MoversAtlas

This map feature depicts water bodies which do not or are not expected to meet applicable state water quality standards. Pollution zones are shown by the type of contaminant present; the zones often span across more than one water body. The quality standards each water body is subject to are designed to protect human health and the aquatic environment. Water bodies which do not meet their quality standards are designated as "impaired" for the pollutants which are causing a problem. So, in a nutshell - the impaired waters shown by this map all have levels of pollutants such as mercury, bacteria, etc. that exceed the safe limits for humans and/or aquatic life. Depending on the type of pollution shown, the recreational use of certain lakes, rivers and beaches might be off-limits; there could be advisories against fish consumption in these areas as well. If you're concerned about the risk posed by polluted water bodies near your home, you can always check with your local government to see if it's safe to swim or eat the fish you catch in them. It is important to note that not all types of pollution are shown in this map feature. Due to the number of possible impairments, some such as nutrient excess or total dissolved solids have been omitted since they are less of a concern than lead or mercury. The omissions have been made to make the map more legible. It is also important to note that if a lake or waterway is shown as clean by this map, it's a good sign but does not necessarily mean that water feature is free of all pollution. Due to time and resource constraints, FDEP cannot catch everything.

Fortunately, there's good news if your dream home is located right next to a polluted lake. Once a water body has been designated as impaired by the Florida Department of Environmental Protection (FDEP), the state begins cleanup and rehabilitation efforts. Specifically, after impaired status is assigned, FDEP calculates pollutant loading limits which are known as Total Maximum Daily Loads (TMDLs). A TMDL is defined as the maximum amount of a pollutant a water body can absorb and remain healthy. Once TMDLs have been set, the FDEP will adopt and implement a plan to reduce pollution levels to amounts allowed by the TMDLs. Ultimately, this effort is supposed to make the water body safe for humans and the environment again. Unfortunately, cleanup can take quite a long time, so some water bodies may remain "impaired" for certain pollutants for years.

What follows is a brief overview of the pollutants you might see listed on your map. Throughout many of the pollutant descriptions you will hear us use the terms "bioacumulate" and "biomagnify". Depending on the definition used, these terms can overlap somewhat, but we'll do our best to explain them here:

The term bioacumulate refers to the buildup of a pollutant within a single organism (i.e. one fish, one clam, etc). Because certain pollutants (like mercury) aren't easily detoxified by aquatic organisms, they simply build up in plant and animal tissue. If a fish's body can't get rid of the mercury it absorbs from its environment, it has to do something with it, so the fish tries to store it away in its liver, muscles and other tissues to minimize the metal's toxicity. This can concentrate the mercury to levels many times higher than you would find in the water itself. The concentrations of some pollutants bioacumulated by fish and other organisms can prove harmful to human beings. It's important to note that pollutants can bioacumulate in organisms without necessarily biomagnifying.

The term biomagnify refers to a phenomenon by which relatively low levels of pollutants dissolved in the water get increasingly concentrated in animals as one moves up the food chain. The process works like this: we start out with a small amount of a pollutant dissolved in a lake; let's keep using our mercury example from above. As plants and algae living in the lake grow and multiply, they absorb tiny amounts of the dissolved mercury. Small fish and insect larva then eat the plants and algae. However, since the minnows and insects eat a lot of plants, they accumulate higher levels of mercury than those present in the plants themselves. Larger fish then eat the minnows and in turn end up with an even higher concentration mercury than the fish they just ate. This process will repeat itself all the way up to the top of the food chain. By the time we get to humans, the concentration of mercury in a fish might be many times higher than it is in the lake water. The pollutant concentrations achieved by large fish via this bioaccumulation phenomenon can be so high that they are actually dangerous to people.

Ammonia and Nitrates - small amounts of ammonia are naturally present in all water bodies and the chemical is actually beneficial to the environment in low concentrations. However, high concentrations of ammonia are extremely toxic to fish and other aquatic organisms, making it an important pollutant in some Florida ecosystems. Dissolved ammonia can also be converted into nitrates which are toxic to humans if ingested. Most ammonia pollution occurs as a result of agricultural stormwater runoff. Animal manure releases large amounts of ammonia as it decomposes and heavy rainstorms can cause the manure to be carried into local ponds/lakes when excess water flows off the farms and into the surrounding environment. Excess ammonia can also enter water bodies from agricultural and domestic fertilizer runoff.

Bacteria - bacteria can be present in the water for a variety of reasons. Many bacteria exist in the water naturally and pose no threat to humans or the environment. However, certain conditions can cause bacteria to become harmful. Even ordinarily non-pathogenic bacteria can cause problems for humans and the environment when they're present in large enough numbers. This can be due, for example, to an excess concentration of nutrients in the water body which triggers a bacterial "bloom". Occasionally, large numbers of pathogenic bacteria (salmonella for example) can be introduced into lakes, streams and beaches from outside. They can hitch a ride into water bodies simply by being present in stormwater runoff and sewage effluent, and they can also be released into the water supply from septic tanks. Typically water bodies such as beaches and lakes get closed when levels of pathogenic bacteria get high enough to pose a risk to people. Pathogenic bacteria can infect people by simply floating around in the water column or by living in/on things people eat (such as shellfish). Bacterial spikes tend to be intermittent, so water bodies labeled as bacterially polluted might not always have an active advisory posted.

Chlorine - Chlorine is the chemical added to municipal drinking water and public pools as a disinfectant which makes it safe to drink or swim in. However, when chlorine gets into natural water bodies such as lakes and streams it can damage their ecosystems by harming beneficial microbes and injuring larger aquatic life. Chorine is also known to react with naturally occurring compounds to create other chemicals which are harmful to both people and aquatic organisms.

Copper - In small amounts, copper is an essential nutrient for many plants and animals. However, larger amounts of the metal can be toxic to the environment. Copper is commonly released into water bodies as a result of mining and agricultural processes. It is also an ingredient in many fungicides. After it's applied to plants and killed the fungi, the copper compounds in the fungicide can wash off the plants and get into lakes and ponds as a result of rain storms. Excessive exposure to copper can cause illness in people though this is relatively rare. Copper is however, highly toxic to a variety of aquatic life including microbes, mollusks and amphibians. It is moderately toxic to fish and insects. By killing off key species in the ecosystem, copper pollution can really damage lakes and streams if it accumulates in high enough quantities. Copper does have some bioaccumulation potential in aquatic environments but does not appear to biomagnify.

Dioxins - dioxins are a group of highly toxic, persistent (long-lived) chemical pollutants that occur as a byproduct of industrial processes such as herbicide production, paper/pulp bleaching and trash incineration. Small amounts of dioxin can also be produced from non-industrial activities such as wood burning and diesel fuel combustion. Many people remember dioxins as the toxins present in Agent Orange, a defoliant used in the Vietnam War which became infamous for the ways it harmed people exposed to it. Dioxins aren't easily broken down in the environment, so once they have been released into an area, they can stay there for a very long time. Remediation is difficult and expensive. Like many other pollutants, dioxins have a tendency to bioaccumulate and reach very high (and toxic) levels in animals which humans eat. However, it is still unclear whether or not dioxins biomagnify within the food chain. Because of their high toxicity, even very low levels of dioxin are presumed to harm to humans. Dioxins cannot be easily detoxified by the human body (or other animals) so the dioxins that humans ingest tend to get stored in fat cells, where they can remain for many years. The effects of dioxin exposure are still debated but many believe dioxins can damage the immune system, nervous system, hormonal system and cause reproductive problems and developmental issues in children; finally they are very likely to cause cancer if absorbed in sufficient quantities.

Lead - Lead poses a number of well documented threats to human health when consumed in sufficient quantities. The health problems caused by lead include damage to the central and peripheral nervous systems, reproductive problems and high blood pressure. Children are especially vulnerable to lead's negative effects. Like many other pollutants covered in this map, lead typically ends up in water bodies as a result of industrial or mining activities. Lead is also released into the environment as a result of improper disposal of lead-acid batteries, electronic devices, and other products. Lead used to be released by cars as well, prior to the banning of leaded gasoline. While you're not likely to absorb a great deal of lead just by swimming or boating in a lake, you could be exposed to higher quantities if you drink the water or if you eat fish and mollusks caught in the water body. Lead bioaccumulates in aquatic organisms but does not biomagnify.

Mercury in Fish Tissue - This one is pretty self explanatory. Lakes, ponds, streams, and beaches falling within this category are home to fish (and probably other creatures) whose bodies contain high levels of mercury. Mercury is of course, a highly toxic heavy metal which causes numerous types of damage to the central and peripheral nervous systems. Mercury is deposited in water bodies through natural processes and through human activities. Coal fired power plants, trash incineration facilities and metal processing plants are some of the human activities that release additional mercury into the environment. Once in the water, mercury both bioaccumlates and biomagnifies in fish and other organisms humans eat, which can cause toxic levels of exposure if sufficient quantities are consumed. Mercury is tough to get rid of so unfortunately, contaminated lakes and ponds tend to stay that way. If a water body near your prospective home is shown as polluted with mercury, contact your local government to see if there are any active fish consumption advisories.

Pesticides in Fish Tissue - Like mercury, this one is pretty self explanatory. Pesticides enter water bodies as a result of agricultural and residential stormwater runoff. Every time somebody sprays their lawn, the pesticides go somewhere, and often that somewhere is a lake or pond near the house. Many pesticides are designed to degrade relatively quickly, but those that don't tend to build up in fish and other creatures. The bioaccumulation and biomagnification of these toxins can obviously be harmful to the lake's inhabitants, but they can also harm humans who eat the fish or spend a lot of time in the water. Check with your local government to see if there are any active fish or swimming advisories in place.

Thallium - Thallium is a toxic metal which is most often released into the environment as a result of copper smelting, petroleum refining, and other industrial processes. It is also found in natural deposits on the Earth's surface. Most thallium is used by the electronics industry. Thallium dissolves easily in water and is readily absorbed through the skin. It also has a tendency to bioaccumulate in animals. In aquatic environments, thallium will kill a variety of organisms, everything from microbes to mollusks and fish. In humans chronic exposure to the metal can cause damage to the nervous system; it is not known whether or not chronic exposure leads to cancer and birth defects in humans. Check with your local government to see if there are any active fish or swimming advisories in place.