Protecting & Restoring Long Island's Peconic Bays

Water Quality

PEP is taking action to reduce nitrogen pollution, harmful algal blooms, pathogens, toxic contaminants, and plastics in the Estuary to support the well-being of people and wildlife.

Clean Waters for Ecosystem Health and Safe Recreation

Fishing, shellfishing, recreation, and tourism on the East End of Long Island are closely tied to the Peconic Estuary’s health, and changes in estuarine health can affect the local economy. Expansion of land development and the human population threatens to impair water quality and he health of these economically important resources and habitats.

Poor water quality is linked to people’s actions on land. In the Peconic Estuary, pollution tends to come from non-point sources like septic systems and residential and agricultural fertilizer, rather than point sources like sewage treatment plants. The pollution enters groundwater or surface waters, which carry it to the estuary.

One of the most serious issues affecting water quality in the Peconic Estuary is excess nitrogen loading, which can cause harmful algae blooms, low dissolved oxygen, and degraded aquatic habitats. Pathogens and toxic contaminants also contribute to water pollution in the Estuary, and can make fish and shellfish unsafe to eat. New and emerging contaminants pose a continued risk to ecological and human health in our watershed. Plastics in the aquatic environment are of increasing concern because of their persistence and effect on the environment, wildlife, and human health.

One of the most serious issues affecting water quality in the Peconic Estuary is excess nitrogen loading.

Poor water quality is tied to our actions on land. In the Peconic Estuary our primary pollution  source comes from many widely distributed sources– this is called non-point source pollution. Non-point source pollution is caused by the movement of water over the land surface (stormwater runoff) or through the ground- this water picks up natural and human-made pollutants, such as fertilizers, pesticides, motor oil, and human and animal waste, and  eventually ends up in lakes, rivers, wetlands, and coastal waters. The biggest sources of non-point source pollution in the Peconic Estuary is wastewater from residential on-site septic systems and cesspools. The second biggest source is fertilizer.

It is important that we understand the connection between human actions on land and the health of the Peconic Estuary.

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Sources of Water Pollution in the Peconic Estuary

Long Island’s Aquifer 

Water Quality Updates

This figure shows the land area that contributes groundwater to the Peconic Estuary, and the amount of time it takes for this groundwater to reach the estuary. The groundwater contains natural and human-made pollutants.

Current Projects

Peconic Estuary Partnership provides program and project updates!

Search here for PEP Program Updates

Nitrogen Management>>

Harmful Algal Bloom Management>>>

Pathogen Management>>>

Toxic and Plastic Pollution Control>>>

Monitoring the Estuary’s Health>>>

Harmful Algal Bloom Management

View of rust tide in the Peconic Estuary captured from a plane.

Harmful algal blooms (HAB) have plagued the Peconic Estuary since at least the mid-1980’s and pose a public and environmental health threat. With an increasing frequency, we are seeing harmful algal blooms in various areas of our Suffolk County waterbodies. Suffolk County’s marine waters are a huge economic driver for Long Island in their contributions to tourism, commerce, fishing, recreation, and more. Safe and attractive waters play a key role in assuring the success of many of these activities.

Current Actions

Pathogen Management

Learn more: Pathogen Pollution in the Peconic Estuary

Contamination of Peconic Estuary waters by bacteria and other pathogenic organisms may result in the closure of bathing beaches and the closure of shellfish beds for human consumption; thus impacting economic and recreational activities on the East End. The Peconic Estuary Partnership is working with its partners to reduce pathogen pollution from stormwater runoff and wastewater.

Current Actions

Peconic Estuary Program Monofilament Recycling Station along the Peconic River.
Peconic Estuary Partnership Monofilament Recycling Station along the Peconic River.

Toxic and Plastic Pollution Control

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Toxic Contaminants in the Peconic Estuary

Plastic Pollution in the Peconic Estuary

PEP’s regional Subwatershed Management efforts, the Agriculture Stewardship Plan, the initiatives of the PEP Citizens Advisory Committee and the Homeowner Rewards Program  are all intended to reduce loadings of pesticides and herbicides. PEP engages a variety of groups (e.g., golf courses, landscapers, municipal land owners, lawn care supply stores, environmental justice communities, etc.) to participate in the Pesticide and Fertilize Elimination/Reduction Program. PEP has also been working on various initiatives to reduce plastics in our waterways.

Current Actions

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