio)
  • Molly Graffam, PhD: Water Resource Geochemical Specialist (bio)

Bruce Horwith, Peconic Land Trust's Natural Resource Consultant

New York State Center for Clean Water Technology at Stony Brook University

  • Christopher Gobler, PhD: Director (bio)
  • Frank M. Russo: Associate Director for Wastewater Initiatives (bio)
  • Stuart Waugh, PhD - Research Scientist (bio)
  • Tom Varley - Manager

Friends of the Long Pond Greenbelt

new septic system with the house in the background

Photo Credit: PW Grosser

Support the Peconic Land Trust
Peconic Land Trust needs your support to protect the working farms, natural lands, and heritage of Long Island.