Coal Ash Management
Coal-fueled power plants produce a number of coal combustion residuals or byproducts commonly referred to as coal ash. Xcel Energy plants consumed about 28.1 million tons of coal in 2014, which is supplied from mines in Colorado and the Powder River Basin in Wyoming. Throughout our system, we try to recycle coal ash whenever possible for beneficial use, such as in concrete products, roadbed material, soil stabilization, engineered-fill material and more. Ash that is not reused is properly disposed.
Learn more about Xcel Energy’s coal ash management.
PCB Phase-out Effort
We have been phasing out equipment that contains PCBs from our transmission and distribution system for many years. The Toxic Substances Control Act of 1979 defines PCB equipment as equipment having a PCB concentration of 500 parts per million (ppm) or more, while PCB-contaminated equipment has a PCB concentration of 50 to 499 ppm.
Xcel Energy has made dedicated efforts to remove all known PCB equipment from its system, including transformers, capacitors and other regulated categories of equipment. This equipment was targeted, removed and replaced with non-PCB equipment. In many cases, we retrofitted systems to accommodate the removal and replacement of regulated equipment with non-PCB equipment.
Other phase-out efforts include the replacement of regulated equipment with non-PCB equipment as systems are upgraded. Any regulated equipment removed from the field is immediately disposed of and replaced with non-PCB equipment unless there are extenuating circumstances associated with the design or procurement of the equipment. Xcel Energy personnel are trained on PCB regulations and the proper identification, handling, removal and disposal of this equipment to facilitate phase-out efforts.
Aside from PCBs that are occasionally discovered during facility upgrade projects in small sealed or previously untested specialized equipment, most of the PCB and PCB-contaminated equipment left on our system is the result of cross-contamination occurring during manufacturing or maintenance activities prior to or shortly after the adoption of the Toxic Substances Control Act.
|PCB and PCB-contaminated oil (gallons disposed)||30,597||53,470||23,075||25,951|
|PCB and PCB-contaminated equipment (units removed from service)||454||721||714||764|
Xcel Energy actively works to recycle material that is no longer used or usable. Recycling simultaneously diverts waste material from landfills while conserving natural resources by becoming raw materials for production of new products.
A unique program initiated in 2009 turns Xcel Energy’s waste polyethylene plastic pipe into a versatile plastic lumber product. Excess waste pipe from natural gas construction projects is collected and consolidated at company locations to ship to a recycling facility, where the pipe is then transformed into plastic lumber.
The table below illustrates the Investment Recovery group’s recycling activity over the last four-year period.
|Scrap polyethylene pipe||64||52||57||83|
Waste Disposition Summary
1 Universal waste includes regulated waste such as fluorescent light bulbs, rechargeable batteries and mercury switches.
2 PCBs (polychlorinated biphenyls) are chemicals controlled under the Toxic Substances Control Act. PCBs were historically used in transformer oil.
3 Special waste includes oily materials recovered from our operations, such as rags, filters, soil and water.
Legacy Manufactured Gas Plant Projects
In the 1800s up until the mid-1900s, gas was manufactured using coal, oil and petroleum. It was used as natural gas is today, primarily for heating, cooking and street lighting. The U.S. Environmental Protection Agency (EPA) estimates that more than 50,000 manufactured gas plant (MGP) facilities operated in the United States between 1815 and 1960. They were owned by municipalities and corporations, including predecessor companies to today’s electric utilities. MGPs produced a variety of wastes and byproducts, including coal tar. Some of the waste and byproducts were sold for reuse or disposed off-site, and some were left at plant sites.
Given the extensive history of our operating companies—going back more than 100 years—Xcel Energy has inherited legacy MGP sites. All the plant facilities were closed and dismantled years ago, and some of the properties where the MGP once operated have been sold. Over the years, Xcel Energy has worked cooperatively with environmental agencies and communities to successfully investigate and/or remediate former MGP sites. We currently have investigation and/or remediation activities underway at eight MGP sites across our service territory.
One of Xcel Energy’s operating companies, Northern States Power Company-Wisconsin (NSPW), is part of an extensive remediation project underway in Ashland, Wis. During the late 1800s and early 1900s, the lakefront in Ashland was one of the busiest industrial ports in the country. It was the site not only of a legacy MGP, but also the site of lumber and wood treatment facilities, as well as a loading area for railroads. The MGP was operated at the site from 1885 to 1947 and provided gas for street lighting and businesses. Later the site was used for a city-owned landfill and waste water treatment plant. NSPW has owned a portion of the Ashland site since 1986.
The site is being cleaned under the supervision of the EPA and the Wisconsin Department of Natural Resources (WDNR). The EPA has identified several parties responsible for the cleanup. Under an agreement with the U.S. Department of Justice, the EPA and WDNR, we have conducted phase 1 of the project, which includes remediation of the impacted soils and groundwater at the site. The project was completed in early 2015. In addition, we have initiated litigation against other potentially responsible parties (PRPs) for cost recovery of their fair share of the cleanup costs. Negotiations among the PRPs, EPA and WDNR are ongoing for the second phase of the remediation, which will address impacted sediments at the site in an area of Lake Superior’s Chequamegon Bay.
Learn more about the Ashland, Wis., project.