The New York State Department of Environmental Conservation (DEC) is continuing its investigation into water quality issues in Ischua Creek, Franklinville, Cattaraugus County, after a large fish and wildlife die-off was reported on August 26, 2025.
DEC Commissioner Amanda Lefton stated, “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. We are committed to holding responsible parties accountable and ensuring the protection of the environment and communities in Cattaraugus County.”
Field teams from DEC have been monitoring water quality daily at various points along Ischua and Olean creeks. Their focus has been on discharge from the Great Lakes Cheese facility’s wastewater treatment operations. The state’s monitoring included testing for a range of parameters that may impact both human health and wildlife.
A preliminary review of laboratory results showed that downstream of the Great Lakes Cheese facility there were low levels of dissolved oxygen and high nutrient concentrations exceeding state standards. Toxic levels of nitrite and ammonia were detected in addition to elevated manganese and total dissolved solids. However, upstream areas met state standards with healthy aquatic life observed.
According to DEC experts, these impacts appear confined to Ischua Creek without evidence that other waterbodies are affected.
Recent data indicates that conditions in Ischua Creek have improved since initial response efforts began. Dissolved oxygen levels now meet state requirements at all monitored sites. Further sampling will be conducted next week to assess whether nutrient levels continue to pose risks for aquatic life. The Recreational Use Advisory for the creek remains active.
No effects on local drinking water supplies have been identified so far. Private wells near the creek were tested by the New York State Department of Health (DOH) and Cattaraugus County Health Department (CCDH), with results showing no indication that they were impacted by the discharge event. Regular well maintenance remains important due to possible contamination from weather events or runoff; more information is available from DOH’s Private Wells website: https://www.health.ny.gov/environmental/water/drinking/private_wells.htm.
The DEC states it will hold any responsible parties accountable for environmental harm caused by this incident while working toward a full restoration plan for Ischua Creek’s ecosystem. The enforcement investigation is ongoing.
Great Lakes Cheese has paused its wastewater discharges into Ischua Creek as required by DEC directives, with oversight continuing on modifications intended to prevent future incidents. The company must show compliance with all relevant permits before resuming operations or discharges into the creek.
In response coordinated by Governor Kathy Hochul, multiple agencies including DEC worked alongside groups such as Cornell PRO-DAIRY and state agriculture departments to support farmers impacted by disruptions at Great Lakes Cheese. Guidance was distributed for Concentrated Animal Feeding Operation (CAFO)-permitted farms regarding milk management practices consistent with permit conditions. Additional collaboration between New York and Pennsylvania agencies allowed rerouting milk shipments initially destined for Great Lakes Cheese so it could be processed elsewhere—helping reduce losses for dairy producers across state lines.
Public updates will continue as new information emerges about recovery efforts at Ischua Creek.
