| Report | Data Sources | Analytic Approach | Limitations | |--------|--------------|-------------------|-------------| | | EPA Safe Drinking Water Information System (SDWIS), American Water Works Association (AWWA) asset inventories | Asset‑age decay curves + Monte‑Carlo simulation of leak‑rate scenarios | Inconsistent reporting frequency among smaller utilities | | Climate‑Health | NOAA Climate Projections, CDC WONDER, WBWH water‑quality monitoring stations | Integrated assessment model (IAM) linking temperature & precipitation to health‑impact functions | Pathogen‑growth models assume uniform treatment efficiency | | Equity | Tribal Water Data Repository, USDA Rural Development surveys, local health department morbidity data | Multi‑level regression (community‑level covariates) + GIS hotspot analysis | Small sample sizes for some tribal nations limit statistical power |
Aging mains are the single biggest driver of non‑revenue water (NRW). The “at‑risk” city cohort (e.g., Detroit, Baltimore, St. Louis) accounts for ≈ 45 % of total leak‑related losses despite representing only 12 % of the national population. reports.wbwh
Recent filings, such as the First Quarter 2026 Results , highlight total revenues of approximately $8.9 billion . | Report | Data Sources | Analytic Approach
(Washington Bureau of Water & Health – “reports.wbwh”) Recent filings, such as the First Quarter 2026