Pending approval by the NYSDOH Environmental Laboratory Approval Program, IEC will be certified in Standard Method 5310B-14: Determination of Total Organic Carbon (TOC) and Dissolved Organic Carbon (DOC) in Non-Potable Waters. This method uses combustion and an oxidation catalyst within a TOC analyzer machine to remove any inorganic carbon and purgeable organic carbon, isolating the organic carbon, which is then converted to CO2. The CO2 is then transported to a non-dispersive infrared detector using carrier gas and measured by software in the machine.

Check out these summer 2025 time-lapse videos depicting dissolved oxygen levels in the western Long Island Sound! These visualizations were developed using surface (1 meter depth) and bottom (1 meter above sediment) dissolved oxygen measurements taken by IEC during our weekly water quality surveys in summer 2025. Low or depleted dissolved oxygen levels in a waterbody is referred to as hypoxia. Hypoxia can result in significant adverse effects on marine life and habitats, which need sufficient dissolved oxygen (>5.00mg/L) to survive and thrive.

In conjunction with New York/New Jersey Harbor and Estuary Program (HEP) and Stony Brook University, Interstate Environmental Commission (IEC) is monitoring the success of eelgrass plants planted by HEP behind living breakwaters on the southern coast of Staten Island. The success of these plants is measured using both habitat and water quality parameters in the summer and fall of 2025 and the spring of 2026. Eelgrass has several vital functions in aquatic ecosystems and can improve water quality and habitat stability.

Pending approval by the NYSDOH Environmental Laboratory Approval Program, IEC will be certified for EPA Method 546: Determination of Total Microcystins and Nodularins in Drinking Water and Ambient Water by Adda Enzyme-Linked Immunosorbent Assay (ELISA). This method measures the total concentration of microcystins based on the detection of a characteristic feature common to microcystins using absorbance of the sample after it has been treated for analysis.

Through funding provided by the Long Island Sound Partnership (LISP), IEC has secured a subaward to support Coalition to Save Hempstead Harbor (CSHH), a group which conducts water-quality monitoring of physical, chemical, and biological indicators of pollution at up to 21 sites in Hempstead Harbor and Glen Cove Creek.

The Septic System Replacement Fund Program, supported by EPA Bipartisan Infrastructure Law funding passed through the New York State Department of Environmental Conservation (NYSDEC) to the Interstate Environmental Commission, will provide financial assistance to eligible homeowners in Nassau and Suffolk County to aid in replacing septic systems or cesspools that impair water quality in the Long Island Sound watershed.

The 2025 Pathogen Monitoring Network season has officially started! Since the beginning of May, ten groups have been sampling throughout Connecticut and New York to gather crucial fecal indicator bacteria data to fill data gaps in the Long Island Sound watershed. This network aims to create a coordinated, geographically strategic, scalable monitoring network for fecal indicator bacteria in the Sound in order to inform sound-wide management and restoration actions. From its start in 2023, the network has grown each year to work towards this goal.

IEC just deployed its first continuous monitoring sonde for readings in the New York/New Jersey Harbor! In conjunction with the New Jersey Department of Environmental Protection (NJDEP), four YSI EXO2 multiparameter sondes will be placed throughout the New York/New Jersey Harbor in order to provide continuous readings of water quality. The deployed sondes will remain in the water year-round when conditions allow and will measure temperature, conductivity, dissolved oxygen, pH, turbidity, and chlorophyll.

The 2024 LIS Hypoxia Season Summary, produced by the Connecticut Department of Energy and Environmental Protection (CTDEEP) using data collected in conjunction with IEC, is now available. 

IEC’s annual “State Summaries” are now published, providing an overview of the organization’s work and impact in the three states in its environmental district throughout the fiscal year 2023-2024. In addition to water quality programs, collaborative activities are shared, including workgroups and committees, public education and outreach.