TONY REED, The Fort Bragg Advocate News, February 27, 2008
The Fort Bragg City Council, also convened as the Redevelopment Agency Monday, heard and commented on some interesting information regarding the possibility of burying contaminated soil on the Georgia Pacific mill site.
Few were present at the regular Town Hall meeting, to hear City environmental consultant Glenn Young, principal geologist of Fugro West Environmental describe exactly how much contaminated soil would have to be cleaned up.
City Manager Linda Ruffing introduced the topic, saying the item was brought forth to be an early opportunity for discussion of how to handle contaminated soils from the coastal trail and parkland areas. The coastal trail is a 100-foot wide strip running along the entire coastline of the G-P mill site. She said one alternative is to consolidate the materials onsite and “cap” them as a long-term means of cleanup.
She said the remedial action plan, a document that dictates how the site will be cleaned, will be released in mid-March, but a preliminary draft is available for review on the department’s Envirostore Website.
At a meeting with the council in November, Department of Toxic Substances Control (DTSC) officials said they would favor capping contaminated soils onsite.
“Once the Remedial Action Plan is formally released for public review by DTSC, there is a 30-day public review period,” Ruffing said. “It’s during that period that the [Redevelopment] Agency will be providing its comment, as well, as to the acceptability of the proposed remedial actions.”
Young opened by discussing the process and contaminants found on the coastal trail area, referred to as Operable Unit A (OU-A).
He said a screening process was used to determine the amount of risk contaminants pose, to humans, animals, plants and personnel involved in future trail construction.
He said based on the information, seven areas were determined to need cleanup. Young said lead, polychlorinated byphenyls (PCBs) and dioxins were found on the site. He said any cleanup operations would be done in a way to protect humans, plants and animals.
Showing a map of the location, Young noted that the consolidation area is located just west of the mill’s nursery. The nursery area is across Highway 1 from Safeway.
Young explained a state requirement that several cleanup alternatives must be examined. While a “no action” alternative is not feasible for the site, Young said it had to be evaluated anyway. Also examined were deed restrictions that would limit certain areas’ future uses so as not to disturb buried contaminants, and the concept of taking the materials offsite.
“The recommended alternative is a combination of removing some of the material, as well as consolidation,” he said. “The materials that would be removed would be those impacted with lead and with PCBs. The soils impacted by dioxin would be those consolidated onsite.”
Where and How Much
Lead was located in an area at the mill’s north end, which was formerly used as a scrapyard and onshore dump, referred to as Glass Beach 2. The area contained lead concentrations of up to 790 parts per million, over a 30 by 60 foot area, ranging to 2 feet in depth. Young said the affected soils totaled 140 cubic yards and would equal six to 10 truckloads to be hauled at a cost of about $43,000.
“From a practical standpoint, that would be a fairly straightforward and easy remedy for that material and that is the preferred alternative,” he said.
Polychlorinated byphenyls (PCBs) were found in a scrapyard site, and measured a magnitude of 27.9 parts per million, over an area of 150 by 200 feet, ranging in depth up to 1 foot and amounting to 990 cubic yards. About 55 to 65 truckloads of contaminated soil would be taken to a landfill at a cost of about $220,000.
Dioxins were found in several locations, ranging from a foot below the surface to 5 feet. He said dioxin levels range from 130 parts per trillion in one area to 316 parts per trillion in another. All affected areas contain an estimated 13,000 cubic yards of contaminated soil, he said.
Young explained that consolidating the soils in one location for capping would cost G-P about $1.5 million, while trucking it offsite would cost about $2.5 million.
Council member Dan Gjerde later argued that while the cost savings to G-P was considered, no information was provided about the better alternative for the citizens of Fort Bragg.
Young noted that factors such as underground water tables have to be considered when burying contaminated soils. In the proposed cap area, Young said the depth to a water table is about 12 feet, while the capping would require digging 6 feet. He said the excavated pit would also have a plastic liner on the bottom, with a fabric layer on top. He said that above the buried materials would be marker beds, a layer that would alert anyone who digs there that they are excavating into buried hazardous materials. A foot of clean soil and a cover of vegetation are typical. Young said since the future use of the area has not been determined, a vegetative cover makes the most sense to prevent erosion while being aesthetically pleasing.
Young noted that for any action a host of permits will be needed, along with approved dust control, trucking and cleanup plans.
He said the proposed capping area comes to nine acres, when only one and a half should be needed to bury materials from OU-A. He said samples would be taken during excavation of contaminated areas, and if the affected area is greater than anticipated, those soils would also be consolidated into the cap area.
“Having an area larger than what’s initially planned on is certainly advantageous, he said. “I don’t believe any of us envision that we would need the whole nine acres.”
Areas where dioxins are removed would be refilled with clean soil from surrounding areas, he said.
He said consolidation areas would have to be maintained and monitored, and a party responsible for that work would have to be determined. Finally, the Redevelopment Agency would need to approve the actions as part of the Polanco Act.
Young noted that deed restrictions would only be needed in certain areas, and that the coastal trail would be restricted from any use but recreational.
With the 30-day comment period on the draft remedial action plan starting in March, a final plan could be approved in April. The Department of Toxic Substances Control may be able to extend the comment period if necessary.
Young said implementation of the cleanup could take four to five months, starting in June. He said offsite hauling could take up to two weeks while onsite capping could take as long as three months.
“Consolidation is a fairly common approach on sites,” said Young. “Putting it under a parking lot is also sometimes the selected surface condition. Sometimes it’s a vegetative cover, sometimes it’s a golf course or a basketball court.”
When asked, Young said some buildings could be placed over cap areas, but utilities and foundation work make it difficult not to disturb capped soils.
“You could do just open space, and that would be fine as well,” he said. “Whatever is identified, you would need operation and maintenance to make sure it’s maintained in that condition and that its integrity is intact.”
Bridgette Deshields, an associate with Arcadis BBL, G-P’s environmental consulting firm, said the nine-acre area was identified as the only area on the mill site where consolidation and capping would take place without encountering ground water.
“Closer to the bluff, we have deeper groundwater, but we then have the issue that it’s closer to the bluff,” she said.
She noted that an acre and a half consolidation area could be placed anywhere in the nine-acre area. The proposed area is currently owned by G-P and not a part of the coastal trail acquisition.
In response to a question from Mayor Doug Hammerstrom, she said the area was not chosen because of an estimate that nine acres would be needed to consolidate contaminated soils.
While some confusion was cleared up later about the possible use of the nine-acre area, more questions arose, including the possibility that it might become a dumping area for waste found on the rest of the site.
In response to a question posed by Council member Dave Turner about the durability of the plastic liner, Young said that it could last longer than 50 years if not exposed to sunlight, water and oxygen.
Compacted clay and other low-permeable liners can be used, said Young, but take a foot of depth to install, rather than the thickness of a plastic sheet.
Council member Meg Courtney asked about contaminants yet to be excavated on other areas of the mill site, and whether it’s expected that those would be added to other consolidated soils buried in the nine-acre area.
Young agreed that more investigation will occur, but said no one from DTSC or G-P has proposed to designate the entire nine-acre area for a future consolidation site. However, he said he would expect that will be discussed, depending on the volume of contaminated soils yet to be excavated on the rest of the site.
“It’s too soon to know what the volumes would be in those other areas anyway,” he said. “At this point, it is geared just for OU-A.”
Gjerde said that if a nine-acre area is accepted for that use by the department and the city council, and determined to be the only place capping can occur, it would become a workable option as cleanup continues.
“By default, we have been told tonight, that this is going to be the dumping ground for the entire mill site,” said Gjerde. “So then, do we want to give up nine acres, over time, as essentially, an off-limits dump site?”
Comparing the area to the eight-acre mill pond, Gjerde asked what could cover an area that large.
Saying it probably wouldn’t be suitable for a dog park, or a nine-acre parking lot, Gjerde said he is skeptical of the direction the council and DTSC are going in regard to dealing with dioxin-contaminated soil.
“I think at this point, why don’t we just say, haul it away,'” he said. “You don’t have to be a mind-reader to see what G-P is going to propose. If, in a relatively limited area of the mill site, they are going to save a million dollars by burying it on site, you can bet they’ll want to save multi-millions by burying it all onsite.”
Local geologist Skip Wollenberg suggested that the consolidation area be created in such a way that soils could be re-excavated and moved if future monitoring shows contaminant leakage.
Saying the area was the highest land onsite, Wollenberg said it makes good geotechnical and engineering sense to designate the nine acres for consolidation.
“I really endorse the concept of having room set aside for sources outside of OU-A,” he said. “Whether it’s nine acres or whether it’s something smaller, it’s very prudent to have that.”
Back to City Council
Turner asked who would be responsible for maintaining capped areas. Young replied, saying a deed restriction would be placed on the future owner of that land, who would have to negotiate responsibility for it prior to selling it.
“Until it’s sold, it would be G-P’s [responsibility],” said Young.
Turner said an advantage to having the materials on site is one of access, so that cleanup methods, such as mushroom remediation, can be tried.
“One of the challenges of the specific plan process is finding a really great use for this capped area,” said City Manager Ruffing.
The meeting closed after more discussion about Coastal Conservancy deadlines and transporting impacted soils, with a comment by Council member Courtney, who said, “Originally, my preference was to have it stay here, because of my belief that this is one world and we are just taking it and putting it somewhere else, but this is not to mention the pollution [created by 600 to 700 truckloads leaving the area].”