MANDAN, N.D. -- Mandan might be ending a 30-year ordeal with a railroad diesel spill after the recovery of nearly 1 million gallons of fuel.
A state health official last week said the city can plan the shutdown of wells used to clean up the Burlington Northern (now BNSF Railway) spill.
Since consultant Leggette, Brashears and Graham Inc. began handling the spill in 2006, nearly 1 million gallons of diesel fuel have been recovered, according to a state Health Department report.
The spill area once reached from the BNSF Railway yard to the Law Enforcement Center and a four-block area from First to Fourth streets. The depth of the spill measured nearly 3 feet above the groundwater and contaminated the soil
City Administrator Jim Neubauer said the Mandan Remediation and Trust will decide Nov. 5 on an action plan to decommission what remains of the 285 extraction wells in the downtown area. Neubauer also is a member of the trust agency, which decides how to spend a $25 million settlement received from the BNSF Railway in 2004 for causing the spill.
About $7.4 million of that fund remains.
Much of the fund has been used to pay the consultant for its well system and to gauge contamination levels, to buyout properties for cleanup work and for entities affected by the spill. The Morton County Commission received $240,000 from the settlement fund to make the ground floor of the Law Enforcement Center usable.
Employees using the ground floor of the center had complained of illness in the 1990s and the ground level was not a work space until the 2010 repairs.
City Commissioner Dennis Rohr, then Mandan Police chief, said he noticed problems when “I felt something bubbling up from the carpet.” Soon after that, staff was removed from the lower floor, he said. The county installed a diesel collector and groundwater separator three years ago, after it reached a cost-share agreement with the Mandan Remediation and Trust.
Another $2.5 million has been placed into a supplemental trust to improve green space in Mandan, Neubauer said.
Seventy-five percent of the 285-unit well system used to recover the contamination could be shut down through the MRT plan in the near future, he said. A timeline for the plan has to be decided by the MRT, he said..
“We’re looking at one to three years before the system can be completely shut down,” said Scott Radig, the waste management director for the state Health Department. “We’re waiting for comments to shut down parts of the remediation system.”
Neubauer said evidence of the contamination first appeared in 1985 when the Law Enforcement Center was being built. LBG’s 2006 assessment showed diesel product depths of nearly 3 feet above groundwater.
“In August of 2013, there was only one well that has over 1 foot of product floating on the water table. There’s a few others with small amounts of free product left,” Radig said. “The majority of the downtown area is completely free of any measurable amounts of fuel floating on the water table.”
“Since this remediation went into place, there has been 353,962 gallons of hydrocarbon products recovered and 417,000 pounds of methane have been recovered,” Radig said. “Before this project, Burlington Northern recovered 600,000 gallons of fuel. We are approaching 1 million gallons of fuel that have been recovered from downtown Mandan.”
Neubauer said the wells on the Collins Avenue and Main Street already have been plugged.
He said the recovery program was divided into three different zones. Each can be controlled independently of the other wells. It was designed so that portions of the wells could be shut down without affecting the other cleanup wells.
“Areas we are looking at shutting down is an area by the depot and this entire area north of First Street,” Radig said.
Radig said the state Health Department has set closure goals for the wells’ shutdown:
* The primary goal is to have a fuel thickness of less than 0.02 feet for at least half a year:
* The minimum requirement for the shutdown is to have less than 0.1 feet of product for half a year.
* The water table elevation must be 1,629 feet or less. The water table is critical because the city is in a wet phase and it’s unknown when the water table will go down.
Wells along the the rail yard boundary will be kept in place for monitoring.
Radig said future costs of the well system will decrease as portions of the system are shut down.
“There will be costs with the abandonment work, plugging the wells and taking down the (well building)” he said.
Neubauer said that the cleanup wells did not cause the downtown economy to slow down, but awareness of the diesel spill contamination did. It seemed to halt the buying or selling of commercial property there. Lenders showed no interest in helping buyers obtain loans because state law could make both the buyers and lenders potentially liable for the contamination cleanup.
“It killed property sales downtown,” Neubauer said.
Because commercial properties could not be sold, many of the buildings deteriorated without needed repairs. Neubauer said the popularity of malls was a universal competitor for street merchants everywhere and took away Mandan downtown customers as well.
He said the remediation trust along with city officials, lenders and merchants worked with their attorneys to draft 2005 legislation to waive lender and buyer liability for the cleanup if a remediation plan was already in place. The legislation passed and the well collection system was installed.
“After the settlement was reached, we could buy property and we had an active remediation plan,” Neubauer said.
He said many residents found it demoralizing to see buildings that stood for decades come down to install the well system, but most of the properties were in poor shape. The city purchased 12 buildings and tore down 10 of them.
“They looked nice on the outside, but many had their roofs leaking. They were in tough shape,” Neubauer said.
He said properties were bought according to how they would benefit the diesel collection system, if there were willing buyers at reasonable price and if it made sense to buy the property instead of routing piping around the buildings.
Neubauer said the remediation plan’s intent was always to renew the buyout properties’ commercial value after the collection system was discontinued. He said Library Square I, Library Square II, Main Street and Collins Avenue and the former furniture store site where the commercial property/apartment complex are located are examples of that.
Neubauer said the city is now in the “soil scrub phase” in removing the small amount of product that remains in the soil. Air is being ventilated into the soil to help bacteria absorb it.
“I am thankful to see how this working,” said City Commissioner Sandra Tibke. “It seemed it has taken a long time to clean up and it has taken a long time to clean up. Here we are in the discussion of shutting down these systems.” She thanked the health department for its help.
“It has had very little negative impact to our downtown,” said Mayor Arlyn Van Beek said of the cleanup. “It’s done a lot of good for our downtown.”
After the shutdown is completed, Neubauer said the remediation trust may decide to keep some of the settlement funds to protect against future contamination risk or add to the supplemental trust for park improvements.