To destroy the Poison Production Substations in Surgical Strike in Far Cry 6, follow the pipelines north east until you find the first sub-station.

Go into the control room and pull the lever.

Go to the south east part of the search area and pull the lever there.

The final lever to pull in the first sub-station is next to the control room with the first lever on the north west side.

Follow the pipes out of the sub-station to the east until you find the second sub-station.

Here you will need to shoot weak points in the pipe to destroy the sub-station. The first weak point is in the south east part of the search area under some walkways.

The second weak point is slightly to the east of the first weak point, again underneath some walkways.

The final weak point for the second sub-station is on the east part of the search area behind the PG-240 yellow tank.

Follow the pipes out of the sub-station to the east until you find the third sub-station.

To destroy the third sub-station you will need to shoot weak points. The first weak point is next to the PG-240 yellow tank next to the ladder.

The second weak point is under water on the west side of the west water pool in the middle of the search area.

The final weak point is in a pipe under the water tower on the north west part of the search area.

Follow the pipes south east out of the third sub-station until you find the fourth and final sub-station.

The first weak point is directly under the PG-240 yellow tank on a pipe leading to it.

The second weak point is on a pipe going east on the other side of the concrete from the PG-240 yellow tank.

To destroy the fourth sub-station you will need to pick up a key that is outside of the search area in the north part of the red zone sitting on a box next to a control panel and some pipes. Take the key to the control room next to the PG 240 yellow tank and pull the middle lever.