Water percolating through the waste leaches calcium hydroxide and becomes alkaline. The precipitated matter eventually forms an impermeable layer, preventing water from percolating to the watertable. California has no "statewide" water right permit process for regulating the use of percolating groundwater. The lakes are fed by underground water percolating through the rocks and into the lakes. It has been described as a "defiant number lined with excitable, percolating percussion". However, most of the current theories have difficulty in describing percolating systems. Delivery hose is divided into two categories&colon; percolating hose, and non-percolating hose. Percolating hose is used mainly to fight forest fires. For instance, connection probability replaces temperature for percolating networks. "He's dead right about a trade issue now percolating in Washington," said the newspaper. He still describes the downflow as being the "percolating".