The oil spill that put some 630 gallons of oil on the ground in northern Forest County and eventually into two high-quality trout streams has been contained.

The spill took place over the weekend at a five-tank battery near Mayburg that is operated by Duhring Resources of Sheffield. Oil made its way to Hastings Run and subsequently into Tionesta Creek, according to Pennsylvania Department of Environmental Protection (DEP) reports.

DEP Water Quality Specialist Supervisor Tony Oprendek said on Thursday that a harbor boom was installed by Duhring on Wednesday at the Nebraska Bridge.

The boom was intended to prevent the spread of oil farther downstream. The bridge is 21 miles downstream of the spill, according to DEP. No sign of oil beyond the bridge was found by agents of DEP and the U.S. Army Corps of Engineers, and the boom was removed on Thursday.

"DEP and the Army Corps decided it wasn't necessary," Oprendek said.

Oprendek credits Duhring Resources with minimizing the impacts of the spill.

"Duhring did a pretty bang-up job with the clean-up," he said. "It is contained."

"Duhring has had eight-man crews out there all day Monday, Tuesday and Wednesday," he said. "Yesterday Duhring had guys kayaking up and down the Tionesta. They found nothing in the way of oil on the Tionesta."

Similarly, DEP and Corps of Engineers agents "didn't see any evidence of oil behind that boom."

A sheen of oil was reported at several points on the Tionesta Creek on Monday. A "little bit of a sheen" was seen on the creek near Mayburg on Wednesday, according to Oprendek.

"Sheen is just a result of a small amount of oil," Oprendek said. Searchers from DEP, the Corps of Engineers and Duhring found "no accumulated pools of oil in any pools or eddies" on the creek.

There is still evidence of the spill in and around Hastings Run, according to Oprendek.

Duhring employees are working on further clean-up.

"They are still up there at the site of the discharge point, cleaning up around the tank battery and in and around Hastings Run," Oprendek said.

No dead fish have been reported by DEP in regard to the spill.

"It was very minimal impact," Oprendek said.

According to Tionesta-based state police, the spill occurred between 3:30 p.m. Friday and 10:30 a.m. Sunday.

Police said on Monday that a "temporary repair device was installed and failed," but "it is unknown if the failure was caused by an act of nature or by an unknown actor."

No updated information was available from state police on Thursday.