What is Blue-Green Algae?
- What we observe as blue-green algae is actually a toxic bacteria called cyanobacteria. Sunlight, warm and still water and nutrients contribute to cell growth and blooms.
- Cyanobacteria may contain one or more toxins within the cell and cell walls called cyanotoxins.
- Cyanobacteria toxicity levels are difficult to measure and can vary from cell to cell and bloom to bloom. One way to roughly gauge probability of toxicity is by appearance; the higher the concentration, based on thickness of the floating cells on the water and the viscosity, is likely to be indicative of higher levels of toxicity. HOWEVER, there are many different toxins that may be present in a single cell or a single bloom, which even in small colonies, could contain high or even lethal levels of toxins.
- Commonly known cyanotoxins include: microcystins, A. Anatoxin, Cylindosporum and Saxotoxin. There are about 60 known variants of microcystin alone.
- The EPA and DOH explained that Ballston Lake is likely to have microcystins present in the cyanobacteria. A. Anatoxin, Cylindosporum and Saxotoxin are less likely to present, but may eventually migrate to NYS waters as with any unwanted marine lifeform.
- Cyanobacteria blooms can be harmless. The best way to determine presence or absence of cyanotoxins is laboratory testing, which may be costly and take a period of time to receive results.
- Cyanobacteria and cyanotoxin life cycles vary based on a number of factors and are not predictable. The best way to determine presence or absence of cyanotoxins is laboratory testing.
How can it affect humans, pets and fish?
- Cyanotoxins enter lifeforms (humans, pets, fish and plants) through ingestion of affected water, airborne ingestion by breathing in water droplets (mist or spray) or absorption through skin, mucosal or other tissue. Pets, particularly dogs that enter infected waters, will get a coating of cyanobacteria on them and ingest the bacteria by subsequently licking their coat.
- Toxins present in cyanobacterial cells can affect liver, digestive and neurological functions as well as cause irritation to skin and tissue. Symptoms are wide ranging and may be unnoticeable, temporary, permanent or even fatal for both humans and pets.
- The degree to which these bodily functions are affected is based on a number of factors: type of cyanotoxin, level of toxicity, amount consumed, exposure time and physiology of the affected lifeform. Transmitted diseases like rabies are either present or not present; and if present can be treated. In other words the pathology of rabies is predictable and treatable. Cyanotoxins may be present in your body, but might not affect you at all, might affect you to a lesser degree or prove fatal. The effect of cyanotoxins is not predictable.
- Fish can accumulate cyanotoxins in their livers as well as muscle tissue. Consumption of fish from an affected body of water may be detrimental to your health.
- Very little information is known about edible plants that are exposed to cyanotoxins. It is likely that the toxins can accumulate in the flesh of the fruits and vegetables and may therefore be inadvisable to consume produce that may have come in contact with cyanobacteria tainted water.
- There are no known treatments once the toxins have entered a lifeform.
How can contamination be minimized?
- Awareness is key. New York State Department of Environmental Conservation monitors Harmful Algal Blooms (HABs or cyanobacteria) on many NYS bodies of water including Ballston Lake. Their website is updated on a weekly basis with information for each monitored body of water. You can subscribe to receive notices and emails on the DEC website. The HAB reports can be found at: http://www.dec.ny.gov/chemical/77118.html.
- If HABs warnings are posted or you notice a bloom, avoid direct (wading, swimming, watersports, ingestion) and indirect (mist or spray commonly encountered while boating) contact with water. The NYS DEC has a link on their website with instructions for reporting HAB sightings: http://www.dec.ny.gov/chemical/77118.html#REPORT.
- Reduce or eliminate the sources of nutrients. Cyanobacteria are fed by the same nutrients that cause so many of the unwelcome aquatic plants to flourish in the lake. The sources of these nutrients can be fertilizer run off from farms in the watershed, “leaky” septic systems that allow nutrient rich effluent to enter the water and specific to Ballston Lake; the large amount of phosphorus at the bottom of the lake. On method for phosphorus treatment is the application of the chemical alum. However, alum use is prohibited by NYS DEC regulations. The completion of the Ballston Lake sewer system (which means attachment of all houses in the watershed) currently has a 2024 completion date*. This will eliminate one of the three major “food” sources for cyanobacteria.
- Prevent pets from entering and drinking lake water.
Can lake water, intended for domestic use, from a private residential water intake be treated to eliminate cyanobacteria and cyanotoxins?
- There are a number of municipal water districts that use fresh bodies of surface water for residential use. They use different treatment techniques and the key to maintaining water purity is continuous testing from point of intake to the point of use.
- There are no “approved” private residential water treatment systems for removal of cyanobacteria and cyanotoxins. Residential water treatment companies are by and large unfamiliar cyanobacteria and cyanotoxins.
- The National Sanitation Foundation (NSF) has point-of-use water filters approved for “reduction” (not elimination) of microcystins. These are just one of the toxins that may be present in cyanobacteria.
- Boiling water in an effort to “purify” will likely cause cyanobacterial cells to rupture and release the toxins into the water. Chlorination and other oxidation methods are also likely to result in the rupture of cells and release of toxins.
- Whole house reverse osmosis or ozone systems may eliminate all toxins. They are much more expensive than other water treatment systems and require continual water testing and maintenance to ensure efficacy.
- If your only option is to draw water from the lake for domestic use consider the following treatment system configuration that might reduce cyanobacteria and cyanotoxins in your drinking, cooking and bathing water:
- Use a large 20-micron polyester pleated filter (at least 8” diameter and greater than 24” in length) at the point of intake. This should stop the intake of zebra mussel larvae and other larger sediments from entering the system. The intake should be placed as far from shore and as deep as possible. Cyanobacteria tends to gather and sink at the shoreline.
- Use a 5-micron filter as the 2nd stage of particulate and sediment removal. This filter should be sized appropriately for water flow and consumption needs and located in the house.
- Use a 1-micron (actual) filter as the 3rd stage of particulate and sediment removal. This filter may remove cyanobacteria cells. This filter should be sized appropriately for water flow and consumption needs and located in the house.
- Use a whole-house granular activated carbon tank in combination with a chlorine contact tank system. (EPA recommends carbon treatment prior to chlorination. Traditional treatment systems place chlorination prior to carbon).
- Use a multistage point-of-use reverse osmosis system that includes powder activated carbon for cooking and drinking water
- Using the above type of filtration and disinfection system may reduce the amount of or eliminate toxins, particularly microcystins. However, other toxins such as A. Anatoxin, Cylindosporum and Saxotoxin may still be present in the water and would probably require daily laboratory testing to determine whether toxins are present. Laboratory testing may be costly and could take days to process each sample.
- The use of bottled water for drinking and cooking may reduce the likelihood of contamination by ingestion for humans and pets.
- Other cautionary notes:
- Washing dishes by hand or in a dishwasher does not necessarily eliminate the toxins from kitchenware (pans, dishes, glasses, flatware, etc.)
- Toxins may be absorbed through skin or mucosal membranes while bathing or showering. Incidental ingestion may occur while showering.
- Cyanobacterial blooms can occur in the winter, depending on conditions, to a lesser degree with a lower probability.
*The sewer system is expected to be in operation by 2019, however homeowners have up to 5 years to connect to the system which would be 2024.
In summary, Ballston Lake has cyanobacteria present and has tested positive for microcystins. Subject matter experts that were informally consulted to gather and compile this information include:
- NYS DEC Division of Water – PhD. Scientist
- NYS Regional Department of Health – Engineer
- NYS Department of Health – Research Scientist, Center for Environmental Health
- EPA Region 2 Clean Water Division – General Physical Scientist
- EPA – Consulting PhD., Cyanobacteria and Water Treatment Specialist
These subject matter experts believe that Ballston Lake may be at risk for increasing levels of toxins. Local and national water treatment companies do not appear to be knowledgeable nor equipped to safely mitigate or eliminate toxins from water drawn from the lake for domestic use. Commercial or municipal water treatment facilities have the equipment, materials, scientists and technicians to continually monitor and treat water to eliminate toxins. There is currently no prescriptive formula to scale these monitoring and treatment methodologies to a private residential systems.