In the early 1980’s, CPS Energy realized that contaminated oil was present in the fuel oil tanks and supply lines at the Mission Road Power Plant. CPS Energy drained the fuel oil and transported it to a disposal facility. Most of the supply line piping was also removed at this time. The two underground concrete storage tanks were left in place.

On September 25, 2000, CPS Energy began the voluntary removal of two empty concrete fuel oil storage tanks from the southern end of the plant property and excavated soil around the tanks and along Mission Road. In addition, CPS Energy removed and replaced soil located between the tank area and the San Antonio River to prepare for potential river beautification projects. The soil from the eastern edge of the property was also removed because it had been compacted by old lead-based paint flaking off the wood plant windows. The windows and additional sources of the paint were removed prior to this soil being excavated. As with the Tank Area, the soil was replaced and planted with grass. The clean-up took about nine months to finish and over 18,000 cubic yards of oily soil were removed and replaced with clean soil.

In 2004, CPS Energy voluntarily decided to remove remaining underground oily soil from a 1972 spill. CPS Energy decided to dig up the oily soil since the City of San Antonio now has plans to make improvements along the San Antonio River. The oily soil area was about 300 feet long and about 200 feet wide and was along the San Antonio River. The clean-up took about seven months to finish and over 14,500 cubic yards of oily soil were removed and disposed.

The latest clean-up project was conducted in 2007. This included the removal of lead painted buildings, old transformers and metal and/or oil contaminated soil. This was a relatively small project which required less than 100 cubic yards of soil to be removed.