Plant-based technologies are suited to remove low to moderate contamination. Plants can take up heavy metal ions but are often sensitive to organic contaminants and grow slowly with only a slight remediation effect. Multiple approaches can be useful to accelerate remediation. The combined action of hydrocarbon-degrading and plant growth-promoting indigenous bacteria can enhance phytoremediation. A three-step approach (landfarming, bioaugmentation, phytoremediation) was applied to a disused industrial area contaminated by nitrogen-containing compounds, alkylaromatic hydrocarbons, copper, and nickel. Fourier transform ion cyclotron resonance mass spectrometry led to the speciation of organic compounds. This technique confirmed the effectiveness of alkylaromatic hydrocarbon remediation.