Carrie Blackmore Smith, and Jennifer Edwards Baker

Cincinnati

Crude oil discovered spilling from an underground pipeline into a stream and marshy pond in a nature preserve in Colerain Township on Monday evening will be "tricky" to clean up, U.S. Environmental Protection Agency officials said Tuesday. They estimated the volume of the spill to be around 10,000 gallons.

The spill, relatively small compared to others reported in recent years -- both in the region and other parts of the country – didn't injure anyone and was contained to the spill site by Tuesday afternoon, according to state and federal Environmental Protection Agency officials.

The EPA and local officials are holding a press conference at 10 a.m. today to update the public on any developments made overnight.

The cost for cleanup could be steep.

Crews will need to "build a road" to get heavy machinery into the spill area, a part of the Oak Glen Nature Preserve, to vacuum up the oil and dig up contaminated soil. With rain in the forecast, a containment structure will be built to capture oil and keep it from reaching the Great Miami River, just some 500 feet away, or spreading out on the site, said Heather Lauer, a spokeswoman for the Ohio EPA.

Right now, the process is expected to take at least a week.

The incident is at least the third time in the last decade that oil has leaked in the Greater Cincinnati and Northern Kentucky region from this pipe, owned by Sunoco Logistics and operated by Mid-Valley Pipeline Co., both subsidiaries of Sunoco. It is the 40th incident since 2006 along the pipeline, which stretches 1,100 miles from Texas to Michigan, according to the U.S. Department of Transportation's Pipeline and Hazardous Materials Safety Administration.

The cause of this most recent leak remains under investigation by the U.S. EPA.

The pipe was laid in the mid-1950s, well before the land was identified as one of four "conservation areas" owned and operated by Great Parks of Hamilton County, which has pieced together the preserve over recent decades. Great Parks' website describes the 364-acre park as "rugged hills with a rich diversity of native trees, shrubs and wildflowers."

A spill "could definitely have been worse later in the spring when all of our wildlife is coming out of hibernation," said Bob Mason, stewardship manager with Great Parks. "Plus, now the ground is still hard, still somewhat frozen, so that helps."

After springing from the earth, the oil ran about half of a mile down a stream into a marshy pond, just west of East Miami River Road.

Even if some of the "sweet crude" – a lighter, thinner oil than sour crude – makes its way into the nearby Great Miam, regional drinking water will not be threatened because water treatment plants are located upstream on the Great Miami in Fairfield and upstream on the Ohio River, said Greater Cincinnati Water Works spokeswoman Michele Ralston.

Communities downstream, including Lawrenceburg and Louisville, also have nothing to worry about at this time, said Jerry Schulte, a manager involved in water protection and emergency response for the Ohio River Valley Water Sanitation Commission.

Federal records show inspectors last checked the pipeline in 2011; the records do not include any current or ongoing inspections.

A system-wide inspection of the 1,119-mile-long pipeline in 2009 resulted in the company paying a $48,700 fine in 2012 for failing to address corrosion problems in the pipeline at the Oregon refinery for three years.

In addition, the operator was issued three warnings stemming from the 2009 inspection. One of them was for failing to inspect the pipeline crossing under the Ohio River between Addyston and Hebron for more than five years. Pipelines that go beneath bodies of navigable water must get additional scrutiny under federal regulation. The pipeline was not checked by running an inspection device through it from May 2004 until August 2009.

In addition, the federal records show Mid-Valley received a warning in 2006 for not having pipeline route markers along a pipeline section in Hebron where people could reach it. And it was fined $35,000 in 2006 for a 2002 inspection where the operator was cited for failing to run a proper program of continuing education reminding people that the pipeline runs through parts of Kentucky and Ohio. The operator had sent calendars to residents living near the pipeline, but didn't include any public agencies or excavation services in the program.

From 2006-13, leaks and spills from the pipeline caused $7.5 million in property damage, $1.3 million done in 2008 in Burlington. In the previous 39 accidents, 88 percent of the oil spilled was recovered.

The new leak was discovered by Gary M. Broughton, who was driving down East Miami River Road about 8 p.m. Monday and smelled a "fuel, oily smell." He got out of his vehicle and saw oil spread across the marshy pond.

"It's absolutely terrible," Broughton told the 911 dispatcher. "It made me sick when I saw it."

Nearby residents later told authorities they had smelled a fuel-like odor but neither the Hamilton County Dispatch Center nor the Southwest Ohio Air Quality Agency received reports of the smell prior to Broughton's call, officials said.

Ron and Sharon Worsley live on a 55-acre farm next to the nature preserve.

Sharon Worsley said she has smelled the oil since the end of last week, but thought it was from her husband pouring diesel into his tractor. The smell hasn't bothered her much, she said.

Her husband said he thought the smell seemed stronger Tuesday morning.

The couple said they don't have any concerns about the pipeline leak.

"I wouldn't want to be swimming in it," Ron Worsley said, "but these things happen."

Details about the pipeline

The pipeline starts in Longview, Texas (about 125 miles east of Dallas), and ends in Samaria, Mich., about 12 miles north of Toledo and about 53 miles southwest of Detroit. Its size varies depending on the location from 8 inches in diameter to 22 inches in diameter. It is only used to carry crude oil, with destinations in Ohio that include a Husky refinery in Lima and a BP refinery in Oregon (suburban Toledo).

Previous leaks

October 2008: Burlington, Ky.



Construction crews struck the line, sending 115,000 gallons of crude oil gushing. Eighty homes in the area were evacuated and some of the oil ended up in the sanitary sewer system and in Gunpowder Creek. After that spill, Sunoco Logistics officials said the line carried about 238,000 barrels per day to refineries in Ohio.

January 2005: Carrollton, Ky.

The same pipeline ruptured, sending 260,000 gallons of oil into the Kentucky River. The slick fouled a large section of the Kentucky River, killed some marine life and forced Louisville officials to take precautions with drinking water from the Ohio River.

Mark Wert, Adam Kiefaber and Brenna Kelly contributed to this report.