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DEC has second proposed rules draft out Initial version met legislative criticism; cover minimum cleanup standards for chemicals in soil, groundwater at contaminated sites TIM BRADNER For Petroleum News
Alaska’s Department of Environmental Conservation has issued a second draft of proposed new rules on minimum cleanup standards for chemicals in soil and groundwater at contaminated sites.
The agency plans a workshop on the new regulations with stakeholders on June 8 in Anchorage, according to Kristin Ryan, director of DEC’s Division of Spill Prevention and Response.
The workshop will be at the BP Energy Center in midtown Anchorage, and will be from 2:30 p.m. to 4:30 p.m.
The second draft follows an initial version of the regulations that met criticism from state legislators in a hearing earlier this year before the Legislature’s Administrative Regulation Review Committee.
The revisions, which mostly tightened the standards, were based on new scientific evidence published by the U.S. Environmental Protection Agency, Ryan said.
Tighter standard for PFOS For one contaminant the latest draft includes standards that are tighter than those proposed last fall, said Sally Schlichting, in DEC’s Contaminated Sites Program.
“One compound, PFOS (perfluorooctanic acid) was made more stringent since the first version of the regulations,” she said. That was done because the only finalized scientific research available was from a published 1998 U.S. Environmental Protection Agency paper, she said.
The revisions overall are DEC’s first major changes of the chemical cleanup standards since 2008. “A lot of new science has been done since 2008 and our regulations have not been kept up to date,” she said.
One major factor in the tightened standards is that DEC now considers that children as well as adults would be “receptors” of chemical pollution through exposure to groundwater contamination.
In current rules adults are considered the primary receptors.
In the real world children are as exposed as adults to pollution, Ryan said.
“Children absorb pollution much more quickly than adults,” so the minimum standard for chemical contamination must be tighter, she said.
Soil-to-groundwater cleanup levels tighter The soil-to-groundwater cleanup levels are tighter in 134 of the chemical compounds because those are the levels in soil that can remain without causing the new, more stringent standards in groundwater, Schlichting said.
Ryan acknowledged the complaints over the tighter standards, however. “Lowering the minimum threshold from 10 parts-per-million to 10 parts-per-billion, for example, means you have to dig up a lot more dirt,” and spend more money, she said.
In the new soil cleanup standards 134 chemicals would have more stringent standards while 26 would be less stringent. The level for one compound on the list, 1,2-Dibromoethane, is unchanged.
The standards can also vary depending on the location, whether in the Arctic permafrost zone, Interior and Southcentral Alaska, or in Southeast Alaska where there is heavy rain.
For groundwater minimums, 132 of 182 chemicals are being made more stringent and 30 less stringent, according to information published by DEC. Two are unchanged: PCBs and lead. Eighteen chemicals were also added to DEC’s list, including methanol. One, Carbazole, was taken off.
Arsenic a special concern Arsenic contamination, associated with historic gold mining, is a special concern because those contaminated sites are widespread across Alaska. About 200 locations have been identified where arsenic is a concern, Ryan said.
Some critics at the legislative hearing argued that the background levels for natural arsenic and some other chemicals in soils is high in many locations, which makes the measurements of thresholds more complex. Arsenic resulting from human activities would have to be differentiated from arsenic put in place by nature, for example.
In some cases, critics argued, the new cleanup standards are below the natural background level of the chemical in the soil.
Ryan said DEC has no intention of forcing property owners to clean up naturally occurring pollution, however. “We are only concerned with arsenic that is put there by someone,” she said. “Also, we will not assume contamination is human-caused unless there is evidence of that,” Ryan said.
An example of a complicated situation with arsenic is at Latouche Island in Prince William Sound, the location of a historic gold mine. “About 100 subdivided lots owned mainly for recreation are on old tailings with high levels of arsenic and cadmium,” she said.
Previous ownership an issue However, one of the mining companies previously involved in ownership there is Rio Tinto, a major company.
Ryan said most large mining companies are cooperative even if the chain of ownership doesn’t precisely identify the as the party actually responsible. Often the identity of the party originally causing the pollution is unknown.
Sometimes companies do fight, however. DEC is in an extended dispute with Koch Industries, for example, over contamination of groundwater at the site of the Flint Hills refinery at North Pole, near Fairbanks.
The refinery is closed but pollution from the plant has contaminated local groundwater including water used for drinking.
Flint Hills contends DEC’s minimum threshold for cleanup is too tight and also that a previous owner of the refinery, Williams, should shoulder some of the costs as well as the state.
Ryan also said physical removal of contamination need not happen as long as it is contained and a monitoring program can verify that.
Danger to environment Meanwhile, many contaminants are a danger to the environment as well as humans, said Schlichting.
“Many of these can persist in the environment for a long time, like tributyltin (used in boat paint), DDT and other herbicides/pesticides, copper, and polycyclic aromatic hydrocarbons (PAHs) like benzo(a)pyrene,” Schlichting said. “These are harmful to marine life, and avian species.”
Other compounds, like mercury PFOS (perflourooctane sulphonic acid) and PFOA (perflourooctanic acid) can bioaccumulate in fish and wildlife. When humans consume these species for food they are exposed to those two compounds, she said.
So far the accumulations in fish and wildlife of these contaminants are coming from other sources, such as atmospheric pollution, Schlichting said. None is linked to contaminated sites.
However, it is possible that if there is leakage from a contaminated site there can be localized bioaccumulation of the chemicals in fish and wildlife, she said.
Ryan said while the contaminated chemical sites are a concern, DEC is actually more worried about contamination from petroleum spills which is widespread, mostly around bulk fuel storage tanks.
Eighty percent of the contaminated sites in Alaska are due to petroleum, Ryan said. However, some of these sites can have chemical contamination as well.
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