Sourcewater Protection Center

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Source water is the untreated “raw” water from streams, rivers, lakes, springs, and underground aquifers that serve as sources of a community’s drinking water.  Source Water Protection (SWP) is a voluntary effort to take action to prevent contaminants from entering public drinking water sources.  The goal of source water protection is to protect both groundwater sources (also called “wellhead protection”) and surface water sources (lakes, streams, rivers) used for drinking water and other human and agricultural uses.

Source water protection planning is a five step process in Pennsylvania.  These five steps are itemized below and pictured on the sidebar.

  1. Form a steering committee
  2. Delineate protection areas
  3. Identify and prioritize contaminant sources
  4. Choose management and protection strategies
  5. Plan for the future

There are two types of source water: surface water and groundwater.

Surface Water is the water that lays on the Earth’s surface in lakes, rivers and streams. It can be contaminated by pollution flowing over the land or directly into lakes, rivers and streams. Pollution can also come from the air or from materials that have become deposited in the bottom of the water body. Pennsylvania has more than 86,000 miles of rivers and streams, and over 4,000 lakes, reservoirs, and ponds. Water systems draw surface water into treatment facilities through intake pipes.

Title 25 Chapter 93, of the Pennsylvania Code defines surface waters as “perennial and intermittent streams, rivers, lakes, reservoirs, ponds, wetlands, springs, natural seeps and estuaries.”

Groundwater is the water beneath the Earth’s surface found in the cracks and spaces between soil, sand and rock particles. Groundwater exists below the surface of the earth in two zones, the moisture contained within the soils and the water table. This is the source for the replenishment of rivers and streams, as well as a source of water for public and private wells. Groundwater is replenished through precipitation that infiltrates downward through the soil and rock openings to the water table, commonly known as groundwater recharge.

Surface water and groundwater can be interconnected, with water flowing from one to the other. Groundwater can become contaminated by pollutants that are deposited on the surface soil or underground but it can take much longer for the contamination to reach a well than a surface water intake. For the same reasons it takes longer for contamination to reach a groundwater source it is also much more difficult to fix groundwater contamination problems once they occur. Water systems draw groundwater into their facilities from wells.

CLEANSAFE, and RELIABLE DRINKING WATER is fundamental to the viability of any community, and as advanced as today’s treatment technologies are, they are not perfect. Not all contaminants can be removed or treated–and it is often far more costly to treat contaminated water than prevent contamination from occurring in the first place.


In Pennsylvania, Source Water Protection programs are voluntary efforts that help community water systems protect their sources of raw water. Having a program in place provides multiple benefits, including:

Public Health Protection – Source water protection planning helps minimize threats to public health through prevention, by keeping harmful contaminants out of the water supply.

Reduced Water Treatment Complexity and Cost – Clean water is simpler and  less expensive to treat and reduces system operation and maintenance costs.

Economic Benefit – Clean and plentiful water enhances the community’s potential to attract employers and tourism, maintains a healthy economy and improves quality of life for residents.

Sustainability – Protecting water resources sustains local ecosystems and assures quality of life for future generations. Costs of protection planning are very low compared with costs of remediation.

Source Water Protection programs are typically designed and implemented with input from a broad range of local stakeholders-and though they share common elements, each is tailored to a community water system’s specific circumstances.

In Pennsylvania, assistance is available through the DEP’s Source Water Protection Technical Assistance Program (SWPTAP), which is designed as a suite of services to help water suppliers to develop and establish local SWP programs.  Review the SWPTAP Fact Sheet.