Susquehanna River Basin's Early Warning System
The Commission designed the Early Warning System (EWS) to help protect the Basin’s drinking water supply. Safe drinking water is a basic need for everyone and the first step towards safe drinking water is to have a clean source of water. The EWS provides a framework for innovative partnerships and protocols and for fostering communication and data sharing among public water suppliers, state/local agency personnel, and the emergency response community for the purpose of enhancing drinking water protection efforts.
The current EWS enhances protections for public drinking water supplies serving about 850,000 people, provides a monitoring network that helps minimize the impact from contaminant spills, and provides data for improving day-to-day treatment operations, further ensuring a continuous and safe supply of drinking water. Furthermore, with heightened national security concerns, the Commission’s EWS has become an important tool for participating water suppliers and emergency management officials.
The EWS was established for Pennsylvanian water suppliers with intakes in the Susquehanna River in 2003 and was expanded into the New York portion of the Basin in 2006. The goal of the system is to monitor the river for changes in water chemistry and the presence of contaminates. The system consists of nine stations that monitor a minimum of pH, turbidity, and temperature. Four of the nine stations have enhanced monitoring for organic carbon contamination. Several of the stations also monitor for conductance and/or dissolved oxygen. The data collected by the nine stations help to minimize the effect of contamination events and improve day-to-day treatment operations.
For more information, please see the following links:
- Early Warning System Fact Sheet
- Real-Time Data and Maps for Water Suppliers (username and password required)
EWS partners include Chester Water Authority, Columbia Water Company, United Water of Pennsylvania, PA American Water Company, Danville Borough Water Department, Elmira Water Board, Binghamton Water and Sewer Department, Kirkwood Water and Sewer Department, U.S. Environmental Protection Agency, Pennsylvania Department of Environmental Protection, and Susquehanna River Heartland Coalition for Environmental Studies.
Uncertainty and potential for error can be associated with environmental monitoring data. No warranty, express or implied, is given as to the accuracy, reliability, utility or completeness of the data hosted on this website, and the Commission shall not be held liable for improper or incorrect use of the data described or information contained on these pages.
pH is a measure of water's acidity/basicity. The range goes from 0–14, with 7 being neutral. A pH of less than 7 indicates acidity, whereas a pH of greater than 7 indicates basicity. pH is really a measure of the relative amount of free hydrogen and hydroxyl ions in the water. Water that has more free hydrogen ions is acidic, whereas water that has more free hydroxyl ions is basic. Since pH can be affected by chemicals in the water, pH is an important indicator of water that is changing chemically. pH is reported in "logarithmic units," like the Richter scale which measures earthquakes. Each number represents a 10-fold change in the acidity/basicity of the water. Water with a pH of 5 is ten times more acidic than water having a pH of six.
The USEPA recommends that public water suppliers maintain pH levels between 6.5 and 8.5. Water with a low pH or acidic water can leach metal from pipes leaving a metallic or sour taste in the water. Acidic drinking water can also stain laundry, leave blue-green stains in sinks and drains, and damage pipes and fixtures. Basic water or water with a pH greater than 7 contains alkaline minerals. These minerals can cause scale build-up on pipes and fixtures. The minerals can also give water an alkaline taste and make coffee bitter. Water suppliers use a variety of chemical additions to control pH levels in their finished water.
Turbidity is the amount of particulate matter that is suspended in water. Turbidity monitors measure the scattering effect that suspended solids have on light: the higher the intensity of scattered light, the higher the turbidity. Material that causes water to be turbid includes:
- finely divided organic and inorganic matter
- soluble colored organic compounds
- microscopic organisms
Turbidity makes the water cloudy or opaque, and is reported in nephelometric turbidity units (NTU). During periods of low flow (base flow), many rivers are a clear green color, and turbidities are low, usually less than 10 NTU. During a rainstorm, particles from the surrounding land are washed into the river making the water a muddy brown color, indicating water that has higher turbidity values. Also, during high flows, water velocities are faster and water volumes are higher, which can more easily stir up and suspend material from the stream bed, causing higher turbidities. Turbidity has far reaching impacts on water treatment plants. The particles that make the water turbid provide food and shelter for pathogens and can carry nutrients, heavy metals and other toxins. If the particles are not removed correctly, they can cause unpleasant tastes and odors in the finished water. To ensure proper treatment, larger qualities of chemicals are needed to remove the additional particles from the water, and filters need to be cleaned or back-flushed more frequently, which increases operational costs.
Water temperature is very important to fish and other aquatic life, as well as for swimmers, fishermen, and industries. Temperature affects the ability of water to hold oxygen and affects chemical reactions used in the treatment process.
Total Organic Carbon
Total organic carbon is the measure of organic carbon, carbon-based molecules derived from living organisms, in the water. Organic carbon can come from decaying plant and animal matter or petroleum-based products. Organic carbon can be found in pesticides, fertilizers and many other products. Organic carbon reacts with the chlorine used to disinfect the water. The byproducts of this reaction are known as disinfection byproducts (DBP) and are carcinogenic. TOC monitors are used to detect organically-based chemical contaminants.
Specific conductance is a measure of the ability of water to conduct an electrical current. It is highly dependent on the amount of dissolved solids (such as salt) in the water. Pure water, such as distilled water, will have a very low specific conductance, and sea water will have a high specific conductance. Rainwater often dissolves airborne gasses and airborne dust while it is in the air, and thus, often has a higher specific conductance than distilled water. Specific conductance is an important water quality measurement because it gives a good idea of the amount of dissolved material in the water.
High specific conductance indicates high dissolved solids concentration; dissolved solids can affect aquatic life, as well as the suitability of water for domestic, industrial, and agricultural uses. At higher levels, drinking water may have an unpleasant taste or odor or may even cause gastrointestinal distress. Additionally, high dissolved solids concentration can cause deterioration of plumbing fixtures and appliances. Relatively expensive water treatment processes, such as reverse osmosis, are needed to remove excessive dissolved solids from water.
The oxygen dissolved in lakes, rivers, and oceans is crucial for the organisms and creatures living in it. As the amount of dissolved oxygen drops below normal levels in waterbodies, the water quality is harmed and creatures begin to die off. Indeed, a waterbody can "die," a process called eutrophication.
A small amount of oxygen, up to about ten molecules of oxygen per million of water, is actually dissolved in water. This dissolved oxygen is breathed by fish and zooplankton and is needed by them to survive.
Rapidly moving water, such as in a mountain stream or large river, tends to contain a lot of dissolved oxygen, while stagnant water contains little. Bacteria in water can consume oxygen as organic matter decays. Thus, excess organic material in our lakes and rivers can cause an oxygen-deficient situation to occur. Aquatic life can have a hard time in stagnant water that has a lot of rotting, organic material in it, especially in summer, when dissolved oxygen levels are at a seasonal low. Although dissolved oxygen is not often used in day-to-day operations of water suppliers, it is still of great value in characterizing the overall health of rivers.