No money to clean up slag on Asarco

By Sito Negron – El Paso Inc.

It could cost up to $20 million to clean more than a million cubic yards of slag from an arroyo that funnels arsenic into the groundwater and the Rio Grande.

Slag is the black byproduct of smelting that’s piled up along Interstate 10 and buried under the giant structures and pavement of the former Asarco site.

But the money allocated to El Paso by a Corpus Christi federal court in the $1.8-billion bankruptcy settlement approved in December 2009, doesn’t cover that portion of the cleanup.

El Paso received $52 million in the settlement. The money, which was placed in a trust, is enough to essentially pave over and drain and treat contaminated water under the site, as well as demolish buildings.

But the Texas Commission on Environmental Quality argues the slag is not a health or environmental hazard, and that’s why cleaning the arroyo was not included in the agency’s remediation plan. The main Asarco is between the river and Interstate 10, but the property also includes the more than 200 acres on the UTEP side of the highway.

“The previous investigation did not reveal any health or environmental concerns in the Parker Brothers arroyo. Therefore, no remedial work is planned for the arroyo,” said TCEQ spokeswoman Andrea Morrow.

“However, we understand the trustee is contemplating work on the arroyo for both beautification and drainage purposes to make the area more attractive and possibly increase the development potential of the former ASARCO property,” she added.

Long-term remedy
While not directly contradicting that, the trustee in charge of the site, Roberto Puga, said he considers the work on the arroyo key to making the site cleanup work.

“In the long term, leaving the arroyo in the condition it’s in would be a disservice. The way the slag is placed inside the arroyo inhibits severely the ability to act as a stormwater watershed,” Puga said. “We think that rehab of the arroyo will help the groundwater problem tremendously.

“The groundwater solution on the books, to suck up water and treat it, is in my opinion not a long term remedy. If we’re able to control groundwater by improving the arroyo … that can drastically reduce groundwater flux beneath the site and we can look at other options for dealing with the groundwater that are more cost effective and sustainable.”

What is it, anyway?
Slag, the byproduct of smelting metals, is black and glassy, and has many uses. Sometimes, the metals content is high enough that it can be recycled. In other cases, crushed slag can be used in concrete, as ballast, in road bedding and other uses.

However, it also can be toxic if it releases its metals, although the glassiness, the result of silica used in the smelting process, generally binds the elements of the slag together.

The Asarco slag is mostly silica and iron, with trace elements of metals, according to site engineers. The major “constituent of concern,” what’s called the COC, that’s been found at elevated levels in the water below the site, is arsenic.

It’s not exactly clear on the Asarco smelter site what might cause the slag to release its bound toxins, although engineers have identified one cause – slag that was ground to a dusty fine-ness.

There is one pile of this material, called “fines,” that was ground down by a company called Ogleby-Norton.

That material, some 130,000 cubic yards next to the Smeltertown cemetery, now stabilized with a layer of emulsion, was blamed by Asarco for the contamination of homes in Sunset Heights and Kern Place.

“In the remedy proposed (by TCEQ) the fines pile was always meant to be dealt with, so there is scope in the budget for that,” said Scott Brown, project manager for Malcolm-Pirnie, the firm that has the cleanup contract.

Puga said that the rest of the slag is being tested to find out what other factors might cause arsenic to leach and how the COCs might vary by location.

“It appears to be correlated to the size of the grain. That’s part of our analysis to find out how small the material can be and still be safe,” Puga said.

One possible use for the slag might be onsite, if the Texas Department of Transportation is able to work with the city on a proposal to place a freeway that roughly parallels I-10 in that area.

“I think that’s the crux here, trying to find the stuff that needs to be put in cells versus stuff that is safe for the environment and can be put to specific use,” Puga said.

So who pays
Mayor John Cook said the city has not discussed paying for any of the cleanup and it did what it could during the bankruptcy process.

“In my humble opinion we squeezed the rock as hard as we could. If you will recall, the only standing we had in the bankruptcy case was the unpaved rights of way contract which had gone into default,” Cook said. “Our standing was dwarfed by those with more significant interests.”

Cook pointed out that the $52 million is to be supplemented by sale of assets. Puga has said that he’s up about $2 million from a year ago, and there are millions more in equipment, scrap metals and other assets yet to be sold, including tons of copper left behind in the smelter.

He’ll use that to supplement the arroyo work, and he’s working with the office of U.S. Rep. Silvestre Reyes to find federal money.

Stormwater
Doug Solon, an onsite engineer, said stormwater collects above the Mission Hills neighborhood, works its way down and across Mesa Street, then runs through the arroyos on the UTEP side, under the freeway and rails, and through the Parker Brothers arroyo on the smelter site down to Paisano Drive, where it goes under the rails and the road and emerges into the Rio Grande.

On the UTEP side, the trustee will have to remove 25,000-cubic yards of slag and debris – pieces of metal, concrete, rocks and bricks from the smelter. It was dumped in the late 1960s, before the completion of I-10. At one time, it filled the arroyo from Mesa to the smelter site.

According to the Remedial Action Work Plan, there are two stormwater collection ponds and five drainage arroyos that are usually dry, except during or after rain or snow.

“These arroyos are the Parker Brothers Arroyo, Ponds 5 and 6 Arroyo, Pond 1 Arroyo, South Terrace Area Arroyo, and the Acid Plant Arroyo,” it reads. “These arroyos convey most groundwater flow and have a great impact on groundwater recharge and transport of contaminants through the Site.”

The report states that groundwater is from eight to 60 feet below the surface. It is contained within an “unconfined alluvial aquifer,” and below that is a “bedrock aquifer.”

While the report states that little is known about the bedrock aquifer, what little work has been done “indicate little to no permeability and minimal groundwater flow. … Based on this information groundwater in the bedrock is not expected to be significantly impacted.”

Can slag save arroyo
An exposed face of about 50-feet shows how much slag filled the arroyo at one time, and an aerial photo of Asarco from 1960 shows the piles of slag extending from the smelter and up into the arroyos, which were less green than they are now, when I-10 forms a barrier that collects water.

Charlie Wakeem, chairman of the Open Space Advisory Board, is active in open space preservation issues. He said it was a surprise to him to see the scope of the slag and the size of the undisturbed arroyos on the UTEP side of the freeway.

“I didn’t realize that there was an arroyo so full of slag and contaminated material on the smelter site itself that fed directly into the Rio Grande. The clean up of the Parker Brothers arroyo is far more important than cleaning up any other part of the ASARCO site,” he said. “Another concern I have is mitigating the contamination in the North and South Arroyos east of I-10. They are very lush, wildlife habitats.”

He said he didn’t know how important it was to preserve the North Arroyo, since he hadn’t seen it yet. But he said the South Arroyo is definitely a high priority.

“Actually, no development should occur from the South Arroyo all the way to UTEP,” Wakeem said. “All of the hillsides south of the South Arroyo should be left in their natural state as well.”