Does My Drinking Water Contain Harmful Toxic Algae?
Like all living things, the health of a drinking water reservoir is dictated by a sensitive balance of chemical and biological characteristics. These traits vary between all waterbodies, meaning balance must be achieved in different ways depending on the function, age and environmental stressors on the aquatic resource. With this in mind, water purification municipalities work tirelessly to ensure the water we drink, cook with and bathe in is balanced in a way that is safe for humans. But with an upturn in the distribution and density of harmful algal blooms (HABs) in our reservoirs, the water purification process is not without its challenges.
A rise in urban and agricultural development has diminished the grassy and forested areas that are most effective at settling stormwater runoff during rainstorms. How does this relate to drinking water quality? When runoff is not directed to natural landscapes or stormwater management facilities designed for its collection, it is instead diverted to impervious surfaces like sidewalks, roadways and parking lots, where it picks up sediment, trash, fertilizers and other nutrient-rich organic materials before eventually flowing into our precious lakes, rivers and reservoirs. Without proactive management strategies in place, these newly introduced nutrient sources can fuel nuisance aquatic plants or harmful cyanobacteria growth in the water we use for consumption.
Under certain conditions, cyanobacteria produce toxins that, at a minimum, can cause noticeable and unpleasant odor and taste compounds in drinking water. In extreme cases, evidence indicates that exposure to these toxins can cause the onset of nervous system complications, neurological diseases like ALS, Parkinson’s and Alzheimer’s, and even death. In addition to the detrimental impacts to human and ecological health, cyanobacteria can lead to unexpected water quality treatment costs, and even reservoir shutdowns, to lower levels to a safe threshold.
The effective management of toxic cyanobacteria is a delicate operation, especially in drinking water reservoirs. Cyanobacteria may be managed with professional algaecide applications; however, it is possible for toxins to be released into the water as a result of this strategy. And these algaecide treatments may be short-lived due to the rapid development of cyanobacteria. Proactive management, therefore, is key to ensuring harmful blooms are prevented or caught early on in development.
Reservoirs and municipalities can benefit from proactive management plans that incorporate regular water quality testing and monitoring, aeration, nutrient remediation and shoreline erosion control. Water quality surveys are the backbone of any successful management effort; they facilitate the collection and analysis of data that can help identify chemical imbalances and seasonal patterns that may signal the onset of a harmful algal bloom. In addition to tracking parameters like dissolved oxygen, alkalinity, salinity and pH, a monitoring program will use professional laboratory testing to monitor levels of nutrients like nitrogen and phosphorous, which serve as the main source of fuel for toxic algae.
If tests reveal that nutrient levels exceed acceptable thresholds, a number of nutrient remediation strategies can be implemented to improve water quality conditions. The application of nutrient remediation products like Phoslock or Alum can help to naturally “lock up” excess nutrients, preventing them from creating imbalanced water quality conditions. Smaller stormwater facilities and waterbodies with increased water movement may be suitable candidates for a new nutrient mitigation solution called Biochar, which is applied to a waterbody in sock-like bags that are removed once full.
These methods are considered a permanent solution for existing nutrients in the waterbody, but may not impact nutrients introduced in the future. Thus, cultivating a beneficial vegetative buffer of native grasses, rushes and flowering plants around a reservoir’s shoreline is necessary to filter new nutrient-rich runoff before it reaches the aquatic resource. Buffers are not meant to be mowed; rather, they are most effective when allowed to grow about 18 inches tall and three to five feet out from the shoreline. Severely damaged or neglected shorelines should be restored to reduce sedimentation. Erosion control solutions like bioengineered shorelines and coconut coir logs can be highly effective at preserving delicate shorelines and reducing nutrient loading.
Erosion control and nutrient remediation strategies can help municipalities significantly reduce the water quality imbalances that give rise to the development of HABs. These steps may be reinforced by proactively increasing circulation and dissolved oxygen levels in the waterbody. Floating fountains or submersed diffused aeration systems function differently, but have a shared purpose of integrating air into the water column – either at the surface or through a pump to the bottom of the resource for vertical mixing. A well-oxygenated waterbody is more effective at naturally converting undesirable nutrients to forms that cannot sustain harmful algal blooms. For more premium and long-lasting dissolved oxygen benefits, nanobubble technology has become the new standard. On-shore nanobubble generators help saturate the water with 79,000x more dissolved oxygen than traditional aeration systems, mitigating the conditions that allow nutrients to fuel algae growth.
Ultimately, the health of our drinking water reservoirs is largely dependent on the proactive measures in place to offset environmental stressors, chemical imbalances and biological characteristics—and these preventative measures tend to be much simpler and easier to incorporate than reactive solutions. As the developed world continues to grow, it’s important to support our municipalities in the preservation and protection of our drinking water resources. Contact your professional lake manager for customized reservoir management recommendations.
Improve Water Quality with Nutrient Remediation
SOLitude Lake Management is a nationwide environmental firm committed to providing sustainable solutions that improve water quality, enhance beauty, preserve natural resources and reduce our environmental footprint. SOLitude’s team of aquatic resource management professionals specializes in the development and execution of customized lake, stormwater pond, wetland and fisheries management programs that include water quality testing and restoration, nutrient remediation, algae and aquatic weed control, installation and maintenance of fountains and aeration systems, bathymetry, shoreline erosion restoration, mechanical harvesting and hydro-raking, lake vegetation studies, biological assessments, habitat evaluations, and invasive species management. Services and educational resources are available to clients nationwide, including homeowners associations, multi-family and apartment communities, golf courses, commercial developments, ranches, private landowners, reservoirs, recreational and public lakes, municipalities, drinking water authorities, parks, and state and federal agencies. SOLitude Lake Management is a proud member of the Rentokil Steritech family of companies in North America.
