STP / ETP/ Water Retaining Structures Leakages

Accessibility
Positive side accessible
Application Method Summary

Prepare CSP 3–4. Choose coating by chemistry exposure: Polyurea for fast heavy‑duty, Coal Tar Epoxy for external chemical zones, 2K cementitious for internal lining. Arrest leaks by PU/VA injection first. Band joints and penetrations. Record DFT and adhesion.

Leakage ID

LQ-STP-ETP

Likely root causes
CracksPoor detailingFailed membraneTile grout failureNegative pressure
Location
Basement
Next Steps

QC/Tests

Recommended Technology Tags
PolyureaCoal Tar EpoxyCementitious 2KInjection Grout
Recommended technologies
Polyurea MembranesCoal Tar Epoxy Coating (High-Solids, Solvent-Free)Cementitious MembraneInjection Grouting Technology
Reference Image
Related applications
08. Effluent Treatment Plant (ETP)
Segment
Basements
Select
Severity
High
Solution Type
Positive-side waterproofingSurface coatingInjection grouting
Specific Area / Component

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Summary

STP/ETP leakages combine continuous immersion, chemical attack, and negative pressure during outages. Systems must resist sewage/effluents and maintain bond under hydrostatic head.

Symptoms

  • Dampness around tank walls and base slab
  • Leaks at pipe inlets/outlets and construction joints
  • Coating blistering or softening in contact zones

Probable causes

  • Incompatible/under‑spec coatings for chemical exposure
  • Insufficient surface prep; osmotic blistering
  • Joint treatment missing or failed; cracks under load

Solution paths

  • Positive‑side heavy‑duty membrane or coating
  • Injection grouting for active leaks at joints
  • Internal negative‑side cementitious/crystalline only as supplementary where positive side cannot be reworked

Recommended technologies

  • Polyurea (2–3 mm) fast‑cure, abrasion and chemical resistant
  • Coal Tar Epoxy high‑solids for external/chemical zones
  • 2K cementitious (potable/non‑potable grades) for internal lining where compatible
  • PU/Vinyl acrylate injection grouts for running leaks

Quick SOP

1) Stop inflow; clean/degrease; shotblast/abrade to CSP 3–4; repair defects.

2) Prime per manufacturer; spray polyurea or apply coal tar epoxy to specified DFT; stripe coat corners.

3) Band/bridge construction joints and penetrations with compatible system; inject where active leaks persist.

4) Cure; re‑commission with staged fill test.

QA / acceptance

  • DFT logs; adhesion ≥1.5 MPa; chemical spot tests; 24–72 hr fill test

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SpecX Masterclass: STP / ETP Leakages Solutions — Coming Soon

Disclaimer

SpecX is an industry initiative & a neutral resource, compiled from industry references and best practices. It is not brand-specific. Always cross-check with project requirements and local codes before finalizing specifications.