BLR: Un-green

Sand Creek: Suncor groundwater contamination prompts additional measures from the CDPHE

Water mixed with an unidentified liquid leaking into
Sand Creek north of downtown Denver, CO,
Wednesday November 30, 2011

December 31, 2011

From The Denver Post (Bruce Finley):

State health officials ordered additional measures on Friday afternoon to minimize environmental harm and prevent people from ingesting contaminated water. Those measures include posting of “Drinking Water Warning” signs at the refinery. Benzene levels in Sand Creek are fluctuating but reached 670 parts per billion on Dec. 22 — 134 times higher than the 5 ppb national drinking water standard. An anonymous tip from a Suncor employee Thursday alerted state health officials to contamination in tap water on the refinery property.

An unidentified liquid floats atop Sand Creek north of downtown Denver, CO,
Wednesday November 30, 2011.

Denver Water authorities, notified around noon Friday by the Colorado Department of Public Health and Environment, immediately began testing the city’s water system for benzene, which can cause anemia, blood problems and cancer. Denver Water reviewed data from recent tests for benzene and found no elevated levels, utility spokeswoman Stacy Chesney said.

Workers contracted by Suncor are using vacuum trucks and 
absorbent material to suck up water mixed with 
an unidentified liquid leaking into Sand Creek north of downtown Denver, CO, 
Wednesday November 30, 2011.

Over the past several weeks, however, monitoring along the creek found that petroleum is entering the creek directly without surfacing, said Warren Smith, a state health spokesman. “The dissolved material is coming in through the bottom of the channel, not through a seep on the bank,” Smith said. The state order requires installation of “an air sparging system” in Sand Creek — similar to a fish tank aerator — by Jan. 6. This is meant to help benzene and other contaminants in the creek evaporate into the air, instead of flowing into the South Platte.

The order also requires Suncor to install a soil vapor extraction system and dig a second “interceptor trench” by Jan. 31 to try to trap hydrocarbons floating in groundwater before they enter Sand Creek. Suncor has tried to make the first trench work better and is providing bottled water to workers, Smith said. Company contractors also have tested 50 of 57 buildings at the adjacent Metro Wastewater Treatment Plant for toxic vapors, finding problems in two. Toxic vapor removal systems have been installed along with a filter and a ventilator on other buildings, he said.

Sand Creek: Suncor crews are constructing a trench to intercept the benzene laden flows

December 3, 2011

Here’s a report from Bruce Finley writing for The Denver Post. He, and the Postin general, have done a very comprehensive job of covering the spill so far. Click through for the whole article and video of the cleanup. Here’s an excerpt:

The latest data show the concentration of cancer-causing benzene at levels 69 times higher than the national drinking-water standards at the point where Sand Creek enters the South Platte River.
Once the trench is completed, U.S. Environmental Protection Agency emergency-response coordinators said, the EPA will scale back the federal role and rely on Colorado health officials to oversee a long-term cleanup…
About 100 feet of the trench is complete. Suncor refining vice president John Gallagher said he expects the work to be completed next week.
Kimbel said state health and Suncor officials now “have got to figure out what the source is, how it is getting there and what they have to do to address it.”[...]
EPA contractors have begun testing for benzene, ethylbenzene, toluene and xylene and on Friday released results from Tuesday and Wednesday. Tests of samples drawn from Sand Creek on Wednesday show benzene concentrations of 1,970 parts per billion at the point where the liquid enters the creek, and 348 ppb at the point where the creek flows into the South Platte. Tests at a location across the main channel of the South Platte showed a concentration of 108 ppb.

More coverage from Bruce Finley writing for The Denver Post. From the article:

No public health warnings have been issued. Kimbel said today that people who stay on the bike path along the Sand Creek Regional Greenway should be safe. A well-delineated “hot zone” has been set up around the area where clean-up crews are working to stop the flow of contaminants into the creek.
Battling snow, freezing temperatures and mud, they have been pushing to catch and contain the liquid as it seeps from the shoreline, preventing further contamination of the creek and South Platte River. Workers also have used heavy machinery to buttress absorbent booms strung across the creek. Suncor is taking “all the action that we believe is necessary,” said John Gallagher, company vice president for refining.
But there’s no easy end in sight to the situation in this industrial zone — a situation that over the past year took a turn for the worse with new hydrocarbon and dissolved petroleum compounds moving in groundwater and surfacing as vapors in nearby Metro Wastewater buildings…
Even before Suncor bought the refinery from Conoco in 2003, pollution now migrating to the wastewater plant — where one building is partly closed and workers have been forced to wear respirators — was documented. Oil refineries have existed at the Suncor property under various owners since the 1930s. About 300 groundwater wells have been drilled around the property and at the wastewater plant to track contamination — 25 of them capable of recovering liquids. Much of what regulators have been monitoring is described as “legacy contamination,” consisting of “mostly tarry asphaltic pockets of petroleum products underground that have not been moving,” said Warren Smith, a state health department spokesman.

More Sand Creek spill coverage here. More oil and gas coverage here and here.