Eight-inch monitoring wells offered by CP Test Services-VALVCO Inc. now have an improved three-bolt design that helps eliminate ground water infiltration. The wells also feature a heavy-duty cast iron lid and collar, and they are certified by an independent laboratory to meet or exceed H-20 roadway loading. The HDPE high-density poly sleeve is available in custom lengths, easily field cut, lightweight, petroleum product resistant and offers high impact performance. The BUNA-N rubber gasket helps ensure a water-tight seal. The monitoring wells also are available in 7- and 12-inch sizes. VALVCO Inc.