The National Monitoring Network in Bulgaria, part of the European Environmental Research Network, indicates a low level of heavy metal contamination. However, localized pollution remains a concern, particularly in the Plovdiv-Asenovgrad area, where a zinc-lead processing plant has affected the soil. Despite numerous environmental protection measures, the region faces the lingering effects of past pollution. This study is based on a unique vegetative experiment involving three types of soils with increasing concentrations of Pb, Cu, and Zn. These concentrations surpass the maximum allowable concentrations for hazardous substances in soils deemed harmful to the environment and human health. Typically, soil acidity is the primary factor affecting the mobility of heavy metals. Our experimental results are an interesting case for contamination without soil exchange acidity as an aggravating factor for plant mobility and bioavailability. To demonstrate the practical application of our findings, we applied zeolite in concentrations of up to 10%. We observed the transfer of heavy metals in economically significant leafy green vegetables. We discovered that soil quality is the primary factor influencing lettuce yields, with zeolite also playing a role. While the amount of zeolite did not significantly affect growth in heavily contaminated soils, its slow release of nutrients makes it a practical solution as a carrier for potassium fertilizers. Our study reveals that adding zeolite to contaminated, neutral, and slightly alkaline soils reduces contamination and enhances specific physiological indicators in test crops, demonstrating improved plant physiological conditions. However, despite the positive results from applying zeolite, we advise against growing vegetables in the area due to the remaining contamination risks.