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City of Philadelphia

Sourcewater Issues

The quality of our drinking water is directly linked to the quality of our source water—the Delaware and Schuylkill rivers. 
The following issues raise concerns related to maintaining a high quality drinking water source for Philadelphia.

Climate Change
Climate change is a change in the statistical distribution of weather over periods of time, ranging from decades to millions of years. In the northeastern United States, climate change has the potential to impact the region’s water supplies in multiple ways. Increased overall precipitation and changes in vegetation could exacerbate stream bank scouring and lead to increased levels of pollutants washing into our waterways. Severe weather could compromise water and wastewater facilities and infrastructure and lead to more frequent spills and accidents. Increased temperatures could foster bacterial growth and substantially decrease the oxygen supply available for aquatic life. Water availability may also become a bigger concern with the potential for climate change to produce more frequent, short-term droughts in our area.

Forest Clearing and Development
Forest clearing miles from Philadelphia to accommodate land development, economic initiatives, such as natural gas drilling, and increasing populations can significantly decrease the quality of our water supply. As an example, if all of the forest in the Schuylkill watershed were cleared for development, fecal coliform levels could increase by over 250%. Consequently, land preservation is an extremely important component of source water protection.

Stormwater Runoff
You may notice that rivers turn brown after heavy rains. That’s because rain runoff scours dirt and sediment from river banks and washes pollutants form the land into the water. Bacteria levels are highest in Philadelphia’s rivers after rain events. According to Rivercast (, conditions on the Schuylkill River are unsuitable for certain types of recreation over 30% of the time due to high bacteria levels.

Agriculture Runoff
According to a federal report, runoff from agriculture land is now considered the primary source of pollutants in streams and rivers in the United States. Over 25% of the land that influences the Schuylkill and Delaware rivers is used for farming. The runoff from land associated with agricultural activities contains bacteria, pathogens, sediment and fertilizers, all of which enter our waterways as runoff during storm events.

Spills and Accidents
Rivers, which serve as drinking water sources not just in Philadelphia, but across the nation, are vulnerable to accidental, natural and deliberate contamination events. Since May 2008, over 50 events including sewage leaks, oil spills and fish die-offs were reported in waterways near Philadelphia. These contamination threats create the need for comprehensive early warning systems for many organizations, purveyors, and industries that rely on high water quality water resources from the Delaware and Schuylkill rivers.

Treated Wastewater Effluent
Hundreds of wastewater treatment plants discharge into the Schuylkill and Delaware rivers above Philadelphia. The Schuylkill River is sometimes as much as 60% treated wastewater discharge during prolonged periods without rain. The water department is closely studying impacts of such high percentages of effluent on overall water quality.

Improper Disposal of Trash/Waste
Many of Philadelphia’s storm drains lead directly to our rivers. Throwing pet waste, leftover paint, toxins or trash down storm drains pollutes our drinking water sources. Through an increased awareness of the connection between “street to stream”, this source of pollution has the potential to be significantly reduced.

Pharmaceuticals get into drinking water because people now take more medications than ever, both prescription and over the counter, and only a small portion of these substances is absorbed in the body. The rest passes through the body, eventually making its way into the rivers and streams that serve as our nation’s drinking water sources. These compounds are at such low concentrations that they cannot be detected unless the most advanced methods are used, and there is currently no indication that such small concentrations pose any public health risk. Studies do show impacts to fish, however, which have constant exposure to these substances.

Pollution from Geese and Wildlife
Geese and other wildlife are sources of contamination in our waterways. A single goose can produce up to three pounds of manure every day and 1,095 pounds of fecal material every year. Just two geese can produce over one ton of fecal material. This waste, which contains bacteria and other harmful pathogens, comes into contact with or is washed into our waterways, presenting public health and drinking water treatment concerns.