Environmental Enlightenment #128

By Ami Adini - Reissued January 6, 2016

This is a SHORT, LIGHT and SIMPLE newsletter. Its purpose is to rekindle in the initiated terminology they have once learned, and enlighten the uninitiated on terms they may have heard but never known the meaning of.

Monitoring Wells and Piezometers

In environmental site assessments we use wells to monitor the conditions of the groundwater. Here is a diagram of the construction of a groundwater monitoring well:

This is a 100-foot deep 4” diameter well (not to scale) with the bottom 30 feet screened. The blank section is a Schedule 40 PVC pipe. The screen is the same pipe but with slots to enable entry of the groundwater. In this case, groundwater is at 80 feet below the surface and the well screen is designed so that 20 feet will be under and 10 feet above the water table.

Erroneously, groundwater monitoring wells are some times called piezometers.

In Greek, piezein means to press, therefore piezo has come to mean pressure. Piezometers are wells designed to measure pressure of the groundwater.

Groundwater develops pressure when it flows through or being retained by confined aquifers.

The above diagram illustrates a confined aquifer underlying a non-confined aquifer. The water in the confined aquifer is under pressure. When a well is inserted, the water will rise in the well. The degree of rise of the water is an indication of the pressure in the aquifer. When we measure the rise, we know the pressure.

Piezometer is a non-pumping well, generally of small diameter for measuring the elevation of a water table. Piezometers may or may not be screened at the bottom.

The diagram below depicts three “nested” piezometers arranged to measure the pressure in the aquifer at different depths.

You can find past issues of our  "Environmental Enlightenment" at amiadini.com Wealth of information about environmental site assessments in the real estate transactions and issues concerning assessment and cleanup of contamination in the subsurface soil and groundwater.

Call me if you have any questions. There are no obligations.

Ami Adini
Ami Adini & Associates, Inc.
Environmental Consultants
Underground Storage Tank Experts
818-824-8102; mail@amiadini.com
www.amiadini.com

Ami Adini is a mechanical engineer, California Registered Environmental Assessor, Level II (Exp.), and president of AMI ADINI & ASSOCIATES, INC. (AA&A), an environmental consulting firm specializing in all phases of environmental site assessments and rehabilitation of contaminated sites. AA&A specializes in practical solutions to environmental concerns using the highest standards of ethics and integrity while providing its clients with maximum return on their investments.