Los Banos Rotary Club History
Engineer Tells Of Underground Supply Problems

Charles H. Sartor, well known Fresno water engineer, presented to members of the Rotary Club in Los Banos Nov. 19 an authoritative review of the valley's underground water supply and some of the problems confronted by farmers who irrigate their lands with deep well water.

Sartor, introduced by Rotarian Perry Ketrich, as probably the person having the greatest knowledge of water both above and below ground in the valley, is associated with Laval Underground Surveys, a subsidiary of Food Machinery and Chemical Corp., of San Jose.

Today, Sartor said, there are some 50,000 deep wells in the valley, costing an estimated $100 million besides the costly pump and motor installations. Together they pump some nine million ac,-ft. of water a year – an amount nearly 18 times the capacity of Millerton Reservoir and nearly twice that of Shasta Reservoir.

Defining a deep well as a very carefully designed and skillfully built structure, sartor said the average life of a deep well is 9 to 10 years. Many times its life is shortened to a few months or few years by any of a large number of causes, and it is the repair and maintenance of these wells with which Sartor is mort concerned at this time.

Until the development of special photographic equipment that permits the taking of pictures below water to the very bottom of the well, Sartor said that trying to determine failure was mostly guess work, and though crude, specialized equipment was developed and used successfully, repair work was the exception rather than the rule.

Since the advent of underwater photography some 10 years ago, a completely new era has been opened by water engineering services, and in addition they have been able, in many cases, to determine original faults and weaknesses and now design and build wells which hold up far longer than those of a few years ago.

Almost half of well failures, he said, are caused by "compression breaks," the wrinkling and breaking of the well casing due to pressure of the earth around it. This is particularly true, he said, in areas where ht eland is shrinking and dropping due to the continuing withdrawal of the underground water supply and drying out of the earth.

High hydrostatic pressure at certain levels also causes many casing failures, he said, and today these are, in most cases, corrected by special machinery which expands the crushed casting to its original size and shape and permits insertion into the well of a new metal sleeve for additional strength.
Bacteria and also growths, which are active in the underground stratas, sometimes effectively plug up the perforated sections of the well casing, causing gradual diminishing of the well's output, and even its eventual failure. Special cleaning equipment has been designed to scrape such crustations from the casing and in many instances the well has been returned to its original full production.

As to the future need of deep wells with the advent of new surface water supply, Sartor said that wells always will be required to firm up the surface supply.

The surface supply, he said, will be dependent at least partially, on the individual water year and when rainfall is below normal farmers must still return to the reserve supply that lies under most of the San Joaquin and Sacramento valleys. It is estimated, he said there are about 90 million ac,-ft. of water in the top 200 feet of the underground supply. This provides a potential total supply for the area of about 1 1-3 years.

Sartor concluded his talk with the showing of a number of the special underwater photos taken in deep wells in this particular area. Most striking was a 3-dimension photo, taken several hundred feet underground and in several hundred feet of water, of a casing failure.

November 22, 1957

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