Massachusetts has more than 500 public and semipublic marine beaches along 204 miles of sandy shore that line Atlantic waters. The monitoring program is a collaborative effort between the local boards of health and the Massachusetts Department of Public Health (MDPH) and is administered by MDPH.
Converting Septic to Sewer Cleans Up Silver Beach
Malfunctioning septic tanks are often implicated in beachwater contamination. The town of Falmouth completed a sewer extension in July 2009 that converted many homes from septic tanks to municipal wastewater treatment. This has improved water quality at New Silver Beach. From 2006 to 2008, 6% of samples at this beach exceeded water quality standards, but in 2009, 2010, and 2011 there were no exceedances.
No-Discharge Zones in Massachusetts
No-discharge zones are designated by the U.S. EPA and prohibit boats from discharging both treated and untreated sewage, which can contaminate beachwater. Within no-discharge zone boundaries, boat operators are required to retain their sewage onboard for disposal at sea (beyond three miles from shore) or onshore at a pump-out facility. In August 2011, a no-discharge zone was designated by the U.S. EPA in the coastal waters off the towns of Chatham, Orleans, Eastham, Wellfleet, Truro, and Provincetown. With the addition of these waters, two-thirds of Massachusetts's coastal waters are now no-discharge zones.
Reducing Combined Sewer Overflows Improves Beachwater Quality
Many urban areas along the coast of Massachusetts are served by combined sewer systems that treat both stormwater runoff and sewage before discharging it to surface waters. These systems can be overwhelmed by the volume of stormwater and sewage they receive during heavy storms, resulting in discharges of raw or partially treated sewage. The Massachusetts Water Resources Authority North Dorchester Bay CSO Storage Tunnel, a 17-foot-diameter combined-sewer overflow tunnel in South Boston, began operating on June 1, 2011. In addition to holding combined-sewer overflows for later treatment, this tunnel stores stormwater flows during all but the largest rainstorms and pumps both stormwater and combined-sewer overflow for treatment as capacity allows, thus preventing a large source of bacteria from reaching the beaches of South Boston. Despite exceptionally heavy rains during the summer of 2011, beachwater quality improved that year at these beaches, with just 4 exceedances of water quality found in 2011 compared with 19 in 2010.
What Does Beachwater Monitoring Show?
In 2011, Massachusetts reported 634 coastal beaches and beach segments. Of these, 12 (2%) were assigned a monitoring frequency of once a day, 566 (89%) a frequency of once a week, 7 (1%) every other week, and 49 (8%) once a month. In 2011, 6% of all reported beach monitoring samples exceeded the state's daily maximum bacterial standard of 104 colonies/100 ml. Samples taken at 31 beaches in Massachusetts exceeded this standard at least 20% of the time. The beaches with the highest percent exceedance rates of the state standard in 2011 were Cockle Cove Creek?Parking Lot in Barnstable County (67%), Kings at Stacy Brook (67%) and Donovans (45%) in Suffolk County, and West Manchester (44%) and Woodbury (39%) in Essex County. Some of those high-exceedance locations are segments of larger beaches whose water quality is not adequately represented by the beaches on this list. Beaches in Norfolk County had the highest exceedance rate of the state standard in 2011 (12%), followed by Essex (10%), Bristol (8%), Nantucket (8%), Dukes (7%), Suffolk (7%), Barnstable (4%), and Plymouth (3%) counties. 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.
Note that in some counties, such as Nantucket County, most of the beaches have a sampling variance. Under Massachusetts regulations, a variance allows for less-frequent sampling at beaches that have no potential sources of contamination and that have gone two years without an exceedance. In these counties, the exceedance rate may be higher in part because the cleanest beaches in the county are not sampled as frequently as other beaches.
In addition to Tropical Storm Irene, there was above-normal rainfall in Massachusetts during the summer of 2011. Close to 5 inches of rain fell in June (half again as much as the historical monthly average), and almost 8 inches fell in August in the Boston area (nearly 2.5 times the historical monthly average). Increased rainfall is generally associated with a decline in beachwater quality because of rain-related sewer overflows as well as stormwater runoff, which can pick up bacteria from roads and other surfaces and carry it to ocean waters. However, Massachusetts did not experience a higher rate of exceedances of the state standard in 2011, a signal that the state is taking effective steps to clean up its beachwater.
* Please note that only samples from a common set of beaches monitored each year from 2007-2011 are included in the bar chart.
What Are Massachusetts's Sampling Practices?
The monitoring season starts as early as Memorial Day at some beaches and lasts through Labor Day for most.
MDPH coordinates the efforts of a range of collaborators including local boards of health, the Barnstable County Department of Health and the Environment, and the Massachusetts Department of Conservation and Recreation. MDPH determines sampling practices, locations, standards, and notification protocols and practices throughout the state. Samples are collected in 3 feet of water, 1 foot below the surface. State water quality regulations require that all public and semipublic freshwater and marine bathing beaches in Massachusetts be monitored during the bathing season for bacterial contamination. (Semipublic beaches are not open to the general public but more than a single owner is allowed use.) The sampling frequency for Massachusetts's beaches is based on use and the potential for pollution problems. As noted above, if a beach has been monitored weekly for the two most recent consecutive years with no exceedance of standards being found, and if a sanitary survey conducted by a registered sanitarian reveals no potential sources of pollution at that beach, the beach managing entity may be allowed to sample less frequently.
Beachwater quality samples must be taken in the areas of greatest bather load. However, beach operators are encouraged also to sample where outfalls and other sources of contamination are present. When an exceedance is found, sampling is generally conducted every day until the standards are met, after which the beach is reopened. Also, beaches that issue preemptive rainfall advisories generally sample on the day of rainfall or the day after. States that monitor more frequently after an exceedance is found or after rainfall will tend to have higher percent exceedance rates and lower total closing/advisory days than they would if their sampling frequency did not increase after an exceedance or a rain event.
How Many Beach Closings and Advisories Were Issued in 2011?
Total closing/advisory days for 479 events lasting six consecutive weeks or less increased 1% to 1,273 days in 2011 from 1,256 days in 2010. For prior years, there were 1,478 days in 2009, 1,102 days in 2008, 567 days in 2007, 1,092 days in 2006, and 680 days in 2005. In addition, there were 4 extended events (283 days total) and no permanent events in 2011. 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 479 events lasting six consecutive weeks or less, 78% (994) of closing/advisory days were due to monitoring that revealed elevated bacteria levels, 12% (151) were preemptive due to tropical storm riptides and related conditions, and 10% (128) were preemptive due to heavy rainfall.
How Does Massachusetts Determine When to Warn Visitors About Swimming?
Beaches are closed to swimming when either the single-sample maximum or the geometric mean standard is exceeded. Whether beach action days are reported to the EPA as closings or advisories, restrictions and notifications are the same. For marine beaches, the standard is a single-sample maximum of enterococcus of 104 cfu/100 ml, or the geometric mean of the 5 most recent samples within the current bathing season of 35 cfu/100 ml. There is no requirement that the geometric mean be calculated on the basis of samples taken over a 30-day period.
In addition to fecal indicator bacteria monitoring, beaches must also be tested for oil, hazardous materials, and heavy metals if there is information indicating possible contamination.
Preemptive rainfall standards are in use at several beaches on Boston Harbor, and preemptive rainfall closings are issued after any significant rainstorm at a bathing beach where there has been a history of violations of water quality standards. In addition to preemptive rainfall closings and closings due to bacterial exceedances, the local board of health and/or MDPH can close a beach if they determine there is a threat to human health for any other reason, such as an oil spill. Beaches can be closed if there is a red tide (a bloom of the harmful algal bacterium Alexandrium) that decreases visibility in the water to such an extent that the beach operator considers it a rescue safety hazard. Local boards of health can also preemptively close beaches that have consistently elevated bacterial indicator levels.
Massachusetts 2011 Monitoring Results and Notice and Advisory Days
||Assigned Monitoring Frequency
||% of samples exceeding state standards
||Closing or Advisory days