Working Near Sewers and Drains

Toolbox Talk Record

Ref: TBT-BUR-009  |  Issue: 1  |  Date: March 2026
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What?

Why?

Biological hazardsRaw sewage contains bacteria, viruses, and parasites that cause serious illness including hepatitis, leptospirosis, and gastroenteritis.
Gas exposureHydrogen sulphide and methane accumulate in sewers. Opening manholes or striking a sewer can release lethal concentrations instantly.
Environmental damageSewer damage causes raw sewage to pollute watercourses and groundwater, leading to Environment Agency prosecution.
Legal liabilityDamaging a public sewer without authority breaches the Water Industry Act 1991 and incurs repair costs and fines.
Do Don't
  • Obtain sewer records and check for both foul and surface water drainage.
  • Use CAT and Genny scanning combined with trial holes to locate sewers.
  • Hand dig within 500mm of a known sewer to avoid mechanical damage.
  • Monitor for hydrogen sulphide gas when opening manholes or working near sewers.
  • Wear appropriate PPE including gloves and face protection near live sewers.
  • Obtain approval from the sewerage undertaker before making new connections.
  • Cover open manholes and excavations to prevent people and debris falling in.
  • Wash hands thoroughly after any contact with sewage or sewer infrastructure.
  • Report any accidental sewer damage immediately to the sewerage undertaker.
  • Vaccinate at-risk workers against hepatitis A and tetanus as recommended.
  • DON'T use mechanical excavation within 500mm of a known sewer position.
  • DON'T open sewer manholes without checking for hazardous gas first.
  • DON'T enter a live sewer or manhole without confined space entry procedures.
  • DON'T assume sewer record drawings are accurate; always verify on site.
  • DON'T discharge construction water or chemicals into the sewer without consent.
  • DON'T touch your face, eat, or drink after contact with sewage-contaminated material.
  • DON'T connect to a public sewer without the sewerage undertaker's written approval.
  • DON'T leave excavations near sewers unsupported; ground movement can fracture pipes.
  • DON'T ignore unusual smells during excavation; they may indicate a damaged sewer.
  • DON'T dispose of contaminated soil or water without proper waste classification.

See also: Safe Digging Practices (HSG47) | CAT and Genny Safe Use