Environment

Record rainfall causes major sewage spill in Greensboro; equivalent to gallons of maple syrup that Maine produces in a year

Click on a yellow icon to see the address and amount of sewage spilled.

The City of Greensboro discharged 675,450 gallons of untreated sewage into parts of Buffalo Creek, a tributary of the Cape Fear River, after record rainfall last week overwhelmed wastewater treatment systems.

On Feb. 6, Greensboro received 3.69 inches of rain, according to the National Weather Service. The previous record of 2 inches was set in 1955.

As required by state law, the city issued press releases listing the amounts and addresses of the spills.  “The area was cleaned and lime was spread on ground surface areas,” a city spokesperson wrote.

Because of the volume of water, the pollution was likely diluted in the creek before it reached towns and cities downstream.

A spokeswoman for the NC Department of Environmental Quality said the agency is investigating several wastewater overflows that occurred because of the storm. “Once the five-day reports come in for all of these spills, our staff will make a determination about whether enforcement actions are warranted,” she said.

How much is 675,000 gallons?

  • The State of Maine produced 675,000 gallons of maple syrup in 2016.
  • An Olympic-size swimming pool holds about 660,000 gallons of water.
  • The amount is equal to 21,774 barrels of beer.
  • It would take 1,054 hours for an Airbus ACJ319 to burn through 675,000 gallons of fuel.
Environment

Where are the floods? State mapping and alert network will tell you.

Waters are rising along the Neuse River in Smithfield, with peak flooding of 20.3 feet forecast to occur at 1 a.m. tomorrow, according to the NC Flood Inundation Mapping and Alert Network. Flood stage is 15 feet.

The map provides real-time flooding conditions along the state’s rivers, as well as trends. The Haw River at Bynum is at a major flood stage of 17.3 feet, but water levels are expected to drop by tomorrow afternoon. The South Catawba River at Lowell crested at 16.2 feet — major flood stage — around noon today, but the river is expected to subside throughout the evening.

The information is critical for people living in low-lying areas, especially near rivers and in flood plains.

The US Geological Survey also has up-to-date information on flood conditions, including rainfall amounts. Swift Creek near Apex received more than 4 inches of rain over the last two days.

Environment

Reverse osmosis removes PFAS better than filtration pitchers — for a price

Drinking water filters in pitchers and refrigerators reduce levels of perfluorinated compounds — PFAS — less effectively than reverse osmosis and two-stage filtration systems, according to a new study conducted by Duke University and NC State University scientists.

Teams lead by professors Heather Stapleton and Detlef Knappe compared the levels of contaminants in raw water and filtered water from 76 point-of-use filters, such as pitchers and in-fridge models. The scientists also tested water from another 13 under-sink reverse osmosis or whole-house systems. The homes were located in central and southeastern North Carolina.

The reverse osmosis and dual-stage systems were “very effective,” Stapleton told reporters today, “and removed at least 90%” of PFAS the scientists tested for. The pitcher, countertop, faucet-mounted and refrigerator filters, which use granulated activated carbon to remove the contaminants, decreased levels by only 50%.

“It’s unclear why,” Stapleton said. The filtration systems are proprietary, and the companies don’t have to release that internal information.

“The whole-house systems were also widely variable,” Stapleton said, “and in some cases actually increased PFAS levels in the water.”

Duke University scientist and professor Heather Stapleton. (Photo: Duke University)

The PFAS-removal efficiency of whole-house systems using activated carbon filters varied widely. In four of the six systems tested, PFSA and PFCA levels actually increased after filtration. Because the systems remove disinfectants used in city water treatment, they can also leave home pipes susceptible to bacterial growth.

“The under-sink reverse osmosis filter is the most efficient system for removing both the PFAS contaminants prevalent in central North Carolina, and the PFEAs, including GenX, found in Wilmington,” said Knappe of NC State. “Unfortunately, they also cost much more than other point-of-use filters. This raises concerns about environmental justice, since PFAS pollution affects more households that struggle financially than those that do not struggle.”

A 10-cup Brita pitcher with two filters runs about $30; replacement filters cost roughly $6 each. But the price of under-sink reverse osmosis systems ranges from $300 to $500, plus installation. Replacement filters run from $80 to $100.

In general, the frequency of filter replacements did not affect the removal or reduction levels. However, Stapleton said that at some homes, the filters did reach “the saturation point.” And in some of those cases, the filtered water contained higher levels of contaminants than the raw water. That could have occurred because the filter membrane essentially sloughed off the excess compounds into the water. It’s important for residents to replace the filters regularly.

“Home filters are really only a stopgap,” said Knappe, whose lab teamed with Stapleton’s to conduct the study. “The real goal should be control of PFAS contaminants at their source.”

NC State University scientist and professor Detlef Knappe (Photo: NC State)

The type of PFAS in the water also influenced the filters’ effectiveness. “Long-chain” compounds such as PFOA and PFOS were more thoroughly removed — 70% to 80% — than “short-chain,” which had reduction rates of 40%.

After 3M and DuPont phased out their manufacture of long-chain compounds, like C8 (so- called because they contain eight carbon atoms), the companies replaced them with short-chain compounds. Those contain four to six carbon atoms. GenX is a short-chain compound.

Environment

Leak in pipe at Chemours plant emitted a type of PFAS into air; amount not independently confirmed

Fifty pounds? Or less than half a pound?

Last fall, Chemours workers discovered a pinhole leak in a pipe at the Fayetteville Works facility that was emitting a type of PFAS, perfluoropropionyl fluoride, into the air. The company initially estimated about 50 pounds of the compound was released, according to its report to the US Coast Guard National Response Center. The center fields pollution and railroad incidents and forwards that information to appropriate federal and state agencies for response.

Today, in a response to an inquiry from Policy Watch, a Chemours spokeswoman said the amount has since been recalculated to be fourth-tenths of a pound.

It’s hard to gauge what is most accurate, since the amount has not been independently confirmed. For context, Chemours reported to DEQ that in the entire year of 2016 it had emitted 66.6 pounds of GenX-related compounds. That figure turned out to be a drastic underestimate. The state Division of Air Quality conducted its own study  and calculated the facility emitted roughly 2,700 pounds in 2016.

Zaynab Nasif, spokeswoman for the state Division of Air Quality said the agency is “currently evaluating any potential enforcement action at this time and continuing to follow up with Chemours’s evaluation of the incident, as well.”

The recent release occurred on Nov. 22, 2019, in the Vinyl Ethers North Tower, according to correspondence between the company and state environmental regulators. Workers discovered the leak incidentally, while they were conducting stack testing. Chemours subsequently “followed shutdown and decontamination procedures” so the hole could be repaired.

The European Chemicals Agency   lists the substance as potentially “fatal if inhaled and contains gas under pressure and may explode if heated.”

Chemours provided nebulizers to workers who were potentially exposed to the compound, but the company said none became ill.

Environment

Why NEPA matters and why the public should speak-up to protect this bedrock environmental law (podcast)

The Trump administration’s move to narrow clean water protections is not the only policy maneuver this month that has North Carolina environmentalists worried.

Earlier this month the administration proposed weakening key aspects of NEPA, the National Environmental Policy Act.

As reporter Lisa Sorg explained on our site:

NEPA doesn’t dictate environmental decisions, but the process is designed to ensure that agencies follow a proper procedure, including robust public input, to reach its conclusions. In other words, as NEPA’s guiding principle states, the law is intended to “… foster and promote the general welfare. Man and nature can exist in productive harmony and fulfill the social, economic and other requirements of present and future generations of Americans.”

For example, NEPA currently requires a full analysis and assessment of environmental impacts, including cumulative and indirect ones – such as climate change. But the Trump administration would would eliminate considerations for climate change impacts – a very real and existential threat – that accompany natural gas pipelines, fracking operations and offshore drilling. Meanwhile, economic considerations would be mandatory.

Last week we sat down with attorney Kym Hunter of the Southern Environmental Law Center to discuss efforts by the Trump administration to gut this 50-year-old landmark rule.

A public comment period on changes to NEPA runs through March 10th. A public hearing will also be held in Washington, DC, on Feb. 25. Details on how and where to comment are on the Council for Environmental Quality website.