As reported in the October 2019 edition of the GAPOA newsletter, testing of Greene Acres Lake (GAL) provided some preliminary information about the water quality of GAL. Water quality is defined as a measure of the suitability of water for a particular use (e.g., swimming; fishing; boating) based on selected physical, chemical, and biological characteristics. In summary, the 2019 data showed that the water quality of GAL is consistent with other freshwater lakes in North America, and that our lake continues to be safe for recreational purposes. However, further monitoring was recommended, because the results showed that GAL contains a level of phosphorus within or above the upper recommended limits compared to many other lakes in Virginia (different lakes have different limits, depending on location). The data also showed the presence of several different species of algae, some of which are well known to be associated with situations commonly known as harmful algal blooms (HABs).
Algae are microscopic organisms that occur naturally in freshwater ecosystems, including the species associated with HABs. Under certain conditions, algae can quickly multiply or "bloom" to a point where algal colonies become visible without the need for a microscope, and blooms may look like foam, scum, mats, or paint floating on the surface of water. Algal blooms can cause damage to aquatic environments by blocking sunlight and depleting oxygen required by other aquatic organisms, restricting their growth and survival, and some species of algae contain toxins that can cause adverse health effects to humans, wildlife, and other animals such as dogs. When algal blooms impair aquatic ecosystems or have the potential to affect human and animal health, they are known as HABs.
While the 2019 data indicate that there is currently a low risk of occurrence and exposure to HABs in our lake, the frequency and geographic distribution of HABs has been increasing regionally (e.g., Lake Anna; Chris Greene Lake), nationally and globally. Starting this month, some of GAL's water quality parameters will be monitored routinely, including water temperature, water clarity, and levels of phosphorus. In addition, routine visual observation of all areas of the lake will be performed, and local meteorological data will be collected and archived. Such information will be used as an early warning system for the occurrence of an algal bloom in GAL. For example, there is a higher probability for the occurrence of an algal bloom when (i) water and ambient temperatures are highest, (ii) there is an increase above normal levels of phosphorus, (iii) there is a cycle of intense and heavy rainfall followed by drought-like conditions, and (iv) there is a high volume of stormwater runoff in to the lake resulting in increased turbidity (cloudiness or less clarity) of the lake's water. If an algal bloom is observed, remedial action will be taken immediately. This information will also serve as a baseline of results for comparison to future monitoring efforts.
The GAPOA community is encouraged to contact our new Water Quality Manager, Mike Casteel, with any comments or suggestions, or to provide any anecdotal or historical information about GAL. Mike would be happy to discuss any water quality and environmental issues and to talk to residents about how they could participate (i.e., become "citizen scientists"). Working together, we will continue to ensure and protect GAL's water quality.
Michael J. Casteel, Ph.D.
Figure Eight Environmental, L.L.C.
371 High Ridge Road, Stanardsville, VA 22973-2557
When in doubt, stay out!
The Virginia Department of Health lists the following things people should do to prevent illness:
· Avoid contact with any area of the lake where water is green or an advisory sign is posted.
· Do not allow children or pets to drink from natural bodies of water.
· Keep children and pets out of the areas experiencing a harmful algae bloom and quickly wash them off with plenty of fresh, clean water after coming into contact with algae scum or bloom water.
· If you or your animals experience symptoms after swimming in or near an algal bloom, seek medical/veterinarian care.
· To ensure fish fillets are safe to eat, properly clean fish by removing skin and discarding all internal organs, and cooking fish to the proper temperature.
· If you suspect you experienced health-related effects following exposure to a bloom, contact the Virginia Harmful Algal Bloom Hotline at 1-888-238-6154. To learn more about harmful algae blooms or to report an algae bloom or fish kill visit www.SwimHealthyVA.com.
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