NY still falls short on Lake Champlain phosphorus targets

Draft plan eyes projects to mitigate key pollutant in lake

By Zachary Matson

Editor’s note: This story has been updated with a new, extended deadline of April 5 for public comments to the plan

New York continues to fall short of phosphorus targets in Lake Champlain, and a new state plan outlines strategies to minimize the key nutrient and major contributor to algal blooms. 

The state’s draft Lake Champlain Watershed Implementation Plan aims to meet phosphorus limits known as the Total Maximum Daily Load (TMDL), or the amount of phosphorus that can be “loaded” into the lake from different sources and at different locations without imperiling the lake’s many uses.

Eric Howe, director of the Lake Champlain Basin Program, likened the lake’s TMDLs to a “pollutant diet for a lake.” That diet is divided between New York and Vermont and is required under the federal Clean Water Act. 

Since the lake’s original TMDL was adopted in 2002, millions of dollars of federal, state and local money has been invested in upgrading wastewater plants, improving agricultural practices and limiting erosion in Lake Champlain’s massive watershed. 

“The challenge is despite efforts across the entire Lake Champlain basin in New York, Vermont and in Quebec to reduce phosphorus loading, the amount of phosphorus delivered to the lake has continued to increase in the past 20 years,” Howe said.

The total phosphorus load to the lake was estimated at 647 metric tons per year during the 1991 hydrologic base year, according to TMDL documents. The current phosphorus load estimated in Lake Champlain now is above 900 metric tons per year. 

Howe said the investments have paid off, citing significant improvements to how phosphorus is treated at wastewater plants in the watershed and noting that phosphorus pollution would have been much worse without steps to limit it under the TMDL mandate. The wastewater treatment plants on both sides of the lake are discharging less phosphorus than their allocations.

“What would the lake look like if we had not done all of that work over the years?” Howe said.

Up for public comment through April 5, the draft plan outlines the latest data on phosphorus loading from New York tributaries to the lake and lists state-funded programs that aim to reduce phosphorus.   

Meanwhile, New York is working to update the underlying phosphorus limits that make up the TMDLs for the state’s portion of the watershed. The update, which must commence by 2026, will account for new science and provide for a fresh public engagement process. 

The federal Environmental Protection Agency updated the Vermont TMDLs in 2016 after the original limits were challenged in court, increasing allocations on that side of the lake by nearly 25%.

The bulk of phosphorus pollution in the lake originates from Vermont, estimated to currently contribute around 631 metric tons per year, about three times New York’s contribution.  Agriculture is the top source of phosphorus across the watershed.

New York represents 37% of the watershed’s land area, nearly 90% of which is forested land. Vermont accounts for 56% of the watershed, and 7% of the land is in Quebec. For TMDL planning, the lake is divided into 13 segments, seven of which include part of New York. Each segment has a target specific to its conditions.

New York’s current overall phosphorus allocation is 119 metric tons per year, but its actual loading is estimated at around 211 metric tons per year. 

Lake Champlain basin grants coming soon

The federal Bipartisan Infrastructure Law approved in 2021 boosted funding to the Lake Champlain Basin Program by a total of $40 million over five years. 

The federal funding will boost the basin program’s ability to invest in projects around the lake to protect land, fund farm practices that minimize phosphorus, improve erosion controls and conserve wetlands.

The basin program plans to award around $13 million in grants this year. Howe said grant programs would be open for submission in the coming weeks. The grants will include funds for:

• Supporting tree nurseries, towns and watershed organizations to increase the supply and the lower the cost of plants used to buffer stream corridors; 
• Helping towns and groups purchase equipment used to combat invasive species;
• Supporting projects to conserve or restore wetland areas on the New York side of the basin;
• Removing and replacing undersized culverts and other barriers that limit important passage for aquatic species.