New Orleans-based Entergy Corp. and New York state regulators are battling over the design of the cooling towers at Indian Point Energy Center, a nuclear power plant, and the impact on aquatic life in the Hudson River, according to The Wall Street Journal.

The plant uses up to 2.5 billion gallons of water a day for cooling and in the process sucks in around 1 billion tiny fish and their eggs each year. Entergy is trying to renew the plant’s federal operating permit. Environmentalists and the state oppose the plan.

State regulators want Entergy to redesign the plant’s cooling tower. Instead of the 50-story stack common to nuclear facilities, New York wants Entergy to build a cluster of 88 structures roughly 90 feet tall, the Journal reports. The water needed for cooling would be reused, reducing the amount needed and protecting fish. The cost is an estimated $1 billion.

Entergy has criticized that idea, saying it is expensive and unproven.

The company’s design calls for installing 144 cylinder-shaped screens with openings 2 millimeters wide. The screens, Entergy says, will allow water through but not fish.

Entergy estimates the cost for this system at $250 million.

New York regulators say this design won’t provide enough protection for aquatic life.

No matter what design the state approves, the Journal article says, the dispute is probably headed for court, with environmentalists or Entergy trying to overturn the decision.