Michigan 2012 Beachwater Quality Summary
Reported Sources of Beachwater Contamination
(number of closing/advisory days)
- 174 (54%) unknown contamination sources
- 84 (26%) other contamination sources
- 64 (20%) stormwater runoff
- 2 (1%) wildlife
Michigan has more than 600 public beaches stretching along more than 3,200 miles of Great Lakes coastline. The Michigan Department of Environmental Quality (DEQ) administers the state's BEACH Act grant.
What Are the Water Quality Challenges and Improvements in Michigan?
Lake St. Clair Metropark Beach
Macomb County is installing green infrastructure to reduce stormwater runoff and improve the water quality at Lake St. Clair. With funds from a Great Lakes Restoration Initiative grant, Macomb County will remove 8,500 square feet of parking lot surface at Lake St. Clair Metropark beach and replace it with a 15,800-square-foot porous-pavement driveway and 11,500-square-foot rain garden including native vegetation. Under the parking lot there will be deep swales to intercept the water, thereby preventing it from directly entering Lake St. Clair. The project is designed to increase infiltration, resulting in lower E. coli levels and fewer beach closures.
Chrysler Park Beach
In 2012, Chrysler Park Beach had the highest exceedance rate (29%) of any Michigan beach. With help from a $500,000 grant from the U.S. EPA, a project is currently under way to to reduce the number of E.coli exccedances and reduce beach closures. The project includes planting geese-deterring grasses to reduce the amount of feces flowing to the water, and re-channeling stormwater into rain gardens for infiltration.
Bryant Park Beach
To protect swimmers from historically high E. coli levels at Bryant Park, The Watershed Center and Traverse City partnered with the Michigan Department of Environmental Quality using funds from the Great Lakes Restoration Initiative to install a new stormwater runoff filtering system. This project includes a series of tanks to remove trash and sediment before the water enters a large underground filtering system. The goal is for bacteria, oils, and other pollutants to be broken down by soil microbes.
Testing has determined that E. coli in the stormwater runoff is likely caused by feces from pets as well as wildlife such as raccoons and deer. Due to increased development in the area and poor design of the stormwater system, runoff frequently would overload the old infrastructure, washing over the beach and eroding large amounts of sand into the bay. The new system should help to reduce E. coli levels and protect swimmers from bacteria.
Other green infrastructure projects are under way at Marquette South Beach, Sherman Park, Four Mile Beach, East Bay Park Beach, Suttons Bay Beach, New Buffalo City Beach, Brimley State Park, and Tawas Bay Beaches.
Rapid Test Methods
Current approved methods for determining fecal indicator bacteria counts in beachwater depend on growth of cultures and take at least 24 hours to complete. Because of this, swimmers do not know until the next day if the water they swam in was contaminated. There is a great deal of interest in technologies that can provide same-day beachwater quality results. After field testing qPCR, which identifies genetic sequences in order to enumerate bacteria, in 2011, a few selected beaches in Michigan began using qPCR to test for enteroccocus in 2012. The Bay County Health Department and Saginaw Valley University are partnering to use qPCR to monitor the Bay City Recreation Area. Several other health departments are using the immunomagnetic separation-adenosine triphosphate (IMS-ATP) rapid method to monitor beaches
Several beaches are using qPCR for microbial source tracking (MST) but not for routine monitoring. Beaches included in this MST effort include Whites Beach in Arenac County; Bay City State Recreation Area in Bay County; Four Mile Beach and Sugar Island Township Park Beach in Chippewa County; Caseville County Park Beach in Huron County; Grand Haven City Beach, Grand Haven State Park, and Rosy Mound Recreation Area in Ottawa County; Pier Park in Wayne County; Traverse City State Park Beach, Bryant Park Beach, and East Bay Park Beach in Grand Traverse County; and St. Clair Shores Veterans Memorial Park Beach and H.C.M.A. Metropolitan Beach Metropark in Macomb County. The procedure for determining whether to issue an advisory or a closure on the basis of predicted water quality results at these beaches is undergoing further testing and refinement during the 2013 beach season. In 2012, notifications at the beaches testing models were based on traditional culture techniques, not on predicted water quality.
Statewide Implementation of Sanitary Surveys
Sanitary surveys are systematic investigations that are used to identify potential sources of human sewage pollution. In 2012, at 238 beaches throughout Michigan, 3,804 routine surveys were conducted when samples were collected, and in-depth sanitary surveys will now be done annually. This effort, funded by the Great Lakes Restoration Initiative, is critical in identifying sources of beachwater contamination, especially during rain events.
What Does Beachwater Monitoring Show?
In 2012, Michigan reported 639 coastal beaches. Of these, 41 (6%) were assigned a monitoring frequency of more than once a week, 200 (31%) once a week, 1 (<1%) once a month, 2 (<1%) less than once a month, and 395 (62%) were not assigned a monitoring frequency. In 2012, 5% of all reported beach monitoring samples exceeded the state's daily maximum bacterial standard of 300 cfu/100 ml. The beaches with the highest percent exceedance rates of the daily maximum standard in 2012 were Chrysler Park Beach in St. Clair County (29%); Rogers Beach (27%) and Manistique Township Park (21%) in Schoolcraft County; Grand Haven State Park in Ottawa County (20%); and Kiwanis Beach in Mackinac County (19%).
Ontonagon County had the highest exceedance rate of the daily maximum standard in 2012 (17%), followed by Arenac (12%), Marquette (9%), Wayne (9%), St. Clair (9%), Ottawa (8%), Mackinac (8%), Chippewa (7%), Menominee (6%), Macomb (6%), Iosco (6%), Berrien (5%), Alpena (5%), Bay (5%), Muskegon (4%), Grand Traverse (4%), Houghton (3%), Van Buren (3%), Presque Isle (3%), Huron (2%), Antrim (2%), Delta (2%), Manistee (2%), Emmet (2%), Allegan (2%), Charlevoix (2%), Alger (1%), Leelanau (1%), Alcona (1%), Sanilac (1%), Cheboygan (1%), and Monroe (1%). No samples taken in Baraga, Benzie, Keweenaw, Oceana, and Mason Counties exceeded the daily maximum standard (note: Baraga, Benzie, and Keweenaw Counties each had only one site monitored in 2012. An additional 12 sites in Baraga County, 6 sites in Benize County, and 13 sites in Keweenaw County were not monitored in 2012).
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.
Michigan Percent of Samples Exceeding the State's Daily Maximum Bacterial Standard for 153 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.
With the state's help, NRDC is hoping to include data for Michigan's federally owned beaches in the future. There is no BEACH Act funding available for these beaches, and their information is not collected and disseminated the way information for non-federal coastal beaches is.
What Are Michigan's Sampling Practices?
The monitoring season runs from April to October. Sampling practices, locations, standards, and notification protocols and practices are uniform throughout the state. Samples are taken 1 foot below the surface in water that is 3 to 6 feet deep. Beaches are selected for monitoring on the basis of location, with priority given to more frequently used beaches, those with a history of bacterial contamination, and those in close proximity to a known bacterial contamination source.
At the discrection of the local health department, the monitoring frequency of a beach that has been closed or placed under advisory can be increased. In most cases, resampling is conducted the day a beach is closed or placed under advisory. States that monitor more frequently after an advisory is issued 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 advisory or closing was issued.
How Many Beach Closings and Advisories Were Issued in 2012?
Total closing/advisory days for 127 events lasting six consecutive weeks or less decreased 20% to 324 days in 2012 from 404 days in 2011. For previous years, there were 363 days in 2010, 342 days in 2009, and 265 days in 2008. In addition, there were no extended or permanent events 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 127 events lasting six consecutive weeks or less, 92% (297) of closing/advisory days were due to monitoring that revealed elevated bacteria levels, 7% (22) were preemptive due to other reasons, and 2% (5) were preemptive due to heavy rainfall.
How Does Michigan Determine When to Warn Visitors About Swimming?
Michigan issues both advisories and closings, using a geometric mean standard of 130 cfu/100 ml for all the individual samples taken during five or more sampling events representatively spread over a 30-day period, and a daily sampling event standard of 300 cfu/100 ml. At each sampling event, three or more samples are taken and the geometric mean of the sampling results is compared with the daily standard. Resamples to confirm an exceedance are sometimes conducted at Michigan's Great Lakes beaches before an advisory or closing is issued.
Some Michigan health departments issue preemptive rainfall advisories, applying standards that are based on rainfall amount. Beach advisories and closures may be issued for riptides, spills, harmful algal blooms, and other potential threats to public health.
As discussed above, some Michigan counties are starting to use models that predict beachwater quality. Such models are not useful at all beaches, but where they are, they provide a cost-effective means of issuing notifications based on current water quality conditions rather than on conditions that existed the day the last sample was collected. The models are constructed using historical data about conditions such as wave height, tide, temperature, and wind speed, combined with monitoring data.
Michigan 2012 Monitoring Results and Closing/Advisory Days