Water: Coastal Zone Act Reauthorization Amendments
I. Forest Chemical Management
Use chemicals when necessary for forest management in accordance with the following to reduce nonpoint source pollution impacts due to the movement of forest chemicals off-site during and after application:
- Conduct applications by skilled and, where required, licensed applicators according to the registered use, with special consideration given to impacts to nearby surface waters.
- Carefully prescribe the type and amount of pesticides appropriate for the insect, fungus, or herbaceous species.
- Prior to applications of pesticides and fertilizers, inspect the mixing and loading process and the calibration of equipment, and identify the appropriate weather conditions, the spray area, and buffer areas for surface waters.
- Establish and identify buffer areas for surface waters. (This is especially important for aerial applications.)
- Immediately report accidental spills of pesticides or fertilizers into surface waters to the appropriate State agency. Develop an effective spill contingency plan to contain spills.
This management measure pertains to lands where silvicultural or forestry operations are planned or conducted. It is intended to apply to all fertilizer and pesticide applications (including biological agents) conducted as part of normal silvicultural activities.
Under the Coastal Zone Act Reauthorization Amendments of 1990, States are subject to a number of requirements as they develop coastal nonpoint source programs in conformity with this measure and will have some flexibility in doing so. The application of this management measure by States is described more fully in Coastal Nonpoint Pollution Control Program: Program Development and Approval Guidance, published jointly by the U.S. Environmental Protection Agency (EPA) and the National Oceanic and Atmospheric Administration (NOAA) of the U.S. Department of Commerce.
Chemicals used in forest management are generally pesticides (insecticides, herbicides, and fungicides) and fertilizers. Since pesticides may be toxic, they must be mixed, transported, loaded, and applied properly and their containers disposed of properly in order to prevent potential nonpoint source pollution. Since fertilizers may also be toxic or may shift the ecosystem energy dynamics, depending on the exposure and concentration, they must also be properly handled and applied.
Pesticides and fertilizers are occasionally introduced into forests to reduce mortality of desired tree species, improve forest production, and favor particular plant species. Many forest stands or sites never receive chemical treatment, and of those that do receive treatment, typically no more than two or three applications are made during an entire tree rotation (40 to 120 years) (Megahan, 1980). Despite the low rate of applications in an area, pesticides can still accumulate within a watershed because there may be many forest sites that receive applications.
Although pesticides and fertilizers are used infrequently in forest operations, they can still pose a risk to the aquatic environment depending on the application technique used (Feller, 1989; Neary, 1985). These chemicals can directly enter surface waters through five major pathways: direct application, drift, mobilization in ephemeral streams, overland flow, and leaching. The input from direct application is the most important source of increased chemical concentrations and is also one of the most easily prevented.
Most adverse water quality effects related to the application of pesticides and fertilizers result from direct application of chemicals to surface waters or from chemical spills (Golden et al., 1984; Fredriksen et al., 1973; Norris and Moore, 1971). Hand application of herbicides generally poses little or no threat to water quality in areas where there is no potential for herbicides to wash into watercourses through gullies (Golden et al., 1984). Norris and Moore (1971) also found that providing buffer areas around streams and waterbodies effectively eliminated adverse water quality effects from forestry chemicals.
3. Management Measure Selection
This measure is based in part on information and experience gained from studies and from use of similar management practices by States. Information on the effects of various pesticide application and fertilization techniques on water quality are summarized in Tables 3-59 through 3-62. Many of the data presented are site-specific or lack clearly specified experimental conditions. However, general trends can be discerned among the studies, and general conclusions on the effectiveness of stream protection practices can be drawn.
a. Pesticide Effects
Most data show that the delivery of pesticides to surface waters from forestry operations is variable, depending on application technique, the presence or absence of buffers, and pesticide characteristics. The studies suggest that negative effects can be greatly reduced by taking precautions to avoid drift or direct application of chemicals to streams and other waterbodies. Norris and Moore (1971) noted that the concentration of 2,4-D in streams after aerial application was one to two orders of magnitude greater in forestry operations without buffers than in areas with buffers (Table 3-59). The elevated concentrations in the nonbuffered area returned to levels comparable to the buffered area after roughly 81 hours from the time of application. Fredriksen and others (1973) noted that in 8 years of monitoring Northwest forest streams for pesticide effects, no herbicide residues were detected in water column samples more than 1 month after aerial application. However, neither aquatic organisms nor sediments were sampled. Herbicide-induced changes in vegetation density and composition may cause indirect effects on streams such as increases in water temperature or nutrient concentration after desiccation of streamside vegetation. Use of unsprayed buffer strips should minimize these effects (Fredriksen et al., 1973).
Riekerk and others (1989) also found that the greatest risk to water quality from pesticide application in forestry operations occurs from aerial applications because of drift, wash-off, and erosion processes. As shown in Table 3-60, they found that aerial applications of herbicides resulted in a surface runoff concentration roughly 3.5 times greater than that of applications to the ground. They suggested that tree injection application methods would be considered the least hazardous for water pollution, but would also be the most labor-intensive.
Norris and others (1991) compiled information from multiple studies that evaluated the peak concentrations of herbicides, insecticides, and fertilizers in soils, lakes, and streams (Table 3-61 (25k)). These studies were conducted from 1967 to 1987. Norris (1967) found that application of 2,4-D to marshy areas lead to higher-than-normal levels of stream contamination. When ephemeral streams were treated, residue levels of hexazinone and picloram greatly increased with storm-generated flow. Glyphosate was aerially applied (3.3 kg/hectare) to an 8-hectare forest ecosystem in the Oregon Coast Range. The study area contained two ponds and a small perennial stream. All were unbuffered and received direct application of the herbicide. Glyphosate residues were detected for 55 days after application with peak stream concentrations of 0.27 mg/L. It was demonstrated that the concentration of insecticides in streams was significantly greater when the chemicals were applied without a buffer strip to protect the watercourse. When streams were unbuffered, the peak concentrations of malathion ranged from 0.037-0.042 mg/L. However, when buffers were provided, the concentrations of malathion were reduced to levels that ranged from undetectable to 0.017 mg/L. The peak concentrations of carbaryl ranged from 0.000-0.0008 mg/L when watercourses were protected with a buffer, but increased to 0.016 mg/L when watercourses were unbuffered.
Another study concluded that the effects of a pellet formulation of picloram applied to an Appalachian mountain forest did not produce any adverse effect on water quality within the 2-year study period (Neary et al., 1985). Similar results were found for a study on the application of sulfometuron methyl in Coastal Plain flatwoods (Neary et al., 1989). These researchers concluded that chemical application should not pose a threat to water quality when chemicals are applied at rates established on the product label and well away from flowing streams.
b. Fertilizer Effects
Moore (1971), as cited in Norris et al. (1991), compared nitrogen loss from a watershed treated with 224 kg urea-N per hectare to nitrogen loss from an untreated watershed. The study demonstrated that the loss of nitrogen from the fertilized watershed was 28.02 kg per hectare while the loss of nitrogen from the unfertilized watershed was only 2.15 kg per hectare (Table 3-62).
Studies by Moore (Table 3-61) indicated that the concentrations of urea-N in runoff varied greatly, but that the greatest opportunity for water quality damage from fertilizer application occurred when the chemical directly entered the waterbody. The peak concentrations were directly proportional to the amount of open surface water within the treated areas, and increases resulted almost entirely from direct applications to surface water. Megahan (1980) summarized data from Moore (1975), who examined changes in water quality following the fertilization of various forest stands with urea. The major observations from this research are summarized as follows (Megahan, 1980):
- Increases in the concentration of urea-N ranged from very low to a maximum of 44 ppm, with the highest concentrations attributed to direct application to water surfaces.
- Higher concentrations occurred in areas where buffer strips were not left beside streambanks.
- Chemical concentrations of urea and its by-products tended to be relatively short-lived due to transport downstream, assimilation by aquatic organisms, or adsorption by stream sediments.
Based on his literature review, Megahan (1980) concluded that the impacts of fertilizer application in forested areas could be significantly reduced by avoiding application techniques that could result in direct deposition into the waterbody and by maintaining a buffer area along the streambank. Malueg and others (1972) and Hetherington (1985) also presented information in support of Megahan's conclusions.
As discussed more fully at the beginning of this chapter and in Chapter 1, the following practices are described for illustrative purposes only. State programs need not require implementation of these practices. However, as a practical matter, EPA anticipates that the management measure set forth above generally will be implemented by applying one or more management practices appropriate to the source, location, and climate. The practices set forth below have been found by EPA to be representative of the types of practices that can be applied successfully to achieve the management measure described above.
- For aerial spray applications maintain and mark a buffer area of at least 50 feet around all watercourses and waterbodies to avoid drift or accidental application of chemicals directly to surface water.
A wider buffer may be needed for major streams and lakes and for application of pesticides with high toxicity to aquatic life. A 100-foot buffer should be used for aerial applications and a 25-foot buffer used for ground spray. Aerial application methods require careful and precise marking of application areas to avoid accidental contamination of open waters (Riekerk, 1989). For specific applications such as hypo hatchet or wick applicator, buffer area widths used for spray applications may be reduced.
- Apply pesticides and fertilizers during favorable atmospheric conditions.
- Do not apply pesticides when wind conditions increase the likelihood of significant drift.
- Avoid pesticide application when temperatures are high or relative humidity is low because these conditions influence the rate of evaporation and enhance losses of volatile pesticides.
- Users must abide by the current pesticide label which may specify: whether users must be trained and certified in the proper use of the pesticide; allowable use rates; safe handling, storage, and disposal requirements; and whether the pesticide can only be used under the provision of an approved Pesticide State Management Plan, management measures and practices for pesticides should be consistent with and/or complement those in the approved Pesticide State Management Plans.
- Locate mixing and loading areas, and clean all mixing and loading equipment thoroughly after each use, in a location where pesticide residues will not enter streams or other waterbodies.
- Dispose of pesticide wastes and containers according to State and Federal laws.
- Take precautions to prevent leaks and/or spills.
- Develop a spill contingency plan that provides for immediate spill containment and cleanup, and notification of proper authorities.
An adequate spill and cleaning kit that includes the following should be maintained:
- Detergent or soap;
- Hand cleaner and water;
- Activated charcoal, adsorptive clay, vermiculite, kitty litter, sawdust, or other adsorptive materials;
- Lime or bleach to neutralize pesticides in emergency situations;
- Tools such as a shovel, broom, and dustpan and containers for disposal; and
- Proper protective clothing.
- Apply slow-release fertilizers, when possible.
This practice will reduce potential nutrient leaching to ground water, and it will increase the availability of nutrients for plant uptake.
- Apply fertilizers during maximum plant uptake periods to minimize leaching.
- Base fertilizer type and application rate on soil and/or foliar analysis.
To determine fertilizer formulations, it is best to compare available nitrogen, phosphorus, potassium, and sulphur in the soils to be treated with the requirements of the species to be sown (Rothwell, 1978).
- Consider the use of pesticides as part of an overall program to control pest problems.
Integrated Pest Management (IPM) strategies have been developed to control forest pests without total reliance on chemical pesticides. The IPM approach uses all available techniques, including chemical and nonchemical. An extensive knowledge of both the pest and the ecology of the affected environment is required for IPM to be effective. A more in-depth discussion of IPM strategies and components can be found in the Pesticide management measure section of the Agriculture chapter of this guidance.
- Base selection of pesticide on site factors and pesticide characteristics.
These factors include vegetation height, target pest, adsorption to soil organic matter, persistence or half-life, toxicity, and type of formulation.
- Check all application equipment carefully, particularly for leaking hoses and connections and plugged or worn nozzles. Calibrate spray equipment periodically to achieve uniform pesticide distribution and rate.
- Always use pesticides in accordance with label instructions, and adhere to all Federal and State policies and regulations governing pesticide use.
5. Relationship of Management Measure Components for Pesticides to Other Programs
Under the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), EPA registers pesticides on the basis of evaluation of test data showing whether a pesticide has the potential to cause unreasonable adverse effects on humans, animals, or the environment. Data requirements include environmental fate data showing how the pesticide behaves in the environment, which are used to determine whether the pesticide poses a threat to ground water or surface water. If the pesticide is registered, EPA imposes enforceable label requirements, which can include, among other things, maximum rates of application, classification of the pesticide as a "restricted use" pesticide (which restricts use to certified applicators trained to handle toxic chemicals), or restrictions on use practices, including requiring compliance with EPA-approved Pesticide State Management Plans (described below). EPA and the U.S. Department of Agriculture Cooperative Extension Service provide assistance for pesticide applicator and certification training in each State.
FIFRA allows States to develop more stringent pesticide requirements than those required under FIFRA, and some States have chosen to do this. At a minimum, management measures and practices under State Coastal Nonpoint Source Programs must not be less stringent than FIFRA label requirements or any applicable State requirements.
EPA's Pesticides and Groundwater Strategy (USEPA, 1991) describes the policies and regulatory approaches EPA will use to protect the Nation's ground-water resources from risks of contamination by pesticides under FIFRA. The objective of the strategy is the prevention of ground-water contamination by regulating the use of certain pesticides (i.e., use according to EPA-approved labeling) in order to reduce and, if necessary, eliminate releases of the pesticide in areas vulnerable to contamination. Priority for protection will be based on currently used and reasonably expected sources of drinking water supplies, and ground water that is closely hydrogeologically connected to surface waters. EPA will use Maximum Contaminant Levels (MCLs) under the Safe Drinking Water Act as "reference points" for water resource protection efforts when the ground water in question is a current or reasonably expected source of drinking water.
The Strategy describes a significant new role for States in managing the use of pesticides to protect ground water from pesticides. In certain cases, when there is sufficient evidence that a particular use of a pesticide has the potential for ground-water contamination to the extent that it might cause unreasonable adverse effects, EPA may (through the use of existing statutory authority and regulations) limit legal use of the product to those States with an acceptable Pesticide State Management Plan, approved by EPA. Plans would tailor use to local hydrologic conditions and would address:
- State philosophy;
- Roles and responsibilities of State and local agencies;
- Legal and enforcement authority;
- Basis for assessment and planning;
- Prevention measures;
- Ground-water monitoring;
- Response to detections;
- Information dissemination; and
- Public participation.
In the absence of such an approved Plan, affected pesticides could not be legally used in the State.
Since areas to be managed under Pesticide State Management Plans and Coastal Nonpoint Source Programs can overlap, State coastal zone and nonpoint source agencies should work with the State lead agency for pesticides (or the State agency that has a lead role in developing and implementing the Pesticide State Management Plan) in the development of pesticide management measure components and practices under both programs. This is necessary to avoid duplication of effort and conflicting pesticide requirements between programs. Further, ongoing coordination will be necessary since both programs and management measures will evolve and change with increasing technology and data.