When water testing a section of pipe between manholes:

When water testing a section of pipe between manholes:

• A. Test plugs should be placed on the upstream side of both manholes
• B. Test plugs should be placed on the downstream side of both manholes
• C. Test plugs should be placed only upstream of the first manhole
• D. Test plugs are not required

Answer: (A)

To get a valid water test on the section between two manholes, you need to confine the length of pipe being tested so water cannot escape into the rest of the sewer. Placing test plugs on the upstream side of both manholes creates a sealed segment between those two plugs. This arrangement blocks flow from the upstream direction into the test section and prevents leakage back into the upstream line through the manholes, giving a closed volume to fill to the required test pressure and accurately check for leaks. If plugs were placed on the downstream sides, water could still escape downstream through the manholes. If you only plugged the upstream side of the first manhole, the far end wouldn’t be sealed, allowing leakage. Not using plugs at all means the section isn’t isolated and the test would not be valid.

To get a valid water test on the section between two manholes, you need to confine the length of pipe being tested so water cannot escape into the rest of the sewer. Placing test plugs on the upstream side of both manholes creates a sealed segment between those two plugs. This arrangement blocks flow from the upstream direction into the test section and prevents leakage back into the upstream line through the manholes, giving a closed volume to fill to the required test pressure and accurately check for leaks.

If plugs were placed on the downstream sides, water could still escape downstream through the manholes. If you only plugged the upstream side of the first manhole, the far end wouldn’t be sealed, allowing leakage. Not using plugs at all means the section isn’t isolated and the test would not be valid.