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| The Gunpowder River, a good quality stream, feeds into the Loch Raven Reservoir, the primary drinking supply for the Baltimore Region. |
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| Test kits are carried in the field to allow for on-site testing that is reqired for some chemical samples. |
Is it safe to go in the water?
Jaws may not be lurking in a deep pool in our backyard stream, but what is in there? Long gone are the days when you could just fling off you’re cowboy hat and help yourself to a drink from the nearby stream on a hot summer day. But thanks to the Clean Water Act, gone too are the days when rivers were so polluted that they posed a fire hazard. Results of DEPRM's mopnitoring are published annually in its NPDES report.
Baltimore County Department of Environmental Protection and Resource Management (DEPRM) monitors more than 100 sites for chemical conditions six to eight times during the year. A sudden rain shower might flush nutrients and bacteria from nearby agriculture into the stream. Our roads act like conduits for pollution in shopping areas and urban neighborhoods. Wildlife, pets, and a failing septic tank will contribute pollutants intermittently so that what’s in the water is constantly changing. This is why monitoring the water on a regular basis is important.
Water samples are collected from selected stream sites using small sterile containers. Just as your doctor doesn’t test you for every known disease, DEPRM conducts sixteen (16) tests for pollutants that are prevalent in streams or are listed by the United States Environmental Protection Agency. Sixteen items are a lot to think about so we often divide them into categories.
The first sets of four tests are for the nutrients nitrogen and phosphorus. Nutrients are chemicals that are vital to growth in plants. Too many nutrients results in the growth of large quantities of algae. Algae can cause algal blooms in the bay and create problems with oxygen levels, water clarity, and contribute to dead zones. Several different forms of nitrogen and phosphorus are tested for in order to get a complete understanding of how much of the chemicals are in the system. Sources of nutrients include fertilizers, sewage, wildlife, agriculture, and atmospheric pollutants.
The problems of water clarity and oxygen levels that nutrients in the stream can cause are also measured in other ways. Total Suspended Solids and Total Solids are measured to provide a measure of the clarity of the water. Biological Oxygen Demand (BOD) indicates the amount of oxygen required by aerobic microorganisms to decompose the organic matter in a sample of water. Chemical Oxygen Demand (COD) indicates the amount of oxygen that is needed to oxidize reactive chemicals in water.
Heavy metals are also a concern. Cadmium, Copper, Zinc and Lead are the metals tested for in the collected water samples. Heavy metals are generally toxic to both wildlife and humans and can cause a variety of problems. The metals often sink into the sediments in the bottom of streams and lakes and are particular problems for aquatic life that lives there. These metals can accumulate in some species of fish that people like to eat then the metals can impact human health.
In addition to analyzing the water for nutrients and heavy metals, DEPRM checks the water for the presence of bacteria in the streams. Some bacteria can be found naturally in soils and streams and some bacteria indicates the presence of human or animal waste in the stream. DEPRM tests for specific bacteria that can indicate the presence of waste and may make people sick. For recreational waters, bacteria levels are checked 13–15 times between May and November.
Baltimore County combines the data from chemical monitoring with information gathered from observing the physical conditions of the stream and from biological surveys to help provide a more complete picture regarding the condition of our waterways. All the data together can help identify the streams that are at risk and contribute to creating an informed plan to reduce pollutants and improve water quality.
To help further understand the condition of the stream measurements of temperature, pH, and the volume of water flowing are taken.
All of these tests are also examined with Biological monitoring conducted and studies made of the physical conditions of the streams. By combining each of these, we have a clearer understanding of the health of the waterways.
Watershed Management and Monitoring
Phone: 410-887-5683
Fax:410-887-3510
E-mail: watersheds@baltimorecountymd.gov
Revised October 29, 2007
Courthouse 