ERM provides a good return on investment

14 February 2012

Environmental Resources Management, Inc. (ERM) and its demolition practice takes an innovative approach to recycling and waste management on its projects. Instead of accepting the premise that most materials will be classified as construction debris or wastes that will have to be disposed of in a landfill, ERM dedicates itself to determining alternate end uses for such materials in line with its principles on sustainability. An ideal example of how ERM implemented this philosophy is the demolition of the former ASARCO smelter in El Paso, Texas, USA.

Smelting operations at the site began in 1887. For a century, the facility conducted operations that included, in addition to lead and copper smelting, cadmium oxide production, zinc recovery, and sulphuric acid refining until the mid-1990s. In 1994 and 1995, after a series of compliance inspections, the Texas Natural Resource Conservation Commission (TNRCC) determined unauthorised discharges of solid waste, wastewater, and storm water had occurred at the site.

On May 20, 2005, the Texas Commission on Environmental Quality (TCEQ) issued a Corrective Action Directive to ASARCO to conduct remedial action for the El Paso site. That same year, ASARCO and related entities declared Chapter 11 bankruptcy. As a result of the bankruptcy proceedings, the United States District Court for the Southern District of Texas in Corpus Christi issued an order confirming the plan of reorganisation. On December 9, 2009, ASARCO placed US$52 million (€40.2 million) in an environmental custodial trust to address remedial activities. The Texas Custodial Trust was formed and appointed Roberto Puga of Project Navigator LTD as trustee.

Defining the task

Roberto awarded ERM the contract to decommission, decontaminate and demolish the site. He established goals of addressing the concerns of the citizens of El Paso that the demolition would be conducted in a regulatory compliant manner and to increase the funds available to the trust such that additional remedial measures not originally included in the settlement could be performed. ERM was selected based on its history and reputation on conducting safe, environmentally conscious work, as well as identifying, developing, and executing plans for disposition of the abandoned assets onsite.

The ERM team, led by Robert Klotzbach and Jeff Bauguss, immediately began to develop an approach that would incorporate ERM's value of sustainability into all aspects of the project. This started with addressing the effects of site work on the environment and the surrounding community, followed by a monetary valuation of all hard assets onsite based on inventories provided by the bankruptcy proceedings and physical inspections of the site.

Site assessments showed significant levels of heavy metals resulting from decades of various smelting operations in the soil and dust within the entire footprint of the facility. As a result, continuous dust monitoring, dust suppression and asset decontamination occurred throughout demolition activities as a part of the site's Community Assurance Plan.

To verify that site operations did not affect the surrounding community, ERM worked to develop a perimeter dust monitoring program. The plan included placing dust monitors around the site that provided 24-hour real time data on dust levels. As part of the ERM goal to deliver sustainable solutions, the dust equipment was powered using renewable energy, with each monitor fastened with an individual solar panel.

Another preventative measure ERM utilised to minimise the effects of the work on the environment was to recycle all captured water on site. Due to the region's arid conditions, dust suppression was a continuous task during activities. Another issue ERM faced was the need to remove visible lose soil and dust accumulations from recyclable materials to reduce the potential for impacted dusts to be released during transport offsite. These processes required large quantities of water, which is a precious commodity for the local community of El Paso, Texas, due to the dry conditions of the Chihuahua Desert.

Water reuse

Prior to ERM's involvement, site management released all captured storm water per the site's storm water permit. The team made the decision to utilise this water for decontamination purposes to reduce the impact on the city of El Paso water supply. ERM designed a filtration system to treat the captured waters from the decontamination procedures and dust suppression to make the water available for reuse in the same task. This dedication to recycling not only reduced the site's impact on the city's water supply but also provided cost savings to the client and the contractors.

As part of the valuation of assets, ERM focused on two unique areas of the site to identify and for which to develop markets for potential reusable assets. These areas were: the acid production plants and the copper process furnaces.

As a by-product to the copper smelting process, sulphate gases were created. In order to reduce the amount emitted into the air, ASARCO collected, cooled, and refined the gases to produce sulphuric acid, a sellable commodity. There were two acid plants in the facility. From these, two commodities were developed, harvested and recycled to the financial benefit of the client. The first asset identified was the lead metal used in the electrostatic precipitators. There were 12 units within the two plants, which provided over 600,000 kg (1.3 million lb) of recyclable lead metal, the funds of which were directly added to the site trust fund.

The second commodity from the acid plants was abandoned low-grade sulphuric acid that remained in multiple tanks within the systems. Usually, this type of substance is neutralised at a very high cost in materials and labour. ERM worked diligently to find a market for the acid and succeeded. The overall net savings to the client by removing the neutralising process was approximately US$250,000 (€193,000).

Copper bottomed

ERM then addressed the idled copper production facility. Through site investigation and research of historical documents, the presence of a potentially large amount of copper matte was discovered in and below the two furnaces on site.

Both furnaces were demolished to expose the refractory brick oven portion of the structure. Once this was accomplished, the refractory was carefully peeled back to reveal the copper matte material. The refractory was taken to a storage facility onsite to be tested for metal content and inventoried for possible reclamation. The copper matte material was excavated and removed, and was also tested for metal content and inventoried.

The demolition of the furnaces allowed for the recovery of the copper cooling jackets, which were sold for US$1.8 million (€1.4 million). The copper matte material excavated from the furnaces amounted to approximately 12,240 m3 (432,000 ft3) of material that will yield approximately 3,175 tonnes (3,500 tons) of copper, 1,250 kg (2,750 lb) of silver and 34 kg (74.8 lb) of gold. The material was sold for US$15 million (€11.5 million). Completion of a contract for the approximately 6,117 m3 (216,000 ft3) of refractory will yield additional funds for the trust while reducing the amount of material destined for land disposal.

At the time of writing, the project has returned over US$25 million (€19.3 million) to the trust to augment the US$52 million that was originally in the trust. This increase in revenue will allow the project to enhance the remedial actions and extend the cleanup far beyond the original plans.

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