Marine Biochemists - A complete Aquatic Management Company

Aquatic pesticide application - past, present, future (An applicator's view)

By James R. Kannenberg Marine Biochemists - Wisconsin

Aquatic Pesticide Injection Boat Picture         Aquatic Pesticide Injection Boat Instrument Picture 

To many people, the words "aquatic" and "pesticide" correlate as well as the words "oil" and "water". The reality of the situation is that there are typically more hazardous compounds existing under kitchen sinks or in storage cabinets in residential garages than on a modern professional applicator's boat. Still, the aquatic chemicals in concentrated form used by a modern professional applicator present definite hazards in their handling and application. Another common misconception is that aquatic pesticides will indiscriminately eradicate all aquatic plants, or conversely, that more chemical is better. Depending on the aquatic situation in question, a modern applicator can determine selectivity or non-selectivity by the type and/or by the application rate of an appropriate aquatic pesticide. With the required accuracy and related hazards of aquatic pesticide application, the modern aquatic pesticide application industry has dictated the need for more precise and safe methods of application.

In the "old" days (ironically within the last decade for some), proper safety equipment on an applicator's boat was scarce if present at all. Tennis shoes or sneakers were common foot wear, chemical aprons or tyvek suits were for the fainthearted DNR inspectors, eye protection other than some stylish sunglasses didn't exist, protective gloves were only for the "nasty", more hazardous chemicals, and label recommendations for the wearing of appropriate safety equipment were only important to know for the state certification exam. The present realization that chronic (long-term) exposure to any chemical may have detrimental side-affects shouts out the need for the use of proper safety gear, and with the availability and relatively small cost, there is little excuse not to have it. The following is a minimal list of what every modern applicator should have available when he/she shows up on a job site to provide proper protection for aquatic pesticide application (the list may be expanded on, and common sense should dictate when the use of an item is necessary):

• Protective neoprene boots (should be high enough to cover mid-shin or higher)

• NIOSH or OSHA approved safety glasses

• Protective face shield

• Dust masks and/or respirators for granular applications

• Protective chemical-resistant gloves (should extend beyond wrist)

• Protective chemical-resistant apron and/or Tyvek suits (should be long enough to extend over tops of boots)

• A readily available first-aid kit including eye-wash material/bottles and fresh water

Protective knee-high neoprene boots are readily available at the local hardware or similar type department stores for under twenty dollars (a small expense to prevent rashes or burns on ankles and feet). Safety glasses are relatively inexpensive, available through local stores or safety supply companies, and today can be as stylish as most sunglasses (though shatter resistance and side shields are a must). Protective face shields are always recommended. Any experienced applicator can tell stories about themselves or someone they know who had a drop of chemical splash up from a mixing bucket and hit the gap between the face and safety glass lens (modern medicine is currently not able to replace eyes - only one pair to a customer, so protect them!) Dust masks and/or respirators may be needed for granular applications, and are readily available from many sources. However, care must be taken whenever using any piece of equipment that could create resistance on breathing (OSHA has very strict guidelines on the use and fit-testing of respirators, and often pulmonary exams are required for liability reasons). Chemical-resistant gloves should always be worn when handling or applying any aquatic chemical, and with low expense and common availability, there is no reason not to have an ample supply available. Chemical-resistant aprons or tyvek suits are available through local safety supply companies and should be worn whenever mixing or applying aquatic pesticides (liquid splashes or dust particles are always a concern). Aprons should cover the top of the boots to prevent the accidental dripping of material into the boots. First aid kits are always an important piece of equipment that should be kept up to date and made available, but the necessity of an eye-wash bottle or similar conveyance is one that the modern applicator knows better than most. A boat for most purposes is not a stable laboratory environment with eyewash stations and showers readily available. An aquatic applicator has to bring his/her own portable clean means of flushing contaminated eyes or faces in the event of chemical splashing. Clothing worn under protective gear during applications should always be washed separately from household clothing to limit exposure to others from accidental contamination (a professional uniform service is sometimes worth the extra cost to limit liability). Severely or even partially contaminated clothing may have to be discarded (small cost for possible long-term exposure).

The past application safety philosophies of "rub a little dirt into it and stop your crying" have been replaced by common sense hazardous material handling protocols. These protocols will ultimately be improved on as protective equipment evolves with the advance of new materials, advanced and streamline (and ultimately more "stylish") designs emerge, and safety education expands with increased understanding and knowledge of aquatic pesticides. The future aquatic applicator may very well look back at this present time and joke about the lack of safety in a similar manner as current applicators laugh about some of the methods of their predecessors.

Along with the advancements of personal protection equipment, modern applicators are constantly improving upon their predecessor's application techniques. The gross basics of applying aquatic pesticides has for the most part not changed, but the fine tuning of these basics has. The basic methods of applying aquatic pesticides are as follows:

• High-volume liquid application pumps - This type of pump consists of a water intake which draws water directly from the body of water being treated, and a chemical intake which draws chemical into the pump's water flow thus accomplishing chemical dilution for even distribution purposes. The outflow from the pump can be directed to a boom-sprayer assembly or a nozzle-type assembly. These types of pumps are almost always driven by gas combustion (2-cycle or 4-cycle) engines.

• Low-volume liquid application pumps - This type of pump relies on a mix tank with the chemical and water premixed (no external continuous water intake). The output (either boom or nozzle assembly) is typically high-pressure, low-volume in nature. Equal dispersion of the chemical requires more consideration toward lower flow rates than high-volume pump systems and the volume of chemical mix is limited, but does eliminate the need to constantly draw dilution water from the treated water body eliminating most boat speed limitations. These types of pumps are typical driven by DC electric motors or gas combustion engines.

• Granular applicators - Types used to disperse granular formulations of aquatic pesticides. The two most popular types are the granular spreader consisting of a holding compartment that feeds material out of a regulated slot to a spinning spread-fan assembly underneath, and the granular blower which incorporates a blower fan with a feeder compartment that allows granular material to enter the air stream created by the fan (the direction of application determined by a directional nozzle). Both types can be modified to apply off the front or rear of a boat.

These methods do not take a lot of technology to use, but current advances in technology and the relatively low cost of this technology as compared to ten years ago has refined the above listed methods allowing the modern applicator to add a great deal of precision to the "art" of aquatic applications.

Of the recent advances in application techniques, the use of digital flow meters for monitoring chemical flow rates has definitely added a new dimension to application accuracy, especially on large-scale applications. Precision in the past has had to rely on good field chemistry calculations, a careful eye watching the level in the mix tank, and a good feel for dilution color as chemical was applied, but with digital read-out, applying chemicals at specified rates is easier than ever. This is especially important in the case of extremely low-rate herbicides where typical application concentrations are in the less than 20 parts per billion range. Draw backs on any flow meter is that most are calibrated for one specific viscosity of liquid. High-viscous liquids may have to be diluted, meters may have to re-calibrated, or conversion charts may be needed to accurately apply liquids of differing viscosity.

Along with the more-affordable flow-monitoring technologies come the more affordable depth determination products now on the market. An on-board depth monitor (typically used for fishing) gives an applicator instant information about a particular area's depth profile. In large-scale applications, flow rates can be more accurately adjusted with constant water depth updates. The obvious limitations of these depth meters are their use in applications where extremely shallow water or extremely dense underwater growth may skew determinations.

Another advancement now made readily available to the modern applicator is the use of Global Positioning Systems for bearing, speed, distance and way-point calculations. These GPS field units can be relatively inexpensive and can typically provide position or distance information within 45 feet or better, and speed determination within a tenth of a mile or better. The accuracy of basic field units can be greatly enhanced by adding base units, but additional base units may be up to three to four times the cost of a basic field unit. Many GPS units are extremely light and compact, and many have the capability to down-load information to a personal computer. There are even GPS units incorporated with depth finders allowing simultaneous marking of location and depth (most units have limited storage capabilities, but lake mapping can often be accomplished with a combination GPS/depth-finder by constantly downloading to an on-board lap-top computer). Depending on the GPS unit involved, it is typically possible to show application transects on a digital map on the GPS unit screen (extremely valuable in determining sufficient coverage of a large area and being able to demonstrate the accuracy of coverage to others).

Modern application technology has also incorporated the use of personal computers. Most application companies use PC's for maintaining customer databases, field data manipulation and correspondence, but modern spreadsheet programs also allow many to program charts that incorporate many factors involved in application work. By using spreadsheet programs, one can calculate precise application charts that can determine chemical amounts required for a given concentration for a given water volume to be treated, the application area covered by the application vessel at a given speed at a given transect width, and the chemical application flow-rate for that area covered at that given speed at a given depth. The combination of GPS technology, digital depth determination, and digital chemical flow-rate monitoring along with computer programming allow for very accurate aquatic applications.

Other improvements in the application of aquatic pesticides are more common sense than not, and their time of incorporation is more generalized than specific. The open mixing containers of yesteryear are still justifiably used today, but more and more, closed "nurse" tanks are making their way aboard applicators' boats. Open "mixing buckets" are still commonly used and considered convenient for most smaller sites, and when used with the proper respect, can prove fairly safe. However, there is always the time when the quick movement of an applicator or boat driver, or the wake of a passing speed boat will cause sloshing of material in an open bucket leaving splash marks on decks, equipment, and very often on applicators. Modern applicators on smaller sites will often opt for a smaller closed container such as a 5 gallon drum with a sufficiently large mouth to allow for addition of chemical while reducing the risk of splashing. If the drum has a seal-able cap, safe agitation of a mixture can be readily accomplished.

Another improvement is the rear mounting of granular application equipment with the addition of GPS technology. This allows forward motion into the wind, and with the use of GPS technology, enhances the accuracy and speed of granular applications in that speed and bearing determination are more readily and accurately available. Accurate speed determination during granular application is extremely important on large-scale applications, and GPS technology allows provides greater accuracy than paddle-wheel style boat speedometers which are fairly inaccurate at lower speeds (under 10 mph). As mentioned before, transect and direction bearing accuracy during large-scale applications is vital in delivering the correct amount of material to the correct treatment area. One may want to incorporate a deep-cycle 12 volt electrical system onto an application vessel to supply power to all of the above mentioned meters and equipment.

Future advancements will most likely bring more affordable technology to the aquatic chemical applicator's level, allowing for even more precise delivery of aquatic pesticides. Most of these technological advances will come from other industries, and aquatic applicators will adapt them to their industry. Aquatic application equipment has almost always been modified from another industry (there is not an aquatic application equipment section at the local department store as of yet). Most liquid application pumps are transfer pumps from the agricultural industry, and most granular spreaders are typically from the agricultural or turf industries. The ingenuity of aquatic applicators, both past and present, has enabled this industry to survive, and will only be built upon as new technologies arise.

Along with the rise of new technologies comes the re-evaluation of the current tools of the industry. New application rates for aquatic pesticides have opened new doorways in dealing with exotic species. Low-dose fluridone applications in the less than 20 part per billion concentration range have prove effective to a significant degree in selective treatment programs for Eurasian Watermilfoil and Curly-leaf Pondweed control. Lower rates of endothol products have also shown enhanced selectivity for Curly-leaf Pondweed control without detrimentally affecting certain other species of pondweed. New formulations of 2,4-D have been utilized to provide even greater selective control of Eurasian Watermilfoil than previous formulations. Chelated forms (and even better double-chelated forms) of copper-based algaecides are now more the norm due to the rapid precipitation of the old time copper sulfate mixtures in hard water conditions (copper sulfate is still commonly used due to areas with soft water conditions and the relative low cost of material even though toxicity effects may be greater). Due to the lower environmental impact of chelated copper algaecides, more and more regulatory agencies are insisting that these forms be used instead of copper sulfate, thus introducing less copper into the environment while still obtaining treatment objectives. The timing of selective aquatic treatments has also been re-evaluated. It has been shown that early season and late season treatments can be extremely effective for controlling certain exotic species without severely hampering native species growth. Controlling exotics when bio-mass levels are low has proven more environmentally sound in that large shifts in dissolved oxygen levels and other negative attributes of organic decay are controlled to a relatively negligible level due to less organic material decaying and water column mixing commonly occurring in early and late season lakes. By limiting exotic growth, native species will have a better opportunity for re-establishment providing for increased bio-diversity and more stable ecosystems.

The goal of ecosystem stabilization, though not a new one for many in the industry, brings up another evolution that has occurred in the aquatic pesticide application industry. In the past (and unfortunately in the present for some), eradication of all aquatic macrophytes in a given treatment area or lake was the desired goal. This concept sends shivers up the educated applicator's spine. Total eradication of all aquatic plants totally de-stabilizes the ecosystems allowing for nothing other than excessive and potentially harmful forms of filamentous and planktonic algae. This is not to say all species of algae are bad. Algae is an extremely important and necessary part of any aquatic ecosystem, but not if it is the only vegetation existing. Algae blooms can often cause detrimental fluctuations in dissolved oxygen levels, and many planktonic forms can be toxic to aquatic inhabitants as well as humans. Today's modern applicator strives to selectively treat exotic species encouraging native specie re-establishment, and to treat other excessive vegetation in more "direct use" areas leaving under utilized areas of native species as nutrient and habitat buffers in the ecosystem. This modern approach of viewing a lake as a whole system rather than many isolated parts is part of the recent shift of the aquatics industry to educate and participate in education concerning integrated lake management.

Integrated lake management education has expanded in recent years to include all aspects of individuals involved. Members of the lake management industry, members of regulatory agencies, members of lake associations, members of formal education establishments, as well as members of communities that affect aquatic systems have all been growing in numbers at local and national conferences. Many of these group are taking a larger role in the education process. One important educational point emphasized more and more at the local level is how the individual in the community can help an aquatic system. Modern applicators are spending more and more time stressing the importance of proper watershed management, especially at the individual homeowner level, than ever before in the past. The fact that the majority of the causes for rapidly declining aquatic ecosystems can be directly related to human activities is a pungent reality that many are having to face. The modern aquatic pesticide applicator realizes this, and stresses this to his/her clients should they want to see stabilization or improvement of their waters. The future of aquatic management education rests on all of the shoulders of all of the a fore mentioned groups. Industry and aquatic societies have taken on larger roles, and will have to continue doing so in the future. With continued cooperation amongst the different factions, public support for proper management programs will grow and shared knowledge will increase being more readily available to individuals, eliminating the confusion commonly experienced in current and past management discussions.

Improved education, safety measures, equipment, application technology, products and application techniques will all have a beneficial impact on today's modern aquatic pesticide applicator. The conscientious modern aquatic applicator uses the technology available and integrates appropriate new ideas and technology to accomplish responsible lake management goals. The future of aquatic pesticide application will bring new products and technologies as well as even more improved methods of using current products and equipment allowing for even more targeted benefits to arise from this valuable tool in the toolbox of integrated lake management professionals. The current and future viability of the aquatic pesticide industry has been directly enhanced by the responsible activities, public education, and industry contributions of the modern applicator and the innovative pioneers of the aquatic pesticide application industry.