[
  {
    "record_id": "SL-001",
    "material": "Vitrified clay (VC)",
    "sewer_application": "Gravity sewer",
    "metric_type": "Directly observed field age",
    "value": "130–142 yrs, structurally intact",
    "sample_scope": "Sewers in 2 German cities",
    "source_title": "Peer-reviewed: Balch et al. 2022 (ScienceDirect)",
    "industry_involvement": "None noted",
    "evidence_grade": "A",
    "access_basis": "Full text",
    "verified_date": "2026-07-20",
    "dataset_version": "2026-07-20"
  },
  {
    "record_id": "SL-002",
    "material": "PVC",
    "sewer_application": "Gravity sewer",
    "metric_type": "Direct field observation",
    "value": "Up to 25 yrs, no deterioration",
    "sample_scope": "7 pipes aged ~11/16/20/25 yrs; Australia",
    "source_title": "Whittle & Tennakoon (PIPA)",
    "industry_involvement": "Author with pipe maker; acknowledged",
    "evidence_grade": "A",
    "access_basis": "Full text",
    "verified_date": "2026-07-20",
    "dataset_version": "2026-07-20"
  },
  {
    "record_id": "SL-003",
    "material": "PVC",
    "sewer_application": "Gravity sewer",
    "metric_type": "Modeled service life",
    "value": "~98 yrs (worst) to 288 yrs (best)",
    "sample_scope": "Same 7 pipes; Australia",
    "source_title": "Whittle & Tennakoon (PIPA) — Fig. 7",
    "industry_involvement": "Same as SL-002; threshold author-selected",
    "evidence_grade": "B",
    "access_basis": "Full text",
    "verified_date": "2026-07-20",
    "dataset_version": "2026-07-20"
  },
  {
    "record_id": "SL-004",
    "material": "Polyethylene (PE)",
    "sewer_application": "Gravity sewer",
    "metric_type": "Direct field observation",
    "value": "Up to 38 yrs, no quality loss",
    "sample_scope": "200 mm SN8; Finland",
    "source_title": "TEPPFA (2014) — p. 7",
    "industry_involvement": "Borealis, LyondellBasell; independent reviewer",
    "evidence_grade": "B",
    "access_basis": "Full text",
    "verified_date": "2026-07-20",
    "dataset_version": "2026-07-20"
  },
  {
    "record_id": "SL-005",
    "material": "Polypropylene (PP)",
    "sewer_application": "Gravity sewer",
    "metric_type": "Direct field observation",
    "value": "Up to 23 yrs, no significant loss",
    "sample_scope": "110 mm SN8; Norway",
    "source_title": "TEPPFA (2014) — p. 7",
    "industry_involvement": "Same as SL-004",
    "evidence_grade": "B",
    "access_basis": "Full text",
    "verified_date": "2026-07-20",
    "dataset_version": "2026-07-20"
  },
  {
    "record_id": "SL-006",
    "material": "PE and PP",
    "sewer_application": "Gravity sewer",
    "metric_type": "Modeled service life (conditional)",
    "value": "100 yrs if EN standards + install limits met",
    "sample_scope": "Solid- and structured-wall; Europe",
    "source_title": "TEPPFA (2014) — Table 4",
    "industry_involvement": "Same as SL-004",
    "evidence_grade": "B",
    "access_basis": "Full text",
    "verified_date": "2026-07-20",
    "dataset_version": "2026-07-20"
  },
  {
    "record_id": "SL-007",
    "material": "Concrete / RCP",
    "sewer_application": "Gravity / combined",
    "metric_type": "Design horizon + documented failure",
    "value": "~100 yr design; 30–50 yrs; down to 10 in extreme MICC cases",
    "sample_scope": "Combined-sewer field case + review",
    "source_title": "Peer-reviewed MICC case study (2015); U.S. EPA sulfide guidance",
    "industry_involvement": "None noted",
    "evidence_grade": "A / B",
    "access_basis": "Abstract / secondary",
    "verified_date": "2026-07-20",
    "dataset_version": "2026-07-20"
  },
  {
    "record_id": "SL-008",
    "material": "Cast iron",
    "sewer_application": "Wastewater (gravity)",
    "metric_type": "Residual-strength evidence",
    "value": "Not established (condition-dependent)",
    "sample_scope": "Wastewater assets",
    "source_title": "Peer-reviewed: Residual strength of ageing cast iron wastewater assets",
    "industry_involvement": "None noted",
    "evidence_grade": "A",
    "access_basis": "Abstract",
    "verified_date": "2026-07-20",
    "dataset_version": "2026-07-20"
  },
  {
    "record_id": "SL-009",
    "material": "Ductile iron",
    "sewer_application": "Gravity sewer",
    "metric_type": "Industry design guidance",
    "value": "50-yr min / 100-yr goal",
    "sample_scope": "Gravity sewer, good practice",
    "source_title": "DIPRA, Ductile Iron Pipe for Wastewater Applications",
    "industry_involvement": "Iron pipe trade association",
    "evidence_grade": "B",
    "access_basis": "Full text",
    "verified_date": "2026-07-20",
    "dataset_version": "2026-07-20"
  },
  {
    "record_id": "SL-010",
    "material": "ABS",
    "sewer_application": "DWV / limited buried use",
    "metric_type": "Standards / application",
    "value": "Not established",
    "sample_scope": "DWV; limited buried use",
    "source_title": "ASTM D2751 (withdrawn 2014); D2680 composite",
    "industry_involvement": "Standards body",
    "evidence_grade": "C",
    "access_basis": "Record",
    "verified_date": "2026-07-20",
    "dataset_version": "2026-07-20"
  },
  {
    "record_id": "SL-011",
    "material": "Orangeburg",
    "sewer_application": "Residential lateral",
    "metric_type": "Municipal field guidance",
    "value": "Not established (failure modes documented)",
    "sample_scope": "Residential laterals",
    "source_title": "City of Ann Arbor, Orangeburg Sewer Piping",
    "industry_involvement": "None noted",
    "evidence_grade": "B",
    "access_basis": "Full text",
    "verified_date": "2026-07-20",
    "dataset_version": "2026-07-20"
  },
  {
    "record_id": "SL-012",
    "material": "Orangeburg",
    "sewer_application": "Residential lateral",
    "metric_type": "Historical advertised expectation",
    "value": "50 yrs (advertised)",
    "sample_scope": "—",
    "source_title": "APWA Minnesota, The Rise and Fall of Orangeburg Pipe",
    "industry_involvement": "None noted",
    "evidence_grade": "C",
    "access_basis": "Full text",
    "verified_date": "2026-07-20",
    "dataset_version": "2026-07-20"
  },
  {
    "record_id": "SL-013",
    "material": "Asbestos-cement",
    "sewer_application": "Mixed water and sewer",
    "metric_type": "Official scoped estimate",
    "value": "60–75 yrs",
    "sample_scope": "Mixed water & sewer; Australia",
    "source_title": "ASEA report",
    "industry_involvement": "Government agency",
    "evidence_grade": "B/C",
    "access_basis": "Full text",
    "verified_date": "2026-07-20",
    "dataset_version": "2026-07-20"
  }
]