Environmental Enlightenment #214
By Ami Adini - Reissued August 16, 2017

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 knew the meaning of.

Power of Simplicity
The EPA’s Citizen’s Guide to Cleanup Technologies

Series 13: Evapotranspiration Covers

See our Newsletter, Environmental Enlightenment #200, for introduction to one highly valuable, plainly written series of Citizen’s Guides published by the EPA at http://www.clu-in.org/products/citguide

With this issue we introduce the EPA’s Citizen’s Guide to Evapotranspiration Covers. You can reach it through the hyperlink under the blue header below.



Evapotranspiration is a made-up combination word: short for Evaporation + Transpiration.

Evaporation from the land
Transpiration from plants
=         Evapotranspiration


Transpiration is the release of water from plant leaves.

(Perspiration is the release of water through the pores of the skin.)

These pictures show water vapor transpired from plant leaves after a plastic bag has been tied around the stem for about an hour.  


Credit: Ming Kei College, Hong Kong

During a growing season, a leaf will transpire many times more water than its own weight.

An acre of corn gives off about 3,000 to 4,000 gallons of water each day.

(Credit: USGS, Water Science for Schools)

In cases of buried contamination, if water percolates through the contamination it will leach out injurious elements and carry them down to groundwater.

Groundwater contamination
Credit: USDA

Caps provide protection from injurious elements in the environment.  

Evapotranspiration covers are caps placed over contaminated material to prevent water from reaching it.


Evapotranspiration covers hold the water.

They prevent water from reaching the buried waste.

In time the cover releases the water back to the atmosphere through evaporation from the land and transpiration from the plants.

Diagram of energy balance for a growing plant.
Credit:  NASA Earth Observatory

Evapotranspiration covers do not destroy or remove contaminants.

They isolate contaminants and keep them in place to prevent the spread of contamination.



Go to the EPA’s Citizen’s Guide to Evapotranspiration Covers http://www.clu-in.org/download/Citizens/a_citizens_guide_to_evapotranspiration_covers.pdf for the rest. It is simple and fun to read.

You can find past issues of "Environmental Enlightenment" at www.amiadini.com with wealth of information about 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 Environmental Services, Inc.
Environmental Engineering Consultants & Contractors
Underground Storage Tank Experts
California Lic. #1009513 A B HAZ ASB
818-824-8102; mail@amiadini.com

Ami Adini is a mechanical engineer, California Registered Environmental Assessor, Level II (Exp.), and president of AMI ADINI ENVIRONMENTAL SERVICES, INC. (AAES), an environmental engineering consulting firm and general contractors specializing in all phases of environmental site assessments, rehabilitation of contaminated sites and upgrading of underground storage tank facilities. AAES provides practical solutions to environmental concerns using the highest standards of ethics and integrity while providing its clients with maximum return on their investments.