the standard water leak test for a new gravity sewer indicates a maximum allowable leakage of ___ gallons per inch diameter per mile

• A. 5
• B. 10
• C. 15
• D. 20

Answer: (B)

In a hydrostatic water leak test for a new gravity sewer, the goal is to verify the line doesn’t lose water faster than a defined limit, ensuring joints and the pipe are watertight. The standard expresses this limit as gallons lost per inch of pipe diameter per mile of pipe. The value of ten is used, so the allowable leakage is 10 gallons per inch of diameter for every mile of pipe tested.

That means for a given section, if you have a pipe with a certain diameter, you multiply that diameter by 10 to get the maximum gallons that can leak per mile. For example, a 12-inch pipe could lose up to 120 gallons per mile, and a 24-inch pipe up to 240 gallons per mile. The test typically involves filling the line with water, letting it sit, and measuring the water loss to ensure it stays at or below this threshold. If leakage exceeds this limit, joints or sections may need repair or replacement to meet the standard.