Capping works well for sealing off contamination from the above-ground environment and reducing underground waste migration. Caps can be put over virtually any site, and can be completed relatively quickly. Capping materials and equipment are readily available. A multilayered cap will usually last for at least 20 years. Proper maintenance will make it last even longer.
Precipitation separates heavy metals from the water they contaminate.
Precipitation changes dissolved heavy metal contaminants into a solid form that can be separated from the water. Water contaminated with heavy metals is treated with chemicals, which cause the metal molecules to stick together and separate from the water. The solids are removed from the water. Precipitation is easy to perform and can be used in many areas. It efficiently treats contaminated groundwater for reuse, and is one of the main methods of treating industrial wastewaters.