Laserfiche WebLink
`P�,If0RN�9 <br /> California Ground Water Association <br /> o 1017 L Street, PMB #312 • Sacramento, CA 95814 • <br /> GyaWATE�'� <br /> 1. Steel Casings measuring 1 inch in diameter to 6 inches in diameter <br /> with a wall thickness .188 to .25 inches shall use a minimum of 50 <br /> grain per foot detonation cord. <br /> 2. Steel Casings measuring 2 inches in diameter to 6 inches in <br /> diameter with a wall thickness greater than .25 inches shall use a <br /> minimum of 100 grain per foot detonation cord. <br /> 3. Steel Casings measuring 6 inches in diameter to 12 inches in <br /> diameter with a wall thickness .188 inches shall use a minimum of <br /> 100 grain per foot detonation cord. <br /> 4. Steel Casings measuring 6 inches in diameter to 10 inches in <br /> diameter with a wall thickness of.25 inch or greater shall use a <br /> minimum of 200 grain per foot detonation cord. <br /> 5. Steel Casings measuring 10 inches in diameter to 18 inches in <br /> diameter with any wall thickness shall use a minimum of 50 grain <br /> per foot detonation cord in conjunction with 150-gram Cast <br /> Boosters. <br /> a. Cast Boosters shall be evenly spaced along the detonation <br /> cord line. <br /> 6. Steel Casings larger than 18 inches in diameter with any wall <br /> thickness shall use a minimum of 50 grain per foot detonation cord <br /> in conjunction with 450-gram Cast Boosters. <br /> a. Cast Boosters shall be evenly spaced along the detonation <br /> cord line. <br /> iii. Blaster In Charge shall always reserve the authority to change blast designs <br /> based on Safety Factors or Un-Disclosed information about the well design. <br /> f. Existing sanitary seals are to be evaluated and accounted for in the blast design. <br /> i. Existing sanitary seals should not be perforated unless evidence of seal <br /> failure is present or suspected seal failure is present. <br /> 1. Extra safety measures shall be implemented to reduce the potential <br /> of fly material during seal perforating operations. <br /> g. Surrounding areas are to be evaluated and accounted for in blast designs. <br /> i. Surface and underground structures as well as utilities must be accounted <br /> for. <br /> h. Redundant firing system should be used to insure proper detonation of the entire <br /> charge during deep set operations. <br /> i. Cement set time retardant is recommended for wells deeper than 400 feet and <br /> required for wells deeper than 1000 feet. <br /> i. Without a set time retardant such as Delvo,cement will harden before the <br /> well can be filled and charges detonated. The result of this is inadequate <br /> flow of cement into native formation after detonation. <br /> ii. Deep wells should be completed in one continuous pour. <br /> AUTHOR TYLOR MCMILLAN <br />