How does recreational water quality impact health?
Massachusetts has over 1,000 freshwater and marine beaches (recreational water). The U.S. Environmental Protection Agency (EPA) and Massachusetts Department of Public Health (DPH) require that these beaches be monitored for bacteria. The presence of these bacteria can mean the water is polluted and people should not be swimming. Swimming in polluted water can cause illnesses, such as nausea, sore throat, earache, skin rash, or fever.
Many factors can affect whether exposure can lead to a health problem. These include the level of contamination, type of exposure (ingestion, inhalation, dermal, orbital, aural, nasal), and the length of contact time with contaminated water. Some populations may be more susceptible to health problems following exposure, such as pregnant woman, children, and immune-suppressed individuals.
How does DPH monitor beach water quality?
Since 2001, DPH's beach regulations (105 CMR 445.000: Minimum Standards for Bathing Beaches) requires all public and semi-public beaches in the state to be monitored for bacteria during the beach season. Examples of semi-public beaches include beaches at summer camps, hotels, condominiums, and country clubs.
Pollution in beach water is often associated with human or animal waste, which may enter the water in a variety of ways, including:
- Stormwater runoff
- Leaking sewer pipes
- Combined sewer overflows (a release of untreated sewage with rainwater)
- Illegal sewer hookups
- Poorly functioning septic systems
- Discharge of sewage by boats
- Pet waste
Most illness-causing organisms are difficult to measure directly, but water samples that contain them also contain bacteria which are easier to measure. When the presence of one organism is used to indicate the presence of another, it is referred to as an "indicator." These "indicator organisms" provide an indication of the presence and quantity of illness-causing organisms in the water.
In Massachusetts, the types of bacteria used as indicator organisms at marine beaches are enterococci and at freshwater beaches are either enterococci or Escherichia coli (E. coli). DPH's beach water quality standards are displayed in the table below. The values given are in colony forming units per 100 milliliters of water (cfu/100 ml), which is a standard way of measuring bacteria in water.
DPH’s beach water quality standards
| Bacteria | Single sample maximum | Geometric mean |
|---|---|---|
| Marine – Enterococci | 104 | 35 |
| Freshwater – Enterococci | 61 | 33 |
| Freshwater – E. coli | 235 | 126 |
The single sample maximum is the DPH standard for the amount of bacteria in the water that should not be exceeded and reflects short-term conditions. It is used to protect swimmers from a brief exposure to high levels of bacteria. The geometric mean is calculated from the five most recent samples and is intended to reflect typical water quality found during the preceding time period (typically a month). It was developed to protect swimmers from potential long-term exposures to levels of bacteria that are below the single sample maximum value, yet consistently elevated.
Water samples that contain levels of bacteria above regulatory standards are called exceedances. Depending upon the water quality history at the beach, either a single or two consecutive exceedances will trigger a beach posting. When this happens, signs must be posted at access points to the beach notifying the public that swimming is unsafe. Signs must remain posted until bacteria counts decrease to levels below the standard.
For more information and resources, visit the beach water quality webpage.
Available data
Current Public Beach Postings
Use the Current public beach postings link to explore the DPH interactive Beach water quality dashboard which provides water quality testing results for the current beach season. It will tell you which beaches are open or closed.
- The dashboard posts daily live data during the beach season (Memorial Day – Labor Day)
Historical Beach Data
Use the Historical beach data link to access beach water quality results from previous years for the following bacteria:
- Marine – Enterococci
- Freshwater – Enterococci
- Freshwater – E. coli
Data are available by year and can be viewed by community, county, and beach.
Data considerations:
- The exact dates of a given beach season vary from beach to beach and are determined by the beach’s operator. Some beaches open as early as Memorial Day, but the majority begin operation when the school year ends in mid-June. Most close for the season around Labor Day.
- The minimum frequency of monitoring required by DPH is weekly. Some beaches with water quality issues may be monitored more frequently. Beaches with very good water quality may be tested less frequently, usually one to two times a month.
- Beginning in 2014, a beach posting may be triggered by either a single sample result or two consecutive sample results that exceed the regulatory standards depending upon the water quality history at the beach.
- When using non-detect values in calculations, one half the detection limit is substituted. For example, if the reported result is <2, the value used in a calculation is 1.
DPH produces annual reports that present and summarize beach water quality statewide.
FAQs
Why is beach water sampled?
The state and federal beaches acts (both enacted in 2000) required that public and semi-public beaches be monitored for bacterial contamination in the water during the bathing season. Massachusetts promulgated regulatory revisions to address these requirements in 2001. Private beaches are not subject to these regulations.
What is a public beach?
A public bathing beach means any bathing beach open to the general public, whether or not any entry fee is charged, that permits access to bathing waters.
What is a semi-public beach?
A semi-public beach means any bathing beach that has common access and/or common use by a group or organization, which can be a bathing beach associated with a hotel, condominium or neighborhood association, summer camps, or a beach club.
Who monitors the beach water quality?
Local boards of health, the Barnstable County Department of Health and the Environment, and the Massachusetts Department of Conservation and Recreation conduct the vast majority of beach water sampling in Massachusetts. Most marine beach samples collected at public beaches are analyzed at Massachusetts Department of Public Health (DPH) contracted laboratories, and the cost of analysis is covered by DPH. Under the beaches acts, DPH is responsible for ensuring the regulations are adhered to by beach operators and local boards of health and providing technical assistance where needed.
How often is the water tested?
Depending on the beach, the water can be tested anywhere from every day to once per month. The testing frequency depends on how likely the beach is to have water quality issues. Infrequently used beaches or beaches that historically have had very few, if any, water quality issues are tested less often, while high-use or historically problematic beaches are tested more often.
What kind of bacteria is marine beach water tested for?
The water at marine beaches is tested for the presence of Enterococci. Enterococci are a group of bacterial species within the Streptococcus genus, some of which (e.g. Streptococcus faecalis) are typically found in human and animal intestines and are therefore present in sewage. These tests are also referred to as indicator organisms.
What are indicator organisms?
Indicator organisms are used to predict the presence of pathogenic, or disease-causing, organisms associated with fecal contamination. While in most cases the indicator organisms themselves are not pathogenic, they have similar life cycles and die-off rates to pathogens and are also found along with pathogens in human and animal waste.
What are the standards for beach water quality in marine water?
In marine waters, the accepted level of Enterococci for a single sample is 104 colony forming units per 100 milliliters (cfu/100 ml) of bathing water or below.
What happens if levels exceed 104 cfu/100 ml?
Any sample that comes back with a count greater than 104 cfu/100 ml is called an exceedance. At the vast majority of beaches statewide, if a sample exceeds water quality standards, then posting will not be required if a sample taken the following day shows compliance with water quality standards. For beaches with a history of more frequent elevated bacteria levels that remain for more than 24 hours, postings will continue to be required after each instance of elevated bacteria levels. A “history” is defined as one or more consecutive exceedances in two or more of the last four beach seasons.
What are the standards for beach water quality in fresh water?
In fresh water, the accepted level of Enterococci for a single sample is 61 cfu/100 ml or below. The freshwater limit is stricter because elevated concentrations of bacteria within a smaller volume of water (such as a lake versus the open ocean) can pose higher risks of illness. Freshwater beaches can also be tested for E. coli instead of Enterococci. The accepted level of E. coli for a single sample is 235 cfu/100 ml or below.
Are beach postings triggered in any other way?
DPH also developed a standard that derives a geometric mean from the last 5 testing results at a beach. The geometric mean may indicate that sample levels are consistently high enough over time to post the beach in order to protect the public from possible swimming-related illness. In marine water, the geometric mean standard for Enterococci is 35 cfu/100 ml. In fresh water, the geometric mean standard for E. coli is 126 cfu/100 ml and the geometric mean standard for Enterococci is 33 cfu/100 ml.
What does it mean for a beach to be posted?
If a beach is posted, it means recreational use of the water is prohibited. You can still go to the beach to take a walk or enjoy any recreational activities that do not involve contact with the water. The beach will remain posted until the bacterial levels have been shown by laboratory analysis to have dropped back down into the desired range.
What type of illness can you get from contact with water contaminated with bacteria?
Swimming in polluted water can cause gastrointestinal symptoms such as nausea, vomiting, diarrhea, and abdominal pain, respiratory symptoms like sore throat, cough, runny nose, and sneezing, eye and ear symptoms including irritation, earache, and itchiness, dermatological symptoms like skin rash and itching, and flu-like symptoms such as fever and chills. Most of these symptoms are minor most of the time but can occasionally be more serious, especially in sensitive populations (e.g. immunocompromised children and elderly).
How can I reduce my risk of illness from swimming?
There are a few things you can do to reduce your risk of illness from swimming. You should find out from your local health department if the beach you want to go to is monitored regularly and posted for closures. You are less likely to be exposed to polluted water at beaches that are monitored regularly and posted for health hazards. Because bacterial levels tend to rise due to runoff after heavy rains, avoiding swimming after heavy rain events would also be prudent. Do not swim near trash and other obvious sources of pollution, such as drainage pipes.
What are the sources of bacteria in the water?
Bacteria may be present in the water due to a variety of sources including but not limited to sewage treatment plant outfalls, illegal sewage hookups, leaking septic tanks, boats dumping sewage directly into the water, and combined sewer overflows. Rain is often a contributing factor to beach water pollution. As rainwater washes over land, it can carry bacteria to the beach.
What about animal wastes on the beach?
Animal waste, such as from dogs or birds, can get into the water and negatively affect water quality at beaches. The bacteria in dog and bird waste can elevate bacterial levels which can lead to beach postings. Properly cleaning up after your pet can lessen the likelihood of your pet's waste contaminating the beach water. Similarly, refraining from feeding birds at beaches should help reduce potential bacterial contamination.
What can I do to enhance water quality at beaches I use?
Everyone can take steps to help reduce contamination and pollution, both at home and at the beach. At home, regularly maintain your septic system. Use natural substances like compost to fertilize gardens and lawns. If you must use fertilizers or pesticides, read the label and use as little as possible. Throw trash away in proper containers. Don't pour anything in storm drains; they are meant only for rainwater and may empty out at your favorite swimming spot. At the beach, throw away your trash and pet waste using public trash receptacles or take it home with you. Pick up trash left by others. Use public restrooms. Dispose of boat sewage in onshore sanitary facilities instead of dumping it into the water. Use walkways instead of walking across dunes; this will help reduce erosion and preserve vegetation that aids in filtering out pollutants from runoff before they reach the beach.
How do I know when a beach is sampled?
Every beach is required to have signage displayed at the beach displaying the dates of operation. Regulations require beach operators to sample within these dates.
How can I find out if the beach is open or has been posted?
Go to the Interactive Beach Water Quality Dashboard and select the region, community, and beach you are interested in to find out its current status.
Related Links
Additional Resources
U.S. Environmental Protection Agency (EPA) Beaches: Information on water pollution at beaches, advisories at specific beaches, and how the EPA protects beach water quality