A spokesman with the Iowa Department of Natural Resources says they’re looking into possible legal action after a manure spill south of Postville killed thousands of fish.D-N-R environmental specialist Tom McCarthy says they traced the source of the spill in Roberts Creek in Clayton County to the Charles Deering hog operation.He says manure storage pits for confinement buildings were drained into an outside storage pit, but there wasn’t enough storage in the outside pit and it overflowed. McCarthy says D-N-R fisheries counted some eight-thousand dead fish.He says it was a pretty significant fish kill that went for a couple of miles. He says they haven’t determined the dollar cost of the dead fish. He says they were “non-game” fish, suckers and darters. McCarthy says Deering has taken action to keep the manure contained. He says Deering is going to pump down the outside pit to gain more storage. He says the D-N-R will write Deering a violation letter for “prohibitive discharge into a stream.” McCarthy says officials in Des Moines will determine if any fines or charges will be levied against Deering. McCarthy says this is the time of year when operators need to keep a close eye on manure storage areas. He says the storage is getting short, and he says streams are warm and have less oxygen, so any amount of manure can cause a lot of damage. McCarthy says tests downstream show the manure had dissipated enough to not cause any more problems on Roberts Creek.