(Milford)– Officials with the Iowa Department of Natural Resources say a crack in a pipeline is what caused some petroleum to leak in a stream south of Milford.
The leak was reported after a farmer who was watering trees Thursday afternoon discovered a sheen and a strong odor of petroleum on an unnamed tributary of the Little Sioux River.
DNR and NuStar Energy officials traced the diesel fuel to a tile line draining a field.
Workers with NuStar Energy worked late into the night Thursday skimming diesel off the creek and a pond. They also excavated parts of the tile line and found a small section of pipe with a corroded area and a crack in it. NuStar officials said the crack took a long time to develop and think the pipe may have been nicked last fall when the drainage tile was put in.
DNR Environmental Specialist Jennifer Christian says it’s a classic example as to why it’s important to call Iowa One Call before doing any digging.
Christian says clean-up of the site will take awhile as about 200 yards of tile line will need to be excavated and replaced. Contaminated soil will be hauled to a landfill. She says the remaining tile line will also need to be flushed, in addition to cleaning up two miles of stream and a farm pond.
She says the DNR will continue to monitor the spill and its clean up and that appropriate enforcement action will be considered.
While a few dead fish were found in the pond, Christian says the fuel leak probably was not the cause. She says it was probably related instead to recent high temperatures or possibly a drop in oxygen levels.
