ASHEVILLE - City officials have instructed property owners to stop refilling a Merrimon Avenue sinkhole, arguing that repeated sediment leaks mean it's not acceptable even as a stopgap solution.

Since the sinkhole's birth in late June, a series of heavy rainstorms have thwarted the property owners' attempts to close the yawning pit in their parking lot. Upwards of 200 tons of sediment were washed away by the culverted stream believed to have caused the sinkhole, only to settle in the Beaver Lake Bird Sanctuary, a wetland that looks more like a field of muck these days.

By early afternoon on July 12, a chain link fence has been erected around the property and a large excavator has begun digging at the site.

Tax records show the property at 1010 Merrimon Ave. is owned by New Day Properties LLC. William Gatewood is listed as its registered agent. He could not be reached for comment.

What's in the water?

Exactly what was in the material used to fill the sinkhole is uncertain. Mike Anderson, an engineer from Advantage Civil Engineering hired by the property owners, declined to confirm or deny whether any chemical additives were mixed into the sediment.

The uncertainty revolves around the term "road bond," which can refer to both a fine-grained gravel and a chemical additive used to make sediments easier to compact. The chemical agent road bond is mildly acidic, according to the websites of companies that produce it. The chemical called road bond can be applied to the sediment called road bond, and Anderson declined to specify if the chemical road bond was used.

Scientists from N.C. Department of Environmental Quality have not collected or analyzed water samples from Beaver Lake Bird Sanctuary to check for potential contaminants, according to department spokeswoman Sarah Young. Department employees visited the Beaver Lake wetlands on July 8, and "no sheen or visible impacts were noted," Young said.

That visit and visual inspection for chemicals occurred three days before the most recent sediment deposition, which was spurred by heavy rains July 11. Even so, the DEQ has no plans to test the water in the future, according to Young.

Because the sediment collected in the wetlands near Beaver Lake, the owners of the sinkhole property received an official notice of violation of wetland standards from the DEQ on July 1. The property owners will be responsible for removing the sediment and any costs associated with restoring the wetland to its former condition.

Young said all sediment loads that arrived after July 1 are considered part of the original violation.

More:Tons of dirt, road bond from Merrimon sinkhole pour into Beaver Lake Bird Sanctuary

Whose plan was this anyway?

Asheville sinkhole fans have scratched their heads, watching the pit empty and refill like clockwork after several heavy rains.

"I'm no engineer," Tom Tribble, immediate past president of the Audubon Society chapter that manages the Bird Sanctuary, said previously. "But I feel that until they fix that pipe, every time it rains whatever material they have in there is going to wash back out."

So who is responsible for the sinkhole-no sinkhole whiplash?

Typically, major earthworks projects like the ones conducted at 1010 Merrimon Ave. require city permits, according to Ben Woody of Asheville's Development Services Department. In emergency situations, that permitting process is sometimes waived to allow property owners to resolve any public safety issues and prevent problems from worsening.

Because the sinkhole is on private property and does not involve any city pipelines, the property owners and their privately-contracted engineers are in the driver's seat when it comes to planning. City engineers only can nix a project if they have serious concerns about its integrity.

"From the information the engineer provided, we said (the plan to fill the sinkhole with sediment) was fine, if that's what he was recommending," said Nancy Watford, site development engineering supervisor at the city's Development Services Department. "And then as it continued to fail, we told him to stop. We told him he needed to find alternative measures to secure the site."

No more sinkhole tourism

Moving forward, a priority for both city officials and the property owners is to quash the sinkhole tourism that has grown in pace with the sinkhole itself.

"Their plan is to secure the site as best they can with fencing and other means until a plan has been developed," said Ric Ledford, a plans reviewer with the Development Services Department. "People need to stay out."

Gary Rowe, an Asheville attorney representing the property owners, said he's been shocked at how bold people have been about approaching the sinkhole's edge — especially those with children in tow. "They'll probably try to jump the fence," Rowe said.

A new pipe — and maybe a new sinkhole?

According to Watford, the engineers have been instructed to change their tack fairly dramatically.

"They're actually replacing (the pipe) from where it was replaced under (Ski Country Sports) to where it was replaced in front of Early Girl Eatery," Watford said.

As followers of local sinkhole lore will recall, there have been five major sinkholes on the 1000 block of Merrimon Avenue since 2006. They're all thought to be the result of failures in the same culverted stream, which was piped and paved over when the property was developed decades ago.

More:Merrimon Avenue sinkhole: 27 feet and growing

"When they're securing the site, they're going to put in a bypass system that allows the water to flow," Watford said. "You will see back-fill of the hole but it will be the larger rip-rap material, with maybe some smaller stones on top, so that the (temporary) bypass pipe doesn't float" during heavy rains.

Watford explained that the property owners have yet to apply for a permit to replace the pipe but tell officials it's in the works.

The permanent fix — "and that's replacing the pipe and shoring the building," Watford said — can't begin until materials are produced in Charlotte and transported to Asheville. She did not specify what materials will be produced.

In the meantime, there are signs of further ground collapse on and near the property. The Citizen Times found a cauldron-sized depression filled with bubbling mud on the Ski Country Sports side of the property line on July 11, and there's a considerable dent forming on the northwest side of the parking lot as of July 12.

Perhaps most ominously, the sinkhole continues to creep further under the building after each rain.