| 摘要 |
A wellhead vault for preventing alteration of the wellhead of a water supply. The vault is a heavy bell-shaped structure, formed of concrete, and having a downwardly facing concavity, and the vault placed over, with the concavity around the wellhead. The vaults too heavy to be removed by human lifting. Lifting elements are provided to allow the vault to be installed and removed by heavy construction equipment. The vault has a vent that communicates between the concavity and the outside, allowing air, but not liquid, liquid or solid contaminants, or animals, to pass through. |
