Montgomery County Water Report

Montgomery County earns a B grade for drinking water quality, scoring 69.0 out of 100. Over the past five years, EPA SDWIS records 1 health-based violation — a single incident worth monitoring.

Under the Clean Water Act §303(d), EPA ATTAINS tracks whether waterways meet quality standards for drinking, recreation, and aquatic life (reporting cycle: 2022). A substantial 44.6% of assessed waterways are impaired (50 of 112 water bodies) across Montgomery County's watersheds. The leading impairment causes are escherichia coli (e. coli) and temperature. Impairment does not mean tap water is unsafe — it measures ambient waterway conditions upstream of treatment, not finished drinking water.

USGS NWIS gauge data (as of 2026-05-14T15:05:00.000-04:00) puts ROANOKE RIVER at 90.4 cfs — well below its long-term average at 37% of mean — low-flow conditions worth noting for water-dependent ecosystems. Streamflow is a leading indicator of drought stress, sediment load, and dilution capacity: low flows concentrate pollutants and warm water temperatures, stressing aquatic life and, in surface-water-dependent systems, the source water quality for treatment plants.

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Montgomery County has moderate coverage with 37 active monitoring sites with 4,821 recent measurements on record. Predominant monitoring categories include physical and nutrient. More monitoring sites generally indicate greater scientific attention to local water conditions — and provide the baseline data that regulators use to set future impairment listings.