DEC Issues Update on Ischua Creek Water Quality

The New York State Department of Environmental Conservation (DEC) is continuing its comprehensive investigation into water quality impacts to Ischua Creek in Franklinville, Cattaraugus County, following reports on August 26, 2025, of a large fish and wildlife die-off.

"DEC took immediate action to address water quality violations and deployed dozens of our experts in water, wildlife, incident management, communications, and enforcement. They have been working diligently on the ground in Cattaraugus County to help fully assess the devastating water quality and habitat impacts to the resource," DEC Commissioner Amanda Lefton said. "We are committed to holding responsible parties accountable and ensuring the protection of the environment and communities in Cattaraugus County."

DEC field teams conducted daily water quality monitoring to comprehensively assess impacts to aquatic life at various locations on Ischua and Olean creeks, including conditions upstream of the Great Lakes Cheese facility in Franklinville. Water quality concerns remain primarily focused on the discharge from facility's wastewater treatment operations. New York State's water quality monitoring included the collection of a broad suite of water quality parameters to evaluate a range of potential water quality issues that could affect human and wildlife health.

DEC today completed a preliminary review of laboratory results from in-stream water quality sampling of Ishua and Olean creeks. The data suggests the creek downstream of the Great Lakes Cheese facility had low dissolved oxygen and high levels of nutrients in exceedance of state standards. This includes levels of nitrite and ammonia in the water that are toxic to fish and other aquatic life. Other water quality parameters which exceeded standards include manganese and total dissolved solids.

Importantly, water quality upstream of the facility's discharge was compliant with state standards and aquatic life in the upstream reaches remains healthy. Based on the current evaluation by DEC's water quality experts, the impacts on water quality are limited to Ischua Creek and did not impact other waterbodies.

Data also shows significant improvements in Ischua Creek in the days since the State's initial response, including dissolved oxygen levels improving and attaining state standards at all locations monitored. Additional water quality sampling is expected next week to determine the recovery of ammonia and other nutrient levels and whether continued risks to fish and other aquatic life exist. The Recreational Use Advisory for the creek remains in effect.

In addition, there remains no indication of impacts to drinking water supplies. The New York State Department of Health (DOH) and Cattaraugus County Health Department (CCDH) tested private wells in the area immediately adjacent to the creek. Data returned to date does not show any indication of impacts to private wells from the discharge to Ischua Creek. Private wells can be impacted by many different germs and chemicals from flooding and extreme weather, runoff, and natural changes in the water that serves the well. The State Department of Health has information about the importance of regular well testing and maintenance on its dedicated Private Wells website.

DEC is committed to holding any parties responsible for the environmental damage to the creek and working towards a comprehensive restoration plan for this critically important ecosystem. DEC's enforcement investigation is ongoing.

DEC is requiring Great Lakes Cheese to take immediate actions to address impacts and investigate the plant's organic waste discharge to Ischua Creek. Following the facility's voluntary pause on wastewater discharges to Ischua Creek, no wastewater is being discharged to the waterbody and DEC is closely overseeing all modifications being proposed to prevent any future discharges that could damage natural resources. The facility will be required to demonstrate full compliance with all State water and air permits before resuming operations and discharges to the creek.

In addition, as part of the multi-agency incident response directed by Governor Kathy Hochul, DEC worked in close coordination with the State Department of Agriculture and Markets (AGM). DEC, AGM, and Cornell PRO-DAIRY promptly collaborated to develop and distribute guidance for Concentrated Animal Feeding Operation (CAFO)-permitted farms and their certified planners to help ensure milk without market value is utilized to the fullest extent as a fertilizer source and incorporated into a farm's nutrient management plan in accordance with CAFO permit conditions. AGM and the New York State Department of Transportation also collaborated with the Pennsylvania Department of Transportation and Pennsylvania Department of Agriculture to support New York farmers by enabling milk trucks traveling from New York to Pennsylvania to receive special permits to help redirect fluid milk originally intended for the Great Lakes Cheese plant to other dairy processing facilities so that this milk can be processed and utilized. This ensures a minimization of any loss of milk and helps strengthen the cooperation between states to ensure the Northeast milkshed works together.

DEC is committed to keeping the public informed as additional information becomes available.