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NOTE: Because we have special programs planned for our general meetings over the next three months, please note that our general meeting locations will vary. Also, as the newsletter goes to the printer, we have not finalized a location for our January General meeting. The location of the January, 2003 General Meeting will be announced in local newspaper and via the hard-working volunteers on our “telephone tree.”
Thursday, November 21, 2002 7:00PM
LCCC General Meeting
Magnolia Room in the Everett Kelly Building on the Lake-Sumter Community College Campus
Mr. Leel Knowles from the USGS will be speaking about groundwater issues in Lake County.
Monday, December 2, 2002 7:00PM
LCCC Board of Directors Meeting
LCWA Meeting Room; 107 N Lake Ave., Tavares
All LCCC members are welcome to attend BoD meetings. We’re always looking for volunteers!
Thursday, December 27, 2002 6:00PM
LCCC General Meeting – Evergreen Party
American Legion Hall, 101 S Bay St, Eustis
Our annual pot-luck get-together! Please bring an entreé, salad, or dessert to share with your fellow members
Monday, January 6, 2003, 7:00PM
LCCC Board of Directors Meeting
LCWA Meeting Room; 107 N Lake Ave., Tavares
All LCCC members are welcome to attend BoD meetings. We’re always looking for volunteers!
Thursday, January 16, 2003, 7:00PM
LCCC General Meeting
Panel participants and meeting location to be announced.
The LCCC Board of Directors will host a panel discussion on the issues related to the presence of cyanobacteria in Lake County’s lakes.
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This issue of the LCCC Newsletter concludes our two-part survey of water quality conditions in the Harris Chain of Lakes. The Harris Chain is a historically beautiful, interconnected series of lakes that form the aquatic heart of Lake County. The headwaters of the Harris Chain are in Lake Apopka. Water from this spring-driven lake moves generally northwest through the six major lakes of the Chain and finally, flowing from the north end of Lake Griffin, becomes the origin of the Ocklawaha River. In the last century, successive alterations in Lake Apopka, and the Harris Chain in general, have created an ideal environment for blooms of algae and toxic bacteria.
The Harris Chain began to feel the impact of man-made changes to its ecosystem after the 1880's as concessions were made on behalf of such economic interests as agriculture, citrus processing, and municipal waste disposal. By the late1960’s these formerly clean and beautiful lakes were recognized as contaminated and in decline.
The first major man-made alteration was the Apopka-Beauclair Canal, begun in 1880. By 1893, all the major lakes in the Harris Chain had been connected by canals and the entire chain, from Lake Apopka to the Ocklawaha River was opened for commerce. These canals critically impacted Lake Apopka in two ways: first, they lowered the lake by four feet, forever changing its hydrography; and second, it exposed the drained muck soils along the shoreline for agriculture. However, although farming had begun on the shoreline of Lake Apopka, it would not prosper until the 1940’s when the motivation to produce food for the war effort coupled with improved technology created the modern “muck farm.”
In the early 1940’s the State Legislature created the Zellwood Drainage and Water Control District. From 1942 to 1947 the District oversaw the diking and draining of 18,000 acres of northern Apopka marshes for the creation of muck farms. Muck farming requires that lake water be pumped onto the farms for irrigation and pest control and that excess water from rainfall be pumped back to the lake. At the peak of the muck farm operations in the 1980’s, 20 billion gallons of nutrient rich water were being discharged back into Lake Apopka annually (about one-third of the total volume of the lake). The concentration of nutrients in the discharge water was about 10 times higher than the lake water.
The periodic dumping of large quantities of nutrient enriched water into a lake in a warm sunny climate sets the stage for a microorganism “bloom.” In small numbers, these microorganisms, such as algae and bacteria, are a natural part of a healthy lake, but in the presence of high nutrient concentrations they will reproduce very rapidly. If the high nutrient concentrations persist, microorganisms can dominate a lake’s ecology, to the detriment of other, larger plants and animals.
Lake Apopka suffered its first algae bloom in 1947. Since then, bloom conditions have been virtually continuous and many desirable species of fish are sparse or absent; and rooted vegetation on the lake bottom is all but gone. A similar situation exists in Lake Griffin, where diked muck farming was established in the Emeralda Marsh.
In as much as the continual blooms in Lake Apopka and Lake Griffin are dependent on high concentrations of nutrients, control of the bloom requires control of the nutrient source. This is the strategy currently employed by the St. Johns Water Management District to clean up both lakes. The Apopka and Emeralda muck farms have been purchased; their pumps no longer spew nutrients into lakes. But, even though the nutrient levels appear to be dropping in Lake Apopka, still the blooms continue. This is because there are other nutrient sources. Nutrients continue to enter the lakes from stormwater and are still being recycled from decades-old sediments on the lake bottoms. Any disturbance of the bottom from wind or current can release nutrients from the deep mat of rotting organic matter. It is clear that controlling all nutrient sources is a very difficult problem that will be with us for a while.
The sheer volume of these blooms are a problem, but the quality of the blooms may be an even larger one. In recent years scientists have learned that some of the blooms in the Harris Chain of Lakes contain toxic blue green algae. The toxic forms are not “true” algae but toxic bacteria known as cyanobacteria. Several species of cyanobacteria which have been identified in the Harris Chain of Lakes have the potential to produce toxic reactions in humans and animals. For more on this see Nancy Lopez’s interesting inquiry into Cyanobacteria in the Member to Member section of this Newsletter.
In closing I would note that as a community we are struggling with this huge, enormously expensive, and seemingly endless task of cleaning up the Harris Chain of Lakes all because we chose to “domesticate” a beautifully functioning natural system for most of the last century. I’m reminded of a bumper sticker, “Don’t mess with the environment, Mother Nature bats last”.
Bernie Yokel, President, LCCC
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Are You A Water Waster? If You Are, Beware!
There are a couple of things I can say about water wasters. One is that they are consistent. It doesn't matter if you are in a drought or a flood, it's sunny or rainy, they will still have their irrigation running at an inappropriate date and time. They also seem to have plenty of money. According to a list compiled at the offices of the St. Johns River Water Management District and the Lake County Water Authority, the greatest residential violators are located in our more affluent neighborhoods. In some neighborhoods, almost every home on the street is listed as a violation. The excuse that I have heard repeatedly is,”I don't have anything to do with that irrigation timer” or “My lawn maintenance company/yardman is responsible for it.” That excuse just doesn't hold water.
Another large water waster in our community tends to be commercial businesses. The type of business that tends to have the most wasters are model home builders followed by banks and churches. Again they tend to blame their property management company instead of being responsible for their property. I wonder if they also tend to ignore their profit margins as much?
Well, to deal with these wasters the Lake County Water Authority has hired 2 Water Patrollers. These Patrollers along with a third hired by St. Johns River Water Management District for Lake and Marion Counties have been on the hunt for water wasters. They have found that one of the best times to catch their quarry is at night. So far, the hunt has been good. However being the conservationist that I am, I hope their easy success gradually becomes more difficult as individuals learn the importance of water conservation.
If you would like to participate in the hunt, just write down the violator’s address, time and date of violation, and a distinguishing feature, such as the color of the home or the name of the business. Next, call the information into the Lake County Water Authority at 343-3777. You can remain anonymous to avoid neighborhood quarrels.
Happy Hunting!
The Anonymous Limnologis
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The subject of November’s general meeting will be about the effects of recently approved and proposed Consumptive Use Permits on groundwater levels, lakes, springs, and wetlands in Lake County from 1998 to 2020. The scheduled speaker is Mr. Leel Knowles, Jr., who is a hydrologist with the U.S. Geological Survey (USGS) office in Altamonte Springs. Because of anticipated interest in this program, we have changed the location to the Magnolia Room in the Everett Kelly Building on the Lake-Sumter Community College Campus. The meeting time has not changed. The meeting will begin at 7:00PM
Mr. Knowles presentation will focus on the results of a recently completed Lake County groundwater study that he conducted. The primary purpose of the USGS study was to simulate and assess the changes in the surficial and Upper Floridan aquifers between 1998 and 2020 as a result of increased groundwater withdrawals from the Floridan aquifer system. The surficial aquifer system is the water-table aquifer that overlies the Floridan aquifer system that collectively contains the Upper and Lower Floridan aquifers. As we all know, the St. Johns River Water Management District has announced that unacceptable impacts to surface- and ground-water resources may begin to occur around 2006 instead of 2020 if all submitted water-use permits are approved and action is not taken to reduce groundwater use.
The USGS study was funded cooperatively with the Lake County Water Authority and the St. Johns River Water and Southwest Florida Water Management Districts. The presentation will include information on long -term rainfall, lake stages, ground-water levels, and springflows. He will discuss the recharge areas that contribute water to the Upper Floridan aquifer for the Mount Dora and South Lake Utilities well fields. These are the well fields that are closest to the major drawdowns occurring in the greater Orlando and southeastern Lake County areas. Also, Mr. Knowles will discuss water quality, including the nutrients concentrations, collected at selected Upper Floridan aquifer wells and springs. This is important because nitrate levels in the collected ground-water samples are elevated significantly above natural background levels throughout much of Lake County.
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Last month I started the Member-to-Member column with a request for 300 to 500 word articles about matters near and dear to the hearts of LCCC’s members. Little did I know that an article in September’s newsletter would strike such a deep chord in the heart of our Recording Secretary, Nancy Lopez. Had I known more about Nancy–other than that she takes excellent minutes for the Board of Directors–I would have known better. Nancy began her career as a math teacher, but most of her professional career was spent studying water: water movement, water quality, and the delicate interplay between water and humanity. She is eminently qualified to ask additional questions about toxic algae in our Lakes and is graciously sharing the answers she received with her fellow LCCC members.
In the last LCCC newsletter Mike Perry, the Executive Director of the Lake County Water Authority, provided an article about toxic algae. He described the pioneering toxic algae monitoring effort that the LCWA initiated in September 2001for the Harris Chain of Lakes. In his article Mr. Perry described some of the monitoring results and referenced some information about protecting our families and friends.
Mr. Perry's article encouraged me to learn more about toxic algae. Because my husband and I live on Lake Dora, the toxic algae issue is especially important to us. Therefore, I have been gathering information from around the world and reviewing the data that Cyanolab has collected under contract to the LCWA between September 2001 and September 2002. I had (and still have) many questions about toxic algae, and I thought other LCCC members might have similar questions. Also, with more information, each of us can make more informed decisions about protecting our families and friends from this health threat. Most of my information is from governmental and scientific sites on the Internet and from telephone calls with representatives of responsible agencies. I have not personally done field or laboratory research on toxic algae, and I am not a toxic algae expert. Highlights of the information that I found are provided below in question and answer form:
1 What are toxic algae? Toxic algae are not truly algae; rather they are bacteria that behave like algae in some respects. For example, they contain chlorophyll, and they can perform photosynthesis. Toxic algae actually should be called “potentially toxic cyanobacteria.” The phrase “potentially toxic cyanobacteria” is used here to make it clear that toxic cyanobacteria do not release their potent toxins all of the time. Also, it is important to know that not all cyanobacteria are potentially toxic. Cyanobacteria occur all over the world in fresh water, salt water, and soils and on rock surfaces. They perform vital functions in the environment. However, under certain conditions some cyanobacteria can be extremely toxic.
2. Are potentially toxic cyanobacteria present in our lakes? Yes. As Mike Perry's article indicated, the Harris Chain of Lakes has high numbers of cyanobacteria, and several different kinds that can be toxic. The highest concentration of total cyanobacteria measured during the past year was over 2,000,000 per milliliter in samples of water taken from Lake Apopka. Only a few thousand of the two million cyanobacteria in those samples were potentially toxic. Over the last year it was not unusual for the levels of total cyanobacteria in some of the other lakes in the Harris Chain to exceed 500,000 per milliliter of water. In almost all of the lakes potentially toxic algae have been measured at or above 100,000 per milliliter at sometime during the last 12 months.
3. What are the signs that cyanobacteria are present in the water? Taste and odor problems can occur when cyanobacteria are present. The odors may be “earthy, musty or grassy.” The taste and odor problems can occur at levels well below levels considered to pose human health concerns, so they can be a helpful warning system. However, one should not try the “taste test” on lakes in the Harris Chain or elsewhere in Florida. Also, high levels of toxins are often associated with cyanobacterial mats or scum floating on the surface of waterbodies. Every health guideline I have seen indicates that people should avoid contact with water that has cyanobacterial mats or scum floating on the surface. However, the most common potentially toxic cyanobacteria in the Harris Chain does not form mats or scum. Therefore, its presence is not as easily recognized. Finally, dead fish or animals in or near the water may be a sign of high toxin levels.
4. Are potentially toxic cyanobacteria harmful to human health? They can be. Actually, all cyanobacteria are believed to produce substances that can irritate the skin and eyes or cause gastrointestinal problems. The varieties of cyanobacteria labeled “toxic” can be even more harmful to people, fish and other animals. However, as stated previously, potentially toxic cyanobacteria do not always release potent toxins. In considering the risk to human health, many factors need to be considered. Some are described here. The risk depends on the concentrations of potentially toxic cyanobacteria or of their toxins in the water. Also, the risk depends on whether and how a person is exposed. If a person ingests water with either high concentrations of potentially toxic cyanobacteria or the toxins themselves, then their health could be at risk.
5. Are some people more at risk than others? Yes. Some individuals have a higher than average risk of harm from these toxins. For example, small children are likely to ingest more water than adults when they are playing in the water, and they also have lower body weights. Other groups of people who are at greater risk are individuals who already have damage to their organs such as kidney damage, cirrhosis of the liver, or hepatitis. The Brazilian dialysis patients mentioned below are an example.
6. What symptoms and diseases are associated with cyanobacterial toxins? The human health effects of cyanobacterial toxins can be chronic, subchronic or acute. Symptoms vary depending on the kind and amount of toxin to which a person is exposed, how the exposure occurs, the duration of exposure, and the vulnerability of the individual. Generally, the symptoms can include vision problems, conjunctivitis, gastroenteritis, vomiting, diarrhea, nausea, ulcers in the mouth, irritation to the airways and breathing difficulties, muscle weakness and skin irritation or rashes. However, more serious health problems can occur. Recent research suggests that some of the cyanobacterial toxins can cause tumors or DNA disruptions. At high enough doses cyanobacterial toxins can be lethal.
Two major categories of toxins have been found in the Harris Chain of Lakes. These are hepatotoxins that can attack the liver and other internal organs and neurotoxins that can affect the nervous system. Microcystin and cylindrospermopsin are hepatotoxins found in the Harris Chain, and anatoxin-a is a neurotoxin found in the Harris Chain. Under some circumstances serious health effects can occur from any of these toxins. For example, the most widely recognized case of human poisoning from cyanobacterial toxins occurred in 1996 in South America. Dialysis patients in Brazil were poisoned by microcystin. More than 50 people died after exposure to microcystin from partially treated water that was included in their dialysis fluid. This dialysis group was highly vulnerable to the toxin. In the last decade, researchers have worked to identify the mechanisms and health effects of cyanobacterial toxins, but much more study is needed.
7. Can fish and animals be affected by these toxins? Yes. Examples are common around the globe. Toxins have caused fish and bird kills, and cattle and other animals have died as a result of exposure. Also, research indicates that the toxins can accumulate in fish. Relatively high levels of anatoxins have been found in the tissues of fish collected from Lake Griffin and in sick white pelicans found on Lake Harney near Titusville. White pelicans were found dead on Lake Harney at the time a Cylindrospermopsis bloom was present. Both cylindrospermopsin and anatoxin-a also were present. During the same time period as the white pelican deaths on Lake Harney, the Lake Harris Conservation Area was experiencing a heavy bloom of Microcystis, and the toxin microcystin was present. As part of the LCWA monitoring program, Cyanolab is conducting bioassays using mice to determine levels of toxicity. They inject the mice with the lake waters. When the toxin levels are significantly elevated, the mice die. Some scientists believe that there may be a link between the cyanobacterial toxins and the high numbers of alligator deaths in Lake Griffin. In other parts of our country, dogs have died after being in water contaminated with potentially toxic cyanobacteria. The most recent cases of dog deaths that I have seen occurred in September 2002 in Vermont and Canada on Lake Champlain.
8. What are the water quality standards for potentially toxic cyanobacteria? There are no national standards for cyanobacteria, potentially toxic cyanobacteria or their toxins in the United States. A few individual states have set standards and some have released health advisories, but Florida has not. Other countries have standards including Canada and Australia. The World Health Organization (WHO) has published guidelines for both drinking water and recreational uses. Often the levels of total cyanobacteria and potentially toxic cyanobacteria in the Harris Chain exceed health limits adopted by other organizations. Sometimes even the levels of the toxins exceed the limits set by other organizations. The WHO guideline for microcystin in drinking water is one microgram per liter (or one part per billion.) The WHO recreational guidelines suggest that bathing be restricted if the total cyanobacteria reach 100,000 per milliliter of water. On the southern coast of Australia around Sydney if potentially toxic cyanobacteria reach 15,000 per milliliter, a “high alert” is issued. I have found no guidelines for the toxins cylindrospermopsin or anatoxin-a.
9. What are the levels of cyanobacteria toxins in the Harris Chain of Lakes? Fortunately, we know more about the toxins in the Harris Chain because of the LCWA monitoring program. Other jurisdictions throughout Florida have potentially toxic cyanobacteria, but most have not implemented monitoring programs. We know that potentially toxic cyanobacteria are regularly releasing toxins in the Harris Chain. Most of the time the levels of toxins appear to be relatively low for recreational uses of the lakes. Since essentially everyone in Lake County uses groundwater for domestic supplies, our primary exposure is assumed to be through recreational contact. There might be some exposure for people that use lake water for irrigation purposes, but I found no information on that.
The cyanobacteria Microcystis is most frequently implicated with human and animal poisonings worldwide. The LCWA monitoring program tracks the levels of Microcystis and the associated toxin microcystin in the Harris Chain. Most of the time the levels of microcystin generally hover around the World Health Organization's (WHO) drinking water guideline of one part per billion. In general terms, the WHO drinking water guideline is based on an adult who is average weight and who drinks the recommended daily amount of water over a normal lifetime. Obviously, the WHO drinking water guideline is not directly applicable for recreational exposure to microcystin. However, during occasional short periods of time the levels of microcystin measured in some of our lakes during the last year have been 10 to 60 times higher than the WHO drinking water guideline for relatively short periods of time. The high levels of microcystin have not persisted from one two-week sampling period to the next in the affected lakes.
Although I have not found health guidelines for either anatoxin-a or cylindrospermopsin, some relatively high levels have been reported in the Harris Chain. The levels of anatoxin-a in Lake Apopka have reached 7 parts per billion in the last year, but the anatoxin-a level is lower in the down stream lakes that are in Lake County. However, scientists consider anatoxins to be more toxic than many microcystins. In the year 2000 cylindrospermopsin was present some of the time in Lake Griffin at levels above 50 parts per billion. The Florida Harmful Algal Bloom Task Force measured these cylindrospermopsin levels as part of another study of cyanobacteria. (The Task Force has conducted limited sampling throughout Florida.) During the last year of monitoring by the LCWA cylindrospermopsin has not been found in the Harris Chain.
10. If the toxins are present in the water, why aren't people getting sick from them? We don't know. Researchers wonder about the lack of officially documented reports of human health problems given the high levels of potentially toxic cyanobacteria in the Harris Chain of Lakes. On the other hand , there are many poorly documented anecdotal cases of skin irritations and other problems in Central Florida that occurred after exposure to potentially toxic cyanobacteria or the toxins. Some of these reports are associated with contaminated drinking water. These drinking water incidents are related to surface water sources, not ground water. I have talked by telephone to representatives of the county and the state health departments. One explanation for the lack of documented cases could be that responsible agencies have not distributed detailed information to doctors and other health providers in Florida describing the cyanobacteria and the toxins that are present and what symptoms to look for. Also, epidemiological studies are needed to determine whether populations exposed to the lakes have a higher than normal incidence of health problems related to the cyanobacterial toxins.
If you or someone you know has experienced such health effects after exposure to lake water, then it is important to see a doctor and, if appropriate, to send a report to the Health Department. Hopefully, such reports would help the Health Department to protect and inform the public about this health threat.
In closing, the LCCC Board of Directors is planning to sponsor a panel discussion about potentially toxic cyanobacteria in the Harris Chain of Lakes during its meeting on January 16, 2003. By that time the official report on the first year of monitoring for the Harris Chain of Lakes should be available for distribution. This meeting will provide an opportunity for all of our members to learn more about potentially toxic cyanobacteria from experts working in Florida.
Nancy Lopez, Recording Secretary
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After four years of drought, Lake County was fortunate to have a wetter-than-average summer. If we could measure our recovery from the drought by the number of times we had to mow the lawn, then we might think our water resources had recovered completely. But the replenishment of our water resources is more complicated than that. Most of our rainwater remains on or near the surface, relatively little seeps all the way down to the Floridan aquifers which are so vital to every aspect of our lives. By all accounts, the Floridan aquifers remain depressed and that means that citizen conservation remains vitally important. With that in mind, LCCC is distributing “Drop by Drop,” a water conservation fact-sheet from the Lake County Water Authority with this newsletter. We hope you find it useful.
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Lake County,
FL
