Our Work / Stewardship

Sagg Pond Watershed

Given that Sagg Pond has recently been impaired by harmful algae blooms and pathogens, the Trust is currently working with partners and the surrounding community to improve the overall conditions. We have partnered with Cornell Cooperative Extension of Suffolk County’s Agricultural Stewardship Program and Marine Program and the New York State Center for Clean Water Technology at Stony Brook University.

Land use and groundwater hydrogeology within the Sagg Pond watershed are among the critical factors affecting local surface water quality. Please stay tuned as we embark on these studies together to offer insights for successive restoration efforts.

Initial Study

In 2019, the New York State Center for Clean Water Technology and the Trust launched a study by Stony Brook University’s Dr. Christopher Gobler to understand the root cause of the blue-green algal blooms occurring in Sagg Pond. The research from this 4-year project will help the Southampton Town Trustees prepare a Sagg Pond Revitalization and Management Plan.

Private funds totaling $224,000 was raised to initiate the study, primarily from neighbors in the Sagg Pond Watershed. Southampton Town and the Town Trustees have committed an additional $112,000 to the effort.

The preliminary findings have confirmed that an over abundance of nitrogen in the water leads to harmful algal blooms in Sagg Pond. The likely sources of nitrogen include fertilizers from farms and lawns, atmospheric deposition, and aging septic systems.

In the summer of 2020, Dr. Gobler and his team installed oyster cages in the pond to see if these native filter feeders can survive and remove excess nitrogen from the water as one of many remediation strategies.

Cornell Cooperative Extension’s Marine program has further complemented this process by initiating research in 2021 to pinpoint the locations of nitrogen-rich groundwater seepage into the pond and potential remediation methods, including the use of Permeable Reactive Barriers (PRB) in specific locations to filter out nitrogen before it reaches the pond.

New York State Center for Clean Water Technology has also sought to understand the source of pathogenic bacteria in Sagg Pond. Through 2019, the Gobler team used microbial source tracking to identify genes originating from humans, dogs (and other small mammals), deer, and birds. They found that the major source of fecal contamination came from dogs and small mammals, most likely carried to the pond via surface runoff.

The preliminary findings of Dr. Gobler’s study were discussed during a Zoom presentation hosted by the Trust for residents within the Sagg Pond watershed in December 2020. Watch the presentation below and click here to see the ongoing data from this research.

Site Characterization

In partnering with Cornell Cooperative Extension’s Marine Program, we are conducting site characterizations along the Trust's Smith Corner Preserve and nearby properties. You’ve most likely seen the boats out there sampling on a summer’s day. The objective is to quantify nitrogen in surface water and groundwater that discharges into the pond along the shoreline.

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)

The Peconic Land Trust and Cornell Cooperative Extension have applied to the Southampton Town Community Preservation Fund* for funds to underwrite this phase of the project. Funding is pending.

Click here for a pdf of the detailed methodology behind this partnered effort.

*The Peconic Land Trust does not collect or distribute the funds from the Community Preservation Fund, CPF, also known as the 2% real estate transfer tax. The 2% real estate transfer fee paid by buyers for the Peconic Bay Region Community Preservation Fund goes directly to the Town in which the property purchased is located.

What is site characterization?

For this project, the site characterization requires the installation of groundwater wells that allow for testing of groundwater conditions and soil borings to evaluate soil characteristics. This work is typically done by CCE staff who use hydraulic drilling equipment such as a Geoprobe(TM) to strategically drill wells with minimal temporary disruptions or disturbances to the property.

One Solution: Permeable Reactive Barriers (PRBs)

The team at CCE has been studying and deploying permeable reactive barriers, a type of green infrastructure that is sub-surface, 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 proven to successfully reduce nitrate within the groundwater seawater mixing zone, and they are of great interest for treating all sources of excess nitrogen, including septic, fertilizer and atmospheric sources.

Biochar in Combination with Permeable Reactive Barriers

The team is also looking at the potential for biochar to increase the effectiveness of PRBs. Biochar is a carbon-rich material -- produced from solid waste generated on farms -- intended for soil application to improve agricultural and environmental quality.

Testing biochar, in combination with woodchips, as a media for use in PRBs is a encouraging new strategy and could enhance the sustainability of the approach. Additionally, using waste products from farms to generate biochar can help link the agricultural industry with a promising new solution for soil health and groundwater remediation.

The team at CCE anticipates PRBs to be a highly applicable for use at the edge of fields on Long Island farm and behind bulkheads, but they also require proper site characterization to evaluate their suitability -- which is what we are currently working on with CCE.

Below, schematic from Cornell Cooperative Extension of a PRB at the edge of a farm field adjacent to an impaired waterbody

Prb graphic

Citation for above: Hiller, K. A., Foreman, K. H., Weisman, D., and Bowen, J. L. (2015). "Permeable Reactive Barriers Designed To Mitigate Eutrophication Alter Bacterial Community Composition and Aquifer Redox Conditions." Appl. Environ. Microbiol., 81(20), 7114-7124, doi:10.1128/AEM.01986-15


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)

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)


The following are resources related to how you can make a difference in the watershed.

Ways you can help:

Lawn Expert Tuesdays at Bridge Gardens:

From Spring until Fall, the Trust is partnering with Paul Wagner of Greener Pastures Organics who is at Bridge Gardens from 3:00 pm to 4:30 pm to offer free advice to homeowners interested in sustainable lawn and landscape care. You can also email LawnExpert@PeconicLandTrust.org and Paul will answer your questions. This program is in partnership with the Perfect Earth Project.

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.

new septic system with the house in the background

Photo Credit: PW Grosser

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