Water: Coastal Zone Act Reauthorization Amendments
Management Measures for Forestry - I. Introduction
A. What "Management Measures" Are
This chapter specifies management measures to protect coastal waters from silvicultural sources of nonpoint pollution. "Management measures" are defined in section 6217 of the Coastal Zone Act Reauthorization Amendments of 1990 (CZARA) as economically achievable measures to control the addition of pollutants to our coastal waters, which reflect the greatest degree of pollutant reduction achievable through the application of the best available nonpoint pollution control practices, technologies, processes, siting criteria, operating methods, or other alternatives.
These management measures will be incorporated by States into their coastal nonpoint programs, which under CZARA are to provide for the implementation of management measures that are "in conformity" with this guidance. Under CZARA, States are subject to a number of requirements as they develop and implement their Coastal Nonpoint Pollution Control Programs in conformity with this guidance and will have some flexibility in doing so. The application of these management measures by States to activities causing nonpoint pollution 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).
B. What "Management Practices" Are
In addition to specifying management measures, this chapter also lists and describes management practices for illustrative purposes only. While State programs are required to specify management measures in conformity with this guidance, States programs need not specify or require implementation of the particular management practices described in this document. However, as a practical matter, EPA anticipates that the management measures generally will be implemented by applying one or more management practices appropriate to the site, location, type of operation, and climate. The practices listed in this document have been found by EPA to be representative of the types of practices that can be applied successfully to achieve the management measures. EPA has also used some of these practices, or appropriate combinations of these practices, as a basis for estimating the effectiveness, costs, and economic impacts of achieving the management measures. (Economic impacts of the management measures are addressed in a separate document entitled Economic Impacts of EPA Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters.)
EPA recognizes that there is often site-specific, regional, and national variability in the selection of appropriate practices, as well as in the design constraints and pollution control effectiveness of practices. The list of practices for each management measure is not all-inclusive and does not preclude States or local agencies from using other technically sound practices. In all cases, however, the practice or set of practices chosen by a State needs to achieve the management measure.
C. Scope of This Chapter
This chapter contains 10 management measures that address various phases of forestry operations relevant to the control of sources of silvicultural nonpoint pollution that affect coastal waters. A separate measure for forestry operations in forested wetlands is included. These measures are:
- Preharvest planning
- Streamside management areas
- Road construction/reconstruction
- Road management
- Timber harvesting
- Site preparation and forest regeneration
- Fire management
- Revegetation of disturbed areas
- Forest chemical management
- Wetland forest management
Each of these topics is addressed in a separate section of this chapter. Each section contains (1) the management measure; (2) an applicability statement that describes, when appropriate, specific activities and locations for which the measure is suitable; (3) a description of the management measure's purpose; (4) the rationale for the management measure's selection; (5) information on the effectiveness of the management measure and/or of practices to achieve the measure; (6) information on management practices that are suitable, either alone or in combination with other practices, to achieve the management measure; and (7) information on costs of the measure and/or of practices to achieve the measure.
Coordination of Measures
The management measures developed for silviculture are to be used as an overall system of measures to address nonpoint source (NPS) pollution sources on any given site. In most cases, not all the measures will be needed to address the NPS sources of a specific site. For example, many silvicultural systems do not require road construction as part of the operation and would not need to be concerned with the management measure that addresses road construction. By the same token, many silvicultural systems do not use prescribed fire and would not need to use the fire management measure.
Most forestry operations will have more than one phase of operation that needs to be addressed and will need to employ two or more of the measures to address the multiple sources. Where more than one phase exists, the application of the measures needs to be coordinated to produce an overall system that adequately addresses all sources for the site and does not cause unnecessary expenditure of resources on the site.
Since the silvicultural management measures developed for the CZARA are, for the most part, a system of practices that are commonly used and recommended by States and the U.S. Forest Service in guidance or rules for forestry-related nonpoint source pollution, there are many forestry operations for which practices or systems of practices have already been implemented. Many of these operations may already achieve the measures needed for the nonpoint sources on them. For cases where existing source control is inadequate, it may be necessary to add only one or two more practices to achieve the measure. Existing NPS progress must be recognized and appropriate credit given to the accomplishment of our common goal to control NPS pollution. There is no need to spend additional resources for a practice that is already in existence and operational. Existing practices, plans, and systems should be viewed as building blocks for these management measures and may need no additional improvement.
D. Relationship of This Chapter to Other Chapters and to Other EPA Documents
- Chapter 1 of this document contains detailed information on the legislative background for this guidance, the process used by EPA to develop this guidance, and the technical approach used by EPA in the guidance.
- Chapter 7 of this document contains management measures to protect wetlands and riparian areas that serve a nonpoint source pollution abatement function. These measures apply to a broad variety of nonpoint sources; however, the measures for wetlands described in Chapter 7 are not intended to address silvicultural sources. Practices for normal silvicultural operations in forested wetlands are covered in Management Measure J of Chapter 3.
- Chapter 8 of this document contains information on recommended monitoring techniques to (1) ensure proper implementation, operation, and maintenance of the management measures and (2) assess over time the success of the measures in reducing pollution loads and improving water quality.
- EPA has separately published a document entitled Economic Impacts of EPA Guidance Specifying Management Measures for Sources of Nonpoint Pollution in Coastal Waters.
- NOAA and EPA have jointly published guidance entitled Coastal Nonpoint Pollution Control Program: Program Development and Approval Guidance. This guidance contains details on how State coastal nonpoint pollution control programs are to be developed by States and approved by NOAA and EPA. It includes guidance on:
- The basis and process for EPA/NOAA approval of State Coastal Nonpoint Pollution Control Programs;
- How NOAA and EPA expect State programs to specify management measures "in conformity" with this management measures guidance;
- How States may target sources in implementing their Coastal Nonpoint Pollution Control Programs;
- Changes in State coastal boundaries; and
- Requirements concerning how States are to implement Coastal Nonpoint Pollution Control Programs.
The effects of forestry activities on water quality have been widely studied, and the need for management measures and practices to prevent silvicultural contributions to water pollution has been recognized by all States with significant forestry activities. Silvicultural activities have been identified as nonpoint sources in coastal area water quality assessments and control programs. Water quality concerns related to forestry were addressed in the 1972 Federal Water Pollution Control Act Amendments and later, more comprehensively, as nonpoint sources under section 208 of the 1977 Clean Water Act and section 319 of the 1987 Water Quality Act. On a national level, silviculture contributes approximately 3 to 9 percent of nonpoint source pollution to the Nation's waters (Neary et al., 1989; USEPA, 1992a). Local impacts of timber harvesting and road construction on water quality can be severe, especially in smaller headwater streams (Brown, 1985; Coats and Miller, 1981; Pardo, 1980). Megahan (1986) reviewed several studies on forest land erosion and concluded that surface erosion rates on roads often equaled or exceeded erosion reported for severely eroding agricultural lands. These effects are of greatest concern where silvicultural activity occurs in high-quality watershed areas that provide municipal water supplies or support cold-water fisheries (Whitman, 1989; Neary et al., 1989; USEPA, 1984; Coats and Miller, 1981).
Twenty-four States have identified silviculture as a problem source contributing to NPS pollution in their 1990 section 305(b) assessments (USEPA, 1992b). Silviculture was the pollution source for 9 percent of NPS pollution to rivers in the 42 States reporting NPS pollution figures in section 305(b) assessments (USEPA, 1992b). States have reported up to 19 percent of their river miles to be impacted by silviculture. On Federal lands, such as national forests, many water quality problems can be attributed to the effects of timber harvesting and related activities (Whitman, 1989). In response to these impacts, many States have developed programs to address NPS pollution from forestry activities.
1. Pollutant Types and Impacts
Without adequate controls, forestry operations may degrade several water quality characteristics in waterbodies receiving drainage from forest lands. Sediment concentrations can increase due to accelerated erosion; water temperatures can increase due to removal of overstory riparian shade; slash and other organic debris can accumulate in waterbodies, depleting dissolved oxygen; and organic and inorganic chemical concentrations can increase due to harvesting and fertilizer and pesticide applications (Brown, 1985). These potential increases in water quality contaminants are usually proportional to the severity of site disturbance (Riekerk, 1983, 1985; Riekerk et al., 1989). Silvicultural NPS pollution impacts depend on site characteristics, climatic conditions, and the forest practices employed. Figure 3-1 presents a model of forest biogeochemistry, hydrology, and stormflow interactions.
Sediment. Sediment is often the primary pollutant associated with forestry activities (Pardo, 1980). Sediment is often defined as mineral or organic solid material that is eroded from the land surface by water, ice, wind, or other processes and is then transported or deposited away from its original location.
Sediment transported from forest lands into waterbodies can be particularly detrimental to benthic organisms and many fish species. When it settles, sediment fills interstitial spaces in lake bottoms or streambeds. This can eliminate essential habitat, covering food sources and spawning sites and smothering bottom-dwelling organisms and periphyton. Sediment deposition also reduces the capacity of stream channels to carry water and of reservoirs to hold water. This decreased flow and storage capacity can lead to increased flooding and decreased water supplies (Golden, et al., 1984).
Suspended sediments increase water turbidity, thereby limiting the depth to which light can penetrate and adversely affecting aquatic vegetation photosynthesis. Suspended sediments can also damage the gills of some fish species, causing them to suffocate, and can limit the ability of sight-feeding fish to find and obtain food.
Turbid waters tend to have higher temperatures and lower dissolved oxygen concentrations. A decrease in dissolved oxygen levels can kill aquatic vegetation, fish, and benthic invertebrates. Increases (or decreases) in water temperature outside the tolerance limits of aquatic organisms, especially cold-water fish such as trout and salmon, can also be lethal (Brown, 1974).
Nutrients. Nutrients from forest fertilizers, such as nitrogen and phosphorus adsorbed to sediments, in solution, or transported by aerial deposition, can cause harmful effects in receiving waters. Sudden removal of large quantities of vegetation through harvesting can also increase leaching of nutrients from the soil system into surface waters and ground waters by disrupting the nitrogen cycle (Likens et al., 1970). Excessive amounts of nutrients may cause enrichment of waterbodies, stimulating algal blooms. Large blooms limit light penetration into the water column, increase turbidity, and increase biological oxygen demand, resulting in reduced dissolved oxygen levels. This process, termed eutrophication, drastically affects aquatic organisms by depleting the dissolved oxygen these organisms need to survive.
Forest Chemicals. Herbicides, insecticides, and fungicides (collectively termed pesticides) used to control forest pests and undesirable plant species, can be toxic to aquatic organisms. Pesticides that are applied to foliage or soils, or are applied by aerial means, are most readily transported to surface waters and ground waters (Norris and Moore, 1971). Some pesticides with high solubilities can be extremely harmful, causing either acute or chronic effects in aquatic organisms, including reduced growth or reproduction, cancer, and organ malfunction or failure (Brown, 1974). Persistent pesticides that tend to sorb onto particulates are also of environmental concern since these relatively nonpolar compounds have the tendency to bioaccumulate. Other "chemicals" that may be released during forestry operations include fuel, oil, and coolants used in equipment for harvesting and road-building operations.
Organic Debris Resulting from Forestry Activities. Organic debris includes residual logs, slash, litter, and soil organic matter generated by forestry activities. Organic debris can adversely affect water quality by causing increased biochemical oxygen demand, resulting in decreased dissolved oxygen levels in watercourses. Logging slash and debris deposited in streams can alter streamflows by forming debris dams or rerouting streams, and can also redirect flow in the channel, increasing bank cutting and resulting sedimentation (Dunford, 1962; Everest and Meehan, 1981). In some ecosystems, small amounts of naturally occurring organic material can be beneficial to fish production. Small streams in the Pacific Northwest may be largely dependent on the external energy source provided by organic materials such as leaves and small twigs. Naturally occurring large woody debris in streams can also create physical habitat diversity for rearing salmonids and can stabilize streambeds and banks (Everest and Meehan, 1981; Murphy et al., 1986).
Temperature. Increased temperatures in streams and waterbodies can result from vegetation removal in the riparian zone from either harvesting or herbicide use. These temperature increases can be dramatic in smaller (lower order) streams, adversely affecting aquatic species and habitat (Brown, 1972; Megahan, 1980; Curtis et al., 1990). Increased water temperatures can also decrease the dissolved oxygen holding capacity of a waterbody, increasing biological oxygen demand levels and accelerating chemical processes (Curtis et al., 1990).
Streamflow. Increased streamflow often results from vegetation removal (Likens et al., 1970; Eschner and Larmoyeux, 1963; Blackburn et al., 1982). Tree removal reduces evapotranspiration, which increases water availability to stream systems. The amount of streamflow increase is related to the total area harvested, topography, soil type, and harvesting practices (Curtis et al., 1990). Increased streamflows can scour channels, erode streambanks, increase sedimentation, and increase peak flows.
2. Forestry Activities Affecting Water Quality
The types of forestry activities affecting NPS pollution include road construction and use, timber harvesting, mechanical equipment operation, burning, and fertilizer and pesticide application (Neary et al., 1989).
Road Construction and Use. Roads are considered to be the major source of erosion from forested lands, contributing up to 90 percent of the total sediment production from forestry operations (Rothwell, 1983; Megahan, 1980; Patric, 1976). (See Figure 3-2.) Erosion potential from roads is accelerated by increasing slope gradients on cut-and-fill slopes, intercepting subsurface water flow, and concentrating overland flow on the road surface and in channels (Megahan, 1980). Roads with steep gradients, deep cut-and-fill sections, poor drainage, erodible soils, and road-stream crossings contribute to most of this sediment load, with road-stream crossings being the most frequent sources of erosion and sediment (Rothwell, 1983). Soil loss tends to be greatest during and immediately after road construction because of the unstabilized road prism and disturbance by passage of heavy trucks and equipment (Swift, 1984).
Brown and Krygier (1971) found that sediment production doubled after road construction on three small watersheds in the Oregon Coast Range. Dyrness (1967) observed the loss of 680 cubic yards of soil per acre from the H.J. Andrews Experimental Forest in Oregon due to soil erosion from roads on steep topography. Landslides were observed on all slopes and were most pronounced where forest roads crossed stream channels on steep drainage headwalls. Another example of severe erosion resulting from forestry practices occurred in the South Fork of the Salmon River in Idaho in the winter of 1965, following 15 years of intensive logging and road construction. Heavy rains triggered a series of landslides that deposited sediment on spawning beds in the river channel, destroying salmon spawning grounds (Megahan, 1981). Careful planning and proper road layout and design, however, can minimize erosion and prevent stream sedimentation (Larse, 1971).
Timber Harvesting. Most detrimental effects of harvesting are related to the access and movement of vehicles and machinery, and the skidding and loading of trees or logs. These effects include soil disturbance, soil compaction, and direct disturbance of stream channels. Logging operation planning, soil and cover type, and slope are the most important factors influencing harvesting impacts on water quality (Yoho, 1980). The construction and use of haul roads, skid trails, and landings for access to and movement of logs are the harvesting activities that have the greatest erosion potential.
Surveys of soil disturbance from logging were performed by Hornbeck and others (1986) in Maine, New Hampshire, and Connecticut. They found 18 percent of the mineral soil exposed by logging practices in Maine, 11 percent in New Hampshire, and 8 percent in Connecticut. Megahan (1986) reviewed several studies on forest land erosion and concluded that surface erosion rates on roads often equaled or exceeded erosion reported for severely eroding agricultural lands. Megahan (1986) found that in some cases erosion rates from harvest operations may approach erosion rates from roads and that prescribed burning can accelerate erosion beyond that from logging alone.
Another adverse impact of harvesting is the increase in stream water temperatures resulting from removal of streamside vegetation, with the greatest potential impacts occurring in small streams. However, streamside buffer strips have been shown to minimize the increase in stream temperatures (Brazier and Brown, 1973; Brown and Krygier, 1970).
Regeneration Methods. Regeneration methods can be divided into two general types: (1) regeneration from seedlings, either planted seedlings or existing seedlings released by harvesting, and (2) regeneration from seed, which can be seed from existing trees on or near the site or the broadcast application of seeds of the desired species. In some areas, regeneration with seedlings by mechanical tree planting is often conducted because it is faster and more consistent. Planting approaches relying on seeding generally require a certain amount of mineral soil to be exposed for seed establishment. For this reason, a site preparation technique is usually needed for regeneration by seeding.
Site Preparation. Mechanical site preparation by large tractors that shear, disk, drum-chop, or root-rake a site may result in considerable soil disturbance over large areas and has a high potential to deteriorate water quality (Beasley, 1979). Site preparation techniques that result in the removal of vegetation and litter cover, soil compaction, exposure or disturbance of the mineral soil, and increased stormflows due to decreased infiltration and percolation, all can contribute to increases in stream sediment loads (Golden et al., 1984). However, erosion rates decrease over time as vegetative cover grows back.
Prescribed burning and herbicides are other methods used to prepare sites that may also have potential negative effects on water quality. These activities are discussed below.
Prescribed Burning. Prescribed burning of slash can increase erosion by eliminating protective cover and altering soil properties (Megahan, 1980). The degree of erosion following a prescribed burn depends on soil erodibility, slope, precipitation timing, volume and intensity, fire severity, cover remaining on the soil, and speed of revegetation. Burning may also increase stormflow in areas where all vegetation is killed. Such increases are partially attributable to decreased evapotranspiration rates and reduced canopy interception of precipitation. Erosion resulting from prescribed burning is generally less than that resulting from roads and skid trails and from site preparation that causes intense soil disturbance (Golden et al., 1984). However, significant erosion can occur during prescribed burning if the slash being burned is collected or piled, causing soil to be moved and incorporated into the slash.
Application of Forest Chemicals. Adverse effects on water quality due to forest chemical application typically result from improper chemical application, such as failure to establish buffers around watercourses (Norris and Moore, 1971). Aerial application of forest chemicals has a greater potential to adversely affect water quality, especially if chemicals are applied under improper conditions, such as high winds (Riekerk et al., 1989), or are applied directly to watercourses.
F. Other Federal, State, and Local Silviculture Programs
1. Federal Programs
Forestry activities on Federal lands are predominantly controlled by the U.S. Department of Agriculture (USDA) Forest Service and Department of the Interior (DOI) Bureau of Land Management (BLM). Private entities operating on Federal lands are regulated by timber sales contracts. The Forest Service has developed preventive land management practices and project performance standards (USEPA, 1991). The Agricultural Stabilization and Conservation Service (ASCS) administers the Forestry Incentives Program (FIP) and Stewardship Incentives Program (SIP). Under FIP, ASCS provides cost-share funds to develop, manage, and protect eligible forest land, with emphasis on enhancing water quality, wildlife habitat, and recreational resources, and producing softwood timber. In addition, the Clean Water Act section 404 regulatory program may be applicable to some forestry activities (such as stream crossings) that involve the discharge of dredged or fill material into waters of the United States. However, section 404(f) of the Act exempts most forestry activities from permitting requirements. Regulations describing 404(f) exemptions, as well as applicable best management practices for section 404, have been published by EPA and the U.S. Army Corps of Engineers (40 CFR 232.3). The management measures in this guidance apply only to nonpoint source silvicultural activities. Clean Water Act section 402 regulations for point source permits exempt these nonpoint silvicultural activities (40 CFR 122.27) except for the section 404 requirements discussed above.
2. State Forestry NPS Programs
Most States with significant forestry activities have developed Best Management Practices (BMPs) to control silviculturally-related NPS water quality problems. Often, water quality problems are not due to ineffectiveness of the practices themselves, but to the failure to implement them appropriately (Whitman, 1989; Pardo, 1980).
There are currently two basic types of State forestry NPS programs, voluntary and regulatory. Thirty-five States currently implement voluntary programs, with 6 of these States having the authority to make the voluntary programs regulatory and 10 States backing the voluntary program with a regulatory program for non-compliers (see Table 3-1 (16k) for more specific types of programs). Nine States have developed regulatory programs (Essig, 1991).
Voluntary programs rely on a set of BMPs as guidelines to operators (Cubbage et al., 1989). Operator education and technology transfer are also a responsibility of State Forestry Departments. Workshops, brochures, and field tours are used to educate and to demonstrate to operators the latest water quality management techniques. Landowners are encouraged to hire operators who have a working knowledge of State forestry BMPs (Dissmeyer and Miller, 1991). Transfer of information on State NPS controls to landowners is also an important element of these programs.
Regulatory programs involve mandatory controls and enforcement strategies defined in Forest Practice Rules based on a State's Forest Practices Act or local government regulations. These programs usually require the implementation of BMPs based on site-specific conditions and water quality goals, and they have enforceable requirements (Ice, 1985). Often streams are classified based on their most sensitive designated use, such as importance for municipal water supply or propagation of aquatic life. Many water quality BMPs also improve harvesting operation efficiency and therefore can be applied in the normal course of forest harvest operations with few significant added costs (Ontario Ministry of Natural Resources, 1988; Dissmeyer and Miller, 1991). Harvest operation plans or applications to perform a timber harvest are frequently reviewed by the responsible State agency. Erosion and sedimentation control BMPs are also used in these programs to minimize erosion from road construction and harvesting activities.
Present State Coastal Zone Management (CZM) and section 319 programs may already include specific BMP regulations or guidelines for forestry activities. In some States, CZM programs have adopted State forestry regulations and BMPs through reference or as part of a linked program.
3. Local Governments
Counties, municipalities, and local soil and water conservation management districts may also impose additional requirements on landowners and operators conducting forestry activities. In urbanizing areas, these requirements often relate to concerns regarding the conversion of forested lands to urban uses or changes in private property values due to aesthetic changes resulting from forestry practices. In rural areas additional requirements for forestry activities may be implemented to protect public property (roads and municipal water supplies). Local forestry regulations tend to be stricter in response to residents' complaints (Salazar and Cubbage, 1990).