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helpful to describe the areal and vertical extent of geologic
<br /> standards have been established, and changes in the status of materials where sealing is needed to prevent the migration of
<br /> .".alifornia county well ordinances. poor quality water.
<br /> Concurrently the Department assembled and evaluated Thus, the Department maintained a concurrent and
<br /> information on the development of well standards in subsequent activity consisting of studies and reports
<br /> California. The information was grouped into three broad describing the application of standards in designated areas
<br /> categories: (1) ground water geology and hydrology, of California. And, in addition to Bulletin 74, the Depart-
<br /> (2) impairment of ground water quality, and (3) water well ment issued a number of reports containing well standards for
<br /> construction practioes. The latter included suggestions and those areas (see Table 1),I
<br /> recommendations on methods and materials from representatives
<br /> of state and federal agencies, steel companies, casing The 1981 Edition
<br /> fabricators, pump manufacturers, water well drilling
<br /> contractors, and'other organizations and individuals The foreword to the 1968 edition stated that:
<br /> concerned with the development and use of ground water.
<br /> "Whereas the standards in this report are as final
<br /> This activity culminated in the publication of the as they can be at the present time, the Department
<br /> standards in their initial draft form, "Recommended Minimum will revise them from time to time. We recognize
<br /> Well Construction and Sealing Standards for Protection of that, as with other published standards, to be
<br /> Ground Water .Quality State of California", Bulletin 74, effective and useful they must be revised and
<br /> Preliminary Edition, July 1962. In March and April 1965, the updated in light of both changes in practice and
<br /> Department conducted a series of public hearings in conjunc- degree of success achieved in their application."
<br /> tion with the Department of Health Services at six cities in
<br /> the State. Discussion and comments received centered on two Sufficient changes in the field of water well construction
<br /> areas: (1) the standards recommended, and (2) means of and experience with applying the 1968 standards warrant
<br /> implementation. Most of those concerned felt that the revising them. Foremost among the changes in construction
<br /> standards, as written, were too general. Accordingly, the practices are:
<br /> Department decided to redraft them.
<br /> 1. The development and use of plastic materials
<br /> Following a review of all prior material and for casing in water wells. A subject only alluded to in the
<br /> comments received during the period 1963 through 1966, the 1968 edition, the use of plastic well casing and screen has
<br /> Department published an interim,edition of the chapter had phenomenal growth in the United States. So much has the
<br /> containing the standards in February 1967. Two public hear- usage increased that a national materials standard has been
<br /> ings on the interim edition were held in May 1967, and developed and a manual of installation practices has just
<br /> written comments were received as part of the record. These been published.
<br /> were also joint hearings with the Department of Health
<br /> Services. 2. The use of the air rotary.drilling method for
<br /> constructing wells in the hard rock areas of the State.
<br /> The eight hearings produced correspondence and an Although this method of drilling was in use in 1968, its use
<br /> extensive file of transcripts containing information, has mushroomed since then. The equipment is very effective
<br /> opinions, and suggestions, which would fill several volumes, and very fast. Coupled with the use of plastic well casing,
<br /> if published. the method has made the construction of a well several
<br /> hundred feet deep in one day a common event in hard rock
<br /> In February 1968 standardE ad Jm their areas.
<br /> current form.
<br /> 3. Rapid growth in the use of well screens in
<br /> For the most part, the standards can be applied place of perforated casing in the intake sections of wells.
<br /> anywhere in the State under practically any conditions. The
<br /> procedures for closing-off the avenues of access, properly 4. Increased use of the reverse-circulation method
<br /> locating a well, destroying an abandoned well, etc., in of well drilling for large diameter deep wells in unconsoli-
<br /> Del Norte County, at the northwest corner of California, are dated formations. It too is an extremely fast method.
<br /> similar to those in western Fresno County. Similarly,
<br /> sealing-off the water in one or more zones or aquifers, to One other report, Bulletin 74-1, "Cathodic Protection Well
<br /> prevent its migration to other zones or aquifers, may be just Standards: State of California", March 1973 deals with
<br /> as desirable for a well in western Merced County as it is at
<br /> one on the Oxnard plain of Ventura County although, perhaps, another kind of well. Cathodic protection wells house
<br /> devices used to alleviate electrolytic corrosion of pipe-
<br /> for different reasons. However, in specific areas of the lines, tanks, and similar installations. Such wells may
<br /> State it has been necessary to define the existing geologic also function as instruments for the deterioration of
<br /> and hydrologic conditions and the circumstances under which ground water quality. For that reason, standards for
<br /> these standards should be applied. For example, it is their construction and destruction have also been issued.
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