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Drinking Water Threats

Whether your drinking water system depends on a "ground water source" (well) or a "surface water source" (streams, rivers, lakes, springs, reservoirs, etc.), it faces many threats to the quality and quantity of water it can supply.

Threats are those conditions which would affect people's health, if the water is used for drinking, cooking and general hygiene purposes and could be either a quality issue or quantity issue.

In many cases the quality of the drinking water source may make the water unappealing (taste and odor concerns), but does not pose a health threat if consumed, so it is not considered a threat.

Threats to your drinking water system may be either "man made" or naturally occurring. Threats to our drinking water sources in the Brodhead Watershed can be considered as Groundwater Threats or Surface Water Threats, although since the two are inseparably linked, a problem with one will inevitably mean a problem with the other.

Groundwater Threats

Man Made Threats

Many human activities can negatively affect groundwater quality as well as quantity. For many years it was generally believed that the filtering capabilities of the soil protected groundwater from contamination by human activities on the surface.

But with the discovery in the 1970's of human-made organic chemicals in groundwater, we began to realize how extensively our activities can affect groundwater. In fact, in a nationwide study commissioned by the U.S. Environmental Protection Agency, 65% of the private wells tested failed to meet at least one drinking water standard.

Those activities that can have a negative impact on groundwater can be categorized in four groups: waste disposal, resource extraction, agricultural practices, and urbanization.

Waste Disposal

The best known source of groundwater contamination is waste disposal sites (landfills), both municipal and industrial, that were in existence before new regulations went into effect in 1988.

Septic systems are another potential source of groundwater contamination. If septic systems are improperly installed or maintained, bacteria, viruses, nitrate, phosphorus, chlorides, and the organic solvents that are found in many household cleaners as well as products sold to "clean" septic systems can all make their way into groundwater. As a result of poor construction or maintenance of their septic systems, rural homeowners are frequently the cause of contamination of their own wells.

Resource Extraction

As mines intersect aquifers and collect water, they interfere with groundwater storage and can lead to lowered water levels in wells.

Drainage from mining degrades water quality as it infiltrates aquifers or discharges into streams. Increased concentrations of iron, manganese, sulfate, and dissolved solids in well water can result. In the Brodhead Watershed, stone quarries can have a negative impact on both groundwater and surface water sources.


Common agricultural practices such as fertilizing and applying pesticides are coming under increased scrutiny because groundwater samples have revealed nitrates and, in some cases, pesticides. The most prevalent problem is high levels of nitrate from overapplication of manure and fertilizer. Nitrate is especially harmful to babies, interfering with the blood's ability to transport oxygen, which causes the baby to suffocate ("blue baby" disease).


Many human activities and land use practices, which proliferate with urbanization, can negatively affect groundwater. Even cemeteries, for example, can contaminate groundwater.

One effect of urbanization is recharge diversion. Soils that have been covered with impervious surfaces-roofs, parking lots, or streets-obviously cannot absorb precipitation. Nor can soils that have been compacted by heavy machinery. As a result, much of the water from rain and snowmelt goes directly into streams and is never available to recharge groundwater.

Large concentrations of people can also lead to overpumping of aquifers. This can result in significant aquifer drawdown, which in turn reduces the quantity of streamflow. Stream water quality then suffers due to higher concentrations of sewage treatment plant effluent. Intensive pumping in coastal areas can cause salt water to be drawn into aquifers and wells. Polluted stream water can also be drawn into drinking water wells.

With increased population comes industrialization and an increase in the amount and variety of industrial activities, many of which can potentially contaminate groundwater. Leaking storage tanks at both industrial sites and gas stations have contaminated groundwater in many instances.

Individual homeowners also impact groundwater through a number of activities. These include improper disposal of used oil and overapplication of fertilizer and pesticides on lawns and gardens. Homeowners use four to eight times the amount of fertilizer and pesticides per acre than farms. Golf courses are another potential source of groundwater contamination from overuse of fertilizer and pesticides.

Natural Contamination

The natural constituents of water that may affect its suitability for drinking and other purposes most commonly found in groundwater are dissolved solids, calcium carbonate, and iron. Concentrations of chlorides and nitrates can also restrict use of water. These constituents enter water by leaching from rocks as water moves through them. Hardness is a property of water, usually measured by the concentration of calcium carbonate, which increases the amount of soap needed to produce lather.

Radon, a naturally occurring radioactive gas formed from decaying uranium or radium deposits, is a natural contaminant of increasing concern. Where radon is present in bedrock it can dissolve in groundwater and become a health hazard either when consumed or when the gas escapes into the air during showering, cooking, and laundering.

Hydrogen sulfide is an infrequent natural contaminant of groundwater caused by water storage in certain types of shale rock. It imparts a characteristic rotten egg odor to the water, but is not seen as a health threat at the levels at which it makes water unpalatable.

Corrosive groundwater is common. Corrosivity involves many factors including high acidity and low concentrations of calcium carbonate. In a recent Penn State survey of groundwater in private wells, 60% had corrosive water. Corrosive water dissolves lead and copper from pipes and plumbing fixtures thus causing a health risk.

Surface Water Threats

Because surface water (rivers, streams, ponds, lakes, reservoirs and springs) are by their nature more "visible," most people have more experience with this water source. Surface waters are often areas of recreation providing us with opportunities for swimming, boating, fishing, and camping. Most of us have pleasant memories and experiences related to these water habitats and view them as a wonder of nature, representing crisp, clear, clean water.

However, surface waters are even more at risk of contamination than groundwater, especially in the Pocono Mountain area where the Brodhead Watershed area is located. This is due to the fact that this area is both a recreational area and a high growth area. This increases the human activity within the watershed and, thus, increases the chances of pollution.

While many of the threats talked about in the Groundwater Threats section relate to surface water sources, surface water because of its readily available nature is even more vulnerable to contamination. Surface waters can be contaminated by pollution from "non-point sources" sometimes called "polluted run-off" or "point sources" - usually permitted discharges from sewage treatment or industrial waste treatment plants.

Non-Point Source Pollution

Non-point source pollution threats are those threats to surface water sources that cannot be traced to one particular discharge location. Run-off from farms, golf courses, street and highway systems, parking lots, recreational fields, leaking storage tanks or septic systems, railroad or vehicle accidents (i.e., chemical and fuel spills), are all considered "non-point source pollution."

Combined, these potential sources of pollution in the Brodhead watershed area pose the greatest threat to the water quality. These threats run the full course of human activity from industrial and manufacturing centers, to the tourist industry, agriculture, residential homes and recreational uses.

Nutrients and pesticides from golf courses, agricultural uses and residential homes threaten the receiving waters. Chemicals and waste products from industrial and commercial facilities, if not properly treated and disposed of, threaten surface waters; air pollution from automobiles and combustion can find its way into the hydrologic cycle; auto and truck accidents can introduce chemicals or fuels into a water source, and run-off from parking lots and streets contains oil and grease, nutrients, sediment and road chemicals.

A contaminated aquifer can influence a surface water source when it discharges into a surface water source (e.g. when groundwater, contaminated by malfunctioning septic systems or overuse of fertilizers or pesticides enters a stream).

Areas with high potential for causing non-point source pollution

Point Source Pollution

Point source pollution occurs at a specific point in the watershed. Generally point source discharges are regulated by permits issued by the Department of Environmental Protection. Most often these are permits for industrial waste, sewerage wastewater or a stormwater discharge. The permitting process attempts to minimize the impact of human activity on the surface water sources.

In the Brodhead Watershed there are numerous discharge permits and discharge points, ranging from systems discharging 1,000 gallons per day up to 2.25 million gallons per day in size. While point source sites do not contribute the volume of discharge to surface water sources that non-point source sites do, they must be maintained and operated properly or they can have an immediate negative impact on the receiving water body.

Point source discharges in the Brodhead watershed

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P.O. Box 339 Henryville, PA 18332 - Phone: (570) 839-1120