Pollutant |
Potential Sources |
Nonpoint Sources |
Point Sources |
Nonpoint Sources |
| Pathogens |
• WWTPs
• CSOs/SSOs
• Permitted
CAFOs
• Discharges from
meat processing
facilities
• Landfills |
• Animals (domestic, wildlife, livestock)
• Malfunctioning septic systems
• Pastures
• Boat pumpout facilities
• Land application of manure
• Land application of wastewater |
• Primarily human health risks
• Risk of illness from ingestion or from
contact with contaminated water
through recreation
• Increased cost of treatment of drinking
water supplies
• Shellfish bed closures |
| Metals |
• Urban runoff
• WWTPs
• CSO/SSOs
• Landfills
• Industrial
facilities
• Mine discharges |
• Abandoned mine drainage
• Hazardous waste sites (unknown or
partially treated sources)
• Marinas |
• Aquatic life impairments (e.g., reduced
fish populations due to acute/chronic
concentrations or contaminated
sediment)
• Drinking water supplies (elevated
concentrations in source water)
• Fish contamination (e.g., mercury) |
| Nutrients |
• WWTPs
• CSOs/SSOs
• CAFOs
• Discharge from
food- processing
facilities
• Landfills |
• Cropland (fertilizer application)
• Landscaped spaces in developed areas
(e.g., lawns, golf courses)
• Animals (domestic, wildlife, livestock)
• Malfunctioning septic systems
• Pastures
• Boat pumpout
• Land application of manure or
wastewater |
• Aquatic life impairments (e.g., effects
from excess plant growth, low DO)
• Direct drinking water supply impacts
(e.g., dangers to human health from
high levels of nitrates)
• Indirect drinking water supply impacts
(e.g., effects from excess plant growth
clogging drinking water facility filters)
• Recreational impacts (indirect impacts
from excess plant growth on fisheries,
boat/swimming access, appearance,
and odors)
• Human health impacts |
| Sediment |
• WWTPs
• Urban
stormwater
systems |
• Agriculture (cropland and pastureland
erosion)
• Silviculture and timber harvesting
• Rangeland erosion
• Excessive streambank erosion
• Construction
• Roads
• Urban runoff
• Landslides
• Abandoned mine drainage
• Stream channel modification |
• Fills pools used for refuge and rearing
• Fills interstitial spaces between gravel
(reduces spawning habitat by trapping
emerging fish and reducing oxygen
exchange)
• When suspended, prevents fish from
seeing food and can clog gills; high
levels of suspended sediment can
cause fish to avoid the stream
• Taste/odor problems in drinking water
• Impairs swimming/boating because of
physical alteration of the channel
• Indirect impacts on recreational fishing |
| Temperature |
• WWTPs
• Cooling water
discharges
(power plants
and other
industrial
sources)
• Urban
stormwater
systems |
• Lack of riparian shading
• Shallow or wide channels (due to
hydrologic modification)
• Hydroelectric dams
• Urban runoff (warmer runoff from
impervious surfaces)
• Sediment (cloudy water absorbs
heat than clear water)
• Abandoned mine drainage |
• Causes lethal effects when
temperature exceeds tolerance limit
• Increases metabolism (results in higher
oxygen demand for aquatic organisms)
• Increases food requirements
• Decreases growth rates and DO
• Influences timing of migration
• Increases sensitivity to disease
• Increases rates of photosynthesis
(increases algal growth, depletes
oxygen through plant decomposition)
• Causes excess plant growth |