Threats

NPDES MD0025496 · Recently flagged

The discharge of copper, a heavy metal pollutant, exceeds permitted limits by 159-172% and poses direct toxicity risks to aquatic organisms in the Piedmont Uplands' sensitive stream ecosystems. The region's moderate-gradient streams and their associated fish communities, including warmwater species and sensitive benthic macroinvertebrates, face bioaccumulation of copper in food webs, leading to reduced reproductive success, neurological impairment, and potential population declines in susceptible species like crayfish and aquatic insects. Continued copper loading will degrade water quality in receiving streams already stressed by the Piedmont's historical land-use patterns, impairing the ecological integrity that supports the region's characteristic diverse fish assemblages and riparian-dependent wildlife.

NPDES MD0051586 · Recently flagged

Aluminum is a sediment-related pollutant that indicates excessive suspended solids and metal contamination in the facility's discharge. The Potomac River and its associated coldwater and warmwater stream habitats in the Piedmont Uplands are at risk, where elevated aluminum concentrations will accumulate in sediments and bioaccumulate in aquatic organisms, degrading water quality and harming sensitive benthic communities, fish populations, and freshwater mussels that depend on clear water conditions. Continued non-compliance will impair the ecological integrity of these Piedmont stream ecosystems through smothering of substrates, reduced light penetration, altered pH and metal toxicity to aquatic life, and potential cascading effects on downstream communities including the Tidal Potomac.

NPDES MD0063801 · Recently flagged

Copper exceedances represent heavy metal contamination that bioaccumulates in aquatic organisms and poses direct toxicity risks to fish, macroinvertebrates, and benthic communities in the Piedmont Uplands' sensitive headwater streams and tributaries. The repeated violations ranging from 33% to 94% above permit limits threaten the region's characteristic warm-water fisheries, mussel beds, and riparian ecosystems that depend on low metal concentrations, while copper accumulation in sediments and food webs will impair reproduction and survival in species already stressed by urban stormwater runoff common to the Piedmont landscape. Continued non-compliance will degrade water quality in receiving streams and downstream reservoirs, reducing aquatic biodiversity and limiting recreational and municipal water use throughout the watershed.

NPDES DC0000141 · Recently flagged

Polynuclear Aromatic Hydrocarbons (PAHs) are toxic organic pollutants derived from incomplete combustion of fossil fuels and industrial processes that persist in the environment and bioaccumulate in aquatic organisms. The Washington Navy Yard's discharge into the Piedmont Uplands' freshwater streams and rivers poses severe risks to these sensitive systems, which depend on clear water and stable substrates for native fish, benthic macroinvertebrates, and riparian vegetation adapted to moderate-gradient flowing waters. Continued PAH discharges at these extreme levels (up to 35,934% above permit limits) will cause acute toxicity in aquatic life, suppress immune function and reproductive success in fish species, contaminate sediments with carcinogenic compounds, and bioaccumulate through food webs to impact predatory birds and mammals dependent on aquatic resources in this historically productive ecoregion.

NPDES MD0020842 · Recently flagged

Copper is a heavy metal pollutant that accumulates in aquatic ecosystems and poses significant toxicity risks to freshwater organisms. In the Piedmont Uplands ecoregion, where limestone-based streams and their associated macroinvertebrate communities are sensitive to metal contamination, sustained copper discharges at 3-10 times the regulatory limit will impair benthic communities, reduce fish populations through gill damage and neurological effects, and bioaccumulate through the food web to affect predatory birds and mammals. Continued violations risk converting healthy Piedmont stream habitats into metal-stressed systems with reduced biodiversity, altered species composition favoring only the most tolerant organisms, and potential impacts to both aquatic life and human communities relying on these waterways for drinking water and recreation.