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Tuesday, 20 July 2010 19:40

Quarry must improve sediment control measures

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A large rock quarry in Waynesville has been cited with a water quality violation for sending mud into nearby Allens Creek.

The Harrison Construction rock quarry, which mines rock used in road building, was issued a notice of violation on July 8 from the N.C. Division of Water Quality. The violations carry the potential for hefty fines, but if problems are fixed immediately, fines usually aren’t imposed.

The quarry has been in the limelight over the past three months due to a controversial expansion plan. Neighbors fed up with the quarry’s practices had complained to state officials about mud running off the quarry and into the creek, and even documented it themselves in photographs.

Neighbors’ action prompted the first water quality inspection of the site in more than four years, which resulted in the violations. Creek samples taken upstream of the quarry were pristine compared to immediately downstream where sediment levels were 100 times higher than what’s allowed under state standards.

Sediment-laden rainwater was running off three areas of the quarry and into Allens Creek unchecked, according to the inspection report. While the quarry had erosion safeguards elsewhere on site, three areas lacked such measures. Runoff from quarry walls, dirt roads, crushing operations and even the asphalt waste pile flowed off the site and into the creek without first passing through erosion check points, according to the report.

The quarry should have noticed the problem itself and alerted state water quality officials. Failing to do so was among six violations the quarry was cited for.

“If they see a bunch of turbid water blowing out, we expect them to let us know they are having issues and what they are doing to fix it,” said Linda Wiggs, a state water quality official in Asheville. “We don’t want to hear it from someone else.”

Wiggs was among a team of four people who inspected the quarry site on June 26. Their official report from the inspection was made public last week. The quarry has until July 26 to explain why turbidity standards were violated and why the Division of Water Quality hadn’t been notified.

Harrison officials did not respond to several phone calls and emails requesting comment for this article.

As a result of the violation, the quarry will have to take water samples in Allens Creek on a monthly basis and send them to state water quality officials until further notice. Normally, the quarry would only have to sample the creek twice a year.

The quarry was also cited for failing to keep proper erosion records. The quarry is supposed to monitor how well its sediment safeguards are working in weekly inspections and keep a log of erosion maintenance.

For example, earthen dams that slow down rainwater and trap sediment before it reaches the creek can quickly become backlogged and must be cleaned out regularly — something that should be noted in the quarry’s log book.

Another technique is to divert muddy water into giant retaining ponds where sediment settles to the bottom. The ponds, too, have to be dug out to maintain the holding capacity.

The quarry’s maintenance logs were inadequate, however.

“They were generalizing a lot of their erosion control inspections. I told them they needed to be more specific,” Wiggs said.

As part of its self-policing, the quarry is supposed to assess its erosion safeguards within 24 hours of a rainfall of half an inch or more, per state water quality standards. But the quarry’s environmental compliance manager splits his time between seven rock quarries — one in each of the seven western counties. Wiggs said that it’s too big a job for one person in the report.

“If they think they can be compliant with one guy running around to that many areas, that’s fine, but we felt like ‘Well, let’s get some other folks doing this,’” Wiggs said.

The inspection report warned that failing to monitor runoff “because personnel are not available during a discharge event is not an acceptable practice.”


Fixing the problem

The quarry must now figure out what new erosion safeguards are needed to stop the unchecked runoff — but also exactly where all the water is coming from, Wiggs said.

Quarry workers told Wiggs they didn’t realize muddy water was escaping from the site without first passing through erosion checkpoints. Quarry workers told Wiggs they thought the water running off the site was clean groundwater seeping out of the excavated pit.

Quarries inevitably hit the groundwater table, and pools of water form in the pits. Quarry workers told Wiggs they thought the pools were merely overflowing, and therefore, they weren’t paying attention to it.

In reality, the runoff from the quarry’s bare slopes and water used to spray down crushing operations — both laden with sediment — were mingling with the pit water, Wiggs said.

“It is recommended a thorough evaluation of this entire drainage take place,” the report states.

The quarry must have a sediment and erosion control plan on file with the state as part of its mining permit. That plan was inadequate, however, as it shows only two locations where runoff leaves the quarry when in reality there are five, Wiggs said.

State mining inspectors had consistently deemed the quarry “in compliance” with its sediment and erosion control plan, without noticing that the plan itself was inaccurate. Jamie Kritzer, public information officer, said mining inspectors focused on whether the quarry was “meeting the conditions of its state mining permit,” and not necessarily the larger issue of storm water runoff.

Wiggs said the sediment and erosion control plan needs to be updated.

“Mines move land. Things shift,” Wiggs said.

Indeed, when the quarry sliced open a new part of the mountainside as part of a major pit expansion in 2008, it apparently created new routes for runoff.

Further exacerbating the issue, a massive rockslide in 2009 reduced a section of the quarry wall to rubble — a loose pile of dirt and rock that is hundreds of feet wide and tall. Rain running off the slide section is contributing to sediment issues, Wiggs said.

Harrison did not waste any time getting to work. Even before the official violation notice arrived in the mail, a team of dozers and dump trucks could be seen at the quarry site shoring up erosion measures day in and day out.

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