WORK PLANS - Laserfiche WebLink

Home Browse Search

1. Well wholly situated in unconsolidated material in an unconfined ground water zone (Figure 9A). If the ground water supplies are within 50 feet (15 metres) of the surface, the upper 20 feet (6 metres) shall be sealed with impervious material and the remainder of the well shall be filled with clay, sand, or other suitable inorganic material (see item D, this section). 4 . 5 2. Well penetrating several aquifers or formations. In all cases the upper 20 feet (6 metres) of the : r E#I5TIIIfi4Ur SEkL well shall be sealed with impervious material. #' r. o EQilEMOiE 20,wie. In areas where the interchange of water between '4 SEA LrNG M411RIA4 aquifers will result in a significant deterioration of the quality of water in one or more aquifers, or will result in a loss of artesian pressure, the well shall be filled and sealed so .as to prevent such interchange. Sand or other CASINGS suitable inorganic material may be placed opposite the --- producing aquifers and other formations where impervious FILL EA sealing material is not required. To prevent the vertical movement of water from the producing formation, impervious 5YIHG __ material must be placed opposite confining formations above iIATE�iIA� - - and below the producing formations for a distance of 10 feet (3 metres) or more. The formation producing the deleterious S RAY EL PKIK water shall be sealed by placing impervious material opposite the formation, and opposite the confining formations :* for a sufficient vertical distance (but no less than 10 feet or 3 metres) in both directions, or in the case of "bottom" A. gpLy� w�L� I UNCONSOLIDATED waters, in the upward direction. (See Figure 9B.) MATERIAL -' In locations where interchange is in no way detri #:� _ F It) MIN o- I mental, suitable inorganic material may be placed opposite the formations penetrated. When the boundaries of the EISEaMG I AQUIFER TO various formations are unknown, alternate layers of ACKFILi I t :impervious and pervious material shall be placed in the well. NEw Be T SEAL4-QFE 5' Max RERFORaYTrOwB Determining the significance of interchange of waters ap g I. 4 r Ifl'111N whose qualities vary and of the loss of artesian pressures, requires extensive knowledge of the ground water basin in *, , question. The Department of Water Resources has over the ;,- ., .,.� µ�° FILLER " years, and frequently in cooperation with agencies such as �,;" -,•-.-�� OR SEALIRS the U. S. Geological Survey, undertaken a number of ground , ' SEALING MATERIAL MATERIAL I water studies and amassed considerable information and CASING E7€ISFJRG 1 data about the subject. Although much is known about the State's ground water supplies, detailed studies suffi- 'y BOREHOLE ciently accurate to define interchange problems have been E%rSTaIf6 GROUT I 1 made only in certain areas. In still other areas, there , is only partial definition of the problem. Examples of " : �' _ SEALr areas where definition has been made are the coastal plain UPPER JSFALM FEATURES g• DEEP WELL WITH AOIJIFER SEAL of Los Angeles County and the eastern part of the Santa URBAN AREA WFLL Clara Valley in Alameda County. An excellent example of a "bottom" water is the saline connate water underlying the Central Valley at varying depths. Figure 9. PROPERLY DESTROYED WELLS