| S.No. | Checkpoint | IS Requirement | Status |
|---|---|---|---|
| A. TEST PROCEDURE | |||
| A1 | Upper manhole sealed; lower manhole filled with water to top (or design level) Acceptance: Water level at top of pipe, maintained for 30 minutes observation | Cl. 10.1 — Filling procedure | |
| A2 | Visual inspection for seepage from joints, pipe walls, or manhole connection points Acceptance: No water seeping from pipe joints, no weeping from manhole walls, dry downstream | Cl. 10.2 — Leakage detection | |
| B. ACCEPTANCE & VERDICT | |||
| B1 | PASS: Zero seepage observed; water level drop ≤1% per 100m length acceptable Acceptance: Drop ≤0.01m per 100m (or <5mm total for typical 500m section), test certificate issued | Cl. 10.3 — Pass condition | |
| B2 | FAIL: If seepage observed, location marked, repair made, and section re-tested Acceptance: Leaking pipe replaced or joint sealed, re-test confirms zero leakage | Cl. 10.4 — Failure response | |
After drainage pipes are installed and backfilled, the only way to verify the system is watertight is to fill it with water and observe. The Leakage / Water Test forces water into the system; any pressure drop or visible water escape indicates leakage that needs rectification before commissioning.
For gravity sewers + storm drains (low-pressure systems), the test typically holds water for 1-7 days; acceptable loss is < 5-10% over 24 hours. For pressurized water mains (high-pressure systems), the test holds at 1.5× working pressure for 1-2 hours with zero loss.
IS 4127:2017 mandates leak testing for all newly-laid sewers; CPHEEO Manual on Water Supply 2024 mandates pressure testing for water mains. Without these tests, defects emerge during operation — at significantly higher cost to repair than during construction.
For gravity sewers / storm drains (low-pressure water-fill test): 1. Seal downstream end with plug; install manometer or sight glass at upstream 2. Fill system slowly from upstream with clean water 3. Allow 2-4 hours for absorption + air bleeding 4. Top up to original level; observe over 24 hours 5. Acceptance: drop < 25 mm over 24 hours for 200 mm pipe; proportionally for other diameters
For pressure pipes (water-fill at pressure): 1. Isolate test section 2. Fill + bleed air 3. Pressurize to 1.5× working pressure (typically 7.5-10 bar) 4. Hold for 1-2 hours 5. Acceptance: pressure drop ≤ 0.5 bar over test duration; no visible leakage
Air-pressure alternative for sewers (IS 4127 Annex F): - Air pump installed at upstream - Pressurize to 0.3-0.5 bar - Hold for 30 minutes; measure pressure drop - Acceptance: drop ≤ 0.05 bar over 30 minutes
Documentation: pre-test conditions, equipment used, pressure / level readings at intervals, weather, ambient temperature, observations, results, sign-off.
1. Pipe joint leakage — visible water at joint → faulty rubber ring; replace ring + retest 2. Manhole wall seepage — water entering through cracks → epoxy injection or wall replacement 3. Pipe wall hairline cracks — gradual seepage along pipe length → replace damaged section 4. Connection leak — branch / lateral connection imperfect → re-fit connection joint 5. High-pressure drop — major rupture in pipe → locate + replace ruptured section 6. Slow pressure decline — multiple minor leaks → systematic inspection + multiple repairs 7. No-leak but flow lost — possibly siphoning to lower elevation; reverse flow during test 8. Test results invalid — pressure gauge mis-calibrated; equipment failure
Companion QA/QC: - Sewer Method Statement (QC-DRN-FRM-001) — pre-construction methodology - Manhole Method Statement (QC-DRN-FRM-002) — manholes - Smoke Test (QC-DRN-TST-002) — alternative leak detection - Drainage Register (QC-DRN-REG-001) — system-level tracking
Codes: - IS 4127:2017 — Code of practice for laying and construction of sewers (test methodology + Annex F) - IS 458:2003 — Precast concrete pipes - IS 8329:2020 — Ductile iron pipes (pressure pipe test methodology) - CPHEEO Manual on Water Supply 2024 — water main pressure testing - CPHEEO Manual on Sewerage 2013 — sewer leak testing