Baltimore County has almost 200 miles of tidal coastline as well as public and privately owned and operated tidal and fresh water recreational bathing beaches. In addition, the availability of these recreational water resources supports a significant number of related activities such as commercial and recreational fishing, skiing, camping, and boating.
The Department of Environmental Protection and Resource Management routinely conducts bacteriological sampling of many of these areas in an effort to provide information to the public on water quality and promote the safe use of these resources. View a map of the associated water sampling areas and locations (PDF - Warning, this file is 2.4MB and may take several minutes to download).
This sampling utilizes the bacteriological indicator organism Enterococci for salt water and E. coli for fresh water. These organisms are found in the intestines of all warm-blooded animals and are important chiefly because, when found in higher concentrations in conjunction with a known or suspected source of sewage contamination, the probable presence of other more pathogenic organisms is indicated.
A history of sampling also helps to provide some of the background information needed to evaluate long-term trends in water quality. Water conditions change constantly. It should be noted that any single sample or group of samples represents a “snap shot in time” and should not be used without other supporting information to characterize the water quality of a particular river, lake, or bay.
Water users should remember that all natural waters support many different microorganisms. Some of these organisms are pathogenic to humans. Most are not. Water users should note that murky or debris-strewn water, which often occurs after violent storms or heavy rains, is a general indication of poor water quality. Excessive storm water runoff after heavy rains can carry pet waste, agricultural waste, or fecal contaminants from brief sewage overflows as well as various chemicals including those associated with commercial and residential lawn care.
Swimmers, skiers, boaters, or any one whose activities will bring them into close contact with natural waters should always take into consideration their own observations before entering the water. Natural waters should never be considered safe for ingestion.
Find out about current Water Contact Alerts and Water Quality Advisories.
Water Contact Alert
Should sampling by the County measure elevated bacteriological levels due to a known or suspected sewage overflow, that would make water activities unsafe or unhealthy at a particular location, a Water Contact Alert will be issued. In the event that these conditions affect a public bathing beach, that beach will be closed. The Water Contact Alert will be posted on this web site and a press release will be issued to major media outlets. Signage may also be posted at points of greatest access to the affected body of water.
In open waters, the public will be advised to minimize water contact and the health risks associated with sewage contaminated waters will be noted. Visit this web site for updates. After a Water Contact Alert has been issued, the conditions, which may have contributed to poor water quality, will be investigated. After those conditions have abated, sampling will resume to determine when the water quality has improved to an acceptable level. The Water Contact Alert will then be lifted.
Water Quality Advisories
When monitoring in open areas of water indicates a widespread, abnormal rise in the concentration of bacteria and there is no known or suspected sewer overflow, a WaterQuality Advisory may be issued. These conditions are typically associated with storm water runoff. Water Quality Advisories are non-regulatory and usually temporary in nature. Advisories are issued to provide recommended precautions for recreational water users and applicable public health recommendations will be noted on this web site. Precautionary signage is not typically posted for Water Quality Advisories, however a Press Release may be issued if conditions are widespread and severe.
Water Quality Signage
In an effort to inform the public regarding specific health related precautions, various types of signage may be found in and around access points to both fresh and tidal waters.
Water Contact Advisory - Blue-Green Algae (PDF)
Water Contact Alert - No Recreational Activities (PDF)
Health Advisory - Back River (PDF)
Health Advisory - Baltimore Harbor (PDF)
Stream Sense (PDF)
Stream Sense Sign Locations (PDF) Provides a list of sign locations to help you locate Stream Sense Signs in your community
Revised June 9, 2009
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