Environmental Stewardship

Superfund

As with much of industry, the emerging environmental standards of recent years have provided us with many difficult challenges. We’ve upgraded our processes to meet increasingly stringent air quality regulations, and in some cases actually defining new standards for our industry.

During the 1990’s, samplings of nearby shallow wells showed nitrate levels above acceptable standards. Further testing identified our evaporation ponds as a source of contamination. These ponds had, for decades, collected cooling tower blowdown and process waste water. In response, we first drilled new deep wells to assure our neighbors of a reliable source of good water. We then moved to eliminate the source of contamination. This was accomplished in 1994 with the installation of a Brine Concentrator (BC) plant at a cost of more than $5 million.

As a result, we became a ‘zero discharge’ operation. All waste water was recycled, with our BC reclaiming up to 90 gallons per minute of water and returning the water as a high purity for our boilers and reducing the demand from the aquifer. As a significant benefit to the community, our well water consumption dropped significantly.

With the source of nitrates defined and eliminated, the next challenge was to remove the excess nitrates from the groundwater. This is being accomplished, in part, by means of a ‘wetland system.’ Basically, the wetland provides a means of removing nitrate through natural processes. Water is pumped from the ground and processed through a series of five shallow ponds.

Within the wetlands the water passes through a biological community of cattails and other water plants. Through the natural cycle of plants growing and dying, the nitrates are converted to oxygen and nitrogen, which are released harmlessly to the atmosphere. The treated water is then released into a dry wash where it seeps back into the shallow aquifer.

Remediation at the Apache Powder Superfund site is well under way. The ponds formerly used for waste water management have been covered and graded. The nitrate concentrations in the extraction well that pumps groundwater to the wetland continue to decrease. The concentrations are now consistently under 100 parts per million. Most of the private shallow wells that were above the EPA drinking water standard of 10 ppm are now consistently below that level.

EPA has issued the decision that we have completed the Superfund construction phase and are moving into routine operation and maintenance. Please see the EPA website or the ADEQ website for more information.