Maryland 2012 Beachwater Quality Summary
Reported Sources of Beachwater Contamination
(number of closing/advisory days)
- 41 (100%) unknown contamination sources
There are 70 coastal beaches in Maryland lining 19 miles of the Atlantic Ocean and the Chesapeake Bay. Beachwater quality is monitored through a program administered by the Maryland Department of the Environment (MDE).
What Are the Water Quality Challenges and Improvements in Maryland?
New Efforts to Reduce Stormwater
When stormwater runs over materials like fertilizer, oil, gas, and bare soil, it can become contaminated and cause erosion. That runoff carries pollution and leads to stream and groundwater contamination. To reduce stormwater pollution, the Maryland General Assembly passed a bill (H.B. 987) in 2012 requiring the city of Baltimore and the nine largest counties (Anne Arundel, Baltimore, Carroll, Charles, Frederick, Harford, Howard, Montgomery, and Prince George's) to adopt and implement a stormwater fee and dedicated fund by July 1, 2013. The funds will help to construct and maintain pollution controls and correct drainage and flooding issues created by stormwater.
Digital Data Acquisition and Processing
The MDE is currently working with Maryland's Department of Health and Mental Hygiene and local health departments to beta test a digital data acquisition and processing system that would facilitate water quality sample collection, sample testing, and data generation/transfer.
Maryland state regulations require sanitary surveys at all beaches prior to beach season. During 2012, the MDE worked with Kent County Health Department to track the flow of stormwater from an effluent pipe near Betterton Beach in Kent County. The findings indicated that the effluent was not flowing in the direction of the beach.
Enterococcus in Beach Sand, Beachwater, and Ocean Sediment
Enterococcus is a fecal indicator bacterium used to determine whether fecal contamination of beachwater may have occurred. Beach managers throughout the country have wondered if enterococcus is growing in beach sand and in ocean sediments and making its way via those routes into beachwater at some locations. If so, enterococcus levels may not be reliable indicators of fecal contamination. In 2010, Maryland took part in a study to investigate the relationship among enterococcus levels in beach sand, ocean sediment, and beachwater. Researchers determined that the concentrations of enterococcus in sand and sediment were not related to its concentration in beachwater, and that while enterococcus can survive in beach sand and sediment, regrowth of enterococci did not occur under laboratory conditions in either sand or sediment from these beaches. The conclusion, at least for the beaches involved in the research, is that enterococcus is not replicating itself in the beach sand and ocean sediment and contaminating the beachwater in that fashion.
What Does Beachwater Monitoring Show?
In 2012, Maryland reported 70 coastal beaches, of which 6 (9%) were assigned a monitoring frequency of more than once a week, 18 (26%) once a week, 24 (34%) every other week, and 19 (27%) once a month; 3 (4%) were not assigned a monitoring frequency. In 2012, 4% of all reported beach monitoring samples exceeded the state's daily maximum bacterial standard of 104 colonies/100 ml (158/100ml for Tier 3 beaches). The beaches with the highest percent exceedance rates of the daily maximum standard in 2012 were Mayo Beach Park in Anne Arundel County (19%), Grove Point Camp in Cecil County (17%), Gunpowder State Park Hammerman in Baltimore County (15%), Sandy Point State Park East Beach in Anne Arundel County (11%), and Elk Neck State Park North East River in Cecil County (8%). Cecil County had the highest exceedance rate of the daily maximum standard in 2012 (10%), followed by Anne Arundel (7%), Queen Anne's (6%), Baltimore (6%), Worcester (2%), and Calvert (1%). No samples taken in Somerset and St Mary's exceeded the daily maximum standard. NRDC considers all reported samples individually (without averaging) when calculating the percent exceedance rates in this analysis. This includes duplicate samples and samples taken outside the official beach season, if any.
Maryland Percent of Samples Exceeding the State's Daily Maximum Bacterial Standard for 64 Beaches Reported 2008-2012*
* Please note that only samples from a common set of beaches monitored each year from 2008-2012 are included in the bar chart.
What Are Maryland's Sampling Practices?
The monitoring season runs from Memorial Day to Labor Day. Sampling and notification activities are delegated to local health departments. Current guidance and regulation are consistent across the board and apply to all coastal beaches in Maryland. Samples are taken in knee-deep water, 1 foot below the water's surface. Priority for monitoring Maryland's coastal beaches is based on the level of bather use, historical water quality, proximity to potential or actual pollution sources (including human and animal fecal contamination sources), beach structure, ecological factors, and any other conditions that could contribute to beachwater quality. Tier 1 beaches (the highest-priority beaches) are assigned a monitoring frequency of once a week, medium-priority beaches (Tier 2) are assigned a monitoring frequency of twice a month, and the lowest-priority beaches (Tier 3) once a month. The Worcester County Health District has opted to monitor Ocean City beaches (6 locations) twice a week. Beaches in Maryland are defined in part by use; those that are not used are not considered to be beaches and are removed from the beach list.
Maryland's beach monitoring program recommends that local health departments sample the following day when a beach is closed or placed under advisory, but limited staffing and resources at some beaches sometimes prevents this. States that monitor more frequently after an exceedance is found will tend to have higher percent exceedance rates and lower total closing/advisory days than they would if their sampling schedule did not increase after an exceedance was found.
How Many Beach Closings and Advisories Were Issued in 2012?
Total closing/advisory days for 7 events lasting six consecutive weeks or less decreased 78% to 41 days in 2012 from 189 days in 2011. In prior years, there were 330 days in 2010, 133 days in 2009, and 61 days in 2008. In addition, there were 2 extended events (98 days total) and 3 permanent events (1,095 days total) in 2012. Extended events are those in effect more than six weeks but not more than 13 consecutive weeks; permanent events are in effect for more than 13 consecutive weeks. For the 7 events lasting six consecutive weeks or less, 100% (41) of closing/advisory days were due to monitoring that revealed elevated bacteria levels.
How Does Maryland Determine When to Warn Visitors About Swimming?
In Maryland, closings are issued for known pollution events or other unsafe conditions, and advisories are issued when bacteria standards are exceeded and no known pollution source is present. All counties notify the public when a beach is closed or an advisory is issued by posting updates on the Maryland Healthy Beaches website, posting signs at the beach, operating phone hotlines, sending press releases, and/or emailing interested parties.
Maryland applies a 30-day geometric mean standard of 35 cfu/100 ml and a daily maximum standard for enterococcus of 104 cfu/100 ml at Tier 1 and Tier 2 coastal beaches. The daily maximum standard at Tier 3 beaches is 158 cfu/100 ml. Three samples are taken per sampling event, and the average of the sampling results is used to determine whether the daily standard is being met. The average of three samples taken per sampling event is used to find five evenly spaced values over a 30-day period that are used to calculate the geometric mean.
If the local health department determines that valid sampling results indicate an exceedance of either the single-sample maximum or geometric mean standard, a notification can be issued without resampling. If the validity of a sample is in doubt, local health departments may resample before issuing an advisory.
Maryland does not have preemptive rainfall advisory standards, but rainfall information for each beach is provided on the Maryland Healthy Beaches website. The public is generally advised to avoid swimming after a significant rain event because polluted stormwater runoff can carry disease-causing organisms to the beach.
If a known pollution source exists, such as a combined sewer overflow, failing sewer infrastructure, or wastewater treatment discharge, the county must close the beach. Maryland is one of the few states that require sewage treatment plants to report all sewage spills in a timely manner to local health departments and the state department of the environment. The local health department or MDE may also issue an immediate closing if there is any other type of dangerous contaminant or condition.
Maryland 2012 Monitoring Results and Closing/Advisory Days