Allegheny River Headwaters Watershed Conservation Plan

Allegheny River Headwaters Conservation Plan
Chapter 3. Water Resources
disposal, resource extraction, agriculture, and urbanization can affect water quality.
Waste disposal is the primary source of groundwater contamination. In 1990, Pennsylvania had
more rural residents than any other state, and one-quarter of homes utilized on-lot septic
systems. Improperly installed or maintained systems can inadvertently introduce bacteria,
viruses, nitrates, phosphorous, chlorides, and organic solvents into groundwater. Activities, such
as draining household chemicals and using a garbage disposal, can impede the effectiveness of
treatment within septic systems. Unlike public wastewater systems that discharge waters to the
surface, individual septic system discharges are released into the groundwater system. However,
septic systems are not the only method of waste disposal that impacts groundwater quality.
Leachate from the 55 illegal dumpsites throughout the watershed and discarding household
chemicals and motor oil into storm drains also impact the quality of water (Fleeger, 1999;
League of Women Voters; Raymond, 1988).
Resource extraction activities, such as mining, oil and gas drilling, and abandoned, unsealed
oil and gas wells are other potential sources of groundwater contamination. Within the project
area, there are 51 active industrial mining permits. Surface and deep mining can alter both the
quality and quantity of groundwater. Quality can be altered through the formation of abandoned
mine drainage and the introduction of iron, manganese, sulfate, and dissolved solids. Oil well
drilling produces brine, which can leak into groundwater if storage lagoons are not properly
lined. In 2009, there were 194 wells drilled within the watershed municipalities, 12 of which
were drilled within the Marcellus Shale formation. Private water wells can be contaminated
from methane gas from nearby gas wells that are under pressure. Abandoned oil and gas wells
that are not sealed leave the potential for groundwater contamination through illegal disposal
into the well; improper or deteriorated casings can allow contaminants to spread between
aquifers (Fleeger, 1999; League of Women Voters; Raymond, 1988).
Some agricultural practices impact the quality of ground and surface waters. The improper
or ill-timed application and over-use of fertilizers increase nitrate and bacteria levels in
nearby waterways. The excessive, ill-timed use and improper storage and handling of pesticides
cause them to leach into the soil or run off into nearby waterways. The contamination affects
humans, land animals that drink the water, plant growth, and aquatic life (Fleeger, 1999; League
of Women Voters; Raymond, 1988).
Human activities, such as construction and highway maintenance, have an impact on water
quality. In urbanized areas, asphalt and concrete pavement impede water infiltration and
groundwater recharge. Instead, water runs off the land, having the potential to pick up
additional contaminants before entering a nearby waterway or eventually penetrating the
ground. Water quantity is another major issue within urbanized areas. Often with large demand,
there is an over withdrawal of water within the aquifer that leads to a drawdown, reducing the
water table and the amount of base flow in local streams. Other urbanized activities that can
affect the quality of groundwater include the use of road salt, storage tanks, chemical spills, and
landfills (Fleeger, 1999; League of Women Voters; Raymond, 1988).
Surface Water
Streams, rivers, wetlands, springs, lakes, and ponds form when the water table intersects with the
land surface, and groundwater reaches the surface to establish the base flow. Once the water reaches the
surface, it becomes surface water. Surface water encompasses all the water on the surface of the earth,
including runoff.
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