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This is an EarthCache located at Bradford Beach in Milwaukee. EarthCache sites do not use stored containers; their treasure is the lessons people learn about our planet when they visit the site.
Not too many years ago, Bradford Beach experienced many beach closings due to high bacterial counts. The city health department reported that E.coli counts exceeded safe levels for 61% of the three-month swimming season. In 2005, a Milwaukee Journal Sentinel article even referred to Bradford as “Milwaukee’s dirtiest beach”. The UWM Great Lakes WATER Institute began sampling the beach sand and water. DNA analysis of the collected bacteria was conducted. One of the main sources of the bacteria was stormwater runoff.
Stormwater is a term used to describe water that originates during precipitation events. It may also be used to apply to water that originates with snowmelt or runoff water from overwatering that enters the stormwater system. Stormwater is of concern for two main issues: one related to the volume and timing of runoff water and the other related to potential contaminants that the water is carrying.
Stormwater that does not soak into the ground becomes surface runoff, which either flows directly into surface waterways or is channeled into storm sewers, which eventually discharge to surface waters. Because impervious surfaces (parking lots, roads, buildings, compacted soil) do not allow rain to soak into the ground, more runoff is generated than in undeveloped areas. This additional runoff can erode watercourses (streams and rivers) as well as cause flooding when the stormwater collection system is overwhelmed by the additional flow. Because the water is flushed out of the watershed during the storm event, little water has the chance to soak into the soil, replenish groundwater, or supply stream base flow in dry weather.
Pollutants entering surface waters during precipitation events is termed polluted runoff. Daily human activities result in deposition of pollutants on roads, lawns, roofs, farm fields, etc. When it rains or there is irrigation, water runs off and ultimately makes its way to a river, lake, or the ocean. While there is some attenuation of these pollutants before entering the receiving waters, the quantity of human activity results in large enough quantities of pollutants to impair these receiving waters.
Unfortunately, some of the polluted stormwater runoff ended up right on Bradford Beach! What could be done to fix this? Nothing less than a sustainable, aesthetic and award winning environmental project. This 2008 rehabilitation of Bradford Beach included the design of a “green stormwater treatment system” capable of capturing up to 90% of the stormwater contaminants reaching the beach. Two of the key components of this system are a bioswale and infiltration basins.
Bioswales are landscape elements designed to remove silt and pollution from surface runoff water. They consist of a swaled drainage course with gently sloped sides and filled with vegetation, compost and/or riprap. The water's flow path, along with the wide and shallow ditch, is designed to maximize the time water spends in the swale, which aids the trapping of pollutants and silt. Depending upon the geometry of land available, a bioswale may have a meandering or almost straight channel alignment. Biological factors also contribute to the breakdown of certain pollutants.
A common application is around parking lots, where substantial automotive pollution is collected by the paving and then flushed by rain. The bioswale, or other type of biofilter, treats the runoff before releasing it to the watershed or storm sewer.
An infiltration basin (also known as a recharge basin), is a type of best management practice (BMP) that is used to manage stormwater runoff, prevent flooding and downstream erosion, and improve water quality in an adjacent river, stream, lake or bay. It is essentially a shallow artificial pond that is designed to infiltrate stormwater though permeable soils into the groundwater aquifer. Infiltration basins do not discharge to a surface water body under most storm conditions, but are designed with overflow structures (pipes, weirs, etc.) that operate during flood conditions.
This project was awarded the 2009 Environmental Public Works Project of the Year from the American Public Works Association. It also achieved Blue Wave certification from the Clean Beaches Council, recognizing it as a robust, healthy and vibrant beach. But most of all, Bradford Beach is restored to its former glory as the crown jewel in the Milwaukee County Park System. The public has embraced the improvements to the park and usage has skyrocketed including volleyball tournaments, swimming, roller blading and simply enjoying the lake beauty. The beach is back and now a destination for people of all ages from near and far.
In order to claim your find of this Earthcache, there are several things you must do:
(1) NO LONGER REQUIRED. First, starting at the posted coordinates, you will find a sign with additional information about the Bradford Beach project. Email me answers to the following (not in your “Found It” log): (a) Where does the greatest percentage of pollution come from? What percent does it account for? (b) Why do beach groomers rake the sand? (c) What other creature is responsible for leaving bacteria on the beach?
(2) Next, go to an informational sign next to one of the infiltration basins. There is one on the walkway just south of the Bath House and another a short walk north of the Bath House. They contain similar information. Once again, email me the answers to the following (not in your “Found It” log): (a) You will notice they do not use the term “infiltration basin” here. What term do they use instead? (b) How many of them are shown along this beach? (c) Which way does the water flow? In or out of the basin?
(3) Next, carefully cross Lincoln Memorial Drive and go to the parking lot. Email me the answers to the following (not in your “Found It” log): (a) Using your GPS, how long is the swale? (b) Approximately how wide is the swale? (c) Which way does the water flow? In or out of the swale?
(4) VOLUNTARY (no longer a requirement): In your “Found It” log, you may include pictures of yourself enjoying Bradford Beach.
Additional Hints
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